Design and low-power testing of a microwave Vlasov mode converter

A circular waveguide with a shaped open end forms the launcher component of a Vlasov mode converter. The authors compare the gain patterns obtained for an open end with a step cut with that for one with a beveled cut. The determination of the gain pattern is the first step in the design of a high-power mode converter intended for X-band (8 to 12 GHz). It is concluded that the optimum waveguide for use in a Vlasov mode converter for high-power microwaves remains the 30 degrees bevel cut. The step-cut waveguide has a slightly inferior gain pattern, and, moreover, the sharp corners on the waveguide edge could cause breakdown problems for high-power applications.<>