Quasi-optical band-rejection filters

Band-rejection filters are used in microwave engineering to provide one or several suppressed frequency bands in the given wavelength range. For the mm and submm wavelength ranges this problem arises in the hot plasma diagnostics at experimental fusion machines. Here, it is necessary to receive a plasma cyclotron radiation signal in a wide frequency range, ensuring that no high-power radiation of microwave heating made by gyrotrons in a narrow band inside this range enters the receiver. Because of the wide application of quasi-optical equipment in plasma diagnostics, the problem of developing quasi-optical band rejection filters is timely