This document describes a printed coplanar two-antenna element designed for dual-band WLAN operation at 2.4 GHz and 5 GHz for use in a MIMO system. The element consists of a planar inverted-F antenna for the 5 GHz band and a monopole antenna for the 2.4 GHz band, both printed on the same substrate with a shared ground plane. Two separate feeds are used to excite the antennas without requiring an external switch. When two of these elements are arranged with a spacing of 10 mm, the resulting four-antenna MIMO system achieves good isolation between all antenna pairs across both operating bands.
Hybrid of Monopole and Dipole Antennas for Concurrent 2.4- and 5-GHz WLAN Acc...Saou-Wen Su
A novel hybrid of a 2.4-GHz monopole antenna and a 5-GHz dipole antenna is presented to provide concurrent 2.4 and 5 GHz band operation for access- point applications. The two antennas are arranged in a collinear structure and printed on a compact dielectric substrate with dimensions 12 mm × 60 mm. The monopole antenna has a meandered radiating strip and is short-circuited to a small ground plane through a shorting strip. The dipole antenna includes two sub-dipoles at the opposite side of a narrow ground plane and fed by a simple T-junction microstrip-line network. The two antennas are closely set with a distance of 1 mm only, yet good port isolation (S21) well below –20 dB can be obtained. With a low profile, the proposed design can easily fit into the casing of some standard access points and allow the 2.4 and 5 GHz band signals to be simultaneously received or transmitted with no external diplexer required. Good omnidirectional radiation has been observed too.
Low-Cost Flat Metal-Plate Dipole Antenna for 2.4/5 GHz WLAN OperationSaou-Wen Su
A low-cost, one-piece, flat-plate dipole antenna for dual WLAN band operation is presented. The dipole antenna is rectangular in shape with the dimensions 10 mm × 37 mm and fed by 50-ohm mini-coaxial cable. By cutting two L-shaped slits in each radiating arm, two dipole arms are obtained, which form a larger dipole and a smaller dipole antennas for the 2.4 and 5 GHz band operation respectively. The dipole arms are further short-circuited, making it possible for the antenna to be fabricated by stamping a single, flat metal plate only. The impedance bandwidth for 2.4/5 GHz WLAN operation is with VSWR below 1.5 and good omnidirectional radiation patterns are also observed.
Integration of Internal 700 MHz and WLAN/WiMAX Antennas for Palm-Sized Mobile...Saou-Wen Su
Two promising, internal, shorted monopole antennas for 700 MHz and WLAN/WiMAX operation are combined in an arrangement with minimized mutual coupling for palm-sized mobile applications. The two stamped, metal-plate antennas with a 2 mm gap therein between can be integrated into a compact configuration and are then mounted near one side of the system circuit board. With the suitable shorting locations and arrangement of the two antennas, good isolation (S21 < –20 dB) between the two ports can easily be obtained. Analysis of placing a CCD shielding cylinder between the two antennas and the two shorting strips joined to form a shorting wall are also conducted. Detailed designs of the two antennas are described, and the results thereof are discussed.
Very-Low-Cost Copper-Wire Antenna for 2.4-GHz WLAN OperationSaou-Wen Su
A very-low-cost copper-wire antenna, easily fabricated by bending a single 70-mm-long copper wire two times, for WLAN operation in the 2.4 GHz band (2400-2484 MHz) is presented. The antenna has a very simple structure and is easily fed by using a 50- mini-coaxial cable. A prototype of the proposed antenna with the overall dimensions 40 mm x 5 mm is constructed and tested.
Printed Omnidirectional Access-Point Antenna for 2.4/5-GHz WLAN OperationSaou-Wen Su
A new design of the printed omnidirectional antenna for applications in 2.4/5-GHz dual-WLAN-band access points is proposed. The antenna consists of a conventional collinear antenna for 2.4 GHz operation and two U stubs for 5 GHz operation. The two U stubs are located near the points where the maximum currents at about 5.5 GHz occurring on the strips of the collinear antenna, and arranged back to back in the same phase for achieving better antenna gain. Detailed analyses of the U stub on the impedance matching over the 5 GH band is presented. A prototype with good omnidirectional radiation across the 2.4/5-GHz WLAN bands is demonstrated.
2009 EuCAP-Hybrid of Monopole and Dipole Antennas for Concurrent WLAN APSaou-Wen Su
A novel hybrid of a 2.4-GHz monopole antenna and a 5-GHz dipole antenna is presented to provide concurrent 2.4 and 5 GHz band operation for access- point applications. The two antennas are arranged in a collinear structure and printed on a compact dielectric substrate with dimensions 12 mm × 60 mm. The monopole antenna has a meandered radiating strip and is short-circuited to a small ground plane through a shorting strip. The dipole antenna includes two sub-dipoles at the opposite side of a narrow ground plane and fed by a simple T-junction microstrip-line network. The two antennas are closely set with a distance of 1 mm only, yet good port isolation (S21) well below –20 dB can be obtained. With a low profile, the proposed design can easily fit into the casing of some standard access points and allow the 2.4 and 5 GHz band signals to be simultaneously received or transmitted with no external diplexer required. Good omnidirectional radiation has been observed too.
Compact Paper-Clip-Shaped Wire Antenna for 2.4 and 5.2 GHz WLAN OperationSaou-Wen Su
A compact dual-WLAN-band antenna, in the shape of a paper clip, is presented. The antenna can easily be manufactured by bending few times a single copper wire with a length of about 65 mm, and operates in the 2.4 and 5.2 GHz bands in the WLAN environment. In addition to the simple configuration, the antenna is easily fed by 50- mini-coaxial cable, which allows it flexibility in a defined location for installation. An experimental prototype of the proposed antenna with the overall dimensions about 5 mm x 23.5 mm is constructed, tested, and demonstrated.
Concurrent 2.4/5-GHz Multi-Loop MIMO Antennas with Wide 3-dB Beamwidth Radiat...Saou-Wen Su
A high-gain, wide-beamwidth, six-loop-antenna MIMO system suited for wireless access points in the concurrent WLAN 2.4 and 5 GHz bands is presented. The antenna system mainly comprises an antenna ground plane and single-band loop antennas, among which the three antennas are designated for 2.4 and 5 GHz operation respectively. The antennas are set in a sequential, rotating arrangement on the ground plane with an equal inclination angle of 60° to form a symmetrical structure, and the 2.4 and 5 GHz loops are facing each other one by one. The experimental results show that good port isolation can be obtained between antenna ports. High-gain, directional radiation patterns with wide 3-dB beamwidth in elevation planes are also observed. Details of a design prototype are described and discussed in the paper.
