Broadband circularly polarised square microstrip antenna using chip-resistor loading

Broadband operation of regular-size and compact circularly polarised microstrip antennas using a chip-resistor loading technique is investigated experimentally. The optimal arrangement is demonstrated of the chip-resistor for broadband operation of circularly polarised microstrip antennas. By introducing the proposed chip-resistor loading technique to a square microstrip antenna with two pairs of slits of different lengths inserted at the patch edges, a compact circular polarisation operation can be obtained. Details of the proposed antennas are described, and experimental results of the circular polarisation performance are presented and discussed