Improved Design of Ka-band Waveguide to Coaxial Right Angle Microwave Transition

The Ka-band (26.5-40 GHz) standard waveguide (WR28) to 50Ω Coaxial (2.92mm Female) microwave transition has been designed indigenously. This is a short-ended ridged waveguide design with disc-loaded coaxial probe [1] based on the principles of field matching and impedance matching. It’s achieved through ridged waveguide, customized coaxial probe and back-short distance [2]-[3]. The compact single piece transition results in the light weight, ease in integration and improved RF leakage of < -88dBm (measured). The full two-port adapter-removal (AR) technique [4]-[5] is used for measuring Scattering parameters on VNA. The measured VSWR and insertion loss are achieved < 1.145 and better than 0.38dB respectively. This reflects significant improvement in comparison with the standard transition (as part of the VNA calibration kit) with VSWR <1.196 and insertion loss better than 0.47dB.