Low profile broadband substrate‐integrated waveguide to rectangular waveguide transition for W‐band automotive radar

Low profile broadband substrate‐integrated waveguide to rectangular waveguide (RWG) transitions have been proposed for RF verification of W‐band automotive radar. The transition is designed on a PCB, which is assembled between the radar board and instrument waveguide port. In the design of the transition, a magnetoelectric (ME) dipole is introduced to excite the basic mode of RWG, and a bowtie slot is designed to excite the ME dipole with a broadband performance. The measured frequency band of back‐to‐back transitions is 68.4–85.3 GHz for a 5 mil RO3003 covered multilayer radar board and 68.6–89.3 GHz for a 10 mil RO3003 covered board, respectively. The calibrated single transition loss is 0.58 and 0.33 dB, respectively. The proposed low profile transitions are robust to assembly errors and convenient for fast RF verification of automotive front‐end in the design stage.