Method and apparatus for detecting a continuous LF wave signal

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.