Integrated AESA Radar Calibration with XR Loopback Measurement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing AESA-based radar systems lack a cost-effective method for in-situ self-calibration that accurately measures relative amplitude and phase differences across hundreds or thousands of RF channels, necessitating expensive precision test equipment and failing to integrate transceiver/AESA top-level calibration for real-time operational verification and health monitoring.
Innovation Solution
A radar receiver/excitor (XR) functions as a precision multi-channel relative amplitude and phase measurement device, performing iterative self-calibration of AESA quadrants using signal injection loopback techniques, eliminating the need for separate calibration devices and enabling system-level health monitoring and self-healing calibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If existing AESA calibration methodologies utilize precision test equipment (PNAs), then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The transceiver calibrates itself by using its own transmit signal and receiver channels, eliminating the need for external precision test equipment. The system performs self-calibration by measuring relative amplitude and phase differences across its own Rx channels using signal injection loopback techniques
Solution Approach 2:
The transceiver serves dual functions: normal radar operation and self-calibration. The same transmit and receive channels used for radar detection are also used for calibration measurements, making the calibration system universal and eliminating separate dedicated calibration equipment
2Device complexity
If transceiver self-calibration is implemented, then device complexity is reduced, but measurement precision may worsen
Solution Approach 1:
The system uses signal injection loopback techniques where the transmit signal is fed back through the receive channels, allowing the transceiver to measure and characterize its own channel responses. This feedback mechanism enables precise relative amplitude and phase measurements without external equipment
Solution Approach 2:
The patent replaces mechanical precision test equipment (PNAs) with an electronic self-calibration system using software-based signal processing and digital signal injection techniques, substituting complex hardware with more manageable electronic and software solutions
3Measurement precision
If iterative quadrant calibration is performed, then measurement precision is improved, but loss of time increases
Solution Approach 1:
The AESA is divided into quadrants or subarrays that can be calibrated iteratively and independently. This segmentation allows the calibration process to break down a large complex system into manageable sections, improving measurement precision while enabling parallel or sequential processing to reduce overall calibration time
4Reliability
If comprehensive hierarchical calibration is implemented, then reliability is improved, but device complexity increases
Solution Approach 1:
The calibration system is organized hierarchically into segments: transceiver-level calibration, quadrant/subarray-level calibration, and full AESA calibration. This segmentation allows comprehensive calibration to be performed in manageable stages, improving reliability while keeping each calibration step relatively simple
Solution Approach 2:
The transceiver performs preliminary self-calibration before AESA-level calibration, establishing a foundation of known good measurements. This preliminary action ensures that subsequent calibration steps build upon accurate baseline data, improving overall reliability
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A system for insitu AESA calibration includes a radar receiver / excitor (XR). The calibrated XR functions as a precision multi-channel relative amplitude and phase microwave frequency measurement device that executes a known AESA calibration methodology. An integrated RF sensor system-level built in test (BIT) is utilized for prognostic health monitoring and self-healing calibration. During calibration, quadrants of the AESA are iteratively calibrated via measurements by the XR. I/Q values are balanced for each quadrant relative to each other without the need for a separately calibrated measurement device for absolute calibration. A near field probe may be disposed for radiative loopback measurements. A T/R calibration circuit receives the loopback measurements and data from a Tx channel.