Application of field analysis method and impedance superposition method in gap-impedance calculation of klystron output circuit

A new method, the field analysis method is used to calculate the gap-impedance in a klystron output circuit based on the analysis of the electromagnetic field components and microwave circuit theory. The impedance superposition method is presented for an output cavity where several resonant modes overlap. The bunched electron beams will interact with all the existing modes and the sum of the gap-impedance in each mode constitutes the overall gap-impedance in the output cavity. This principle can also be used to calculate the imaginary part for a given real part of the gap-impedance. An example illustrates that the maximum resulting error between the field analysis method and the equivalent gap impedance method is less than 1.5%, and the maximum error between the mode overlapping method and