Low-cost and compact 3D circularly polarized Microstrip antenna with high efficiency and wide beamwidth

摘要

A compact three-dimensional (3D) circularly polarized (CP) microstrip antenna is presented in this paper. The antenna adopts three low-cost printed circuit boards to form an integrated and closed 3D structure, and the radiation patch and the feed patches are etched on the surface of that. A crossed slot is cut on the radiation patch to miniaturize the antenna, and triangular feed patches are introduced to increase the bandwidths. In addition, because of the utilization of a low-loss series feed line, the antenna has a high efficiency of more than 95%. A prototype of the antenna is measured to validate the method. The dimensions of the antenna is 0.064 x 0.36 ( is the wavelength in free space at 1.2 GHz). The results indicate that the impedance bandwidth for voltage standing wave ratio 2 reaches 23%, and the bandwidth for axial ratio (AR) 3 dB reaches 10.1%. In the overlap band, the gains are > 4.5dBic. Additionally, the 3 dB beamwidth is more than 114 degrees, and the beamwidth for AR 3 dB is more than 131 degrees at 1.2 GHz.