Method and apparatus for detecting a continuous LF wave signal

• US 7,730,773 B2
• Filed: 09/25/2008
• Issued: 06/08/2010
• Est. Priority Date: 09/25/2008
• Status: Expired due to Fees

• Current Assignee: Michelin Recherche et Technique SA (Compagnie Generale DES Etablissements Michelin SCA), TRW Automotive USLLC (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: Michelin Recherche et Technique SA (Compagnie Generale DES Etablissements Michelin SCA), TRW Automotive USLLC (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Inventors: Bortolin, Dino
• Primary Examiner(s): Allen; Andre J
• Application Number:
  US12/237,644
• Publication Number:
  US 20100071454A1
• Time in Patent Office: 621 Days
• Field of Search: None
• US Class Current: 73/146.5
• CPC Class Codes: B60C 23/0433 Radio signals

Abstract

An apparatus for detecting a continuous wave (CW) signal including a demodulator demodulating a received CW signal and providing a demodulated signal, an edge detector for detecting an edge of the demodulated signal and thereby, detecting the CW signal and a switchable short-circuit of the demodulator, edges being formed in the demodulated signal when the demodulator is temporarily short-circuited during receipt of the CW signal.

Claims

1. An apparatus for detecting a continuous wave (CW) signal, the apparatus comprising:

a demodulator demodulating a received CW signal and providing a demodulated signal;

an edge detector for detecting an edge of the demodulated signal and thereby, detecting the CW signal; and

a switchable short-circuit of the demodulator, edges being formed in the demodulated signal when the demodulator is temporarily short-circuited during receipt of the CW signal.

2. The apparatus of claim 1, further comprising an antenna for receiving the CW signal.

3. The apparatus of claim 2, wherein the CW signal is a low frequency (LF) signal.

4. The apparatus of claim 3, further comprising a filter for filtering the CW signal.

5. The apparatus of claim 1, wherein the demodulator, the edge detector and the switchable short-circuit are mounted on an application specific integrated circuit (ASIC).

6. The apparatus of claim 5 wherein the ASIC is programmable to actuate the switchable short-circuit at predetermined periodic intervals.

7. The apparatus of claim 6, wherein the demodulator comprises an envelope detector.

8. The apparatus of claim 7, further comprising an antenna for receiving the CW signal.

9. The apparatus of claim 1 further comprising:

a first antenna for receiving the CW signal;

a pressure sensor for detecting air pressure; and

a second antenna for providing an output signal.

10. An apparatus for detecting a CW signal, the apparatus comprising:

receiving means for receiving the CW signal;

demodulating means for determining an envelope of the received CW signal;

edge detecting means for detecting an edge of the envelope and thereby detecting the CW wave signal; and

short-circuiting means for temporarily short-circuiting the demodulating means, edges being formed in the envelope when the demodulating means is temporarily short-circuited during the receipt of the CW signal.

11. The apparatus of claim 10, wherein the short-circuiting means, the demodulating means and the edge detecting means are mounted on a programmable ASIC.

12. The apparatus of claim 11, wherein the ASIC activates the short-circuiting means at predetermined periodical intervals.

13. The apparatus of claim 10 further comprising:

pressure sensing means; and

signal sending means for providing a signal indicative of a sensed pressure.

14. The apparatus of claim 10, wherein the demodulating means comprises an envelope detector.

15. The apparatus of claim 10, wherein the receiving means comprises an antenna.

16. A method for detecting and processing a CW signal, the method comprising:

receiving a CW signal at an antenna;

providing the CW wave to an input of a demodulator;

providing an output of the demodulator to an edge detector;

activating a short-circuiting switch to short-circuit the demodulator at predetermined periodical intervals;

deactivating the short-circuiting switch to create a rising edge in the output of the demodulator; and

detecting the rising edge at the edge detector.

17. The method of claim 16, further comprising:

signaling a pressure sensor to sense a pressure; and

providing a signal indicative of the sensed pressure to a second antenna.

18. The method of claim 16, wherein the deactivating occurs a predetermined amount of time after the activating.

19. The method of claim 18, wherein the activating and deactivating occurs at periodic intervals.