Hybrid of Monopole and Dipole Antennas for Concurrent 2.4- and 5-GHz WLAN Acc...Saou-Wen Su
A novel hybrid of a 2.4-GHz monopole antenna and a 5-GHz dipole antenna is presented to provide concurrent 2.4 and 5 GHz band operation for access- point applications. The two antennas are arranged in a collinear structure and printed on a compact dielectric substrate with dimensions 12 mm × 60 mm. The monopole antenna has a meandered radiating strip and is short-circuited to a small ground plane through a shorting strip. The dipole antenna includes two sub-dipoles at the opposite side of a narrow ground plane and fed by a simple T-junction microstrip-line network. The two antennas are closely set with a distance of 1 mm only, yet good port isolation (S21) well below –20 dB can be obtained. With a low profile, the proposed design can easily fit into the casing of some standard access points and allow the 2.4 and 5 GHz band signals to be simultaneously received or transmitted with no external diplexer required. Good omnidirectional radiation has been observed too.
Low-Cost Flat Metal-Plate Dipole Antenna for 2.4/5 GHz WLAN OperationSaou-Wen Su
A low-cost, one-piece, flat-plate dipole antenna for dual WLAN band operation is presented. The dipole antenna is rectangular in shape with the dimensions 10 mm × 37 mm and fed by 50-ohm mini-coaxial cable. By cutting two L-shaped slits in each radiating arm, two dipole arms are obtained, which form a larger dipole and a smaller dipole antennas for the 2.4 and 5 GHz band operation respectively. The dipole arms are further short-circuited, making it possible for the antenna to be fabricated by stamping a single, flat metal plate only. The impedance bandwidth for 2.4/5 GHz WLAN operation is with VSWR below 1.5 and good omnidirectional radiation patterns are also observed.
Integration of Internal 700 MHz and WLAN/WiMAX Antennas for Palm-Sized Mobile...Saou-Wen Su
Two promising, internal, shorted monopole antennas for 700 MHz and WLAN/WiMAX operation are combined in an arrangement with minimized mutual coupling for palm-sized mobile applications. The two stamped, metal-plate antennas with a 2 mm gap therein between can be integrated into a compact configuration and are then mounted near one side of the system circuit board. With the suitable shorting locations and arrangement of the two antennas, good isolation (S21 < –20 dB) between the two ports can easily be obtained. Analysis of placing a CCD shielding cylinder between the two antennas and the two shorting strips joined to form a shorting wall are also conducted. Detailed designs of the two antennas are described, and the results thereof are discussed.
Very-Low-Cost Copper-Wire Antenna for 2.4-GHz WLAN OperationSaou-Wen Su
A very-low-cost copper-wire antenna, easily fabricated by bending a single 70-mm-long copper wire two times, for WLAN operation in the 2.4 GHz band (2400-2484 MHz) is presented. The antenna has a very simple structure and is easily fed by using a 50- mini-coaxial cable. A prototype of the proposed antenna with the overall dimensions 40 mm x 5 mm is constructed and tested.
Printed Omnidirectional Access-Point Antenna for 2.4/5-GHz WLAN OperationSaou-Wen Su
A new design of the printed omnidirectional antenna for applications in 2.4/5-GHz dual-WLAN-band access points is proposed. The antenna consists of a conventional collinear antenna for 2.4 GHz operation and two U stubs for 5 GHz operation. The two U stubs are located near the points where the maximum currents at about 5.5 GHz occurring on the strips of the collinear antenna, and arranged back to back in the same phase for achieving better antenna gain. Detailed analyses of the U stub on the impedance matching over the 5 GH band is presented. A prototype with good omnidirectional radiation across the 2.4/5-GHz WLAN bands is demonstrated.
2009 EuCAP-Hybrid of Monopole and Dipole Antennas for Concurrent WLAN APSaou-Wen Su
A novel hybrid of a 2.4-GHz monopole antenna and a 5-GHz dipole antenna is presented to provide concurrent 2.4 and 5 GHz band operation for access- point applications. The two antennas are arranged in a collinear structure and printed on a compact dielectric substrate with dimensions 12 mm × 60 mm. The monopole antenna has a meandered radiating strip and is short-circuited to a small ground plane through a shorting strip. The dipole antenna includes two sub-dipoles at the opposite side of a narrow ground plane and fed by a simple T-junction microstrip-line network. The two antennas are closely set with a distance of 1 mm only, yet good port isolation (S21) well below –20 dB can be obtained. With a low profile, the proposed design can easily fit into the casing of some standard access points and allow the 2.4 and 5 GHz band signals to be simultaneously received or transmitted with no external diplexer required. Good omnidirectional radiation has been observed too.
Compact Paper-Clip-Shaped Wire Antenna for 2.4 and 5.2 GHz WLAN OperationSaou-Wen Su
A compact dual-WLAN-band antenna, in the shape of a paper clip, is presented. The antenna can easily be manufactured by bending few times a single copper wire with a length of about 65 mm, and operates in the 2.4 and 5.2 GHz bands in the WLAN environment. In addition to the simple configuration, the antenna is easily fed by 50- mini-coaxial cable, which allows it flexibility in a defined location for installation. An experimental prototype of the proposed antenna with the overall dimensions about 5 mm x 23.5 mm is constructed, tested, and demonstrated.
Concurrent 2.4/5-GHz Multi-Loop MIMO Antennas with Wide 3-dB Beamwidth Radiat...Saou-Wen Su
A high-gain, wide-beamwidth, six-loop-antenna MIMO system suited for wireless access points in the concurrent WLAN 2.4 and 5 GHz bands is presented. The antenna system mainly comprises an antenna ground plane and single-band loop antennas, among which the three antennas are designated for 2.4 and 5 GHz operation respectively. The antennas are set in a sequential, rotating arrangement on the ground plane with an equal inclination angle of 60° to form a symmetrical structure, and the 2.4 and 5 GHz loops are facing each other one by one. The experimental results show that good port isolation can be obtained between antenna ports. High-gain, directional radiation patterns with wide 3-dB beamwidth in elevation planes are also observed. Details of a design prototype are described and discussed in the paper.
An Internal Wideband Monopole Antenna for UMTS/WLAN Dual-Mode Mobile PhoneSaou-Wen Su
An internal wideband metal-plate monopole antenna for mobile phone applications is presented. The antenna is easily fabricated by bending a single metal plate and suitable to be embedded within the casing of a mobile phone as an internal antenna. Further, the antenna shows a wide operating bandwidth of about 5 GHz (about 1.8−6.7 GHz), making it easy to cover the UMTS band and the 2.4/5.2/5.8 GHz WLAN bands for mobile/WLAN dual-mode operation for a mobile phone.
Realization of Dual-Dipole-Antenna System for Concurrent Dual-Radio Operation...Saou-Wen Su
The study of the mutual coupling between the two simple strip dipole antennas is first carried out and investigated. The results show that the coupling or the antenna port isolation is almost separation distance independent when the two dipole antennas are arranged to be of orthogonal polarization. Following this characteristic, a novel dual-dipole-antenna system aimed for concurrent 2.4 and 5 GHz band operation and at the same time, to achieve very compact integration of two individual antennas with separate feeds is proposed. The two dipole antennas are etched on a two-layered dielectric substrate with dimensions 30 mm × 30 mm. On the front layer is put the 2.4 GHz dipole, which is perpendicular to the 5 GHz dipole located on the bottom layer. Though the two dipoles are stacked up with a distance of 0.8 mm only, port isolation can still be below –15 dB. The proposed dual-dipole-antenna system is a promising candidate for the antenna solution that enables simultaneous dual-radio operation.
