Broadband Microstrip-Coplanar Stripline-Fed Circularly Polarized Spiral Antenna

摘要

A wideband microstrip-coplanar stripline-fed circularly polarized spiral antenna is presented. An electromagnetic coupled wideband balun from microstrip line to coplanar stripline is developed to feed the spiral antenna. The antenna shows a measured return loss of better than 10 dB from 6.85 GHz to 11.9 GHz. The axial ratio is smaller than 3 dB from 7 to 11.5 GHz