Determining material category based on the polarization of received signals

1. A radar device configured to detect an object, the radar device comprising:

transceiver circuitry configured to transmit radar signals having a first polarization type towards the object, wherein the transceiver circuitry includes an antenna array configured to:

receive radar signals having the first polarization type reflected from the object; and

receive radar signals having a second polarization type reflected from the object, the second polarization type being different than the first polarization type; and

processing circuitry configured to:

interleave a first operating mode and a second operating mode;

determine reflectivity values for the radar signals having the first polarization type reflected from the object in the first operating mode;

determine reflectivity values for the radar signals having the second polarization type reflected from the object in the second operating mode; and

determine a material category of the object based on the reflectivity values for the radar signals having the first polarization type reflected from the object and the reflectivity values for the radar signals having the second polarization type reflected from the object.

2. The radar device of claim 1 , wherein the processing circuitry is configured to determine the material category at least in part by selecting the material category from a set of material categories including a conductive surface, vegetation, and a human.

3. The radar device of claim 1 ,

wherein the processing circuitry is further configured to determine a power ratio of the radar signals having the first polarization type reflected from the object and the radar signals having the second polarization type reflected from the object, and

wherein the processing circuitry is configured to determine the material category of the object based on the power ratio.

4. The radar device of claim 3 , wherein the processing circuitry is configured to determine the material category of the object at least in part by:

determining a conductive material category for the object in response to determining that the power ratio of the radar signals exceeds a first threshold ratio; and

determining an insulative material category for the object in response to determining that the power ratio of the radar signals does is less than a second threshold ratio.

5. The radar device of claim 3 , wherein the processing circuitry is further configured to associate a set of voxels with the object based on a power ratio of radar signals reflected from the set of voxels and further based on a Bayesian classifier algorithm.

6. The radar device of claim 1 ,

wherein the processing circuitry is further configured to determine a phase relationship between the radar signals having the first polarization type reflected from the object and the radar signals having the second polarization type reflected from the object, and

wherein the processing circuitry is configured to determine the material category of the object based on the phase relationship.

7. The radar device of claim 1 , wherein the processing circuitry is configured to determine the material category of the object based on an algorithm including, as input variables:

a power ratio of the radar signals having the first polarization type reflected from the object and the radar signals having the second polarization type reflected from the object; and

a phase relationship between the radar signals having the first polarization type reflected from the object and the radar signals having the second polarization type reflected from the object.

8. The radar device of claim 1 , wherein the antenna array comprises a second array of patch elements, and wherein the transceiver circuitry comprises:

a circuit board;

transmit circuitry including a first array of patch elements integrated into the circuit board and configured to transmit the radar signals having the first polarization type; and

receiver circuitry including the second array of patch elements integrated into the circuit board and configured to:

receive the radar signals having the first polarization type reflected from the object; and

receive the radar signals having a second polarization type reflected from the object.

9. The radar device of claim 1 ,

wherein the first polarization type comprises right-hand circular polarization, and

wherein the second polarization type comprises left-hand circular polarization.

10. The radar device of claim 1 , wherein the processing circuitry is configured to determine the material category at least in part by forming a beam at an intermediate frequency of the transceiver circuitry.

11. The radar device of claim 1 , wherein the processing circuitry is further configured to:

determine a color for a graphical representation of the object; and

output, for display, a graphical user interface including the graphical representation of the object with the color.

12. The radar device of claim 1 , wherein the processing circuitry is configured to determine an electrical conductivity of the object based on the radar signals having the first polarization type reflected from the object and the radar signals having the second polarization type reflected from the object.

13. A method for detecting an object, the method comprising:

causing transceiver circuitry to transmit radar signals having a first polarization type towards the object;

causing an antenna array of the transceiver circuitry to receive radar signals having the first polarization type reflected from the object;

causing the antenna array of the transceiver circuitry to receive radar signals having a second polarization type reflected from the object, the second polarization type being different than the first polarization type;

interleaving a first operating mode and a second operating mode;

determining reflectivity values for the radar signals having the first polarization type reflected from the object in the first operating mode;

determining reflectivity values for the radar signals having the second polarization type reflected from the object in the second operating mode; and

determining a material category of the object based on the reflectivity values for the radar signals having the first polarization type reflected from the object and the reflectivity values for the radar signals having the second polarization type reflected from the object.

14. The method of claim 13 , further comprising determining a power ratio of the radar signals having the first polarization type reflected from the object and the radar signals having the second polarization type reflected from the object,

wherein determining the material category of the object is based on the power ratio.

15. The method of claim 13 , further comprising determining a phase relationship between the radar signals having the first polarization type reflected from the object and the radar signals having the second polarization type reflected from the object, and

wherein determining the material category of the object is based on the phase relationship.

16. A radar device configured to detect an object, the radar device comprising:

transceiver circuitry configured to:

transmit radar signals having a first polarization type towards the object;

receive radar signals having the first polarization type reflected from the object; and

receive radar signals having a second polarization type reflected from the object, the second polarization type being different than the first polarization type; and

processing circuitry configured to:

determine a power ratio of the radar signals having the first polarization type reflected from the object and the radar signals having the second polarization type reflected from the object;

determine a material category of the object based on the power ratio at least in part by:

determining a conductive material category for the object in response to determining that the power ratio of the radar signals exceeds a first threshold ratio; and

determining an insulative material category for the object in response to determining that the power ratio of the radar signals does is less than a second threshold ratio.

17. The radar device of claim 16 , wherein the processing circuitry is configured to determine the material category at least in part by selecting the material category from a set of material categories including a conductive surface, vegetation, and a human.

18. The radar device of claim 16 ,

wherein the processing circuitry is further configured to determine a phase relationship between the radar signals having the first polarization type reflected from the object and the radar signals having the second polarization type reflected from the object, and

wherein the processing circuitry is configured to determine a material category of the object based on the phase relationship.

19. The radar device of claim 16 , wherein the processing circuitry is configured to determine the material category of the object based on an algorithm including, as input variables:

the power ratio of the radar signals having the first polarization type reflected from the object and the radar signals having the second polarization type reflected from the object; and

a phase relationship between the radar signals having the first polarization type reflected from the object and the radar signals having the second polarization type reflected from the object.

20. The radar device of claim 16 , wherein the transceiver circuitry comprises:

a circuit board;

transmit circuitry including a first array of patch elements integrated into the circuit board and configured to transmit the radar signals having the first polarization type; and

receiver circuitry including a second array of patch elements integrated into the circuit board and configured to:

receive the radar signals having the first polarization type reflected from the object; and

receive the radar signals having a second polarization type reflected from the object.