A Broadband and Compact SICL to Waveguide Transition

In this paper, a waveguide to substrate integrated coaxial line (SICL) transition structure with broadband and compact characteristics is proposed. In this design, the rectangular patch probe is used to realize the signal transition between the TEM wave transmitted by SICL and the TE10 wave transmitted by rectangular waveguide (RWG). In order to achieve broadband function, U-slots are loaded on the probe, and stacked patches and stepped ridge waveguide transformer are used to improve the transition impedance bandwidth. The simulated results show that return loss greater than 10 dB is achieved in fractional bandwidth of 45.5 % (22.23 - 32GHz) and insertion loss is better than 1dB. The broadband and compact transition structure proposed in this paper has broad application prospects in microwave and millimeter wave circuit systems.