Five‐way radial filtering power divider using single‐layer substrate integrated waveguides and microstrip resonators

This paper proposes a five‐way radial filtering power divider based on single‐layer substrate integrated waveguides (SIW) and microstrip resonators. The SIW circular cavity and the quarter‐mode SIW are connected in the radial direction, and microstrip resonators are added at the connection to form a hybrid structure, the design of which makes the structure more compact and can provide adjustable band‐pass filter response. A prototype was manufactured. The final measurement results show that the insertion loss is 1–1.5 dB, the 3 dB fractional bandwidth is 6.5%, the out‐of‐band rejection is greater than 32 dB from 10.2 to 19.5 GHz, and the out‐of‐band rejection at frequency below 8.3 GHz is greater than 37 dB. The amplitude difference and phase difference of each output port are 0.5 dB and 0.25°, respectively.