A circularly polarized antenna array with sequential-phase feed network.

In this paper, a simple broadband circularly polarized (CP) patch antenna design is proposed. The antenna uses a 2 × 2 array fed by a sequential-phase feed network to improve the axial ratio (AR) bandwidth and gain, and an L-shaped slot is used to remove the coupling between the feed network and the radiation patches. Similarly, to reduce coupling, the height between two substrates is discussed as an important parameter. The proposed antenna is fabricated to verify the simulated results. Measured results show that the impedance bandwidth is 65.2% (1.68–3.31 GHz), the AR bandwidth obtained at the same time is 61.6% (1.86–3.39 GHz), and the effective relative bandwidth is 58% (1.86–3.31 GHz), and the peak gain is about 7.13 dBi at 2.7 GHz. [ABSTRACT FROM AUTHOR]