Patent ID: 7760038
Filing Date: 2010-07-20
Classification: H03B

Abstract:
1. A voltage controlled oscillator having an active element, comprising: a resonating unit for generating an oscillation frequency according to a resonance capacitance; a frequency tuning unit, connected to a source terminal of the active element, for tuning the oscillation frequency; and a negative resistance adjusting unit, connected to the frequency tuning unit, for generating a negative resistance to adjust the oscillation frequency, the negative resistance adjusting unit including a varactor diode for finely adjusting the negative resistance, wherein the frequency tuning unit includes a coupling line and a varactor diode so as to minimize the degradation of quality factor, and wherein the negative resistance adjusting unit includes an interdigital capacitance and a varactor diode and adjusts the negative resistance by varying an electrical length of the source terminal according to capacitance of the varactor diode.