Design Of A Ka-Band Meander-Line Circular Polarizer

To solve the problems of poor axial ratio and narrow bandwidth when transforming line polarization wave into circular polarization wave, this dissertation makes a deeply study on the optimization design of meander-line polarizer for circular polarization and novel innovative parameter optimization designs are proposed, which have been verified by experimental results.In this paper, two novel types of meander-line polarizer for circular polarization containing external use-type circular polarization and built-in-type circular polarization, are proposed for mm-wave applications. To improve the axial ratio and achieve wide bandwidth, we study cycle structure unit, do parameters research and summarize the change rules of parameters. The distance between circular polarization and feed source is especially researched to suppress the excitation of mechanical processing. Under that situation, the performance of circular polarization is stable. Simulation and test data of 10-mil-thick circular polarization show that the designed polarization, working at 30GHz, can achieve a bandwidth of 10% with axial ratio lower than 3dB,5% lower than 2dB and 2.3% lower than 1dB,which can meet with the needs of line polarization wave transforming into circular polarization wave. Furthermore, we also design a 60-mil-thick circular polarization with two sides etched wire, working at 30GHz. Simulations and test data show that they can achieve a bandwidth of 8.3% with axial ratio lower than 3dB,5.3% lower than 2dB and 2.7% lower than 1dB, respectively.