On-chip reflection coefficient measurement system

Patent metadata

Field	Value
Publication number	US-12442893-B2
Application number	US-202318323967-A
Country	US
Kind code	B2
Filing date	May 25, 2023
Priority date	May 25, 2023
Publication date	Oct 14, 2025
Grant date	Oct 14, 2025

Abstract

A device may include a receive (Rx) antenna input to couple an Rx antenna to an Rx chain, and a signal coupler to inject the test signal toward the Rx antenna. The device may include an Rx antenna switch to, in a first switch state, cause the Rx antenna to be isolated from the Rx chain and, in a second switch state, permit the test signal to probe the Rx antenna. The Rx chain may measure a phasor of a first baseband signal generated based on a first reflected test signal and a phasor of a second baseband signal generated based on a second reflected test signal. The device may include a control circuit to compute a complex ratio based on the phasors, compute a measured reflection coefficient based on the complex ratio and using a transfer function, and monitor an impedance matching of the Rx antenna.

First claim

What is claimed is:

1. A device, comprising:
a receive (Rx) antenna input to couple an Rx antenna to an Rx chain;
a test signal generator to generate a test signal;
a signal coupler to inject the test signal toward the Rx antenna;
an Rx antenna switch configured to:
cause, while in a first switch state, the Rx antenna to be isolated from an Rx chain to generate a first reflected test signal, and
permit, while in a second switch state, the test signal to probe the Rx antenna to generate a second reflected test signal;

the Rx chain configured to:
measure a phasor Y 1 of a first baseband signal generated based on the first reflected test signal, and
measure a phasor Y 2 of a second baseband signal generated based on the second reflected test signal; and

a control circuit configured to:
compute a complex ratio CR based on the phasor Y 1 and the phasor Y 2 ,
compute a measured reflection coefficient Γ m based on the complex ratio CR and using a transfer function H, and
monitor an impedance matching of the Rx antenna based on the measured reflection coefficient Γ m .

2. The device of claim 1 , wherein the transfer function H is based on a first parameter, a second parameter, a third parameter, and a fourth parameter, wherein the fourth parameter is set to a value of 1.

3. The device of claim 1 , wherein the transfer function H is based on a first parameter, a second parameter, a third parameter, and a fourth parameter, wherein values of the first parameter, the second parameter, and the third parameter are frequency dependent values and the fourth parameter is set to a value of 1.

4. The device of claim 1 , wherein the transfer function H is based on a first parameter, a second parameter, a third parameter, and a fourth parameter, wherein values of the first parameter, the second parameter, and the third parameter are frequency independent values and the fourth parameter is a frequency dependent value.

5. The device of claim 1 , wherein the Rx chain comprises a local oscillator (LO) configured to:
ramp a frequency of oscillation of the LO from a first frequency to a second frequency over a first period of time while the Rx antenna switch is in the first switch state, and
ramp the frequency of oscillation of the LO from the first frequency to the second frequency over a second period of time while the Rx antenna switch is in the second switch state.

6. The device of claim 1 , wherein the Rx antenna is a first Rx antenna, the measured reflection coefficient Γ m is a first measured reflection coefficient Γ m , and wherein the control circuit, to monitor the impedance matching of the first Rx antenna, is configured to:
evaluate the impedance matching of the first Rx antenna based at least in part on a difference between the first measured reflection coefficient Γ m and a second measured reflection coefficient Γ m associated with a second Rx antenna of the device.

7. The device of claim 1 , wherein a value of a parameter of the transfer function H is based on a set of scattering parameters associated with a connection of the Rx antenna, a set of scattering parameters associated with the Rx antenna, and a set of scattering parameters associated with the signal coupler.

8. The device of claim 1 , wherein a value of a parameter of the transfer function H is based on a set of directivity values, a set of reflectivity values, and a set of source impedance values.

9. The device of claim 1 , wherein a value of a parameter of the transfer function H is based on tuning the value of the parameter so as to minimize a cost function.

