Waveguide to strip line transition in Ka-band using LTCC technology

In this paper, a novel waveguide to strip line transition based on LTCC(Low Temperature Co-fired Ceramic) technology at Ka-band is presented. To improve the bandwidth and impedance matching, two major improvements are done, which includes the multilayer step-shape matching structure buried beneath the probe and the gradual-change structure used on substrate layers. According to the simulated results of HFSS, the return loss is better than 15dB and the insertion loss is less than 0.3dB, over the specified frequency range from 33.3GHz to 37.4GHz. The simulated size of the transition is compact(8.4mm×8mm×0.94mm).