Radar Transceiver Self-Test for DAC Linearity in Phase Shifting
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Solution Overview
Problem
Radar transceivers lack an effective method for self-testing the linearity of digital-to-analogue converters, which is crucial for ensuring accurate phase shifting and transmitter performance, particularly in radar systems where beam forming is essential.
Innovation Solution
A radar transceiver design incorporating a digital controller, digital-to-analogue converter, phase shifter, dummy load, and resistor network, along with a testing module and controller module, enables a self-test mode to measure the linearity of the digital-to-analogue converter by providing a range of digital control signals and measuring the analogue output, allowing for the determination of resistance values and generation of digital codes for comparison during normal and service operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a dummy load is added to enable self-testing of the digital-to-analogue converter, then measurement capability is improved, but device complexity increases
Solution Approach 1:
A dummy load is introduced as an intermediary component that replicates the electrical characteristics of the phase shifter without requiring the actual phase shifter to be present during testing. This dummy load serves as a mediator between the digital-to-analogue converter and the testing module, enabling linearity measurements to be performed on the DAC without disrupting normal transceiver operation. The dummy load presents the same impedance and loading conditions as the actual phase shifter, ensuring accurate measurement results.
2Reliability
If self-test functionality is implemented, then reliability is improved, but device complexity increases
Solution Approach 1:
The transceiver is equipped with self-service capabilities through the integration of a testing module and controller module that enable automatic linearity verification of the digital-to-analogue converter. The controller module autonomously controls the testing module to perform measurements, compare results against predetermined thresholds, and generate pass/fail indications without requiring external intervention. This self-service approach enhances reliability by enabling continuous monitoring and detection of DAC degradation or faults.
Solution Approach 2:
A feedback mechanism is implemented where the testing module measures the linearity of the digital-to-analogue converter and provides results back to the controller module. The controller module compares the measured linearity values against predetermined thresholds and generates appropriate feedback signals indicating whether the DAC is operating within acceptable parameters. This feedback loop enables real-time verification of transmitter performance and triggers alerts or protective actions when linearity degradation is detected.
3Manufacturing precision
If production self-test and service self-test modes are implemented, then manufacturing precision is improved, but device complexity increases
Solution Approach 1:
The testing system is designed with dynamic capabilities to operate in two distinct modes: production self-test mode and service self-test mode. The controller module dynamically switches between these modes based on operational context. In production mode, the system performs comprehensive linearity verification during manufacturing with access to all testing resources. In service mode, the system performs simplified linearity checks during field operation with limited resources. This dynamic approach allows the same hardware to fulfill different testing requirements with optimized performance for each mode.
Data Source
AI summary
The disclosure relates to a radar transceiver having a transmitter comprising a phase shifter. Example embodiments include a radar transceiver (200) having a normal mode of transmitter operation and a self-test mode of operation, the transceiver (200) comprising: a digital controller (116) configured to provide a digital control signal indicative of a phase shift; a digital to analogue converter (122) configured to receive the digital control signal and provide an analogue signal in accordance with the phase shift; a phase shifter (124) configured to receive the analogue signal and provide a phase shifted output signal for transmission; a dummy load (240) connected to receive the analogue signal from the digital to analogue converter (122) and to provide an analogue output; a resistor network (331) connected across an output of the dummy load (240); a testing module (335) configured to measure the analogue output of the dummy load (240); and a controller module (339) configured to control operation of the dummy load (240), testing module (335) and digital controller (116) during the self-test mode of operation by: enabling the dummy load (240); operating the digital controller (116) to provide a range of digital control signals to the digital to analogue converter (122); and operate the testing module (335) to measure the analogue output of the dummy load (240) to determine a measure of linearity of the digital to analogue converter (122).