MIMO Radar Antenna Calibration via Inverse Coupling Matrices
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Solution Overview
Problem
MIMO radar antenna arrays face dysfunction due to lack of proper calibration, leading to antenna mismatches that result in poor sidelobe suppression and false alarms, especially in scenarios with high dynamic range targets.
Innovation Solution
The implementation of a method using Inverse Coupling Matrices (ICMs) and Pattern Reconstruction techniques to calibrate antenna mismatches, compensating for gain and phase mismatches across multiple elevation angles, and applying these corrections in a 2D angular spectrum to improve sidelobe suppression.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If antenna elements are manufactured with enhanced phase and gain, then manufacturing precision is improved, but antenna mismatch increases causing poor sidelobe suppression
Solution Approach 1:
The patent applies preliminary action by performing calibration measurements and computing Inverse Coupling Matrices (ICMs) before actual radar operation. The calibration process pre-characterizes antenna element mismatches in gain and phase, storing correction factors that are applied during signal processing to eliminate sidelobe interference.
Solution Approach 2:
The patent changes parameters by computing and applying complex-valued Inverse Coupling Matrices that adjust gain and phase parameters of antenna elements. The calibration process measures actual antenna characteristics and transforms these measurements into correction factors that modify the electrical parameters to achieve optimal array performance.
2Measurement precision
If calibration is performed at multiple elevation angles, then measurement precision is improved, but calibration complexity increases
Solution Approach 1:
The patent segments the calibration process into multiple elevation angle measurements (e.g., 0 degrees, 30 degrees, 60 degrees, 90 degrees). Each elevation angle provides independent measurement data that is processed separately to extract gain and phase mismatch information, which are then combined to form complete Inverse Coupling Matrices for 2D angular spectrum applications.
Solution Approach 2:
The patent transitions from single-elevation-angle calibration to multi-elevation-angle calibration, adding the elevation dimension to the calibration process. This dimensional expansion enables accurate calibration for 3D spatial targets by measuring antenna characteristics from multiple angular perspectives, creating a more comprehensive calibration model.
3Object-generated harmful factors
If Inverse Coupling Matrices are applied in 2D angular spectrum, then sidelobe suppression is improved, but processing complexity increases
Solution Approach 1:
The patent implements feedback by using calibration measurements to compute Inverse Coupling Matrices that are then applied to correct received signals. The calibration process provides feedback information about actual antenna performance deviations, and the ICM application feeds back corrected signals with suppressed sidelobes, creating a closed-loop system that eliminates mismatch effects.
Solution Approach 2:
The patent introduces Inverse Coupling Matrices as an intermediary between raw received signals and final processed outputs. These complex-valued matrices act as transformation mediators that convert uncalibrated antenna array responses into calibrated outputs with proper sidelobe suppression, facilitating accurate target detection and angle estimation.
Data Source
AI summary
For example, a radar apparatus may include a processor configured to generate radar information based on input radar data, the input radar data based on radar signals of a Multiple-Input-Multiple-Output (MIMO) radar antenna, wherein the processor is configured to generate the radar information by calibrating an antenna Mismatch (MM) of the MIMO radar antenna in a first dimension of an Azimuth-Elevation domain according to a plurality of one-dimensional (1D) Inverse Coupling Matrices (ICMs), the plurality of 1D ICMs corresponding to a plurality of antenna sub-arrays of the MIMO radar antenna and to a plurality of angles in a second dimension of the Azimuth-Elevation domain.