A wide bandwidth transformer between a post-wall waveguide line and microstrip line in millimeter waveband

In this paper, we propose a wide bandwidth transformer structure between a microstrip line and a post-wall waveguide line to better interconnect with the RFIC in the millimeter wave band. For bandwidth enhancement, the quasi-metal cavity is set in the middle of the post-wall waveguide line. The Connection to the IC, the quasi-coaxial structure is designed for feeding. The structures are designed at 60GHz. For reflection below -15dB, the frequency bandwidth of the model with a quasi-metal cavity is improved by about 6.63% relative to the model without a quasi-metal cavity.