关键词: 变容二极管, 背靠背拓扑, VCO, 电调滤波器, 调频电路

Abstract:

In view of the parasitic modulation,frequency jitter,frequency distortion,AM to PM noise,etc.caused by the varactor nonlinearity in the actual application circuit,this paper uses back-to-back topology (BBS) varactors to improves the voltage-controlled linearity and to reduce the RF modulation frequency jitter and phase noise of the circuit.It parasitic modulation caused by the varactor nonlinearity is restrained with simpler voltage regulation.The study has important reference value to the circuits that widely use varactors as the electrically tunable components.

Key words: varactor;back to back topology;VCO;electrically tunable filter;frequency modulation circuit