Superregenerative circuit

• US 6,421,535 B1
• Filed: 05/12/1999
• Issued: 07/16/2002
• Est. Priority Date: 05/12/1999
• Status: Expired due to Fees

• Current Assignee: Northrop Grumman Corporation
• Original Assignee: Xetron Corp. (Honeywell International Inc.)
• Inventors: Dickerson, Roger, Chess, Jimmy, Lorthioir, Jack
• Primary Examiner(s): Bost, Dwayne
• Assistant Examiner(s): PERSINO, RAYMOND B
• Application Number:
  US09/310,220
• Time in Patent Office: 1,161 Days
• Field of Search: 455/215, 455/336, 455/338, 455/339, 333/109
• US Class Current: 455/338
• CPC Class Codes: H03D 11/02 for amplitude-modulated oscillations

Abstract

A superregenerative circuit which is operable in a transmit mode and a receive mode of operation. A superregenerative oscillator and a single antenna are functional in both modes. To minimize any undesired RF energy which may be radiated during the receive mode of operation, the circuitry includes decoupling means connected between the antenna and the oscillator.

During reception, the oscillator is periodically quenched, and received signals are recovered by circuitry which obtains, during unquenched periods, time samples indicative of the time required for the RF energy to build up to a predetermined level in the oscillator circuit.

Claims

1. An RF superregenerative circuit operable in at least a receive mode of operation, comprising:

(A) a superregenerative oscillator having an oscillator output, said oscillator including an amplifier having an input and an output, a resonant circuit arrangement connected to said output of said amplifier, and feedback means connecting said resonant circuit with said input of said amplifier;

(B) circuit means for controlling the oscillatory condition of said oscillator;

(C) antenna means;

(D) decoupling means connected in circuit between said antenna means and said oscillator and operable to minimize any RF energy radiated by said superregenerative circuit, via said antenna means, when in said receive mode of operation;

(E) utilization means connected to said output of said oscillator;

(F) said circuit means being operable to provide said oscillator with, periodic signals to allow oscillation thereof; and

wherein

(G) said utilization means includes timing circuitry operable to measure the time difference between the time that said circuit means allows oscillation and the time that the magnitude of said oscillations attain a predetermined reference level.

2. An RF superregenerative circuit operable in at least a receive mode of operation, comprising:

(A) a superregenerative oscillator having an oscillator output, said oscillator including an amplifier having an input and an output, a resonant circuit arrangement connected to said output of said amplifier, and feedback means connecting said resonant circuit with said input of said amplifier;

(B) circuit means for controlling the oscillatory condition of said oscillator;

(C) antenna means;

(D) decoupling means connected in circuit between said antenna means and said oscillator and operable to minimize any RF energy radiated by said superregenerative circuit, via said antenna means, when in said receive mode of operation; and

(E) utilization means connected to said output of said oscillator;

(F) said superregenerative circuit being additionally operable in a transmit mode of operation; and

wherein

(G) said decoupling means includes a) a receive path, b) a transmit path and c) a 4-port directional coupler;

(H) one port of said directional coupler being connected to staid feedback means, another port of said directional coupler being connected to said amplifier input, another port of said directional coupler being connected to said transmit path and the fourth port of said directional coupler being connected to said receive path.

3. A superregenerative circuit according to claim 2 wherein:

(A) said receive path includes a receive amplifier.

4. A superregenerative circuit according to claim 2 wherein:

(A) said transmit path includes a transmit amplifier.

5. A superregenerative circuit according to claim 2 wherein:

(A) said receive path includes a receive amplifier;

(B) said transmit path includes a transmit amplifier; and

which includes

(C) a transmit/receive switch operable to electively connect either said receive path or said transmit path to said antenna means.

6. A superregenerative circuit according to claim 5 wherein:

(A) said antenna means is a single antenna which is used for both receiving and transmitting.

7. A superregenerative circuit according to claim 2 which includes:

(A) a printed circuit board to which said oscillator, circuit means, and decoupling means are attached;

(B) said antenna means being constituted by a wire positioned above said printed circuit board, and electrically connected to said decoupling means.

8. A superregenerative circuit according to claim 2 which includes:

(A) a printed circuit board to which said oscillator, circuit means, and decoupling means are attached;

(B) said antenna means being integral with said printed circuit board, and electrically connected to said decoupling means.