Design and implementation of circularly polarised microstrip antenna array using a new serial feed sequentially rotated technique

Investigation results on circularly polarised microstrip antenna arrays at 2.45 GHz are presented. Effects of the feed network in the sequentially rotated technique to improve the antenna performance are reported. A new serial feed sequentially rotated to construct coplanar-fed arrays of large size, that improves antenna performance, is proposed. The results achieved show that this technique not only leads to an improvement in bandwidth, but also results in a better radiation pattern with lower sidelobe levels in the E and H radiation planes. A new 2 x 2 antenna subarray that has been arranged using the serial-feed sequentially rotated technique was fabricated. The measurement results for resonant frequency, return loss, axial ratio, bandwidth and radiation pattern confirm the integrity of the simulation results.