Digital Dithering for Phased Array Quantization Errors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Phased array antennas with quantized phase shifters suffer from quantization errors, which increase side-lobe levels due to the finite number of digitalization bits, leading to degraded performance and higher costs with higher bit-count phase shifters.
Innovation Solution
Implementing digital dithering techniques to rapidly switch between the states of quantized phase shifters, achieving a time-averaged phase value close to the desired state, even with low-resolution phase shifters, thereby reducing quantization errors and side-lobe levels without additional hardware costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If quantized phase shifters with more bits are used, then antenna performance improves and side-lobe levels decrease, but hardware cost and complexity increase
Solution Approach 1:
The patent applies dynamics by making the phase shifter states time-varying through dithering. Instead of using a fixed high-bit phase shifter, the system rapidly switches between low-bit phase states according to a dither sequence, creating an effective time-averaged phase that reduces quantization errors while maintaining low hardware complexity
Solution Approach 2:
The patent implements periodic action through dithering sequences that cyclically switch phase shifter states. By periodically transitioning between discrete phase states according to predetermined sequences, the system achieves effective phase resolution beyond the native quantization levels without requiring higher-bit hardware
Solution Approach 3:
The patent ensures continuity of useful action by maintaining rapid dithering transitions that create an effectively continuous phase control from discrete states. The high-speed switching between phase states produces a continuous time-averaged phase effect, eliminating the discontinuous quantization errors that would otherwise degrade performance
2Device complexity
If low-bit phase shifters are used, then hardware cost and complexity decrease, but quantization errors increase and side-lobe levels rise
Solution Approach 1:
The patent introduces an intermediary dithering mechanism between the low-bit phase shifter and the antenna elements. This dithering process acts as a mediator that transforms the coarse discrete phase states into an effective fine-resolution phase control through rapid switching and time-averaging, thereby improving precision without increasing hardware bit depth
Solution Approach 2:
The patent changes the temporal parameter of phase control by introducing time-varying dither sequences. By modulating the phase states over time according to specific dither patterns and then averaging the results, the system effectively changes the resolution parameter from the native low-bit precision to a higher effective precision without hardware modification
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Systems and methods disclosed herein provide techniques for reducing quantization errors and side lobe levels in phased array antennas. The states of a quantized phase shifter of a phased array antenna may be dithered to achieve a time-averaged value that reduces quantization errors. By rapidly switching between the different states of the quantized phase shifter, a time-average value close to a desired phase state may be achieved with a low resolution phase shifter.