A broadband microstrip-to-waveguide transition using planar technique

This paper presents a novel methodology, which employs a multi-layer structure to act as an interconnection between a microstrip and a rectangular waveguide. A Ka-band microstrip-to-waveguide transition consisting of two back-to-back mode converters are designed and implemented on a microwave printed circuit board. The field-matching between the microstrip and the partially filled rectangular waveguide can obtain excellent scattering characteristics of over 40% bandwidth and low transmission loss of -0.28 dB. These attractive performances indicate that the proposed microstrip-to-waveguide transition can provide a feasible approach to integrate all the RF front-end components in one module by using a conventional PCB (printed circuit board) fabrication process.