Method of generating self-test signals, corresponding circuit and apparatus

Patent metadata

Field	Value
Publication number	US-11860223-B2
Application number	US-202117479510-A
Country	US
Kind code	B2
Filing date	Sep 20, 2021
Priority date	Jan 3, 2017
Publication date	Jan 2, 2024
Grant date	Jan 2, 2024

Abstract

A radio-frequency receiver includes built-in-self-test (BIST) circuitry which generates a self-test signal. A local oscillator signal is divided. A self-test oscillation signal is generated, based, at least in part, on the frequency-divided local oscillation signal. The self-test signal is generated based on the self-test oscillation signal. The BIST circuitry includes a divider, which divides the self-test oscillation signal. The frequency-divided local oscillation signal and the divided self-test oscillation signal are used to perform one or more of generating the self-test oscillation signal and controlling the generation of the self-test oscillation signal. The radio-frequency receiver may be an automotive radar receiver.

First claim

The invention claimed is:

1. A method of testing or calibrating a radio-frequency receiver, comprising:
generating, using a first digital-to-analog converter, a common coarse tuning signal, wherein the common coarse tuning signal is an analog voltage signal;
generating, using a modulator, a first fine-tuning signal;
generating a second fine-tuning signal using a second digital-to-analog converter;
setting, using the common coarse tuning signal and the first fine-tuning signal, a first oscillation frequency of a first oscillator of the radio-frequency receiver;
generating a local oscillator signal of the radio-frequency receiver using the first oscillator;
applying frequency division to the local oscillator signal, producing a frequency-divided signal;
setting, using the common coarse tuning signal, a second oscillation frequency of a second oscillator of the radio-frequency receiver, wherein the common coarse tuning signal is received by the first oscillator and the second oscillator;
generating a radio-frequency test signal of the radio-frequency receiver using the second oscillator;
generating, using the radio-frequency test signal and the frequency-divided signal, a self-test signal of the radio-frequency receiver and
performing diagnostic operations on the radio-frequency receiver using the self-test signal, performing calibration operations on the radio-frequency receiver using the self-test signal, or performing diagnostic and calibration operations on the radio-frequency receiver using the self-test signal.

2. The method of claim 1 , comprising:
fine-tuning the second oscillation frequency of the second oscillator using the second fine-tuning signal.

3. The method of claim 1 , comprising:
fine-tuning the second oscillation frequency of the second oscillator using the first fine-tuning signal.

4. The method of claim 2 , comprising:
selectively fine-tuning the second oscillation frequency of the second oscillator to produce chirp modulation.

5. The method of claim 1 wherein the frequency-divided signal is a first frequency-divided signal, and the method comprises:
applying frequency division to the radio-frequency test signal, generating a second frequency-divided signal; and
comparing the first and second frequency-divided signals.

6. The method of claim 1 , comprising:
mixing the local oscillator signal with a received signal received by the radio-frequency receiver.

7. The method of claim 1 , comprising:
applying the radio-frequency test signal to a variable gain amplifier.

8. The method of claim 7 , comprising:
monitoring a power of an output of the variable gain amplifier.

9. The method of claim 1 , comprising:
setting an intermediate frequency of the radio-frequency receiver based on a difference between the first oscillation frequency of the first oscillator and the second oscillation frequency of the second oscillator.

10. A radio-frequency receiver, comprising:
a first digital-to-analog converter, which, in operation, generates a common coarse tuning signal, wherein the common coarse tuning signal is an analog voltage signal;
a modulator, which in operation, generates a first fine-tuning signal;
a second digital-to-analog converter, which, in operation, generates a second fine-tuning signal;
a first oscillator, which, in operation, generates a first oscillation signal having a first oscillation frequency that is set using the common coarse tuning signal and the first fine-tuning signal;
a first frequency divider, which, in operation, frequency divides the first oscillation signal, generating a first frequency-divided signal;
a second oscillator, which, in operation, generates a radio-frequency test signal having a second oscillation frequency that is set using the common coarse tuning signal, wherein the common coarse tuning signal is received by the first oscillator and the second oscillator; and
test circuitry, coupled to the second oscillator and the first frequency divider, which, in operation,
generates a self-test signal of the radio-frequency receiver based on the radio-frequency test signal and the first frequency-divided signal; and
performs diagnostic operations on the radio-frequency receiver using the self-test signal, performs calibration operations on the radio-frequency receiver using the self-test signal, or performs diagnostic and calibration operations on the radio-frequency receiver using the self-test signal.

11. The radio-frequency receiver of claim 10 , wherein:
the second oscillation frequency is set using the common coarse tuning signal and the first fine-tuning signal.

12. The radio-frequency receiver of claim 10 , wherein:
the second oscillator, in operation, receives the second fine-tuning signal; and
the second oscillation frequency is set using the common coarse tuning signal and the second fine-tuning signal.

13. The radio-frequency receiver of claim 12 , comprising control circuitry, which, in operation, selectively controls the second digital-to-analog converter to generate the second fine-tuning signal to produce chirp modulation.

14. The radio-frequency receiver of claim 10 , comprising:
a second frequency divider coupled between the second oscillator and the test circuitry, which, in operation, frequency divides the radio-frequency test signal, producing a second frequency-divided signal, wherein the test circuitry, in operation, compares the first frequency-divided signal with the second frequency-divided signal.

15. A system, comprising:
an antenna circuit;
a first digital-to-analog converter, which, in operation, generates a common coarse tuning signal, wherein the common coarse tuning signal is an analog voltage signal;
a modulator, which in operation, generates a first fine-tuning signal;
a second digital-to-analog converter, which, in operation, generates a second fine-tuning signal;
a first oscillator, which, in operation, generates a first oscillation signal having a first oscillation frequency that is set using the common coarse tuning signal and the first fine-tuning signal;
a mixer coupled to the first oscillator and to the antenna circuit, wherein the mixer, in operation, generates an intermediate frequency signal;
a first frequency divider, which, in operation, frequency divides the first oscillation signal, generating a first frequency-divided signal;
a second oscillator, which, in operation, generates a radio-frequency test signal having a second oscillation frequency that is set using the common coarse tuning signal, wherein the common coarse tuning signal is received by the first oscillator and the second oscillator; and
test circuitry, coupled to the second oscillator and the first frequency divider, which, in a test mode of operation,
generates a self-test signal based on the radio-frequency test signal and the first frequency-divided signal; and
performs diagnostic operations on the system using the self-test signal, performs calibration operations on the system using the self-test signal, or performs diagnostic and calibration operations on the system using the self-test signal.

16. The system of claim 15 , comprising an automotive radar sensor integrated circuit including the first oscillator and the first frequency divider.

17. The system of claim 16 , wherein the automotive radar sensor integrated circuit includes the second oscillator and the test circuitry.

Assignees

• St Microelectronics Srl

Inventors

• Maiellaro Giorgio
• Scuderi Angelo
• Bruno Angela
• Scaccianoce Salvatore

Classifications

• G01R31/2884 Primary

  using dedicated test connectors, test elements or test circuits on the IC under test (G01R31/2855 takes precedence) · CPC title

• G01R31/2832

  Specific tests of electronic circuits not provided for elsewhere (G01R31/2801, G01R31/316 take precedence) · CPC title

• G01S7/4056 Primary

  specially adapted to FMCW · CPC title

• G01S7/4069

  involving a RF signal injection · CPC title

• H04B17/0085 Primary

  using test signal generators · CPC title