Simulation and comparison of two classes of circularly polarized triple-frequency antennas

Two classes of circularly polarized antennas for triple-frequency operation are presented and discussed in this paper. To achieve triple-frequency operation, the proposed microstrip antenna has three layers, and each arm of the quadrifilar helical antenna consists of three elements with different length. The two triple-frequency antennas can both get circular polarized hemispherical pattern with miniaturized compact size. The bandwidth of VSWR < 2 at each frequency is enough for practical operation. The simulation results and analysis are presented.