Improved breakdown threshold (multipaction and ionic) in lumped element filters

摘要

Using a mechanical surface treatment on the interior of the filter housing, we have increased the multipaction threshold by at least a factor of 5, for lumped element filters with passbands in the 150 to 250 MHz area. With multipaction resulting from a resonant buildup of secondary electrons emitted from adjacent surfaces, we thought that if resonance could be avoided, the build up of electrons could be avoided. This should result in less plasma present within the otherwise-resonant spaces and should then also result in an increase in the breakdown threshold of the generated plasma. It is noted that the inner surface of the filter enclosure is not intrinsically a part of the operation of a lumped element filter.