Active microwave filters on the basis of transistorized immitance converters

The physical principles underlying the design of active microwave filters on the basis of transistorized immitance converters are examined. The basic filter parameters are investigated; filter circuits are analyzed; and methods of the electric control and parameter stabilization for these circuits are considered. The particular advantages of field effect transistors are stressed and it is noted that multicircuit bandpass active filters can be used to construct electrically controlled active microwave delay lines with zero losses or signal amplification.