FMCW Radar BIST Using Switchable Coupling for Transient Signal Monitoring
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional built-in self-test (BIST) systems in radar systems are not time-aligned with radar chirps, making it difficult to detect transient signal failures and cannot monitor multiple analog signals simultaneously through a common analog-to-digital converter (ADC).
Innovation Solution
The method involves switchably coupling multiple analog signals from selected nodes in the radar system to a fewer number of monitor ADCs within the BIST system, allowing for time-aligned monitoring during radar chirps and using a single common ADC to monitor multiple signals, enabling real-time detection of failures and calibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional BIST systems are used to monitor radar transceiver circuits, then the system can detect failures during operation, but the system cannot detect transient failures that occur only during radar chirps because the BIST is not time-aligned to the chirps
Solution Approach 1:
The BIST system is configured to activate monitoring functions in advance of expected transient failure events. The monitor ADC is pre-configured to capture signals at specific time intervals that align with radar chirp occurrences, ensuring that transient failures are captured before they disappear. This preliminary positioning of monitoring resources enables detection of brief anomaly events.
Solution Approach 2:
The BIST system implements periodic monitoring synchronized to the radar chirp cycle. The monitor ADC samples analog signals at regular intervals that correspond to the repeating chirp pattern, creating a rhythmic monitoring scheme. This periodic action ensures that transient failures occurring during any chirp cycle have a high probability of being captured during the next monitoring window.
2Productivity
If multiple monitor ADCs are used to monitor multiple analog signals simultaneously, then all signals can be monitored at once, but the device complexity and cost increase significantly
Solution Approach 1:
Multiple monitoring functions are merged into a single monitor ADC through time-division multiplexing. The BIST system sequentially connects the monitor ADC to different analog signal sources during different time slots within each radar frame. This combining approach allows one ADC to perform the work of multiple ADCs while reducing component count and system complexity.
Solution Approach 2:
The BIST system dynamically reconfigures the monitor ADC's input connections during operation. Switches or multiplexers dynamically route different analog signals to the monitor ADC at different times based on the current monitoring phase. This dynamic switching enables a single static ADC component to monitor multiple dynamic signal sources effectively.
3Device complexity
If a single common ADC is used to monitor multiple analog signals, then device complexity is reduced, but the ability to simultaneously monitor all signals is compromised
Solution Approach 1:
The single monitor ADC operates in periodic cycles, systematically sampling different analog signals in a predetermined sequence within each radar frame. This periodic sampling schedule ensures that all critical signals are monitored regularly without requiring simultaneous ADC resources. The periodic nature minimizes total monitoring time while maintaining comprehensive coverage.
Solution Approach 2:
The BIST monitoring using the single ADC is continuous throughout radar operation, seamlessly transitioning from one signal to the next without idle gaps. The ADC continuously samples signals in a round-robin fashion, ensuring that monitoring action is always productive. This continuous operation eliminates wasted time between monitoring different signals.
Data Source
AI summary
A FMCW radar system with a built-in self-test (BIST) system for monitoring includes a receiver, a transmitter, and a frequency synthesizer. A FMCW chirp timing engine controls timing of operations at least one radar component. The BIST system includes at least one switchable coupling for coupling a first plurality of different analog signals including from a first plurality of selected nodes in the receiver or transmitter that are all coupled to a second number of monitor analog-to-digital converters (ADCs). The second number is less than (<) the first plurality of different analog signals. The BIST system includes a monitor timing engine and controller operating synchronously with the chirp timing engine, that includes a software configurable monitoring architecture for generating control signals including for selecting using the switchable coupling which analog signal to forward to the monitor ADC and when the monitor ADC samples the analog signals.