10. A method, comprising:
injecting, by a signal coupler, a test signal toward a receive (Rx) antenna;
preventing, by an Rx antenna switch in a first switch state, the test signal from probing the Rx antenna to generate a first reflected test signal;
permitting, by the Rx antenna switch in a second switch state, the test signal to probe the Rx antenna to generate a second reflected test signal;
measuring, by a component of an Rx chain, a phasor Y 1 of a first baseband signal generated based on the first reflected test signal;
measuring, by a component of the Rx chain, a phasor Y 2 of a second baseband signal generated based on the second reflected test signal;
computing, by a control circuit, a complex ratio CR based on the phasor Y 1 and the phasor Y 2 ;
computing, by the control circuit, a measured reflection coefficient Γ m based on the complex ratio CR and using a transfer function H; and
monitoring, by the control circuit, an impedance matching of the Rx antenna based on the measured reflection coefficient Γ m .

11. The method of claim 10 , wherein the transfer function H is based on a first parameter, a second parameter, a third parameter, and a fourth parameter, wherein the fourth parameter is set to a value of 1.

12. The method of claim 10 , wherein the transfer function H is based on a first parameter, a second parameter, a third parameter, and a fourth parameter, wherein the first parameter, the second parameter, and the third parameter are frequency dependent values and the fourth parameter is set to a value of 1.

13. The method of claim 10 wherein the transfer function H is based on a first parameter, a second parameter, a third parameter c, and a fourth parameter, wherein values of the first parameter, the second parameter, and third the parameter are frequency independent values and the fourth parameter is a frequency dependent value.

14. The method of claim 10 , further comprising:
ramping a frequency of oscillation of a local oscillator (LO) from a first frequency to a second frequency over a first period of time while the Rx antenna switch is in the first switch state, and
ramping the frequency of oscillation of the LO from the first frequency to the second frequency over a second period of time while the Rx antenna switch is in the second switch state.

15. The method of claim 10 , wherein the Rx antenna is a first Rx antenna, the measured reflection coefficient Γ m is a first measured reflection coefficient Γ m , and wherein monitoring the impedance matching of the first Rx antenna comprises:
evaluating the impedance matching of the first Rx antenna based at least in part on a difference between the first measured reflection coefficient Γ m and a second measured reflection coefficient Γ m associated with a second Rx antenna.

16. The method of claim 10 , wherein a value of a parameter of the transfer function H is based on a set of scattering parameters associated with a connection of the Rx antenna, a set of scattering parameters associated with the Rx antenna, and a set of scattering parameters associated with the signal coupler.

17. The method of claim 10 , wherein a value of a parameter of the transfer function H is determined based on a set of directivity values, a set of reflectivity values, and a set of source impedance values.

18. The method of claim 10 , wherein a value of a parameter of the transfer function H is determined based on tuning the value of the parameter so as to minimize a cost function.

19. A device, comprising:
a receive (Rx) antenna input to couple an Rx antenna to an Rx chain;
a test signal generator to generate a test signal;
a signal coupler to inject the test signal toward the Rx antenna;
an Rx antenna switch configured to:
cause, while in a first switch state, the Rx antenna to be isolated from an Rx chain to generate a first reflected test signal, and
permit, while in a second switch state, the test signal to probe the Rx ant

Assignees

• Infineon Technologies Ag

Inventors

• Obermueller Thomas
• Schwarz Andreas
• Herzinger Stefan
• Berger Bernhard
• Schmalzl Stefan
• Ahmed Faisal
• Furqan Muhammad

Classifications

• G01R29/0892 Primary

  Details related to signal analysis or treatment; presenting results, e.g. displays; measuring specific signal features other than field strength, e.g. polarisation, field modes, phase, envelope, maximum value · CPC title

• G01S13/343

  using sawtooth modulation · CPC title

• G01S7/4021

  of receivers · CPC title

• G01S7/4017

  of HF systems · CPC title

• G01S7/032

  Constructional details for solid-state radar subsystems · CPC title