Identification and analysis of source emissions through harmonic phase comparison
First Claim
1. A method comprising:
- receiving an electromagnetic energy emission with an antenna connected to a receiver; and
using a processor to;
select a candidate harmonic of a device from an expected spectral region of the electromagnetic energy emission,use a frequency location of the candidate harmonic to determine frequency locations of additional harmonics,identify, from the received electromagnetic energy emission, at least two of said additional harmonics,measure a phase of each harmonic, andcompare the measured phases to identify the device as a source or a non source of the electromagnetic energy emission.
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Abstract
The present invention is a signal processing method to significantly improve the detection and identification of source emissions. More particularly, the present invention offers a processing method to reduce the false alarm rate of systems which remotely detect and identify the presence of electronic devices through an analysis of a received spectrum the devices'"'"' unintended emissions. The invention identifies candidate emission elements and determines their validity based on a frequency and phase association with other emissions present in the received spectrum. The invention compares the measured phase and frequency data of the emissions with a software solution of the theoretically or empirically derived closed-form expression which governs the phase and frequency distribution of the emissions within the source. Verification of this relationship serves to dramatically increase the confidence of the detection.
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Citations
24 Claims
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1. A method comprising:
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receiving an electromagnetic energy emission with an antenna connected to a receiver; and using a processor to; select a candidate harmonic of a device from an expected spectral region of the electromagnetic energy emission, use a frequency location of the candidate harmonic to determine frequency locations of additional harmonics, identify, from the received electromagnetic energy emission, at least two of said additional harmonics, measure a phase of each harmonic, and compare the measured phases to identify the device as a source or a non source of the electromagnetic energy emission. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A device comprising:
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an antenna, a receiver connected to said antenna and configured to receive an electromagnetic energy emission, and at least one processor configured to; select a candidate harmonic of a device from an expected spectral region of the electromagnetic energy emission, use a frequency location of the candidate harmonic to determine frequency locations of additional harmonics, identify, from the received electromagnetic energy, at least two of said additional harmonics, measure a phase of each harmonic, and compare the measured phases to at least one of identify the device as a source or a non source of said electromagnetic energy emission. - View Dependent Claims (19, 20, 21, 22, 23)
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24. A method comprising the steps of:
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(a) receiving unique harmonic spectral regions of an electromagnetic energy emission with an antenna connected to a receiver; (b) selecting, with a processor, from an expected spectral region of frequencies received in step (a), a candidate harmonic of a device; (c) determining, with said processor, a frequency location of said candidate harmonic; (d) determining, with said processor from said unique harmonic spectral regions received in step (a) and based on said frequency location of said candidate harmonic determined in step (c), frequency locations for at least two additional harmonics, each from a respective unique spectral region received in step (a); (e) measuring, with said processor, phase values of said candidate and said at least two other harmonics selected or determined in steps (b) and (d); and (f) determining, with said processor in accordance with at least one logic algorithm, a time phase relationship of said candidate and said at least two additional harmonics to identify said device as a source or a non source of said electromagnetic energy emission.
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Specification