A Bent, Shorted, Planar Monopole Antenna for 2.4 GHz WLAN ApplicationsSaou-Wen Su
A simple, bent monopole antenna well useful for WLAN applications in the 2.4 GHz band is presented. The monopole antenna has a rectangular radiating plate in general and is short-circuited to a small antenna ground and an assembly plate. The assembly plate is not only used as a supporting plate for antenna installation but also regarded as antenna ground. With a low profile of the monopole and use of the coaxial-line feed, the antenna has much flexibility in the placement inside a wireless device. Good radiation characteristics have been observed too.
Very-Low-Profile Monopole Antennas for Concurrent 2.4- and 5-GHz WLAN Access-...Saou-Wen Su
A very-low-profile, six-antenna MIMO system aimed at operating in the concurrent 2.4 and 5 GHz bands for WLAN access-point applications is proposed. The MIMO system consists mainly of an antenna ground plane and six short-circuited monopole antennas, among which the three antennas are designated for 2.4 and 5 GHz operation respectively. The antennas are set in a sequential, rotating arrangement on the ground plane, and the 2.4 and 5 GHz antennas are facing each other one by one. The results show that well port isolation can be obtained together with good radiation characteristics. With a low profile of 6 mm in height, the proposed design can easily fit into wireless access points or routers and allow the 2.4- and 5-GHz band signals to be simultaneously received and transmitted with no need of external diplexer.
2008 IEEE AP-S-Internal Wideband Monopole Antenna For MIMO Access-Point Appli...Saou-Wen Su
A three-antenna MIMO system capable of generating a wide operating bandwidth of 2400-5850 MHz for access-point applications is introduced. The proposed design is based on a bent metal-plate monopole antenna with a compact size of 20 × 20 × 14 mm3. The three antennas are equally spaced along the perimeter of a circular ground and all generate a wide bandwidth of larger than 4 GHz. With the antenna short-circuiting facing the center of the ground, not only the overall antenna size is reduced but also good isolation of less than -20 dB can easily be obtained. Calculated envelope correlation is also less than 0.002 across the operating band.
Compact Vertical Patch Antenna for Dual-Band WLAN OperationSaou-Wen Su
A new compact patch antenna, which is arranged perpendicular to a circular ground plane, for WLAN operation is presented. The antenna consists mainly of one driven patch and one shorted parasitic patch, which both wind along two concentric circles. A constructed prototype covering the 2.4 and 5 GHz WLAN bands is demonstrated. Good broadside radiation characteristics are obtained across the operating bands. Details of the proposed patch antenna and experimental results are presented and discussed.
Design of a Dual-Band Microstrip Patch Antenna for GPS,WiMAX and WLAN.IOSR Journals
The A multi band microstrip patch antenna has been designed for GPS,WiMAX and WLAN
applications. The proposed antenna is designed by using substrate of RT duroid having permittivity of about 2.2
and loss tangent of 1.The substrate is having thickness of 6mm at which a trapezoidal patch antenna with V slot
has been introduced in this paper. The designing results like S11 parameter return loss,VSWR and field pattern
is plotted successfully. The obtained result is having a two band resonance with S11 less then -10dB and VSWR
less than 2.
So a dual band trapezoidal microstrip patch antenna has been designed and all results are plotted.Simmulating
software used is IE3D.
2009 IEEE AP-S-Compact Coaxial-Line-Fed Printed Monopole Antenna for Lower-Ba...Saou-Wen Su
A compact, printed, ultrawideband (UWB) monopole antenna suitable to be as an internal antenna attractive for future UWB applications is demonstrated. The proposed antenna is of a small form factor with the dimensions 6 mm × 33 mm and can easily be fed by 50-ohms mini-cable line. The antenna mainly comprises a monopole antenna, a feeding strip and a ground plane, all printed on a small FR4 substrate. The monopole antenna is printed on both layers of the substrate with an end portion on the back for control of the first/lower resonant mode of the antenna. The feeding strip in between the monopole antenna and the ground plane is further offset to achieve better impedance matching and proper upper-edge operating frequency. With the proposed antenna structure, which provides an operating bandwidth of larger than 2.7 GHz, the impedance bandwidth by 10-dB return loss can easily cover the 3.1–4.85 GHz band, the lower band of the UWB operation.
A Review of Multi Resonant Slotted Micro Strip Patch Antenna (MPA) for IMT, W...IJEEE
In this paper, a stacked multi resonant slotted micro strip patch antenna (MPA) has been proposed which is suitable to be used for GSM, WLAN standard and WiMAX applications. The antenna has been designed using substrate of FR4 material. In the designed stacked antenna, substrates having different thickness has been used. The bottom stack of designed antenna has a radiating patch of circular shape and the patch on the upper stack has rectangular shape and is flexible in nature. The antenna has a feed line which is connected to circular patch to feed power to the antenna. The feed line has to be of suitable width to match the antenna impedance with port impedance of 50 ohms. The designed antenna has a defected ground structure in order to improve the antenna performance. The antenna performance has been measured in terms of antenna parameters such as impedance bandwidth (GHz), Return loss (dB), antenna impedance (ohms), VSWR and Directivity (dBi). The designed antenna results have been simulated in CST Microwave Studio 2010. The practically designed antenna has been tested successfully by using Network analyzer E5071C. It has been observed that the practical results closely match with theoretical results.
Characteristic Comparison of U-Shaped Monopole and Complete Monopole AntennaIOSR Journals
A monopole antenna is a type of radio antenna formed by replacing one half of a dipole antenna with
a ground plane at right-angles to the remaining half. Monopoles may be used from a few hundred KHz through
several GHz in frequency and are commonly one-quarter of a wave length long, but may be shorter or longer.
Monopole antennas exhibit high gain and improved efficiency in a surprisingly small package. Monopole
antenna can be designed to exhibit wideband capabilities. The different available monopole antennas are dual
band printed monopole antenna, cross-slot monopole antenna, U-shaped monopole antenna, triangular shaped
monopole antenna and a wideband monopole antenna. This paper deals with the comparison obtained from the
results such as return loss, VSWR, current distribution, and the radiation pattern of simple U-shaped and
complete monopole antenna
Internal Wideband Monopole Antenna for MIMO Access-Point Applications in the ...Saou-Wen Su
A three-antenna MIMO system capable of generating a wide operating bandwidth of 2400-5850 MHz for access-point applications is introduced. The proposed design is based on a bent metal-plate monopole antenna with a compact size of 20 × 20 × 14 mm3. The three antennas are equally spaced along the perimeter of a circular ground and all generate a wide bandwidth of larger than 4 GHz. With the antenna short-circuiting facing the center of the ground, not only the overall antenna size is reduced but also good isolation of less than -20 dB can easily be obtained. Calculated envelope correlation is also less than 0.002 across the operating band. The design prototype of the antenna is discussed in detail in the paper.
