Millimeter-Wave Broadband Waveguide-to- Microstrip Transition Using a Bifurcated Probe
Bo Zhang, Yong Zhang, Chengkai Wu, Tianhao Cao
Abstract
In this letter, a novel waveguide-to-microstrip vertical transition using a bifurcated probe is presented. The bifurcated probe consists of a pair of thin parallel <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$E$ </tex-math></inline-formula> -plane probes and bend branches, which forms a strong current crowding effect for electromagnetic energy coupling from rectangular waveguide and broadband impendence matching. Therefore, the bifurcated probe can effectively reduce the sensitivity of probe dimensions to transition performance and design difficulty. To demonstrate this concept, a back-to-back bifurcated probe transition operating at WR-4.3 band (170–260 GHz) was fabricated and measured. Measured results show the double transition covers the entire WR-4.3 band with a minimum return loss (RL) of 16 dB and an average insertion loss (IL) of 0.84 dB, respectively.