%0 Journal Article %T A Compact Ka-Band Broadband Waveguide-Based Traveling-Wave Spatial Power Combiner with Low Loss Symmetric Coupling Structure %A Zhi-Yong Kang %A Qing-Xin Chu %A Qiong Sen Wu %J PIER Letters %D 2013 %I EMW Publishing %R 10.2528/PIERL12111311 %X A compact Ka-band broadband waveguide-based traveling-wave spatial power combiner is presented. The low loss micro-strip probes are symmetrically inserted into both broadwalls of waveguide, quadrupling the coupling ways but the insertion loss increases little. The measured 16 dB return-loss bandwidth of the eight-way back-to-back structure is from 30 GHz to 39.4 GHz (more than 25%) and the insertion loss is less than 1 dB, which predicts the power-combining efficiency is higher than 90%. %U http://www.jpier.org/pierl/pier.php?paper=12111311