Integrated multi-channel RF circuit with phase sensing

Patent metadata

Field	Value
Publication number	US-11837797-B2
Application number	US-202117412694-A
Country	US
Kind code	B2
Filing date	Aug 26, 2021
Priority date	Jan 10, 2018
Publication date	Dec 5, 2023
Grant date	Dec 5, 2023

Abstract

A circuit includes a radio frequency (RF) channel including an input node and an output node and being configured to receive an RF oscillator signal at the input node and to provide an RF output signal at the output node; a mixer configured to mix an RF reference signal and an RF test signal representative of the RF output signal to generate a mixer output signal; an analog-to-digital converter configured to sample the mixer output signal in order to provide a sequence of sampled values; and a control circuit configured to provide a sequence of phase offsets by phase-shifting at least one of the RF test signal and the RF reference signal using one or more phase shifters, calculate a spectral value from the sequence of sampled values; and calculate estimated phase information indicating a phase of the RF output signal based on the spectral value.

First claim

What is claimed is:

1. A circuit, comprising:
a radio frequency (RF) transmitter channel including an input node and an output node and being configured to receive an RF oscillator signal at the input node and to provide an RF output signal at the output node, wherein the output node is configured to be coupled to a transmit antenna;
a monitor circuit including a mixer configured to mix an RF reference signal and an RF test signal that represents the RF output signal to generate a mixer output signal, wherein the monitor circuit includes a coupler coupled to the RF transmitter channel and configured to couple out a portion of the RF output signal to generate the RF test signal;
an analog-to-digital converter configured to sample the mixer output signal at a plurality of sampling times in order to provide a sequence of sampled values; and
a control circuit coupled to the analog-to-digital converter and configured to:
provide a sequence of phase offsets by phase-shifting at least one of the RF test signal or the RF reference signal using one or more phase shifters such that a phase offset between the RF test signal and the RF reference signal is successively increased according to the sequence of phase offsets,
wherein the analog-to-digital converter is configured to sample the mixer output signal for each phase offset of the sequence of phase offsets to provide the sequence of sampled values,

calculate a spectral value of the sequence of sampled values, and
calculate estimated phase information indicating a phase of the RF output signal based on the spectral value.

2. The circuit of claim 1 , wherein the monitor circuit further comprises:
a phase shifter coupled to the mixer and configured to receive the RF oscillator signal and generate the RF reference signal by applying a selected phase shift to the RF oscillator signal, thereby determining a phase of the RF reference signal used by the mixer, wherein the phase shifter is configured to provide the RF reference signal to the mixer.

3. The circuit of claim 2 , wherein an input of the phase shifter is coupled to the input node of the RF channel.

4. The circuit of claim 2 , wherein the phase shifter is configured to receive the RF oscillator signal and apply the sequence of phase offsets to the RF oscillator signal to generate the RF reference signal having the sequence of phase offsets with respect to the RF oscillator signal.

5. The circuit of claim 4 , wherein the phase shifter is configured to apply the sequence of phase offsets to the RF oscillator signal to generate the RF reference signal by changing the selected phase shift applied to the RF oscillator signal in equidistant phase steps.

6. The circuit of claim 1 , wherein the sequence of sampled values are direct current (DC) values corresponding to the sequence of phase offsets of the RF reference signal.

7. The circuit of claim 1 , wherein the RF channel includes a phase shifter coupled to and arranged between the input node and the output node,
wherein the phase shifter is configured to receive the RF oscillator signal and generate the RF output signal by applying a selected phase shift to the RF oscillator signal, thereby determining a phase of the RF output signal used by the mixer.

8. The circuit of claim 7 , wherein the phase shifter is configured to receive the RF oscillator signal and apply the sequence of phase offsets to the RF oscillator signal to generate the RF output signal having the sequence of phase offsets with respect to the RF oscillator signal.

9. The circuit of claim 8 , wherein the phase shifter is configured to apply the sequence of phase offsets to the RF oscillator signal to generate the RF output signal by changing the selected phase shift applied to the RF oscillator signal in equidistant phase steps.

10. The circuit of claim 8 , wherein the sequence of sampled values are direct current (DC) values corresponding to the sequence of phase offsets of the RF output signal.

11. The circuit of claim 1 , wherein the RF test signal and the RF reference signal provided to the mixer have a same frequency.

12. A method, comprising:
providing a radio frequency (RF) test signal to a radar transmitter circuit;
mixing an RF reference signal and an RF test signal that represents an RF output signal of the radar transmitter circuit to generate a mixer output signal;
repeatedly selecting a phase offset according to a sequence of phase offsets;
applying each selected phase-offset according to the sequence of phase offsets by phase-shifting at least one of the RF test signal or the RF reference signal such that a phase offset between the RF test signal and the RF reference signal is successively increased to generate the sequence of phase offsets;
sampling the mixer output signal a plurality of times to generate a sequence of sampled values associated with the sequence of phase offsets, wherein sampling the mixer output signal include sampling the mixer output signal for each phase offset of the sequence of phase offsets to provide the sequence of sampled values;
calculating a spectral value from the sequence of sampled values; and
calculating estimated phase information indicating a phase of the RF output signal based on the spectral value.

13. The method of claim 12 , wherein calculating the estimated phase information comprises:
calculating the spectral value from the sequence of sampled values, the spectral value being a complex-valued spectral value; and
calculating an argument of the complex-valued spectral value, the argument being an estimation of the phase of the RF output signal.

14. The method of claim 12 , wherein the sequence of phase offsets is a sequence of equally spaced phases distributed over one or more full phase rotations.

15. The method of claim 14 , the method further comprising:
providing a sequence of weight factors,
wherein the weight factors depend on a number of periods in the sequence of sampled values and on a number of sampled values of the sequence of sampled values.

16. The method of claim 12 , wherein phase offsets included in the sequence of phase offsets are equally spaced with a spacing of 90 degrees and a number of phase offsets of the sequence of phase offsets is an integer multiple of four.

17. The method of claim 12 , wherein phase offsets included in the sequence of phase offsets are equally spaced with a spacing that equals an integer multiple of 360 degrees divided by a number of phase offsets of the sequence of phase offsets.

18. The method of claim 12 , wherein applying each selected phase offset according to the sequence of phase offsets comprises:
using a first phase shifter to phase-shift the RF test signal by a first phase shift value; and
using a second phase shifter to phase-shift the RF reference signal by a second phase shift value, wherein each selected phase offset corresponds to a difference between the second phase shift value and the first phase shift value.

19. A method, comprising:
providing an RF oscillator signal at an input node of an RF channel;
generating an RF output signal at an output node of the RF channel based on the RF oscillator signal;
mixing an RF reference signal and an RF test signal that represents the RF output signal to generate a mixer output signal;
generating a sequence of phase offsets corresponding to a plurality of sampling times by repeatedly phase-shifting at least one of the RF test signal or the RF reference signal using one or more phase shifters such that a phase offset between the RF test signal an

Assignees

• Infineon Technologies Ag

Inventors

• Schrattenecker Jochen O
• Christoffers Niels
• Fiore Vincenzo
• Gstoettenbauer Bernhard
• Kollmann Helmut
• Melzer Alexander
• Onic Alexander
• Stuhlberger Rainer
• Zinnoecker Mathias

Classifications

• H01Q3/36 Primary

  with variable phase-shifters · CPC title

• G01S7/032 Primary

  Constructional details for solid-state radar subsystems · CPC title

• G01S7/35

  Details of non-pulse systems · CPC title

• G01S7/4008

  of transmitters · CPC title

• G01S7/4017

  of HF systems · CPC title