Topology Analysis and Design of Passive HEMT Millimeter-Wave Multiple-Port Switches

This paper discusses different topologies for millimeter-wave (MMW) multiple-port switches, and analyzes the insertion loss, isolation, and limitation of bandwidth. It is observed the performances of a MMW multiple-port switch are decided by both multiple-port topology and the structure of the constituted unit single-pole-single-throw switches, but dominated by its topology. To verify the analysis, two types of multiple-port switch are designed, one is a distributed switch and the other is based on a filter-integrated switch, using different topologies. The net-type multiple-port topology based on a distributed switch demonstrates a measured insertion loss of 4-5 dB with isolation better than 25 dB in 48-65 GHz. In 43-66 GHz, the binary-ring multiple-port topology based on a filter-integrated switch shows a measured insertion loss of 3-4.5 dB with isolation better than 30 dB.