An Ultra-Wideband Power Combining in Ridge Waveguide for Millimeter Wave

In this article, a novel and efficient ultra-wideband power-combining method over K (18-26 GHz) and Ka (26-40 GHz) band is presented. Ridge waveguide power combiners and contactless transition between ridge waveguide and double microstrip lines will be used in this method. By using this method, a 16-way power combiner system is designed to work in the bandwidth of 18-40 GHz through 3-D electromagnetic field simulation and optimization. A back-to-back configuration of this combiner system is manufactured. The measured power-combining efficiency is higher than 78% within the designed frequency. By using 16 GaAs monolithic-microwave integrated-circuit (MMIC) medium power amplifiers, the active combiner system produces up to a maximum power output of 3.9 W with a power variation of ±1.3 dB within the bandwidth of 18-40 GHz. The measured power added efficiency (PAE) within the operating bandwidth is up to 16%.