NOVEL APERTURE-COUPLED MICROSTRIP-LINE FEED FOR CIRCULARLY POLARIZED PATCH ANTENNA

A wideband circularly polarized patch antenna is proposed. The wide impedance and axial ratio bandwidths are achieved by the proposed feeding mechanism, which entails the use of a circular microstrip line coupling through four Γ-shaped slots to generate four sequentially phased sources to excite the single layer patch antenna. The proposed antenna can provide an SWR bandwidth of over 16.5% (for SWR<1.5) and an axial-ratio bandwidth of 13.3% (for AR<3 dB). The performance of the antenna has been confirmed by both measurement and simulation. The antenna gain is enhanced and backlobe radiation is reduced by placing a reflector at an optimized location.