SUPERREGENERATIVE AMPLIFIER OSCILLATOR WITH TUNNEL DIODE

• US 3,621,465 A
• Filed: 05/19/1969
• Issued: 11/16/1971
• Est. Priority Date: 07/22/1968
• Status: Expired due to Term

• Current Assignee: Charles A. Beaty
• Original Assignee: Charles A. Beaty
• Inventors: Charles, A. Beaty
• Primary Examiner(s): John Kominski
• Application Number:
  US04/862,542
• Time in Patent Office: 911 Days
• Field of Search: 331/107 307/322,287 325/105 332/16
• US Class Current: 331/107.00T
• CPC Class Codes: G01S 7/28 Details of pulse systems
• CPC Class Codes: G01S 7/34 Gain of receiver varied automatically during pulse-recurrence period, e.g. anti-clutter gain control
• CPC Class Codes: H03D 11/00 Super-regenerative demodulator circuits applications in responders G01S

Abstract

A superregenerative amplifier/oscillator having a tunnel diode as the negative resistance device, operates in the linear mode in response to a quench pulse. The tunnel diode is biased at the valley point of its forward voltage characteristic curve. The quench pulse overcomes the bias and places the tunnel diode on the negative resistance slope of its characteristic curve thereby allowing buildup of oscillations in the superregenerative amplifier/oscillator. Automatic gain control is provided by sampling the superregenerative amplifier/oscillator output in response to maximum signal input, and controlling the width of the quench pulse in accordance with the amplitude of the superregenerative amplifier/oscillator output.

Claims

1. In a superregenerative circuit of the type having a resonant circuit, an input for connecting radio frequency pulses to said resonant circuit and an output terminal connected to said resonant circuit, the improvement comprising, a. a tunnel diode connected to said resonant circuit, b. means for biasing said tunnel diode at the valley point of its forward voltage characteristic curve, and c. means responsive to a pulse applied thereto for shifting the operating point of said tunnel diode to a point on the negative resistance slope of its forward voltage characteristic curve.

2. In a superregenerative circuit of the type having a resonance circuit to which input radiofrequency pulses are applied, a controllable negative resistance device connected to the resonant circuit for causing buildup of oscillations in said tuned circuit when in the negative resistance state, the improvement comprising, a. said controllable negative resistance device being a tunnel diode, b. biasing means connected to said tunnel diode for biasing said tunnel diode at the valley point of its forward voltage characteristic curve, and c. pulse receiving means connected to said tunnel diode and said biasing means for overcoming said bias and placing said tunnel diode in the negative resistance region.