An experimental study of orthomode couplers for use in power combining and distribution

The rotary switch is the combination of two orthomode couplers such that the effective angular displacement of the couplers controls the power flow from the two input ports to the designated output port. The operation of the device depends entirely on the scattering matrix of an orthomode coupler. The assembly consists of two identical ends in circular waveguide, which may be effectively rotated with respect to each other about the longitudinal axis by rotation of the half-wave plate. A half-wave plate provides differential phase shift of pi to the two principal polarization planes. A 3 GHZ device was tested over a range of power levels up to 500 kW peak on an S-band magnetron test set; the phase shifter vane was set at 0 deg. No breakdown occurred.