Design of Reconfigurable Microstrip Patch Antenna for WLAN ApplicationEditor IJMTER
In this paper we propose a rectangular microstrip patch antenna with inset fed which can
operate at 2.4 GHz (IEEE 802.11b) & 5.8 GHz (IEEE 802.11a) WLAN applications. Various slot is
cut into the antenna structure which changes the surface current path resulting in dual resonant
frequency. Further by embedding any switch into a slot, reconfiguration can be achieved i.e. the
antenna can only be used in unlicensed 2.4 GHz band. The achieved directivity is greater than 5db and
the bandwidth obtained is much greater than the required bandwidth. The proposed antenna is
simulated using High Frequency Structure Simulator.
A Three-in-One Diversity Antenna System for 5 GHz WLAN ApplicationsSaou-Wen Su
A novel, three-in-one antenna system suitable for WLAN operation in the 5 GHz band is presented. The design is based upon incorporating one slot and two dipole antennas into a compact multi-antenna system that has comparable dimensions of a single mobile-unit antenna element. The three antennas are arranged parallel to each other with the two dipoles set on the right and left sides of the slot respectively. With this arrangement, not only can compact integration of three individual antennas be realized, pattern diversity and polarization diversity are also obtained. A design prototype has been constructed and tested. The results show that the coupling or the antenna port isolation is below –20 dB and good radiation characteristics have been observed.
Conical Shaped Monopole Antenna for Multiband Wireless Applicationsiosrjce
IOSR Journal of Electronics and Communication Engineering(IOSR-JECE) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of electronics and communication engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in electronics and communication engineering. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
These slides are presented for my final year project. It is designed by HFSS and fabricated hardware for experimental measurement of S11 and Radiation Pattern Measurement. It is better to download the slides to see all the results presented as I put in animations.
An Internal Wideband Monopole Antenna for UMTS/WLAN Dual-Mode Mobile PhoneSaou-Wen Su
An internal wideband metal-plate monopole antenna for mobile phone applications is presented. The antenna is easily fabricated by bending a single metal plate and suitable to be embedded within the casing of a mobile phone as an internal antenna. Further, the antenna shows a wide operating bandwidth of about 5 GHz (about 1.8−6.7 GHz), making it easy to cover the UMTS band and the 2.4/5.2/5.8 GHz WLAN bands for mobile/WLAN dual-mode operation for a mobile phone.
Realization of Dual-Dipole-Antenna System for Concurrent Dual-Radio Operation...Saou-Wen Su
The study of the mutual coupling between the two simple strip dipole antennas is first carried out and investigated. The results show that the coupling or the antenna port isolation is almost separation distance independent when the two dipole antennas are arranged to be of orthogonal polarization. Following this characteristic, a novel dual-dipole-antenna system aimed for concurrent 2.4 and 5 GHz band operation and at the same time, to achieve very compact integration of two individual antennas with separate feeds is proposed. The two dipole antennas are etched on a two-layered dielectric substrate with dimensions 30 mm × 30 mm. On the front layer is put the 2.4 GHz dipole, which is perpendicular to the 5 GHz dipole located on the bottom layer. Though the two dipoles are stacked up with a distance of 0.8 mm only, port isolation can still be below –15 dB. The proposed dual-dipole-antenna system is a promising candidate for the antenna solution that enables simultaneous dual-radio operation.
A Bent, Shorted, Planar Monopole Antenna for 2.4 GHz WLAN ApplicationsSaou-Wen Su
A simple, bent monopole antenna well useful for WLAN applications in the 2.4 GHz band is presented. The monopole antenna has a rectangular radiating plate in general and is short-circuited to a small antenna ground and an assembly plate. The assembly plate is not only used as a supporting plate for antenna installation but also regarded as antenna ground. With a low profile of the monopole and use of the coaxial-line feed, the antenna has much flexibility in the placement inside a wireless device. Good radiation characteristics have been observed too.
Very-Low-Profile Monopole Antennas for Concurrent 2.4- and 5-GHz WLAN Access-...Saou-Wen Su
A very-low-profile, six-antenna MIMO system aimed at operating in the concurrent 2.4 and 5 GHz bands for WLAN access-point applications is proposed. The MIMO system consists mainly of an antenna ground plane and six short-circuited monopole antennas, among which the three antennas are designated for 2.4 and 5 GHz operation respectively. The antennas are set in a sequential, rotating arrangement on the ground plane, and the 2.4 and 5 GHz antennas are facing each other one by one. The results show that well port isolation can be obtained together with good radiation characteristics. With a low profile of 6 mm in height, the proposed design can easily fit into wireless access points or routers and allow the 2.4- and 5-GHz band signals to be simultaneously received and transmitted with no need of external diplexer.
2008 IEEE AP-S-Internal Wideband Monopole Antenna For MIMO Access-Point Appli...Saou-Wen Su
A three-antenna MIMO system capable of generating a wide operating bandwidth of 2400-5850 MHz for access-point applications is introduced. The proposed design is based on a bent metal-plate monopole antenna with a compact size of 20 × 20 × 14 mm3. The three antennas are equally spaced along the perimeter of a circular ground and all generate a wide bandwidth of larger than 4 GHz. With the antenna short-circuiting facing the center of the ground, not only the overall antenna size is reduced but also good isolation of less than -20 dB can easily be obtained. Calculated envelope correlation is also less than 0.002 across the operating band.
Compact Vertical Patch Antenna for Dual-Band WLAN OperationSaou-Wen Su
A new compact patch antenna, which is arranged perpendicular to a circular ground plane, for WLAN operation is presented. The antenna consists mainly of one driven patch and one shorted parasitic patch, which both wind along two concentric circles. A constructed prototype covering the 2.4 and 5 GHz WLAN bands is demonstrated. Good broadside radiation characteristics are obtained across the operating bands. Details of the proposed patch antenna and experimental results are presented and discussed.
Design of a Dual-Band Microstrip Patch Antenna for GPS,WiMAX and WLAN.IOSR Journals
The A multi band microstrip patch antenna has been designed for GPS,WiMAX and WLAN
applications. The proposed antenna is designed by using substrate of RT duroid having permittivity of about 2.2
and loss tangent of 1.The substrate is having thickness of 6mm at which a trapezoidal patch antenna with V slot
has been introduced in this paper. The designing results like S11 parameter return loss,VSWR and field pattern
is plotted successfully. The obtained result is having a two band resonance with S11 less then -10dB and VSWR
less than 2.
So a dual band trapezoidal microstrip patch antenna has been designed and all results are plotted.Simmulating
software used is IE3D.
