A Low-Profile Wideband Circularly Polarized Crossed-Dipole Antenna

作者:Yang, Wanjun; Pan, Yongmei*; Zheng, Shaoyong; Hu, Pengfei
来源:IEEE Antennas and Wireless Propagation Letters, 2017, 16: 2126-2129.
DOI:10.1109/LAWP.2017.2699975

摘要

A low-profile crossed dipole antenna with wide bandwidth is investigated in this letter. The double-sided printing crossed dipoles consisting of four-stepped rectangular patches are fed by a pair of vacant-quarter printed rings, generating circularly polarized radiation. Two adjacent axial-ratio (AR) passbands with AR < 3 dB are generated due to the stepped rectangular patches, and they are merged together by adding an additional dielectric slab above the ground plane, resulting in a very wide AR band-width. Also, an irregular ground plane is used for the antenna, which can desirably enhance the boresight gain without involving high-profile cavity. To verify the feasibility of the proposed design, a prototype operating at C-band has been fabricated and measured. Reasonable agreement between the simulated and measured results is obtained. The prototype has a low profile of 0.13 lambda(0) (in terms of the center frequency of passband), a 10-dB impedance bandwidth of 66.9%, a 3-dB AR bandwidth of 55.1%, and an average gain of approximately 10.4 dBic within passband.