A Circularly Polarized Patch Antenna Array with Reduced Mutual Coupling Using the Aperture-Loading Decoupling Technique

An aperture-loaded decoupling strategy for 1 × 8 circularly polarized (CP) patch antenna array is presented in this article. By introducing an additional coupling path, the mutual coupling between adjacent antennas is cancelled. The result shows that more than 20- dB isolation enhancement is obtained by applying this strategy at the center frequency of 3.38 GHz. Mutual coupling between both adjacent and non-adjacent elements are suppressed to less than -25 dB. Moreover, the impedance bandwidth and axial ratio (AR) is also improved with decoupling. Compared with conventional CP antenna decoupling methods, the proposed approach has the characteristics of low profile, compact size, and low impact for the ground plane. It is shown that the AR bandwidth can be enhanced using the proposed decoupling method.