2009 IEEE AP-S-Compact Coaxial-Line-Fed Printed Monopole Antenna for Lower-Ba...Saou-Wen Su
A compact, printed, ultrawideband (UWB) monopole antenna suitable to be as an internal antenna attractive for future UWB applications is demonstrated. The proposed antenna is of a small form factor with the dimensions 6 mm × 33 mm and can easily be fed by 50-ohms mini-cable line. The antenna mainly comprises a monopole antenna, a feeding strip and a ground plane, all printed on a small FR4 substrate. The monopole antenna is printed on both layers of the substrate with an end portion on the back for control of the first/lower resonant mode of the antenna. The feeding strip in between the monopole antenna and the ground plane is further offset to achieve better impedance matching and proper upper-edge operating frequency. With the proposed antenna structure, which provides an operating bandwidth of larger than 2.7 GHz, the impedance bandwidth by 10-dB return loss can easily cover the 3.1–4.85 GHz band, the lower band of the UWB operation.
A Review of Multi Resonant Slotted Micro Strip Patch Antenna (MPA) for IMT, W...IJEEE
In this paper, a stacked multi resonant slotted micro strip patch antenna (MPA) has been proposed which is suitable to be used for GSM, WLAN standard and WiMAX applications. The antenna has been designed using substrate of FR4 material. In the designed stacked antenna, substrates having different thickness has been used. The bottom stack of designed antenna has a radiating patch of circular shape and the patch on the upper stack has rectangular shape and is flexible in nature. The antenna has a feed line which is connected to circular patch to feed power to the antenna. The feed line has to be of suitable width to match the antenna impedance with port impedance of 50 ohms. The designed antenna has a defected ground structure in order to improve the antenna performance. The antenna performance has been measured in terms of antenna parameters such as impedance bandwidth (GHz), Return loss (dB), antenna impedance (ohms), VSWR and Directivity (dBi). The designed antenna results have been simulated in CST Microwave Studio 2010. The practically designed antenna has been tested successfully by using Network analyzer E5071C. It has been observed that the practical results closely match with theoretical results.
Characteristic Comparison of U-Shaped Monopole and Complete Monopole AntennaIOSR Journals
A monopole antenna is a type of radio antenna formed by replacing one half of a dipole antenna with
a ground plane at right-angles to the remaining half. Monopoles may be used from a few hundred KHz through
several GHz in frequency and are commonly one-quarter of a wave length long, but may be shorter or longer.
Monopole antennas exhibit high gain and improved efficiency in a surprisingly small package. Monopole
antenna can be designed to exhibit wideband capabilities. The different available monopole antennas are dual
band printed monopole antenna, cross-slot monopole antenna, U-shaped monopole antenna, triangular shaped
monopole antenna and a wideband monopole antenna. This paper deals with the comparison obtained from the
results such as return loss, VSWR, current distribution, and the radiation pattern of simple U-shaped and
complete monopole antenna
Internal Wideband Monopole Antenna for MIMO Access-Point Applications in the ...Saou-Wen Su
A three-antenna MIMO system capable of generating a wide operating bandwidth of 2400-5850 MHz for access-point applications is introduced. The proposed design is based on a bent metal-plate monopole antenna with a compact size of 20 × 20 × 14 mm3. The three antennas are equally spaced along the perimeter of a circular ground and all generate a wide bandwidth of larger than 4 GHz. With the antenna short-circuiting facing the center of the ground, not only the overall antenna size is reduced but also good isolation of less than -20 dB can easily be obtained. Calculated envelope correlation is also less than 0.002 across the operating band. The design prototype of the antenna is discussed in detail in the paper.
Design of Reconfigurable Microstrip Patch Antenna for WLAN ApplicationEditor IJMTER
In this paper we propose a rectangular microstrip patch antenna with inset fed which can
operate at 2.4 GHz (IEEE 802.11b) & 5.8 GHz (IEEE 802.11a) WLAN applications. Various slot is
cut into the antenna structure which changes the surface current path resulting in dual resonant
frequency. Further by embedding any switch into a slot, reconfiguration can be achieved i.e. the
antenna can only be used in unlicensed 2.4 GHz band. The achieved directivity is greater than 5db and
the bandwidth obtained is much greater than the required bandwidth. The proposed antenna is
simulated using High Frequency Structure Simulator.
A Three-in-One Diversity Antenna System for 5 GHz WLAN ApplicationsSaou-Wen Su
A novel, three-in-one antenna system suitable for WLAN operation in the 5 GHz band is presented. The design is based upon incorporating one slot and two dipole antennas into a compact multi-antenna system that has comparable dimensions of a single mobile-unit antenna element. The three antennas are arranged parallel to each other with the two dipoles set on the right and left sides of the slot respectively. With this arrangement, not only can compact integration of three individual antennas be realized, pattern diversity and polarization diversity are also obtained. A design prototype has been constructed and tested. The results show that the coupling or the antenna port isolation is below –20 dB and good radiation characteristics have been observed.
Conical Shaped Monopole Antenna for Multiband Wireless Applicationsiosrjce
IOSR Journal of Electronics and Communication Engineering(IOSR-JECE) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of electronics and communication engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in electronics and communication engineering. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
These slides are presented for my final year project. It is designed by HFSS and fabricated hardware for experimental measurement of S11 and Radiation Pattern Measurement. It is better to download the slides to see all the results presented as I put in animations.
HFSS MICROSTRIP PATCH ANTENNA- ANALYSIS AND DESIGNShivashu Awasthi
ANALYSIS AND DESIGN OF MICROSTRIP SQUARE PATCH ANTENNA USING HFSS SIMULATION TOOL.
Its the Final Year Presentation at 75% of its full flow.
Hopefully It should Help..do leave your reviews and suggestions / queries.
Thanks.
Study of user effects on two-port MIMO antennas at 2.4 GHz and 5.8 GHz for Wi...journalBEEI
In this paper, two multiple input multiple output (MIMO) antennas for Wi-Fi/WLAN mobile applications are proposed. The designed two-port MIMO antennas are made up of planar inverted-F antennas (PIFAs). The antenna elements for both designs are symmetrical and placed on the short-edged corners of the substrate used, FR4. The performance of both antennas in the presence of user’s hand is compared in terms of impedance bandwidth and efficiency. An upward shift of up to 0.17 GHz in impedance bandwidth was found for 2.4 GHz and 5.8 GHz antenna. Due to the smaller size of antennas at 5.8 GHz compared to antennas at 2.4 GHz, the antennas are less obstructed by hands and thus the exhibited total efficiency of up to 45.58 % in the presence of human hand. The designed antennas have been fabricated for validation purpose. It is shown that there is a good agreement between simulated and measured results.
Sectoral dual-polarized MIMO antenna for 5G-NR band N77 base stationnooriasukmaningtyas
Massive internet of things (IoT) in 5G has many advantages as a future technology. It brings some challenges such as a lot of devices need massive connection. In this case, multiple-input multiple-output (MIMO) systems offer high performance and capacity of communications. There is a challenge of correlation between antennas in MIMO. This paper proposes three-sectors MIMO base station antenna for 5G-New Radio (5G-NR) band N77 with dual polarized configuration to reduce the correlation. The proposed antenna has a maximum coupling of -16.90 dB and correlation below 0.01. The obtained bit error rate (BER) performance is very close to non-correlated antennas with bandwidth of 1.87 GHz. It means that the proposed antenna has been well designed.
