Microwave radar sensor modules

• US 9,986,934 B2
• Filed: 01/29/2015
• Issued: 06/05/2018
• Est. Priority Date: 01/29/2014
• Status: Active Grant

• Current Assignee: California Institute of Technology
• Original Assignee: California Institute of Technology
• Inventors: Lux, James Paul, Kalantar Ohanian, Richard, Quintero, Raymond, Torrez, Troy Michael, Ishikawa, Keizo, McKee, Michael Ray, Haque, Salman-ul Mohammed, Holmes, Sarah, Spurgers, Carl
• Primary Examiner(s): Gregory, Bernarr E
• Application Number:
  US14/609,354
• Publication Number:
  US 20150208945A1
• Time in Patent Office: 1,223 Days
• CPC Class Codes: A61B 2560/0252 using ambient temperature
• CPC Class Codes: A61B 5/0507 using microwaves or terahertz waves
• CPC Class Codes: A61B 5/113 occurring during breathing

Abstract

Systems and methods for detecting biometrics using microwave radar sensor modules are disclosed. Integrated microwave sensor modules can include a transmitter unit configured to generate at least one continuous wave transmit signal based upon at least one frequency control signal, a receiver unit configured to utilize a cancellation path to cancel contributions to a return signal based upon at least one cancellation path control signal, and a microcontroller unit that includes a processor, a memory containing a microcontroller application, where the microcontroller application configures the processor to generate at least one frequency control signal to generate least one CW transmit signal having a plurality of frequencies, generate at least one cancellation path control signal to automatically adjust the cancellation path in real time, receive at least one demodulated signal, digitize the at least one demodulated signal, and update the at least one frequency control and cancellation path control signals.

Claims

1. An integrated microwave sensor module comprising:

a transmitter unit comprising a variable frequency microwave source connected to at least one transmitter unit amplifier, where;

the variable frequency microwave source is configured to generate at least one continuous wave (“

CW”

) transmit signal based upon at least one frequency control signal received from a microcontroller unit; and

the at least one transmitter unit amplifier is configured to receive and amplify the at least one CW transit signal;

a receiver unit configured to receive at least one return signal and utilize a cancellation path to cancel contributions to the return signal that are not the result of reflections from a target comprising a vector modulator, a combiner, a vector demodulator, and at least one receiver unit amplifier, where;

the vector modulator is configured to receive at least one cancellation path control signal from the microcontroller unit, sample the at least one CW transmit signal, and adjust an amplitude and phase of the sampled CW transmit signal based upon the at least one cancellation path control signal;

the combiner is configured to receive the adjusted transmit signal and combine it with the at least one return signal;

the at least one receiver unit amplifier is configured to amplify the combined signal; and

the vector demodulator is configured to receive the amplified combined signal, sample the at least one CW transmit signal, and generate two baseband signals by coherently demodulating the amplified combined signal using the sampled CW transmit signal;

a microcontroller unit configured to communicate with the transmitter and receiver units comprising;

a processor;

a memory containing a microcontroller application, wherein the microcontroller application configures the processor to;

generate at least one frequency control signal, wherein the at least one frequency control signal can configure the transmitter unit to generate least one CW transmit signal having a plurality of frequencies;

generate at least one cancellation path control signal, wherein the at least one cancellation path control signal can configure the receiver unit to automatically adjust the cancellation path in real time;

receive at least one demodulated signal from the receiver unit;

digitize the at least one demodulated signal; and

update the at least one frequency control and cancellation path control signals based upon the received at least one demodulated signal.

2. The integrated microwave sensor module of claim 1, wherein the variable frequency microwave source is a voltage controlled oscillator.

3. The integrated microwave sensor module of claim 1, wherein the at least one transmitter unit amplifier is connected to at least one transmit antenna configured to propagate at least one beam using the amplified CW transmit signal set at a plurality of frequencies.

4. The integrated microwave sensor module of claim 3, wherein the at least one return signal is associated with reflections from objects of the at least one beam, where the return signal comprises at least one signal component having a static phase associated with reflections from nonmoving objects and at least one signal component having time varying phase associated with at least one target.

5. The integrated microwave sensor module of claim 4, wherein the microcontroller application further configures the processor to automatically adjust cancellation paths associated with each of the plurality of frequencies.

6. The integrated microwave sensor module of claim 1, wherein the microcontroller unit further comprises at least one digital-to-analog converter for processing the at least one transmitter frequency control signal.

7. The integrated microwave sensor module of claim 1, wherein the microcontroller unit further comprises a plurality of digital-to-analog converters for processing the at least one cancellation path control signal.

8. The integrated microwave sensor module of claim 1, wherein receiver unit further comprises a low pass filter to filter the demodulated signal.

9. The integrated microwave sensor module of claim 1, wherein the microcontroller unit further comprises a plurality of analog-to-digital converters that digitizes the at least one demodulated signal received from the receiver unit.

