A Suspended-Substrate Ku-Band Symmetric Radial Power Combiner

This letter presents a novel eight-way radial power combiner that exhibits wide bandwidth and very low insertion loss. The peripheral ports of this power combiner use low loss suspended substrate stripline. A cylindrical cavity is introduced as the power combining structure to obtain high combining efficiency and high power handling capability. The proposed power combining structure successfully integrates planar transmission lines with a 3-D cavity structure to realize a wide band, low loss, and compact eight-way power combiner. Measured results show a bandwidth of 3.6 GHz from 12.1 to 15.7 GHz with return loss better than 19 dB and insertion loss less than 0.17 dB, which agree very well with simulated results.