Ka-band Substrate Integrated Waveguide Isolator with Novel Matched Load

This paper covers the design of a Substrate Integrated Waveguide (SIW) isolator with a novel resistive load. The electromagnetic simulation results are presented and compared with the characteristics of a SIW-based isolator with a loaded microstrip output. It is shown that the developed tantalum-based resistive load provided 21% bandwidth in terms of the isolation level between the terminals equal to -20 dB, showing a 7% improvement compared to a SIW-based isolator with a loaded microstrip output and 25% load length reduction.