Radar Transceiver Self-Test for DAC Linearity in Phase Shifting
Find Innovative SolutionsGenerate Solutions
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
Incorporating a dummy load and resistor network connected to a digital controller and testing module, allowing for the measurement of analogue outputs during a self-test mode, enabling the determination of linearity and resistance values, and switching between normal and self-test modes to ensure operational reliability.
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 performing the actual phase shifting function. This dummy load serves as a test interface, allowing the testing module to measure the digital-to-analogue converter's linearity by monitoring the analogue signal at the dummy load output, thereby enabling measurement capability without requiring external test equipment.
Solution Approach 2:
The dummy load is designed as a simplified copy of the phase shifter's electrical interface, replicating its input-output characteristics. By copying the essential electrical behavior of the phase shifter, the dummy load provides a safe and isolated means to test the digital-to-analogue converter without risking damage to the actual phase shifter or disrupting normal transceiver operation.
2Measurement precision
If the dummy load is enabled for testing, then linearity measurement is achieved, but normal transmitter operation is affected
Solution Approach 1:
The dummy load is designed with dynamic switching capability, allowing it to be selectively enabled or disabled based on operational mode. During normal transmitter operation, the dummy load is disabled to prevent any impact on signal integrity and transmitter performance. During self-test mode, the dummy load is enabled to facilitate linearity measurements. This dynamic configuration ensures that the measurement capability does not compromise normal operation.
Solution Approach 2:
The transceiver signal path is segmented into two parallel paths: one through the actual phase shifter for normal operation, and another through the dummy load for testing. This segmentation allows independent operation of each path, enabling the testing function to be activated without interfering with the primary transmitter function, thereby maintaining reliability during normal operation.
3Reliability
If continuous monitoring is implemented, then reliability is improved, but energy consumption increases
Solution Approach 1:
Instead of continuous monitoring, the testing module operates periodically by switching between normal transmitter mode and self-test mode. The controller enables the dummy load and activates the testing module only during scheduled self-test intervals, while the actual phase shifter remains operational. This periodic operation reduces the average power consumption of the testing module while maintaining reliable monitoring of transmitter performance over time.
Data Source
Figure 1
Figure 2
Figure 3
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).