DESIGN OF A NOVEL MICROSTRIP MIMO ANTENNA SYSTEM WITH IMPROVED ISOLATIONjantjournal
A novel compact two element MIMO (Multiple Input Multiple Output) antenna system for WLAN applications with improved isolation characteristics is presented in this paper. The proposed antenna resonates at 5.4 GHz frequency with good return loss characteristics. A 2×2 MIMO antenna system is developed using the proposed antenna giving good isolation of -31 dB between the two antennas. The surface current distribution and radiation pattern of the proposed MIMO system are also presented. The developed antenna system can be used in modern wireless systems employing MIMO technology.
DESIGN OF A NOVEL MICROSTRIP MIMO ANTENNA SYSTEM WITH IMPROVED ISOLATIONjantjournal
A novel compact two element MIMO (Multiple Input Multiple Output) antenna system for WLAN applications with improved isolation characteristics is presented in this paper. The proposed antenna
resonates at 5.4 GHz frequency with good return loss characteristics. A 2×2 MIMO antenna system is developed using the proposed antenna giving good isolation of -31 dB between the two antennas. The surface current distribution and radiation pattern of the proposed MIMO system are also presented. The developed antenna system can be used in modern wireless systems employing MIMO technology.
DESIGN OF A NOVEL MICROSTRIP MIMO ANTENNA SYSTEM WITH IMPROVED ISOLATIONjantjournal
A novel compact two element MIMO (Multiple Input Multiple Output) antenna system for WLAN applications with improved isolation characteristics is presented in this paper. The proposed antenna resonates at 5.4 GHz frequency with good return loss characteristics. A 2×2 MIMO antenna system is developed using the proposed antenna giving good isolation of -31 dB between the two antennas. The surface current distribution and radiation pattern of the proposed MIMO system are also presented. The developed antenna system can be used in modern wireless systems employing MIMO technology.
DESIGN OF A NOVEL MICROSTRIP MIMO ANTENNA SYSTEM WITH IMPROVED ISOLATIONjantjournal
A novel compact two element MIMO (Multiple Input Multiple Output) antenna system for WLAN applications with improved isolation characteristics is presented in this paper. The proposed antenna resonates at 5.4 GHz frequency with good return loss characteristics. A 2×2 MIMO antenna system is developed using the proposed antenna giving good isolation of -31 dB between the two antennas. The surface current distribution and radiation pattern of the proposed MIMO system are also presented. The developed antenna system can be used in modern wireless systems employing MIMO technology.
DESIGN OF A NOVEL MICROSTRIP MIMO ANTENNA SYSTEM WITH IMPROVED ISOLATIONjantjournal
A novel compact two element MIMO (Multiple Input Multiple Output) antenna system for WLAN applications with improved isolation characteristics is presented in this paper. The proposed antenna resonates at 5.4 GHz frequency with good return loss characteristics. A 2×2 MIMO antenna system is developed using the proposed antenna giving good isolation of -31 dB between the two antennas. The surface current distribution and radiation pattern of the proposed MIMO system are also presented. The developed antenna system can be used in modern wireless systems employing MIMO technology.
DESIGN OF A NOVEL MICROSTRIP MIMO ANTENNA SYSTEM WITH IMPROVED ISOLATIONjantjournal
A novel compact two element MIMO (Multiple Input Multiple Output) antenna system for WLAN applications with improved isolation characteristics is presented in this paper. The proposed antenna resonates at 5.4 GHz frequency with good return loss characteristics. A 2×2 MIMO antenna system is developed using the proposed antenna giving good isolation of -31 dB between the two antennas. The surface current distribution and radiation pattern of the proposed MIMO system are also presented. The developed antenna system can be used in modern wireless systems employing MIMO technology.
DESIGN OF A NOVEL MICROSTRIP MIMO ANTENNA SYSTEM WITH IMPROVED ISOLATIONjantjournal
A novel compact two element MIMO (Multiple Input Multiple Output) antenna system for WLAN applications with improved isolation characteristics is presented in this paper. The proposed antenna resonates at 5.4 GHz frequency with good return loss characteristics. A 2×2 MIMO antenna system is developed using the proposed antenna giving good isolation of -31 dB between the two antennas. The surface current distribution and radiation pattern of the proposed MIMO system are also presented. The developed antenna system can be used in modern wireless systems employing MIMO technology.
DESIGN OF A NOVEL MICROSTRIP MIMO ANTENNA SYSTEM WITH IMPROVED ISOLATIONjantjournal
A novel compact two element MIMO (Multiple Input Multiple Output) antenna system for WLAN applications with improved isolation characteristics is presented in this paper. The proposed antenna resonates at 5.4 GHz frequency with good return loss characteristics. A 2×2 MIMO antenna system is developed using the proposed antenna giving good isolation of -31 dB between the two antennas. The surface current distribution and radiation pattern of the proposed MIMO system are also presented. The developed antenna system can be used in modern wireless systems employing MIMO technology.
DESIGN OF A NOVEL MICROSTRIP MIMO ANTENNA SYSTEM WITH IMPROVED ISOLATIONjantjournal
A novel compact two element MIMO (Multiple Input Multiple Output) antenna system for WLAN applications with improved isolation characteristics is presented in this paper. The proposed antenna resonates at 5.4 GHz frequency with good return loss characteristics. A 2×2 MIMO antenna system is developed using the proposed antenna giving good isolation of -31 dB between the two antennas. The surface current distribution and radiation pattern of the proposed MIMO system are also presented. The developed antenna system can be used in modern wireless systems employing MIMO technology.
DESIGN OF A NOVEL MICROSTRIP MIMO ANTENNA SYSTEM WITH IMPROVED ISOLATIONjantjournal
A novel compact two element MIMO (Multiple Input Multiple Output) antenna system for WLAN applications with improved isolation characteristics is presented in this paper. The proposed antenna resonates at 5.4 GHz frequency with good return loss characteristics. A 2×2 MIMO antenna system is developed using the proposed antenna giving good isolation of -31 dB between the two antennas. The surface current distribution and radiation pattern of the proposed MIMO system are also presented. The developed antenna system can be used in modern wireless systems employing MIMO technology.
DESIGN OF A NOVEL MICROSTRIP MIMO ANTENNA SYSTEM WITH IMPROVED ISOLATIONjantjournal
A novel compact two element MIMO (Multiple Input Multiple Output) antenna system for WLAN applications with improved isolation characteristics is presented in this paper. The proposed antenna resonates at 5.4 GHz frequency with good return loss characteristics. A 2×2 MIMO antenna system is developed using the proposed antenna giving good isolation of -31 dB between the two antennas. The surface current distribution and radiation pattern of the proposed MIMO system are also presented. The developed antenna system can be used in modern wireless systems employing MIMO technology.
