2 kw, 250 MHz Bandwidth, Ku-BAND klystron amplifier

Abstract

The Varian VKU-7812 six-cavity klystron amplifier produces 2 kW of communications quality cw power at 20 percent efficiency with 30 dB gain over 250 MHz 1 dB bandwidth within the 14.0 to 14.5 GHz frequency band. This compact new tube employs permanent-magnet focusing and is entirely air cooled. The double-tuned, filter-loaded output circuit provides an interaction impedance of five to six thousand ohms over the bandpass. The microperveance 1.25, convergence 50 electron gun produces a high quality 0.03 inch diameter beam which is confined within the 0.05 inch tunnel by a pair of samarium cobalt radially magnetized magnets producing a main field of 5 kg. Intercavity drift lengths, R/Q and driver cavity loading were computer optimized for gain, bandwidth and efficiency with minimum magnet size, while also eliminating gain cancellations.