Receiver Channel Test Signal Injection for Phase Calibration

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Solution Overview

Problem

Wireless receiver systems with multiple antennae face challenges in maintaining angular measurement accuracy due to variations in receiver amplitude and phase response over time, which can lead to decreased performance and require frequent recalibration or replacement, especially in applications with functional safety requirements.

Innovation Solution

A wireless receiver system with a test signal generating circuit that injects test signals into each receiver channel, allowing for the measurement of amplitude and phase differences, enabling reliable assessment and calibration of receiver channels, even after initial calibration coefficients become inaccurate.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If initial calibration coefficients are used without retesting, then device complexity is reduced, but measurement precision deteriorates due to variations in receiver amplitude and phase response over time

Engineering Contradiction:
Improvecalibration procedureVSAvoidangular measurement accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent implements preliminary action by incorporating a test signal generating circuit and test signal injection paths into the receiver system during manufacturing. This allows calibration coefficients to be determined and stored in advance, and enables periodic retesting without adding complex external calibration equipment. The test signal path is pre-configured to inject signals at the antenna input, allowing amplitude and phase variations to be measured and recalibration performed as needed, thus maintaining measurement precision while managing device complexity through integrated design.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If receiver channels are tested frequently to detect performance deterioration, then reliability is improved, but loss of time increases due to repeated testing and recalibration procedures

Engineering Contradiction:
Improveperformance detection reliabilityVSAvoidtesting and recalibration time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies self-service by implementing a built-in self-test (BIST) capability where the receiver system tests itself using an integrated test signal generating circuit. The test signal is injected into receiver channels through coupling paths, and the system automatically measures amplitude and phase variations without requiring external test equipment or manual intervention. This self-testing mechanism enables frequent reliability checks with minimal time loss, as the system performs calibration autonomously using its own resources.

Inventive Principle:
Principle #25Self-service

3Measurement precision

If test signals are injected upstream of the amplifier, then measurement completeness is improved, but harmful factors increase due to amplifier interference and noise

Engineering Contradiction:
Improveamplitude and phase measurement accuracyVSAvoidamplifier noise and interference
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent applies segmentation by dividing the test signal injection into two separate paths: one path injects test signals upstream of the amplifier (at the antenna input) to measure complete receiver channel performance including the amplifier, and another path injects test signals downstream of the amplifier (at the mixer input) to measure only the downstream components. This segmentation allows selective testing based on which components need evaluation, enabling measurement of amplitude and phase variations while avoiding amplifier noise and interference when testing downstream components alone.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3327961B1Receiver testing
Publication Date: 2019.11.06 NXP BV
  • EP3327961B1 patent drawingFigure 1
  • EP3327961B1 patent drawingFigure 2
  • EP3327961B1 patent drawingFigure 3

AI summary

Receivers and methods of testing are described. A receiver includes a plurality of receiver channels, each including an amplifier for receiving a signal from an antenna and a mixer downstream of the amplifier. A test signal generating circuit is configured to generate test signals. A signal path connects the test signal generating circuit and each receiver channel and couples to each receiver channel at a coupling between the amplifier and a mixer. A test signal from the test signal generating circuit is injectable to the parts of the receiver channel downstream of the amplifier. The test signal may alternatively be injected into the entire receiver channel. The receivers and methods may be used in wireless systems, such as radar systems and radio systems.