Design Of A Dual-Feed Dual-Band And Circular Polarization Microsrtip Antenna

Beidou satellite navigation system is the independent development of our country and can be compatible with the world’s other satellite navigation systems. On October25,2012,our country successfully launched the16th Beidou satellite navigation into the predetermined transfer orbit. It’s expected that the Beidou satellite navigation system will cover and service for the whole world in the next ten years. As an important component in the navigation system,antenna plays an important impact on the performance of the entire system. In order to receive both the Beidou and GPS signals, we need to study a dual-band circularly polarized microstrip antenna.At the above background,the thesis is about to design a dual-feed dual-band and circularly polarlized microstrip antenna.The antenna is composed of two layers and two patches, feeded by two coaxial probe which directly connected with the upper patch through the holes on the lower patch,so the antenna can be more smaller.The antenna works in the GPS L1band(1575.42MHz) and the Beidou navigation system downlink S band(2483.5MHz-2500MHz).The main contribution and new results of the thesis includes:1. Researching and designing a dual-band and circularly polarlized microstrip antenna which can receive both the Beidou and GPS signals.And also giving the antenna’s structural parameters which has been optimized.Simulating and analyzing the performance of the designed antenna,including the reflection coefficient, VSWR,radiation pattern,the current distribution and gain.2. Simulation and analyzing the structural parameters particularly the length and width of the loaded stub’s influences on the antenna’s performance.3. Analyzing the band characteristics of the antenna which is based on the Sierpinski fractal structure.By changing the scale factor of the original rectangular antenna like one and second iteration,it has given the fractal structure of iterative design for the multi-frequency microstrip antenna through comparing the band numbers of two iterations.And illustrating the guiding significance of the fractal structure to the dual-frequency antenna design.