Bandwidth enhancement of a circularly polarized tapered crossed slot antenna with corner parasitic directors

摘要

This paper presents a single-feed wideband circularly polarized (CP) antennawith tapered crossed slots and corner directors. According to the multimoderesonance concept, the antenna uses two identical cross placedVivaldi-like tapered slots as the wideband radiating elements, and four rectangularparasitic patch directors are connected on each corner of the groundfor further enhancing the bandwidth. A simple second-order steppedmicrostrip line with a via on the other side of the substrate is used to feedthe antenna. Two pairs of capacitors and inductors are placed on each slotto realize a 90° phase difference for CP operation. The proposed antenna isdesigned, fabricated and measured. Simulation results are in good agreementwith the measured results that demonstrate a 10 dB impedance bandwidth(IMBW) from 1.98 to 5.71 GHz (3.73 GHz, 97.01%) and a 3 dB axialratio bandwidth (ARBW) from 2.13 to 3.91 GHz (1.78 GHz, 58.94%). Theantenna outperforms most of the reported cross slot antennas for its wideIMBW and ARBW.