A coaxial fed double L-slot microstrip patch antenna array was designed for multi-band operation for WLAN and WiMAX applications. A single rectangular patch antenna with a center frequency of 3.6 GHz was designed for WiMAX. Double L-slots were added to reduce the resonance frequency to 2.6 GHz, suitable for WLAN frequencies from 2.23-5.35 GHz. Simulation results showed return losses of -21 dB at 3.8 GHz for WiMAX and -20 dB at 5.1 GHz for WLAN for the antenna array. The antenna exhibits good impedance matching performance and omnidirectional radiation patterns for both WiMAX and WLAN applications.

1. PRESENTED BY:
Musa Hussain
1
PRESENTED TO:
Sir Ibtisam Aslam

2. ANTENNA AND RADIOWAVE PROPAGATION
Project Title:
Co-axial Fed Double L-Slot Micro strip Patch Antenna Array.
2

3. Outline:
Overview.
Antenna Design.
Design Figures.
Simulation Results.
Conclusion.
3

4. Overview:
 In this presentation, a co-axial fed double L-shaped slotted micro-strip patch antenna array is
presented for multi-band operation satisfying WLAN (Wireless Local Area Network) and WiMAX
(Worldwide interoperability for Microwave Access) application.
 A single micro-strip rectangular patch antenna is designed with center frequency at 3.6 GHz for
WiMAX application and it also reduces the resonance frequency using double L-slot on the patch
from 3.6 GHz to 2.6 GHz, which is also suitable for WLAN (IEEE 802.11b standard frequencies
from 2.23GHz to 5.35 GHz) applications.
4

5. Overview:
The simulation results such as radiation pattern and return loss are simulated using Ansoft HFSS.
Measured and simulated results of return loss for both single patch and array antenna are analyzed
and presented.
5

6. Antenna Design:
The geometry of proposed single infinite ground Co-axial fed dual-band antenna is shown in
Figure 1 and the side view is shown in Figure 2.
 The antenna is fabricated on FR4 epoxy substrate with dielectric constant of 4.4, thickness 3.2
mm.
 The antenna consists of a rectangular patch in which two L-shaped slots are embedded.
 The advantages of coaxial feeding technique are, the feed can be placed at any location at
patch in order to achieve better impedance matching and to avoid unwanted radiations from the
feed.
6

7. Design Figures:
7

8. Antenna Design:
Initially a single patch antenna with coaxial feed was designed. In order to improve the
performance of the antenna a double patch antenna array was designed on same substrate
with separate feed for two patches.
The widths of both L- slots are same with dimension of 1mm but the length is different along X-
axis and Y-axis.
The dimensions of the L-slots and feed positions are varied to obtain desired operating range of
WiMAX and WLAN.
8

9. lengthof the rectangular patch isL=15.1mm.
Width of the rectangular patch W=25.4 mm.
Slot lengthL1=8 mm, L2=6 mm and having width
Ws=1mm.
The height of the co-axialfeed is 3.2mm.
9

10. Simulation Results:
Design of Double L slot single antenna: Design of Double L slot array antenna:
10

11. Simulation result of S parameter of the
Single antenna.
11

12. Simulation result of S parameter of the
Array antenna.
12

13. Applications:
WLAN
WiMAX.
GPS system.
Can also be used for Radio Applications.
Used in Mobile Satellite communication System.
13

14. Conclusion:
A compact coaxial fed double L slot Micro strip patch antenna array was designed to achieve
both WiMAX and WLAN applications.
 By employing coaxial feed technique the antenna exhibits good impedance match
performance and achieves a return loss of -21 dB at 3.8GHz for WiMAX and a return loss of -
20dB is achieved at 5.1 GHz for WLAN.
The radiation pattern of proposed antenna is omnidirectional for both WiMAX/WLAN
applications.
14

15. 15