Patent ID: 6549084
Filing Date: 2003-04-15
Classification: H03B

Abstract:
A variable frequency oscillator having low phase noise characteristics, comprising:a) a transistor having an emitter, a collector and a base; b) a first inductor having a first terminal and a second terminal, said first terminal connected to said base; c) a first capacitor having a first terminal and a second terminal, said first terminal connected to said second terminal of said first inductor, and said second terminal connected to ground; d) a first resistor having a first terminal and a second terminal, said first terminal connected to the junction of said first capacitor and said first inductor, and said second terminal connected to ground; e) a second resistor having a first terminal and a second terminal, said first terminal connected to the junction of said first capacitor and said first inductor; f) a second capacitor having a first terminal and a second terminal, said first terminal, connected to said second terminal of said second resistor, and said second terminal connected to ground; g) a third capacitor having a first terminal and a second terminal, said first terminal connected to said collector; h) an RF output terminal connected to said second terminal of said third capacitor; i) a second inductor having a first terminal and a second terminal, said first terminal connected to the junction of said third capacitor and said collector, and said second terminal connected to the junction of said second resistor and said second capacitor; j) a DC supply voltage terminal means connected to the junction of said second resistor and said second capacitor; k) a resonator means connected to said emitter, said resonator means having a first end, a second end and a tap, said first end connected to ground, said second end connected to a tuning voltage input means and said tap connected to said emitter, said resonator means responsive to said tuning voltage input means; and l) a third resistor and a fourth capacitor connected in parallel, said third resistor and said fourth capacitor connected in series with said tap and said emitter.