31-03-2012, 03:49 PM
BANDWIDTH ENHANCEMENT OF CIRCULAR MICROSTRIP ANTENNAS
[attachment=19344]
INTRODUCTION
The circular microstrip antennas are one of the different shapes of microstrip antennas which are widely used due to their advantages , in spite of these advantages there is some drawbacks that may affect their wide usage, one of these drawbacks is the narrow bandwidth which is < 2 % for a single patch, many techniques suggested to enhance this narrow bandwidth such as using a thick substrate [1], stacked configuration[2], capacitive feed [3], proximity coupling ,these techniques lead to a bandwidth improvement of 15~20 %.
SIMU
with the published results, it gave a good
matching
LATION PROCEDURE In order to be confident in Microwave Office results, two different published papers were been simulated using the package and the results were compared
The first paper is of (LO) [5] in which a circular patch with a radius of 8 cm printedon a dielectric substrate of a dielectric constant of ( = 2.62) and a thickness of ( = 0.159) cm and works on a resonance frequency of
DESIGN PROCEDURE
3.GN PROCEDURE A circular microstrip antenna has been designed using the equations above, it consists of a circular patch of radius ® printed on a dielectric substrate of thickness (h) and relative permittivity constant (εr). The antenna was fed by a coaxial feed and the feed position was chosen by trial and error in order to give a good matching which is 50Ω and the parameters of the ant
equation above and they are:
RESULTS
represents the return loss of the single circular patch, and the -10 dB return loss bandwidth is 10 MHz (which is 1.408% with respect to the resonance frequency). Figure-8 represents the input im
patch, and Figure-9 (a and b) represents the E-plane and H-plane of the radiation pattern.
[attachment=19344]
INTRODUCTION
The circular microstrip antennas are one of the different shapes of microstrip antennas which are widely used due to their advantages , in spite of these advantages there is some drawbacks that may affect their wide usage, one of these drawbacks is the narrow bandwidth which is < 2 % for a single patch, many techniques suggested to enhance this narrow bandwidth such as using a thick substrate [1], stacked configuration[2], capacitive feed [3], proximity coupling ,these techniques lead to a bandwidth improvement of 15~20 %.
SIMU
with the published results, it gave a good
matching
LATION PROCEDURE In order to be confident in Microwave Office results, two different published papers were been simulated using the package and the results were compared
The first paper is of (LO) [5] in which a circular patch with a radius of 8 cm printedon a dielectric substrate of a dielectric constant of ( = 2.62) and a thickness of ( = 0.159) cm and works on a resonance frequency of
DESIGN PROCEDURE
3.GN PROCEDURE A circular microstrip antenna has been designed using the equations above, it consists of a circular patch of radius ® printed on a dielectric substrate of thickness (h) and relative permittivity constant (εr). The antenna was fed by a coaxial feed and the feed position was chosen by trial and error in order to give a good matching which is 50Ω and the parameters of the ant
equation above and they are:
RESULTS
represents the return loss of the single circular patch, and the -10 dB return loss bandwidth is 10 MHz (which is 1.408% with respect to the resonance frequency). Figure-8 represents the input im
patch, and Figure-9 (a and b) represents the E-plane and H-plane of the radiation pattern.