A high power microwave duplexer using secondary electron resonance

A high-power S-band duplexer has been developed, in which power activated switching is accomplished through the mechanism of secondary electron resonance (multipactor) rather than through gas discharge. Advantages of the multipactor discharge, which occurs in high vacuum (10^-9mm Hg), include low noise, very long life, and short recovery times of the order of an RF cycle. The multipactor discharge occurs in a plane-parallel, high-voltage gap within an RF resonator, if the frequency, field strength, and gap spacing are related as follows: 1) Electrons, accelerated by the electric field, traverse the gap in one half RF period. 2) The impact energy of the electrons is such that the secondary emission ratio is larger than one.