Compact Size, Equal-Length and Unequal-Width Substrate Integrated Waveguide Four Channel Phase Shifter

Objectives: In the past decade, Substrate Integrated Waveguide (SIW) phase shifters have attracted a lot of attentions, they are key components extensively deployed in phased array antennas, electronic scanning radars and other applications. In this paper a novel SIW four channel phase shifter is proposed. Methodology: It consists of five ports from which four ports act as output channels and the remaining is applied as a feed port. Also this substrate is integrated with a waveguide phase shifter designed to operate at 10 GHz. Phase channels are made by SIW with equal length and unequal width. The width of the phase channels differ from each other and can be controlled. The equations and the process of the whole design are preceeded by mathematical analysis. The propagation constant of the output signals and output phases in output channels have been adjusted by changing only the width of the output arms. Findings: As a result, a novel phase shifter is obtained. The experimental results of the prototype at 10GHz represents 22.5, 45, 67.5 degrees phase difference between one of the outputs in comparison to other outputs respectively. The measured bandwidth is 1.3 GHz bandwidth which has conformity with the simulation results. With the change of the position, the number of added vias and the width of output channels, a different phase shift can be obtained. The measurement of return loss and transmission coefficients are in good agreement with the simulation results in the proposed band. Application/Improvements: Therefore, such a SIW phase shifter is a good candidate for development of a compact size and integrated microwave systems.