Design of Dual-Band Beam Switching Array for Adaptive Antenna Applications Using Hybrid Directional Coupler and E-Shape Slot Radiator

摘要

The proposed research work presents a design of a dual-band 4-element planar beam-steering antenna array with a feed network. Beam steering array is implemented with two different schemes for S-Band adaptive antenna applications. A design procedure is derived in detail, and a prototype, including the array and a planar feeding network, is built and tested for the first scheme. The array is capable to generate 4 beams in different directions based on the input applied to the port of the Hybrid Directional Coupler. Scanning range covered by this array is, in E-plane from - 45 degrees to + 10 degrees and in H-plane from - 25 degrees to + 25 degrees. Inter-element spacing is optimized with D1 = 86 mm and D2 = 40 mm to achieve maximum directive gain, which is 12.6 dBi at 3.6 GHz and 9.29 dBi at 2.4 GHz. Return Loss obtained is - 40.76 dB at 3.6 GHz and - 24.58 dB at 2.4 GHz. The planar feed network is designed with Wilkinson Power Dividers and Hybrid Directional Coupler. When the array is operated with 3.6 GHz, beam steering will be in positive directions and when it is operated with 2.4 GHz, beam steering will be in negative directions for E-Plane. Beam switching, based on the input applied to the port of directional coupler will be in the H-Plane for both frequency bands.