REJECTION FILTER Russian patent published in 1997 - IPC

FIELD: radio engineering; devices for rejecting concentrated noise arriving at radio receiver input together with legitimate signal. SUBSTANCE: used as rejection filter is known double-stage parametric amplifier with separate harmonic-pumping generators wherein first stage is modified to operate as nonregenerative parametric input-signal converter by adequate selection of operating frequencies and second stage operates in regenerative mode, as usual; pumping generators are frequency-controlled devices. All these conditions provide for shaping rejection gap with desired rejection band width on specified frequency range of given circuit pass band within the range of amplitude-frequency response of first-stage signal circuit. EFFECT: simplified circuit arrangement of rejection filter. 2 dwg