Patent ID: 6218909
Filing Date: 2001-04-17
Classification: H03B

Abstract:
A voltage controlled oscillator (VCO) having a plurality of frequency bands, comprising:resonator means comprising a capacitance and a tapped inductor connected at one end to ground;a frequency range switching circuit comprising a DC blocking capacitor and a signal diode coupled in a series combination between ground and said tap point on said inductor, a range control signal coupled via a resistor to the junction between said DC blocking capacitor and said signal diode, said frequency range switching circuit operative to short said tap point to ground in response to a range control signal thereby switching the range of oscillation frequencies of said oscillator;wherein the removal of said range control signal generates a cutoff bias across said signal diode via self rectification of RF voltage produced by said VCO;tuning means operative to vary the frequency of oscillation of said oscillator within a frequency range in accordance with a tuning voltage input thereto;amplifier means connected to said resonator for generating an oscillation signal as determined by said resonator; andfeedback means connected to said amplifier means and adapted to ensure the oscillation of said oscillator.