A millimeter wave, space-charge focused, extended interaction oscillator

A light weight, extended interaction oscillator capable of producing 10 watts output at 35 to 50 Gc, without magnetic focusing, is being developed. The extended interaction oscillator utilizes a resonated section of fundamental backward wave, coupled cavity delay line. Very large values of Rsh/Q may be obtained with relatively short circuit lengths, which is an advantage of the extended interaction circuit over the conventional resonator. When the electron beam velocity is made slightly greater than the fundamental circuit wave phase velocity, energy is transferred from the slow space-charge wave to the circuit. Because the interaction circuits are short, space-charge focused electron beams have been employed, eliminating the need for focusing magnets.