Design of waveguide-microstrip transition circuit in Ka-band

This paper introduces a new kind of rectangular waveguide-microstrip transition structure with a trapezoidal probe and triangular transition section in Ka-band. While The printing structure is very easy to fabricate and doesn't need to test. This structure can replace fin-line transition and has a practical value. The measured results show that the return loss is below -9dB and the transmission loss is -1.1dB~-3.4dB when the frequency ranges from 26.5GHz to 37.5GHz.