Wideband transition from coaxial to double ridged waveguide

A design of transition from coaxial to double ridged waveguide that operates in octave bandwidth is presented. The proposed design of the transition is based on the utilization of disc-ended probe with conical part and fixing coaxial sections. Octave operating bandwidth (S11 better than -23 dB) of the transition was achieved via multiparametric optimization. The numerical results obtained by the finite-difference time-domain method are included.