DESIGN OF A NOVEL MICROSTRIP MIMO ANTENNA SYSTEM WITH IMPROVED ISOLATIONjantjournal
A novel compact two element MIMO (Multiple Input Multiple Output) antenna system for WLAN applications with improved isolation characteristics is presented in this paper. The proposed antenna resonates at 5.4 GHz frequency with good return loss characteristics. A 2×2 MIMO antenna system is developed using the proposed antenna giving good isolation of -31 dB between the two antennas. The surface current distribution and radiation pattern of the proposed MIMO system are also presented. The developed antenna system can be used in modern wireless systems employing MIMO technology.
DESIGN OF A NOVEL MICROSTRIP MIMO ANTENNA SYSTEM WITH IMPROVED ISOLATIONjantjournal
A novel compact two element MIMO (Multiple Input Multiple Output) antenna system for WLAN applications with improved isolation characteristics is presented in this paper. The proposed antenna resonates at 5.4 GHz frequency with good return loss characteristics. A 2×2 MIMO antenna system is developed using the proposed antenna giving good isolation of -31 dB between the two antennas. The surface current distribution and radiation pattern of the proposed MIMO system are also presented. The developed antenna system can be used in modern wireless systems employing MIMO technology.
DESIGN OF A NOVEL MICROSTRIP MIMO ANTENNA SYSTEM WITH IMPROVED ISOLATIONjantjournal
A novel compact two element MIMO (Multiple Input Multiple Output) antenna system for WLAN applications with improved isolation characteristics is presented in this paper. The proposed antenna resonates at 5.4 GHz frequency with good return loss characteristics. A 2×2 MIMO antenna system is developed using the proposed antenna giving good isolation of -31 dB between the two antennas. The surface current distribution and radiation pattern of the proposed MIMO system are also presented. The developed antenna system can be used in modern wireless systems employing MIMO technology.
A broadband MIMO antenna's channel capacity for WLAN and WiMAX applicationsIJICTJOURNAL
This paper describes the findings of a research into the multiple input multiple output (MIMO) channel capacity of a broadband dual-element printed inverted F-antenna (PIFA) antenna array. The dual-element antenna array is made up of two PIFAs that are meant to fit on a teeny-tiny and small wireless communication device that runs at 5 GHz. The device's frequency range is between 3.5 and 4.5 GHz. These PIFAs are also loaded into the device during the installation process. In order to investigate the channel capacity, the ray tracing method is employed in two different kinds of circumstances. For the purpose of carrying out this analysis of the channel capacity, both the simulated and measured mutual couplings of the broadband MIMO antenna are utilized.
Similar to Printed Coplanar Two-Antenna Element for 2.4/5 GHz WLAN Operation in a MIMO System (20)
A One-Piece Flat-Plate Dipole Antenna for Dual-Band WLAN OperationSaou-Wen Su
A simple, one-piece, flat-plate dipole antenna suitable for dual-band WLAN applications is presented. The antenna is structured to be of an L shape to fit in corners of possible wireless electronics devices. The two radiating arms of the dipole antenna are further short-circuited through a narrow shorting strip at the corners, making it possible for the antenna to be manufactured by stamping a single, flat metal plate only one time. That is, the proposed antenna in the mass-production phase can be at lower cost. In addition, by cutting an L-shaped slit at proper location in each radiating arm, a dual-band operation can easily be obtained. The design prototype of the antenna in the 2.4/5.2 GHz bands is discussed in detail in the article.
A Probe-Fed Patch Antenna with a Step-Shaped Ground Plane for 2.4 GHz Access ...Saou-Wen Su
This Letter demonstrates a new design of a probe-fed patch antenna with a modified antenna ground, and a constructed prototype ideal for applications in a 2.4-GHz WLAN access point is presented. The antenna has a thick air substrate for broadband operation and is fed by an inclined probe pin at the edge of the patch bent portion. The antenna ground comprises different portions and is in the shape of a step. With the proposed probe feed and ground configuration, good impedance bandwidth with VSWR below 1.5 over the 2.4 GHz WLAN band can be obtained. In addition, good broadside radiation characteristics have also been observed.
Matching a Bluetooth Headset Antenna on a Small System Ground by Using a Cond...Saou-Wen Su
A simple yet effective method for matching a compact planar inverted- F antenna (PIFA) on a small system circuit board for Bluetooth-headset applications is presented. The antenna is perpendicular to and extends along the top and right sides of the system ground, making it possible for the antenna to occupy almost no limited board space. Results have shown that by introducing a thin conductive wire soldered to the bottom corner of the system ground, good input matching over the 2400-2484 MHz band can easily be achieved for the PIFA mounted on a small ground of length less than a quarter wavelength at 2440 MHz. Radiation measurements of the proposed design in a real headset attached to a standard head phantom are also taken.
Wideband Rod-Dipole Antenna with a Modified Feed for DTV Signal ReceptionSaou-Wen Su
A wideband rod-dipole antenna with a modified feed for DTV signal reception in the 470-862-MHz UHF band is presented. The antenna consists of two retractable rod-dipole arms, which are connected to the opposite top corners of the modified feed. The feed is in the shape of a rectangle with dimensions 20 mm × 40 mm and divided into two portions by a U slit. The antenna can generate nearby resonant modes to attain a wide operating band, exceeding 60% bandwidth with VSWR below 3, much larger than that of the conventional center-fed dipole antenna. In addition, with the two dipole arms designed at the production stage to be able to swivel around, the antenna radiation and polarization thereof can easily be adjusted for better DTV signal reception without moving the whole antenna structure.
2005 IEEE AP-S-Compact Printed Band-Notched UWB Slot AntennaSaou-Wen Su
A compact printed ultra-wideband (UWB, 3.1 ~ 10.6 GHz) circular slot antenna having a notched frequency band at 5 GHz is presented. The antenna is a uniplanar structure and occupies a compact area of 25 x 26 mm2 only (side length less than 27% of the lower edge frequency at 3.1 GHz). The antenna has a U-slotted circular stub embedded inside the circular slot. By choosing the length of the U-slot cut in the circular stub to be about a half-wavelength of the desired notched frequency, a band-notched UWB operation is obtained.
2005 IEEE AP-S-Internal Shorted Patch Antenna for UMTS Mobile PhoneSaou-Wen Su
A novel design of feeding and short-circuiting an internal patch antenna for mobile phones is presented. The patch antenna is with a simple rectangular patch and is fed through and short-circuited to a small ground plane (denoted as antenna ground here) protruded from the main or bottom ground of a folder-type mobile phone. With the presence of the small antenna ground, which can function as a shielding wall, the proposed antenna can be placed in close proximity to the RF shielding metal box in the mobile phone, with very small effects on the antenna performances.
