Bandstop filter for radio transceiver - has fixed capacitors in series with LC elements to prevent accepted signal being reflected

摘要

The bandstop filter, for a radio transceiver, has its reactive components in its pass region compensated such that the passed frequency is not reflected. - This is achieved by including fixed capacitors in series with each coupling inductor in the series chain of filter elements. - Each element consists of a coupling inductor inductively coupled to a variable LC circuit and electrically connected to a variable earthed capacitor. If the frequency being passed is the frequency being stopped, additional inductors are connected in series with the earthed capacitors.