Cost‐Effective Inline WR‐19 Waveguide‐to‐Coaxial Adapter With a Printed Circuit Board Based Ridge Structure

Abstract This study proposes a structure that replaces the stepped metallic ridge of an inline waveguide‐to‐coaxial adapter operating in the 40–60‐GHz band with a ridge structure based on a printed circuit board (PCB). The PCB‐based ridge is designed using stepped via holes and patterned copper foil to provide an impedance‐matching function without the need for metal processing. A prototype device was manufactured and measurements were made using a vector network analyser (VNA). Based on simulations and measurements, reflection coefficients of less than –15 dB were achieved across the entire band. Therefore, the proposed adaptor performs well in the U‐band at low cost.