Design of a miniaturized Ku-band rectangular waveguide-coaxial-microstrip transition structure

A transition structure of rectangular waveguide-coaxial line-microstrip-gold wire-chip pad is proposed in this paper. In the design, three-step rectangular waveguide is adopted, which is fed from the bottom of the microstrip through the coaxial structure (glass insulator). The microstrip and the chip pad are interconnected with gold wire. According to the classical microwave theory, HFSS software is used to model, simulate and optimize. By adjusting the height and width of rectangular steps, as well as the key parameters of coaxial and microstrip, it is achieved that the return loss is less than -20.7dB and the insertion loss is less than 0.06dB in the range of 14.5-18GHz band. This transition structure has a broad application prospect and can be used in TR modules and can be connected with waveguide antennas in SAR system.