Development of a Simple Broadband Microstrip to Waveguide Transition

A novel microstrip to waveguide transition fabricated on a single substrate is proposed. The transition is based on a proximity fed E-shaped patch antenna element which allows for double resonances. Thus the bandwidth of the transition can approximately be doubled compared to a transition which utilizes a regular patch element without increasing the transversal dimensions. The influence of the critical patch parameters is discussed. Numerical resultsshow an input reflection coefficient below -15 dB between 15.97 GHz and 16.49 GHz and a minimal insertion loss of 1 dB. The bandwidth is approximately 3.2% at the center frequency of operation (16.23 GHz). Measurement results of the fabricated transition are presented and compared with simulation results.