Uniform-Field Over-Mode Waveguide for Spatial Power-Combining Applications

A new and effective millimeter-wave waveguide packaging technique suitable for 1-D spatial power-combining applications is presented. The transition structure using narrow corporate channels preserves the uniform field distribution when expanding the ${E}$ -plane width of a standard waveguide to several wavelengths. A Q-band test module, containing back-to-back transitions for an increased width from 2.84 to 52 mm, shows an average insertion loss of 0.34 dB in the 40-50-GHz range. The radiation patterns from an open-end module, cut in half from the original test module, confirm uniform field distribution across the over-mode guide aperture.