10. The integrated microwave sensor module of claim 1, wherein the microcontroller unit is connected to a host computer.

11. The integrated microwave sensor module of claim 1, wherein the microcontroller unit further comprises a temperature sensor configured to take a temperature measurement related to the sensor module.

12. The integrated microwave sensor module of claim 11, wherein the microcontroller application further configures the processor to generate an updated frequency control signal based upon the temperature measurement.

13. The integrated microwave sensor module of claim 11, wherein the microcontroller application further configures the processor to generate an updated cancellation path control signal based upon the temperature measurement, wherein the temperature measurement can provide an a priori starting point for adjusting the cancellation path.

14. The integrated microwave sensor module of claim 1, wherein the microcontroller application further configures the processor to validate the demodulated signals and format for further processing.

15. The integrated microwave sensor module of claim 14, wherein the microcontroller application further configures the processor to provide range resolution by processing time and frequency measurements.

16. The integrated microwave sensor module of claim 1, wherein the transmitter unit is implemented on a first printed-circuit-board (“

PCB”

), the receiver unit is implemented on a second PCB, and the microcontroller unit is implemented on a third PCB.

17. The integrated microwave sensor module of claim 1, wherein the transmitter and receiver units are separate and synchronized.

18. The integrated microwave sensor module of claim 1, wherein the integrated microwave sensor module is synchronized with another integrated microwave sensor module.

19. The integrated microwave sensor module of claim 1, further comprising N transmitter units, M receive antennas, and N×

M receiver units to simultaneously processes multiple frequencies.

20. The integrated microwave sensor module of claim 1, wherein the vector modulator can be an alternate discrete implementation comprising a quadrature hybrid coupler, a first and second discrete mixers, and a power combiner.

21. The integrated microwave sensor module of claim 20, wherein the quadrature hybrid coupler receives a sampled CW transmit signal from the transmitter unit and splits the received sampled CW transmit signal into a first and second split signals that are 90 degrees apart in phase.

22. The integrated microwave sensor module of claim 21, wherein the first discrete mixer is configured to receive the first split signal and a first input control signal and output a first mixer signal.

23. The integrated microwave sensor module of claim 22, wherein the second discrete mixer is configured to receive the second split signal and a second input control signal and output a second mixer signal.

24. The integrated microwave sensor module of claim 23, wherein the first and second mixer signals are combined using the power combiner to generate a cancellation signal.

25. An integrated microwave sensor module comprising:

a transmitter unit comprising a voltage controller oscillator (“

VCO”

) connected to at least one transmitter unit amplifier, where;

the VCO is configured to generate at least one continuous wave (“

CW”

) transmit signal based upon at least one frequency control signal received from a microcontroller unit;

the at least one transmitter unit amplifier is configured to receive and amplify the at least one CW transit signal; and

wherein the at least one transmitter unit amplifier is connected to at least one transmit antenna configured to propagate at least one beam using the amplified CW transmit signal set at a plurality of frequencies based upon the at least one frequency control signal;

a receiver unit configured to receive at least one return signal and utilize a cancellation path to cancel contributions to the return signal that are not the result of reflections from a target comprising a vector modulator, a combiner, a vector demodulator, and at least one receiver unit amplifier, where;

the vector modulator is configured to receive at least one cancellation path control signal from the microcontroller unit, sample the at least one CW transmit signal, and adjust an amplitude and phase of the sampled CW transmit signal based upon the at least one cancellation path control signal;

the combiner is configured to receive the adjusted transmit signal and combine it with the at least one return signal;

the at least one receiver unit amplifier is configured to amplify the combined signal;

the vector demodulator is configured to receive the amplified combined signal, sample the at least one CW transmit signal, and generate two baseband signals by coherently demodulating the amplified combined signal using the sampled CW transmit signal; and

wherein the at least one return signal is associated with reflections from objects of the at least one beam, where the return signal comprises at least one signal component having a static phase associated with reflections from nonmoving objects and at least one signal component having time varying phase associated with at least one target;

a microcontroller unit configured to communicate with the transmitter and receiver units comprising;

a processor;

a memory containing a microcontroller application, wherein the microcontroller application configures the processor to;

generate at least one frequency control signal, wherein the at least one frequency control signal can configure the transmitter unit to generate least one CW transmit signal having a plurality of frequencies;

generate at least one cancellation path control signal, wherein the at least one cancellation path control signal can configure the receiver unit to automatically adjust the cancellation path in real time;

receive at least one demodulated signal from the receiver unit;

digitize the at least one demodulated signal; and

update the at least one frequency control and cancellation path control signals based upon the received at least one demodulated signal;

at least one digital-to-analog converter for processing the at least one transmitter frequency control signal;

a plurality of digital-to-analog converters for processing the at least one cancellation path control signal; and

a plurality of analog-to-digital converters that digitizes the at least one demodulated signal received from the receiver unit.