2007 IEEE AP-S-Internal UWB Metal-Plate Monopole Antenna for a Wireless USB D...Saou-Wen Su
A novel ultra-wideband (UWB) monopole antenna suitable to be mounted on the printed circuit board (PCB) of a wireless universal serial bus (USB) dongle as an internal antenna is presented. The proposed antenna in the study is a U-shaped metal plate monopole antenna easily fabricated from bending a simple metal plate onto a foam base of a compact size of 6 x 11 x 20 mm3. The antenna mainly comprises a pair of wide-ended radiating arms and a bevelled feeding transition. When the antenna is mounted at the top portion of the PCB, one end of the radiating arm is also short-circuited to the system ground plane. With the proposed antenna structure, which can provide a very wide operating bandwidth of larger than 7.6 GHz, the antenna’s impedance bandwidth can easily cover the 3.1–10.6 GHz UWB band.
2. two symmetrical slits are cut out of the monopole antenna to MIMO system in the next section are based on the fixed value 10
meander the excited surface currents, which leads to a compact mm for the distance d. The results of the radiation characteristics
size for the 2.4-GHz antenna. For testing the two-antenna element between the two-antenna element with one antenna excited and the
in experiments, two short 50- mini-coaxial cables with I-PEX two proposed elements with two antennas excited will be analyzed
connectors are utilized. The inner conductor of the coaxial cable is too.
connected to the feeding point (points A and C) and the outer
braided shielding is connected to the grounding point (points B 3. RESULTS AND DISCUSSION
and D).
Figure 2 shows three possible arrangements, denoted as com- 3.1. The S Parameter Analyses
binations 1 to 3 here, of the two proposed two-antenna elements. Figures 3(a) and 3(b) show the measured and simulated reflection
Notice that the configuration presented in Figure 1(a) is for com- coefficients (S11 for the 2.4-GHz antenna, S22 for the 5-GHz
bination 1 arrangement. The two proposed elements are spaced antenna) and isolation (S21). It is first noticed that in general, the
apart at a distance of d in the lateral direction. That is, both the experimental data compare favorably with simulation results,
shorter edges of the two elements are facing each other. In this which are based on the finite element method using Ansoft HFSS.
case, a low-profile MIMO system having four antennas is formed. The impedance matching in both the 2.4- and 5-GHz bands is
The obtained MIMO system has a height of 11 mm and can be much less than 10 dB, and the isolation between the antennas
installed in some space inside the housing of a wireless device. The remains under 15 dB over the operating bands. Also notice that
distance d plays an important role in influencing isolation behavior a higher resonant mode is found at about 3.4 GHz, which is mainly
in the two proposed elements. A larger d can result in better attributed to a dipole-like resonant mode well excited in the
isolation in general, which have been recently reported with sim- monopole antenna. In this case, the simulated surface currents in
ilar interests [5, 6]. Between any two of the four antennas, the the antenna and the ground plane are observed to be distributed in
isolation of less than 15 dB, which is usually demanded for the opposite direction with null currents existing at one third of the
practical applications in industry, can be achieved when the dis- ground plane from the monopole antenna. On the other hand the
tance d is larger than 10 mm. The studies for the four-antenna current distribution is found to be in the same direction in both the
antenna and the ground plane when the antenna operates in the
monopole resonant mode at about 2.42 GHz.
The isolation behavior between the antennas of the two ele-
ments in the MIMO system for combinations 1 to 3 was also
studied, and the results are shown in Figures 4(a)– 4(c). For com-
bination 1, it is first seen that the isolation is all less than 15 dB
within the bands of interests. Isolation between the same antennas,
i.e. the antennas 1 and 3, is the poorest in the antenna’s operating
band, i.e. the 2.4-GHz band, as the characteristic is reasonably
expected. Also worth noticing that the isolation S32 is not better
than S41 even though the distance between the antennas 2 and 3 is
much longer than the distance between the antennas 1 and 4. The
phenomenon is largely because the factor in the influence of
isolation in this four-antenna MIMO system is decided more by
antenna radiation patterns (pattern diversity) than by the separation
distance (spatial diversity) [7]. The maximum radiation of the
5-GHz PIFA has been found to be in the direction of the antenna
(a) ground (see inset in Fig. 5), thus leading to much degraded
isolation for the antennas 2 and 3.
For combinations 2 and 3 in Figures 4(a) and 4(b), the worst
isolation is seen with the two same antennas placed adjacent to
each other. The isolation S41 and S32 are about the same due to the
same arrangement for the antennas 1, 4 and 2, 3. The isolation S42
in the 5-GHz band is not better in combination 2 than in combi-
nation 1, even the combination 2 with a longer separation distance
between the two PIFAs. The results also indicate that the isolation
property in this MIMO system can be affected more by the
radiation patterns (the maximum radiation of the 5-GHz antennas
in combination 2 facing each other) than by the separation dis-
tance.
3.2. The Radiation Characteristics
Figures 5(a) and 5(b) plot the measured and simulated 3D radiation
patterns for the two-antenna element studied in Figure 1 at 2442
(b) and 5490 MHz, the center operating frequencies of the 2.4- and
5-GHz bands respectively. The far-field measurement was con-
Figure 3 Refection coefficients (S11 for the 2.4-GHz antenna and S22 for ducted at a 3 3 7 m3 anechoic chamber at Lite-On Technol-
the 5-GHz antenna) and isolation (S21) between the two antennas: (a) ogy, Taipei. First, the measured and simulated results are not
measured results; (b) simulated results. [Color figure can be viewed in the appreciably different. The radiation characteristics for the 2.4-GHz
online issue, which is available at www.interscience.wiley.com] antenna here resemble those of the dipole antenna, in which
1636 MICROWAVE AND OPTICAL TECHNOLOGY LETTERS / Vol. 50, No. 6, June 2008 DOI 10.1002/mop
3. (a) (b)
(c)
Figure 4 Simulated S-parameters (S31, S41, S32, S42) for the two proposed elements in the four-antenna MIMO system in Figure 2 with d 10 mm: (a)
for combination 1; (b) for combination 2; (c) for combination 3. [Color figure can be viewed in the online issue, which is available at www.interscience.
wiley.com]
omnidirectional radiation is obtained in the horizontal cut (the x–y
plane in this case). That’s because the ground-plane length corre-
sponds to a quarter-wavelength at around about center operating
(a)
(a)
(b) (b)
Figure 5 The 3D radiation patterns at 2442 and 5490 MHz for the Figure 6 Measured peak antenna gain and measured radiation efficiency
antennas studied in Figure 3: (a) measured results; (b) simulated results. for the antennas studied in Figure 3; (a) for the 2.4-GHz antenna; (b) for the
[Color figure can be viewed in the online issue, which is available at 5-GHz antenna. [Color figure can be viewed in the online issue, which is
www.interscience.wiley.com] available at www.interscience.wiley.com]
DOI 10.1002/mop MICROWAVE AND OPTICAL TECHNOLOGY LETTERS / Vol. 50, No. 6, June 2008 1637