Mirror-Symmetric Phased Array Cells for Low ARC at Wide Scan Angles
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Solution Overview
Problem
Phased array antennas face challenges in maintaining low active reflection coefficient (ARC) over wide scan angles, especially at millimeter-wave frequencies, due to strong coupling between antenna elements, which degrades performance and efficiency.
Innovation Solution
The implementation of a phased array antenna design with mirror-symmetric antenna cells and asymmetric coupling structures, such as crossbars and rings, to manipulate couplings and prevent coherent summation of coupling terms, thereby reducing the sensitivity of ARC to scan angles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If antenna elements are placed close together to achieve compact phased array, then array size is reduced, but coupling between elements increases causing high active reflection coefficient
Solution Approach 1:
The patent applies asymmetry by placing different asymmetric scatterers at different locations within the unit cell. Each scatterer has a specific geometry (e.g., L-shaped, T-shaped, or rectangular) that is asymmetric with respect to the antenna element, creating non-uniform coupling manipulation across the array while maintaining compact spacing
2Adaptability or versatility
If antenna spacing is reduced to half-wavelength for wide angle scanning, then grating lobes are avoided, but coupling terms coherently sum causing high ARC over wide scan angles
Solution Approach 1:
The patent implements local quality by introducing location-specific asymmetric scatterers within each unit cell. Each scatterer's geometry and position are optimized for its specific location relative to the antenna element, creating spatially varying coupling characteristics that prevent coherent summation across different scan angles while maintaining half-wavelength spacing for wide-angle operation
Data Source
AI summary
An apparatus including: a phased array antenna for transmitting/receiving beamformed signals on a plurality of beams using a common frequency- and time-limited physical channel resource; said phased array antenna including: an array of antenna cells for electromagnetic radiation, wherein the antenna cells include: an antenna element; a first coupling structure at a first side of the antenna element for manipulating coupling with an adjacent antenna cell at a first side of the antenna element; a second coupling structure at a second side of the antenna element opposite to the first side for manipulating coupling with another adjacent antenna cell at the second side of the antenna element; a coupling factor of the first coupling structure differing from a coupling factor of the second coupling structure; wherein adjacent antenna cells of the array of antenna cells are mirror-symmetric structures.