Coupling suppression study of miniaturized BDS/GPS multifunctional transceiver antenna based on quarter-mode substrate integrated waveguide

Abstract

In this paper, a miniaturized BDS/GPS multifunctional antenna based on quarter-mode substrate integrated waveguide (QMSIW) is designed. Firstly, the dimension of the antenna is significantly reduced by using QMSIW technology. Secondly, the bandwidth of the antenna unit is widened by applying the multimode resonance theory. Thirdly, the four units are rotated and placed orthogonally with a reasonable layout to reduce the isolation between the units. Finally, the four units operating at 1268/1575/1616/2492 MHz are grouped in the array and loaded with the combined resonant structure to suppress the coupling between the units further. The designed antenna array covers the bands of BDS-2 B3, GPS L1, BDS-1 L and BDS-1 S, achieving 35 MHz (1255–1290 MHz), 50 MHz (1540–1590 MHz), 45 MHz (1605–1650 MHz) and 80 MHz (2480–2560 MHz) respectively, with the operating bandwidth and peak gain are 4.22, 5.68, 5.09 and 6.3 dBi. It is worth mentioning that after the decoupling process, the isolation degree between the antenna units is significantly improved. And the peak isolation degree between the four units finally drops to −34.3 dB (S12), −29.20 dB (S23 in GPS L1) and −30.29 dB (S23 in BDS-1 L) respectively.