Spurious Outputs from High Power Microwave Tubes and Their Control

The emission of spurious outputs from microwave tubes has been known for a long time. With steady increase in transmitter power level, receiver sensitivity and number of radiating equipment, the problem of spurious outputs has taken on greater significance in terms of radiation interference. As the power levels of high power tubes have increased so have the spurious output power levels, and in a microwave system the presence of the spurious power may have deleterious effects such as arcing in chokes, arcing at flanges and signal transmission through ionized duplexers. In addition, if large amounts of spurious power are generated, the microwave tube may suffer in its own performance by decreased efficiency and by introducing an objectionable amount of amplitude and phase instability of the fundamental frequency output.