Small-signal gain calculations for electrostatically focused klystrons

The small-signal gain of an electrostatically focused klystron (ESFK) will be different from that of a conventional klystron because the drift tube is not dc field free and the RF bunching process is altered. A method for calculating the small-signal gain of an ESFK, based on a space-charge wave analysis of the lens cell, is presented. Calculated and measured values of small-signal gain for several different ESFK's are given.