Varactor tunable RF filters having low distortion and high signal level capability

摘要

An agile frequency converter provides IF-RF level exchange and notch filtering. System noise and spurious levels generated by channel frequency conversion is reduced in applications requiring broadband combining of frequency converters to form multichannel composite signal. A pair of varactor banks is connected in an arrangement whereby varactor pairs are connected in parallel and capacitor pairs are connected in anti-parallel. Tuning is achieved by circuitry for tuning first and second varactors.