Remote detection of electronic devices
AssigneeLos Alamos National Security, LLC
InventorsStephen L. Judd, Clifford M. Fortgang, David C. Guenther
Life of this patent
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Abstract
An apparatus and method for detecting solid-state electronic devices are described. Non-linear junction detection techniques are combined with spread-spectrum encoding and cross correlation to increase the range and sensitivity of the non-linear junction detection and to permit the determination of the distances of the detected electronics. Nonlinear elements are detected by transmitting a signal at a chosen frequency and detecting higher harmonic signals that are returned from responding devices.
Claims30
An apparatus for remotely locating solid-state electronics, comprising in combination:
- an RF generator for generating a chosen frequency RF signal;
- a signal splitter for dividing the RF signal into a transmitted portion and a reference portion;
- a modulator for encoding a chosen code onto the transmitted portion of the RF signal;
- a controller for generating the chosen code, and for directing the code to said modulator;
- a power amplifier for amplifying the encoded RF signal;
- an antenna for transmitting the amplified, encoded RF signal;
- an antenna for receiving a similarly encoded second harmonic frequency of the encoded RF signal;
- a demodulator for receiving the second harmonic frequency and the chosen code delayed by a selected time interval from said controller, and for removing the modulation from the second harmonic frequency;
- a frequency doubler for doubling the frequency of the reference portion of the RF signal;
- a mixer for comparing the doubled frequency of the reference portion of the RF signal with the demodulated second harmonic frequency, and for generating a DC signal if the doubled frequency of the reference portion of the RF signal is correlated with the demodulated second harmonic frequency;
- and
- a computer for receiving the DC signal, for directing said controller and for calculating distance between located solid-state electronics and said transmitting antenna.
A method for remotely locating solid-state electronics, comprising the steps of:
- generating a chosen frequency RF signal;
- dividing the RF signal into a transmitted portion and a reference portion;
- encoding a chosen code onto the transmitted portion of the RF signal;
- amplifying the encoded RF signal;
- transmitting the amplified, encoded RF signal;
- receiving a similarly encoded second harmonic frequency of the encoded RF signal;
- removing the encoding from the second harmonic frequency;
- doubling the frequency of the reference portion of the RF signal;
- comparing the doubled frequency of the reference portion of the RF signal with the second harmonic frequency for which the encoding has been removed;
- generating a DC signal if the doubled frequency of the reference portion of the RF signal is correlated with the second harmonic frequency for which the encoding has been removed;
- and
- calculating a distance between located solid-state electronics and the location of said step of transmitting the amplified, encoded RF signal.
Dependencies are inferred from the claim text.