OTA Antenna Array Testing via Spatial Channel Model
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Solution Overview
Problem
Conventional over-the-air (OTA) testing methods for antenna arrays, especially in 5G mmWave systems, are time-consuming and require a large number of probes and channels in anechoic chambers, making them inefficient for characterizing the performance of antenna arrays with integrated RF transceivers lacking RF connectors.
Innovation Solution
The method involves associating probes with specific beams instead of clusters and rays in the channel model, allowing for near-field OTA testing in a simplified chamber with fewer probes, and implementing a spatial OTA model to control channel characteristics within a test zone, enabling efficient beam management testing by including multiple beams.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional over-the-air testing methods are used for antenna arrays, then measurement accuracy is maintained, but testing time increases significantly and the number of probes required increases
Solution Approach 1:
The patent segments the antenna array into multiple sub-arrays, where each sub-array can be independently tested with fewer probes. This segmentation allows parallel testing of different sub-arrays, significantly reducing the total testing time while maintaining measurement accuracy for each segment
Solution Approach 2:
The patent implements preliminary calibration of the probe array and sub-arrays before actual measurements. This preliminary action establishes reference data and calibration matrices that enable faster subsequent measurements without requiring repeated full-calibration procedures, thereby reducing testing time while preserving measurement precision
2Measurement precision
If conventional over-the-air testing methods are used for antenna arrays, then comprehensive channel characterization is achieved, but the number of probes and channels required increases
Solution Approach 1:
The patent divides the antenna array into multiple sub-arrays and associates each sub-array with a specific probe or probe group. This segmentation reduces the total number of probes needed compared to testing the entire array simultaneously, while still achieving comprehensive channel characterization through systematic measurement of each sub-array
Solution Approach 2:
The patent makes each probe capable of measuring multiple sub-arrays at different time instances through a systematic measurement procedure. This multi-functionality allows a smaller number of probes to characterize the complete channel matrix by sequentially measuring different sub-arrays, reducing the total probe count while maintaining comprehensive characterization capability
3Device complexity
If antenna arrays are integrated with RF transceivers without RF connectors, then device integration and miniaturization are improved, but conventional testing methods become inapplicable
Solution Approach 1:
The patent introduces a probe array as an intermediary between the integrated antenna array and the measurement system. Since RF connectors are eliminated, the probe array serves as the necessary interface to couple electromagnetic fields from the antenna elements to the vector network analyzer, enabling testing of integrated devices without physical connectors
Solution Approach 2:
The patent replaces the mechanical connector-based testing approach with an electromagnetic field-based near-field measurement system. Instead of using physical RF connectors and cables, the system uses electromagnetic coupling between the probe array and antenna elements to transfer signals for measurement, enabling testing of connectorless integrated devices
Data Source
AI summary
A system provides OTA testing of a DUT having a DUT antenna array for forming physical beams. The system includes dual-polarized probes or probe groups, an anechoic chamber, a wireless channel emulator, and a test instrument. The dual-polarized probes or probe groups receive the physical beams formed by the DUT antenna array. The anechoic chamber houses the DUT antenna array and the probes or probe groups. The wireless channel emulator is coupled to the probes or probe groups for receiving the physical beams, and generates a calibrated OTA channel model having simulated beams corresponding to the physical beams. The calibrated OTA channel model simultaneously provides isolated wireless cable connections corresponding to the simulated beams, and emulates fading channel conditions. The test instrument, coupled to the wireless channel emulator, establishes a communications link with the DUT and evaluates performance characteristics of the DUT based on the calibrated OTA channel model.