Patent ID: 6380816
Filing Date: 2002-04-30
Classification: H03B

Abstract:
A voltage controlled oscillator oscillating at a frequency in accordance with a control voltage, the voltage controlled oscillator comprising:a pair of differential transistors, in which a first electrode of one transistor is connected to a first electrode of the other transistor, and an input electrode of one transistor is connected to a second electrode of the other transistor with regard to each of the transistors; a surface acoustic wave resonator connected between the second electrodes of said pair of differential transistors; a first capacitor coupled between the input electrode of at least one transistor of said pair of differential transistors and the second electrode of the other transistor; a voltage controlled current source connected to the first electrodes of said pair of differential transistors for flowing currents having a value in accordance with said control voltage; first and second current limiting circuits, each provided between said voltage controlled current source and said first electrodes of said differential transistors; and a resistance element connected in parallel with said surface acoustic wave resonator.