Performance characteristics of a high power, pulsed, X-band reentrant stream crossed-field amplifier

Development work on reentrant stream crossed-field amplifiers at S-F-D laboratories has resulted in a highly refined X-band amplifier capable of 400 kw peak and 2 kw average power output. The tube has been tested extensively from 9.1 Gc to 9.4 Gc, although operation is possible over a much wider range. The tube has a gain of 15 db with signal to noise ratio greater than 40 db when measured through a 3 Mc bandwidth filter. Greater gain is possible at reduced Signal to noise ratio. This is typical of a crossed-field amplifier and this feature will be described in detail. In addition, the dependence of phase linearity as a function of gain will be discussed. Departures from linearity of less than 10 degrees over 300 Mc bandwidth are obtained at 15 db gain with the tube operating into a VSWR of 1.3. Departure from linearity is even less when operating into a matched load.