SYSTEMS AND METHODS FOR FOREIGN OBJECT DETECTION
Systems, methods, and devices for foreign object detection are disclosed. In one embodiment, a device for detecting the presence of a foreign object in an area being monitored may include an antenna including a receive path configured to detect a sample RF signal; a RF transceiver coupled to the antenna that generates and monitors modulation and demodulation of a RF field; a memory for storing a RF reference signal; and at least one computer processor configured to receive the sample RF signal from the RF transceiver and to determine a correlation between the sample RF signal and the RF reference signal, and to determine whether the correlation is indicative of a perturbation in the RF field.
1 . A device for detecting the presence of a foreign object in an area being monitored, comprising:
an antenna including a receive path configured to detect a sample RF signal;
a RF transceiver coupled to the antenna that generates and monitors modulation and demodulation of a RF field;
a memory for storing a RF reference signal; and
at least one computer processor configured to receive the sample RF signal from the RF transceiver and to determine a correlation between the sample RF signal and the RF reference signal, and to determine whether the correlation is indicative of a perturbation in the RF field.
2 . The device of claim 1 , wherein the RF transceiver further transmits a RF carrier signal with 100% amplitude-shift keyed modulation.
3 . The device of claim 1 , wherein the RF transceiver further transmits a RF carrier signal with frequency-shift keying modulation.
4 . The device of claim 1 , wherein the RF transceiver further transmits a RF carrier signal with phase-shift keying modulation.
5 . The device of claim 1 further comprising:
a matching circuit that matches an impedance of a transmitter output of the RF transceiver to that of the antenna.
6 . The device of claim 1 , wherein the controller further generates an alert indicative of the perturbation in response to the correlation being below a threshold.
7 . The device of claim 1 , wherein the controller generates a signal disabling a host device in response to the correlation being below a threshold.
8 . The device of claim 1 , wherein the correlation is based on a comparison between different time domain signals of the sample RF signal and the RF reference signal.
9 . The device of claim 1 , wherein the antenna, the RF transceiver, and the at least one computer processor configured are integrated into an unattended host device.
10 . A method for detecting the presence of a foreign object in an area being monitored, comprising:
an information processing apparatus including at least a memory, a communication interface, and at least one computer processor:
transmitting a RF carrier signal;
receiving a sample RF signal in response to the transmission of the RF carrier signal;
retrieving a RF reference signal from memory;
comparing a RF reference signal to the sample RF signal to determine a correlation;
generating an alert signal based on the correlation.
11 . The method of claim 10 , wherein the RF carrier signal comprises 100% amplitude-shift keyed modulation.
12 . The method of claim 10 , wherein the RF carrier signal comprises frequency-shift keying modulation.
13 . The method of claim 10 , wherein the RF carrier signal comprises phase-shift keying modulation.
14 . The method of claim 10 , wherein the RF carrier signal is generated using a pseudo-random bit sequence.
15 . The method of claim 10 , wherein the reference signal is determined based on sampling a RF signal in a known environment.
16 . The method of claim 10 , wherein the reference signal is determined by loading a known RF signal.
17 . The method of claim 10 , wherein the alert is generated when the correlation is below a threshold.
18 . The method of claim 10 , wherein the alert comprises a warning message.
19 . The method of claim 10 , wherein the alert disables a host device.
20 . The method of claim 10 , wherein the step of comparing the RF reference signal to the sample RF signal to determine the correlation comprises comparing different domains and second RF signals.