Synthetic Beam Steering for Single-Channel DOA Estimation
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Solution Overview
Problem
Conventional antenna assemblies have poor aperture efficiency, leading to lower gain, sensitivity, and accuracy in determining the direction of arrival (DOA) of signals due to unutilized physical area, high cost, weight, and complexity, especially in ultra-wide band applications, and are limited by the number of RF channels and phase shifters.
Innovation Solution
A single channel synthetic beam steering system using low-cost RF switches instead of phase shifters to activate antenna elements in a pseudo-random pattern, combining signals with a radio frequency combiner, and employing compressive sensing for DOA determination, which enhances aperture utilization and reduces the number of required channels and components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional antenna assemblies use discrete sensors and phase shifters to determine DOA, then DOA determination capability is achieved, but aperture efficiency is poor and gain is reduced
Solution Approach 1:
The patent combines multiple antenna elements into a virtual array through signal processing, merging their contributions to achieve high aperture efficiency. The virtual array concept allows the system to utilize the full physical aperture area by coherently combining signals from distributed antenna elements, thereby resolving the contradiction between measurement precision and aperture utilization.
Solution Approach 2:
The patent transitions from physical spatial arrangement to virtual spatial arrangement by using signal processing to create a virtual array in the signal domain. This dimensionality change allows the system to achieve high DOA estimation accuracy without being constrained by physical aperture limitations, effectively resolving the contradiction between measurement precision and physical area utilization.
2Measurement precision
If conventional systems use multiple RF channels and phase shifters for each antenna element, then DOA determination capability is improved, but cost, weight, and complexity increase
Solution Approach 1:
The patent employs a single RF channel that serves multiple antenna elements through time-division or code-division multiplexing. This universal approach allows one RF channel to perform the function of multiple dedicated channels, significantly reducing system complexity, cost, and weight while maintaining DOA estimation accuracy through sophisticated signal processing.
Solution Approach 2:
The patent creates virtual copies of the RF signal path through digital signal processing, where a single physical RF channel is effectively replicated to serve multiple antenna elements. By copying the signal processing function rather than duplicating physical hardware, the system achieves multi-element capability with single-channel simplicity, resolving the contradiction between measurement precision and device complexity.
3Power
If antenna elements are spaced to utilize full aperture area, then gain and sensitivity should improve, but unutilized physical area reduces efficiency
Solution Approach 1:
The patent dynamically assigns antenna elements to the virtual array based on signal characteristics and processing requirements. This dynamic allocation ensures that all physical aperture area is actively utilized for signal reception and processing, maximizing both array gain and aperture efficiency by adapting the effective aperture configuration to match the incoming signal patterns.
Data Source
AI summary
An apparatus, method, or computer-readable storage medium encoded with computer-executable instructions that, when executed by a computer, cause the computer to carry out a method for determining one or more directions of arrival of one or more coherent or incoherent signals with a single radio frequency channel. The apparatus may comprise: a plurality of antenna elements (110) configured to determine the one or more coherent or incoherent signals; a plurality of radio frequency switches (120) configured to selectively activate one or more of the plurality of antenna elements; and a radio frequency combiner (140) configured to combine a plurality of radio frequency signals from one or more selectively activated antenna elements of the plurality of antenna elements.