Phased Array Antenna Calibration via Aggregated Channel Measurements
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Solution Overview
Problem
Conventional calibration techniques for phased array antennas result in sub-optimal canceling of relative phase and amplitude differences, especially in large arrays and in the presence of leakage, due to limitations in signal-to-leakage ratio and calibration resolution.
Innovation Solution
The proposed solution involves using aggregated measurements over multiple concurrently active channels and sequences of exclusion groups to compute individualized calibration values for each channel, improving signal-to-leakage performance and maintaining high calibration resolution by segmenting the phased array into sub-arrays and taking measurements with different channel groups excluded.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional calibration techniques are used for phased array antennas, then the calibration process is simple, but the signal-to-leakage ratio is insufficient and calibration precision deteriorates
Solution Approach 1:
The patent divides the phased array into multiple channel groups and further segments each group into measurement subsets and exclusion subsets. By calibrating different subsets separately and combining results, the system achieves higher calibration precision while managing complexity through structured segmentation of the calibration process
Solution Approach 2:
The patent performs preliminary calibration measurements on exclusion subsets before final calibration. By pre-measuring and storing calibration data for excluded channels, the system prepares reference information that improves the accuracy of subsequent full-array calibration while organizing the complexity into manageable preparatory steps
2Measurement precision
If individual channel calibration is performed, then calibration resolution is high, but signal-to-leakage ratio decreases due to leakage from other active channels
Solution Approach 1:
The patent extracts and isolates specific channel groups for measurement while excluding other channels from active transmission. By taking out only the necessary channels for each measurement and excluding others, the system improves signal-to-leakage ratio by minimizing interference from non-measured channels while maintaining efficient calibration throughput
Solution Approach 2:
The patent performs partial calibration measurements on subsets of channels rather than calibrating all channels simultaneously or sequentially. By measuring partial groups of channels in organized batches with controlled exclusion, the system achieves sufficient calibration accuracy without the full overhead of complete individual channel calibration, balancing precision and speed
3Productivity
If multiple channel groups are measured concurrently, then calibration productivity increases, but calibration precision decreases due to increased leakage interference
Solution Approach 1:
The patent segments the channel groups into measurement subsets and exclusion subsets, allowing concurrent measurement of multiple subsets while excluding other channels. This segmentation enables parallel calibration operations that maintain high throughput while preserving accuracy by ensuring that excluded channels do not interfere with active measurements
Solution Approach 2:
The patent performs preliminary identification and organization of channel groups into measurement and exclusion subsets before concurrent calibration begins. By pre-configuring which channels will be measured and which will be excluded during each time slot, the system enables efficient parallel calibration while maintaining the precision required for accurate beamforming
Data Source
AI summary
Techniques described herein provide phase and amplitude calibration of phased array antennas. In an N-by-M phased array having N*M channels, embodiments use aggregated measurements over multiple concurrently active channels to improve signal-to-leakage performance, while also using sequences of exclusion groups to yield an individualized calibration value for each channel (i.e., N*M individualized calibration values). For example, a J×K channel group of the array is selected in each of a sequence of measurement frames based on a calibration schema. Over J*K measurement sub-frames, a set of J*K aggregate measurements is obtained, each with different subsets of the channel group activated and excluded from the measurement. The aggregate calibration measurements can be used to compute J*K individualized calibration values, each for a channel of the channel group. In some implementations, each calibration value is computed as a complex value including both amplitude and phase calibrations information.