Miniaturized circularly polarized patch antenna using coupled shorting strip and capacitive probe feed

摘要: Abstract This paper proposes a single-feed miniaturized circularly polarized (CP) patch antenna aimed to cover Chinese BeiDou navigation satellite system (BDS) B3 band (1268.52 ± 10.23 MHz). Four unbalanced circular patches as perturbation elements are loaded onto corners of square radiator ensure CP property. To simultaneously realize miniature size and adequate bandwidth, each is coupled an L-shaped shorting strip consisting horizontal arc-shaped connected the ground plane through vertical pin. In addition, capacitive probe feed fulfilled by embedding annular gap used compensate large inductance due thick substrate, therefore good impedance matching can be obtained. The occupies overall λ0/8 × λ0/8 × λ0/13.6, where λ0 denotes free space wavelength at 1268 MHz. Experimental results show that it achieves 10-dB return loss bandwidth 75 MHz (1237–1312 MHz) 3-dB axial ratio (AR) 31 MHz (1253–1284 MHz). measured AR beamwidth gain above 170° 4.0 dBic, respectively, across entire BDS band.