Circularly Polarized Slotted Conductor-backed Coplanar Waveguide (CBCPW) Antenna Array with Sequentially Rotated Feeding Structure

Abstract

In this paper, circularly polarized slotted antenna arrays on conductor-backed coplanar waveguide (CBCPW) operating at Ku band are proposed. Radiating slots along the propagation direction of the parallel-plate mode in the CBCPW structure are etched to radiate into the air. By appropriately arranging the position and tilt angle for each slot, we can implement a kite-shaped linearly polarized antenna array with high gain and narrow beamwidth. Combining four linearly polarized arrays with a sequentially rotated feeding structure can produce a circularly polarized slotted CBCPW antenna arrays. Two arrangements of the sequential rotation method with the feeding phases in a 0 degrees, 90 degrees, 0 degrees, 90 degrees fashion and a 0 degrees, 90 degrees, 180 degrees, 270 degrees fashion are used. The measured gains are 24.889 dBiC for the 0 degrees, 90 degrees, 0 degrees, 90 degrees arrangement and 24.691 dBiC for the 0 degrees, 90 degrees, 180 degrees, 270 degrees arrangement, respectively. The bandwidths of the axial ratio (AR) below 3 dB are 330 MHz and 370 MHz,