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### Various types of antenna used for transmitting and receiving

1. Laxmi Institute of Technology, Sarigam Department of Electronics & Communication (6 SEM) Engineering Presentation On Horn, Slot & Patch Antenna Submitted by:- Name: EnrollnmentNo.  JayBaria  Vikas Choudhary 150860111003 150860111004 Approved byAICTE, New Delhi;Affiliated to Gujarat Technological University, Ahmedabad Guided by:- Ms. Suchita Borkar HOD (ECE) LIT, Sarigam.
2. Horn Antenna :-  A Horn Antenna or microwave Horn is an antenna that consists of a flaring metal waveguide shaped like a Horn to direct radio waves in a beam.  Horns are widely used as antennas at UHF and microwave frequencies, above 300 MHz .  A Horn Antenna is used to transmit radio waves from a waveguide(a metal pipe used to carry radio waves) out into space, or collect radio waves into waveguide for reception.  Extension of waveguide in form of horn is called Horn Antenna.
3. Working:- -A Horn Antenna converts the electric power into radio waves and vise versa. It is usually used with a radio transmitter or radio receiver. - It provides a gradual transition structure to match the impedance of a tube to the impedance of free space, enabling the waves from the tube to radiate efficiently into space.
5. Gain :- Horns have very little loss, so the directivity of a horn is roughly equal to its gain. The gain G of a pyramidal horn antenna (the ratio of the radiated power intensity along its beam axis to the intensity of an isotropic antenna with the same input power) is:
6. To find the directivity, the maximum radiation is formed. That is, Umax = U(ǉ,Ф)|max = r2/2ǈ|E|2 max For most horn antennas |E|max is directed nearly along the z- axis (ǉ= 0). Thus, |E|max = [ |Eǉ|2 max + |EФ|2 max]1/2 = Directivity :-
7. F(t) = [ C(t) - j S(t) ] Since kx = ky = 0 t1= - t & t2 = t C(-t) = - C(t) S(-t) = - S(t) Directivity :-
8. Umax = U(ǉ,Ф)|max = r2/2ǈ|E|2 max = |F(t)|2 = [ C2( + S2( The total power radiated can be simply integrating the average power density over the aperture of the horn. ) )] ǈ ǈ Directivity :-
9. Directivity :-
10. Types of HornAntenna: • E-plane sectored horn • H-plane sectored horn • Pyramidal horn antenna • Conical horn antenna • Exponential horn antenna
11. 00 300 600 900 12 00 12 00 900 600 300 1 0 2 0 3 0 1 0 2 0 3 0 Relativepower(dBdown) E- and H-Plane Patterns of the E-Plane Sectoral Horn:- E-Plane H-Plane 15 00 15 00 18 00
12. E- and H-Plane Patterns of the H-Plane Sectoral Horn:- E-Plane H-Plane 00 300 600 900 12 00 12 00 900 600 300 1 0 2 0 3 0 1 0 2 0 3 0 Relativepower(dBdown) 15 00 15 00 18 00
13. E and H-Plane Patterns :- E-Plane H-Plane 00 300 600 900 12 00 15 00 18 00 15 00 12 00 900 600 300 1 0 2 0 3 0 1 0 2 0 3 0 Relativepower(dBdown)
14. E- and H-Plane Patterns of The Conical Horn Antenna :- E-Plane H-Plane 00 300 600 900 12 00 15 00 18 00 15 00 12 00 900 600 300 1 0 2 0 3 0 1 0 2 0 3 0 Relativepower(dBdown)
15. Advantages of Horn Antenna :- • They can operate over wide ranges of frequencies. • Very wide bandwidth, for example allowing it to operate from 1GHz to 20GHz, 20:1. • High Directivity. • High gain. • Support for wide applications.
16. Applications : • They are used as feeders (called feed horn) for larger antenna structures such as parabolic antennas, as directive antennas for such devices as radar guns, automatic doors openers, microwave radiometer. • Acommon element of phase array. • Satellite and microwave communications. • Used in the calibration, other high gain antenna. • Used for making electromagnetic interference measurement.
17. Microstrip Patch Antenna :- • MicrostripAntenna was Invented by Bob Munson in 1972 . • Microstrip antennas are attractive due to their light weight, conformability and low cost. • These antennas can be integrated with printed strip-line feed networks and active devices. This is a relatively new area of antenna engineering. • The radiation properties of micro strip structures have been known since the mid 1950’s. • A Microstrip Patch antenna consists of a radiating patch on one side of a dielectric substrate which has a ground plane on the other side. • The patch is generally made of conducting material such as copper or gold and can take any possible shape. • The radiating patch and the feed lines are usually photo etched on the dielectric substrate.
