Design of Substrate Integrated Waveguide Sum-Difference comparator

The model and simulation of a novel substrate integrated waveguide (SIW) sum-difference comparator based on 3 dB-coupler with 90deg phase delay is proposed. Equivalent model method is used to determine initial geometric sizes and numerical software simulation is used to make optimization and obtain electrical characteristic variations and electromagnetic field distributions. An example comparator is presented for operating at 26 GHz, followed with S-parameter curves and field distributions. This comparator can be used in high-frequency minimized direction-finding radar systems.