WIDE AXIAL RATIO BANDWIDTH, HIGH GAIN, AND LOW PROFILE CAVITY BACKED CIRCULARLY POLARIZED ELLIPTICAL ARRAY FOR SATELLITE APPLICATIONS

In this paper, a novel wide axial ratio bandwidth (ARBW), high gain, and low profile lefthand circularly polarized [4 × 4] elliptical microstrip array suitable for Ku-band satellite TV reception applications is introduced. A careful study has been done to get the optimum design to be suited for these application requirements. A circularly polarized microstrip patch with two stubs opposite to each other to produce two orthogonal modes is presented. The proposed element has 1.49 GHz 10-dB return loss bandwidth (RLBW), 0.44 GHz 3-dB Axial-ratio band (ARBW), and 6.9 dBi gain. A novel substrate integrated waveguide (SIW) feeding structure is investigated. Using the advantage of the output ports phase response of the SIW feeding network, two structures have been investigated. First, a [2 × 2] circular array has been designed, and although it has reached a good RLBW, this structure does not achieve the required ARBW for the above-mentioned application. Further, a compact [2 × 2] sequential feeding network is designed to widen the ARBW. The measurement shows a very good result with about 12 dBi gain, 14.8% RLBW, and 12% ARBW. Finally, a [4×4] duple sequential feeding array is designed to increase the gain of the antenna to about 19 dBi, with 13% RLBW and 20.7% ARBW. In addition to that, the final antenna profile is 0.0184λ.