Ridge waveguide in output circuit of klystron

In the development of a new L band klystron, in order to reduce the size, weight and power waste of magnetic focusing system, the size of output waveguide should be reduced. To solve this problem, a ridge waveguide was used in the output circuit. To validate this method, a ridge waveguide output circuit was designed and tested. The circuit’s voltage standing wave ratio is under 1.2 within 10% band width and theoretical power capacity is 490 MW.The output circuit with a ridge waveguide is compact and easy to make and test,and it has been used in the L band klystron．