18. Basic Structure Microstrip patch Antenna L= Length of the Micro-strip Patch Element W = Width of the Micro-strip Patch Element t= Thickness of Patch h = Height of the Dielectric Substrate. Microstrip Rectangular Patch Antenna
19. Some of the Typical Shapes of Patch 8 Rectangular Square Circular Elliptical Circular ring Triangular
20. Feeding Techniques:  Coaxial feed  Microstrip feed  Proximity coupled microstrip feed  Aperture coupled microstrip feed  Coplanar wave guide  Line Feed
21. 1-Microstrip Line Feed :  In this type of feed technique, a conducting strip is connected directly to the edge of the microstrip patch.  This kind of feed arrangement has the advantage that the feed can be etched on the same substrate to provide a planar structure.
22. 2-Coaxial Feed :- The Coaxial feed or probe feed is a very common technique used for feeding Microstrip patch antennas. The main advantage of this type of feeding scheme is that the feed can be placed at any desired location inside the patch in order to match with its input impedance. This feed method is easy to fabricate and has low spurious radiation. However, its major disadvantage is that it Coaxial Ground Plane Connector Substrate Patch provides narrow bandwidth and is difficult to model since a hole has to be drilled in the substrate . and the connector protrudes outside the ground plane, thus not making it completely planar for thick substrates . Probe fed Rectangular Microstrip Patch Antenna from top Probe fed Rectangular Microstrip Patch Antenna from side view
23. 3-Aperture Coupled Feed In this type of feed technique, the radiating patch and the microstrip feed line are separated by the groundplane . Coupling between the patch and the feed line is made through a slot or an aperture in the ground plane. The coupling aperture is usually centered under the patch, leading to lower cross polarization due to symmetry of the configuration. Aperture-coupledfeed The amount of coupling from the feed line to the patch is determined by the shape, size and location of the aperture.
24. This type of feed techniƋue is also called as ͞the electromagnetic coupling scheme͟ . Proximity-coupled Feed Two dielectric substrates are used such that the feed line is between the two substrates and the radiating patch is on top of the upper substrate. The main advantage of this feed technique is that it eliminates spurious feed radiation and provides very high bandwidth due to overall increase in the thickness of the microstrip patch antenna. This scheme also provides choices between two different dielectric media, one for the patch and one for the feed line to optimize the individual performances. Matching can be achieved by controlling the length of the feed line and the width-to-line ratio of the patch. The major disadvantage of this feed scheme is that it is difficult to fabricate because of the two dielectric layers which need proper alignment. Also, there is an increase in the overall thickness of the antenna. 4-Proximity Coupled Feed
25. Comparing the different feed techniques :-
26. Advantages:  Low fabrication cost, hence can be manufactured in large quantities.  Easily integrated with microwave integrated circuits (MICs).  Capable of dual and triple frequency operations.  Supports both, linear as well as circular polarization.  Low cost , Less size , Low Mass .  Mechanically robust when mounted on rigid surfaces.  High Performance  Light weight and low volume.
27. Applications: Used in mobile satellite communication system. Direct broad cast telivision(DBS). Wiƌe less LAN’S. Feed elements in coaxial system GPS system. Missiles and telementry UHF Patch Antennas for Space
28. Slot Antenna:-  Slot antennas are used typically at frequencies between 300 MHz and 24 GHz. The slot antenna is popular because they can be cut out of whatever surface they are to be mounted on, and have radiation patterns that are roughly omni directional (similar to a linear wire antenna, as we'll see).  The polarization of the slot antenna is linear. The slot size, shape and what is behind it (the cavity) offer design variables that can be used to tune performance.
29. Slot Antenna Design
30. Babinet’s Principle -Relates the radiated fields and impedance of an aperture or slot antenna to that of the field of its dual antenna. -The dual of a slot antenna would be if the conductive material and air were interchanged - that is, the slot antenna became a metal slab in space.
31. Complementary Antennas
32. Babinet's principle relates these two antennas. impedance The first result of the states that the the slot antenna (Zs) is related to impedance of its dual antenna (Zc) by the relation: In the above, free space. is the intrinsic impedance of
33. Main advantages are :- 1) Its size, 2) Design Simplicity, 3) Robustness, 4) Versitile, 5) Convenient adaptation to mass production using PC board technology.
34. Thank you…!!