Design of Ka-band probe transitions

The transition way of microstrip to coaxial line, coaxial line to waveguide and microstrip-coaxial line-waveguide of Ka band is analyzed in this paper, and a compensation structure of microstrip-coaxial line-waveguide transition is mentioned. This probe transition way was simulated by microwave CAD software and the result shows the compensation structure reduce the insertion loss effectively, thus has a perfect performance. From 30 to 37 GHz, the insertion loss is below 0.4 dB, which corresponding the simulation results basically.