Tuneless narrow-band super-regenerative receiver

• US 6,904,101 B1
• Filed: 02/17/2000
• Issued: 06/07/2005
• Est. Priority Date: 02/17/2000
• Status: Expired due to Fees

• Current Assignee: Lear Corporation
• Original Assignee: Lear Corporation
• Inventors: Tang, Qingfeng
• Primary Examiner(s): Bocure, Tesfaldet
• Assistant Examiner(s): Kumar, Pankaj
• Application Number:
  US09/506,043
• Time in Patent Office: 1,937 Days
• Field of Search: 375/338, 375/339, 375/375, 375/316, 455/215, 455/336, 455/85, 455/86, 455/76, 455/318, 327/524, 327/100, 327/182, 327/548, 327/530, 327/596, 331/1.R, 331/1, 331/4, 331/18, 331/172, 331/173, 331/187, 331/177.R, 331/177
• US Class Current: 375/316
• CPC Class Codes: H03D 11/02 for amplitude-modulated oscillations
• CPC Class Codes: H03D 11/06 for angle-modulated oscillations
• CPC Class Codes: H04B 1/30 for homodyne or synchrodyne receivers demodulator circuits H03D1/22

Abstract

A super-regenerative receiver is provided with a regenerative oscillator controlled by a frequency sweep circuit to control the bandwidth at which the receiver can receive a signal. A quench control circuit controls both the regenerative oscillator and the frequency sweeping circuit to “turn on” at the same time. The frequency sweep circuit forces the regenerative oscillator to function as a center frequency movable bandpass filter allowing the receiver to automatically tune to the actual transmitter frequency f_tx to provide the best reception. This allows the receiver/filter bandwidth to be very narrow. The receiver operates as an amplitude detector, as well as a frequency or phase detector, thereby allowing the same receiver to detect AM (ASK) signals and FM or FSK signals without adding a frequency discriminator.

Claims

1. A narrow bandwidth, super-regenerative receiver comprising:

a signal detector having a regenerative oscillator for detecting a signal transmitted at a particular transmit frequency;

a quench circuit connected to the regenerative oscillator for interrupting the oscillation of the oscillator at a predetermined frequency; and

a frequency sweeping circuit connected to the regenerative oscillator and the quench circuit, wherein the quench circuit is arranged to cycle the regenerative oscillator and the frequency sweeping circuit on and off together, and the frequency sweeping circuit controls operation of the regenerative oscillator to a desired narrow bandwidth around the transmit frequency.

2. The receiver of claim 1 further comprising:

for a center frequency f_c, a sweep frequency f_s, a quench frequency f_q, a data rate or a maximum base band frequency of the transmitted signal f_d, and a sweep frequency bandwidth BW_s, the following design characteristics;

BW_s=1-3% f_c;

f_s=f_q;

f_s>

2 fd; and

f_c>

>

f_s or f_q.

3. The receiver of claim 2 wherein f_s=10f_d.

4. The receiver of claim 1 wherein the frequency sweeping circuit comprises a surfaced acoustic wave resonator.

5. The receiver of claim 1 wherein the frequency sweeping circuit comprises a ceramic resonator.

6. The receiver of claim 1 wherein the frequency sweeping circuit comprises an LC resonator.