A broadband waveguide power splitter and combiner using in spatial power combining amplifier

This paper presents a K band 3dB broadband waveguide power splitter/combiner analyzing and designing steps. In order to achieve broadband performance and at the same time to minimize the difficulty and sensitivity in the mechanical fabrication, the design uses three equal branches, simulated bandwidth is about 3.5GHz which over desirable requirement in operating frequency bands. There are good agreements between the experimental results and simulations. Measured results for this waveguide power splitter/combiner shows return loss greater than 20dB, isolation of through port and coupler port is greater than 24dB, isolation of input port and isolated port is greater than 22dB, and VSWR of each port is below 1.2.