WEIGHTED TUNABLE VARACTOR CIRCUIT WITH IMPROVED FREQUENCY TUNING SENSITIVITY AND DIFFERENTIAL VOLTAGE CONTROLLED OSCILLATOR

摘要

PURPOSE: A tunable weighting varactor circuit and a differential voltage-controlled oscillator are provided to respectively vary a capacity of each divided section, thereby effectively improving a frequency tuning sensitivity. CONSTITUTION: An oscillation circuit part(100) provides negative resistance by a MOS transistor of a differential structure in which a cross combination of a gate and drain between a first and second output terminal. An inductor circuit part(200) provides inductance between the first and the second output terminal. A capacitor bank part(300) includes a plurality of capacitor units connected to the inductor circuit part in parallel. The capacitor bank part provides variable capacitance according to a selection of a plurality of capacitor units. A tunable weighting varactor circuit(400) is connected to the inductor circuit part in parallel. A current source(500) supplies a constant current in a circuit part formed between the first and second output terminal.