Intrusion detector and method for improved sensitivity

1. A motion detector comprising:

a module to detect movement;

intermediate processing circuitry coupled to an output from the module, wherein the intermediate processing circuitry is activated intermittently to produce a plurality of independent pulsed output signals derived from a first signal received from the output of the module; and

cross-correlation circuitry coupled to the intermediate processing circuitry to process the plurality of independent pulsed output signals to produce a single motion indicating output signal,

wherein each of the plurality of independent pulsed output signals is produced concurrently by a respective one of a substantially identical string of components of the intermediate processing circuitry.

2. The motion detector as in claim 1 wherein the respective one of the substantially identical string of components of the intermediate processing circuitry includes a respective amplifier to amplify the first signal.

3. The motion detector as in claim 2 wherein the respective amplifier is an operational amplifier.

4. The motion detector as in claim 1 wherein the cross-correlation circuitry includes a digital signal processor.

5. The motion detector as in claim 1 wherein the intermediate processing circuitry is activated intermittently by control circuits.

6. The motion detector as in claim 5 wherein the control circuits include switchable power supply circuits.

7. The motion detector as in claim 1 further comprising a housing that carries the module, the intermediate processing circuitry, and the cross-correlation circuitry.

8. The motion detector as in claim 7 wherein the intermediate processing circuitry is activated intermittently by control circuits.

9. The motion detector as in claim 8 further comprising transmission circuits coupled to the control circuits to communicate with a displaced location by one of a wired or wireless medium.

10. The motion detector as in claim 9 further comprising a battery coupled to at least the control circuits.

11. A method comprising:

an intrusion sensor module generating a first signal indicative of motion in a predetermined sensing window;

an intermediate frequency processing module receiving the first signal;

substantially identical strings of components of the intermediate frequency processing module concurrently establishing a plurality of independent output signals derived from the first signal;

cross-correlation circuitry of the intermediate frequency processing module processing each of the plurality of independent output signals to produce a single motion output signal;

transmitting the single motion output signal to a monitoring system; and

the monitoring system determining a presence of the motion from a value of the single motion output signal.

12. The method as in claim 11 wherein a respective one of the substantially identical strings of components establishes a respective one of the plurality of independent output signals as a respective digital pulse train.

13. The method as in claim 11 further comprising transmitting the single motion output signal via a wired or wireless medium.

14. A motion detector comprising:

a micro-wave based module to detect movement;

intermediate processing circuitry coupled to an output from the micro-wave based module to produce a plurality of independent output signals derived from a first signal received from the output of the micro-wave based module; and

cross-correlation circuitry coupled to the intermediate processing circuitry to process the plurality of independent output signals to produce a single motion indicating output signal,

wherein each of the plurality of independent output signals is produced concurrently by a respective one of a substantially identical string of components of the intermediate processing circuitry.

15. The motion detector as in claim 14 wherein the respective one of the substantially identical string of components of the intermediate processing circuitry includes a respective amplifier series coupled to a respective analog-to-digital converter.