Corrugated substrate integrated waveguide distributed amplifier

A distributed amplifier directly compatible with half-mode substrate integrated waveguide is proposed. In halfmode substrate integrated waveguide (HMSIW), the top and bottom conductors of the printed circuit board form the top and bottom walls of the waveguide, whilst a row of vias form the side-wall. The vias can be replaced by quarter-wave open-circuit stubs to form the half-mode corrugated substrate integrated waveguide (HMCSIW) thereby isolating the top and bottom walls from each other at DC. In the distributed amplifier, FETs are used to periodically couple of pair of HMCSIWs. The HMCSIWs allow convenient biasing of the FETs without additional RF chokes and can be connected to HMSIWs via de-coupling capacitors. Simulations and measurements of a distributed amplifier operating from 4 GHz to 7 GHz demonstrates the feasibility of this approach.