UWB Vivaldi Array Antenna on Doubly Curved Surface
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional antenna arrays face challenges in achieving ultra-wide bandwidth and high field-of-view on doubly curved surfaces due to issues with mutual coupling and aperture efficiency, particularly on doubly curved surfaces where simulating periodic tiling and accounting for mutual coupling between adjacent elements is complex, leading to suboptimal performance and low aperture efficiency.
Innovation Solution
The development of an ultra-wide band (UWB) antenna array configured to conform to a doubly curved surface using a quadrilateral mesh structure, where each unit cell is designed to optimize array gain, with electrically cooperating antennas distributed along the mesh edges, allowing for wide-angle electronic scanning and improved aperture efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If planar arrays are used to maximize antenna gain, then gain is improved, but field-of-view is limited due to projected area falling off as cos(θ)
Solution Approach 1:
The patent applies spherical curvature to the antenna array by distributing radiating elements over the surface of a sphere rather than using a flat planar configuration. This spherical geometry maintains a consistent projected area in all directions, eliminating the cos(θ) degradation that limits planar arrays. The spherical arrangement allows the array to achieve wide field-of-view coverage while maintaining high gain through optimal element distribution across the curved surface.
2Adaptability or versatility
If arrays are placed on singly curved surfaces to enable wider fields-of-view, then field-of-view is improved, but design and simulation complexity increases on doubly curved surfaces
Solution Approach 1:
The patent specifically chooses a spherical surface (a type of doubly curved surface) as the geometric foundation for the antenna array. This spherical geometry provides mathematical regularity that simplifies the simulation process compared to arbitrary doubly curved surfaces. The spherical symmetry allows for systematic element distribution and facilitates the use of spherical coordinate systems in electromagnetic simulation, reducing design complexity while achieving wide field-of-view coverage.
Solution Approach 2:
The patent transforms the design approach by changing the fundamental geometric parameter from planar to spherical coordinates. This parameter change enables the use of spherical harmonic expansions and other mathematical tools that simplify the analysis of doubly curved surfaces. By working in spherical coordinates with regular angular spacing, the patent reduces the complexity of simulating mutual coupling and electromagnetic interactions compared to irregular doubly curved geometries.
3Reliability
If conformal arrays use narrowband elements with large inter-element spacing, then mutual coupling is reduced, but aperture efficiency decreases due to grating lobes
Solution Approach 1:
The patent changes the operating parameter regime by using ultra-wideband elements that operate over more than one octave of bandwidth. This parameter change allows the array to maintain small inter-element spacing (less than 0.5λ at the highest operating frequency) while avoiding grating lobes across the entire bandwidth. The wideband operation transforms the relationship between element spacing and wavelength, enabling dense packing without the grating lobe problems that plague narrowband conformal arrays.
Solution Approach 2:
The patent employs dynamically adjustable beamforming across a wide frequency range to adaptively control radiation patterns. By using digital beamforming techniques that can dynamically adjust phase and amplitude weights across the ultra-wideband spectrum, the system can suppress grating lobes and optimize aperture efficiency at different frequencies and scan angles, rather than being constrained by fixed narrowband element patterns.
4Adaptability or versatility
If UWB arrays are designed on doubly curved surfaces to achieve wide field-of-view, then field-of-view is improved, but simulating periodic tiling and mutual coupling becomes complex
Solution Approach 1:
The patent applies spherical geometry to create a regular, periodic-like structure on a doubly curved surface. The spherical arrangement with uniform angular spacing creates a highly symmetric pattern that simplifies simulation compared to irregular doubly curved surfaces. This spherical periodicity allows for the use of spherical harmonic expansions and Fourier-based techniques to analyze mutual coupling, reducing computational complexity while maintaining the wide field-of-view benefits of curved surface arrays.
Data Source
AI summary
Various embodiments are directed to systems, apparatus and methods providing an ultra-wide band (UWB) antenna configured to conform to a doubly curved surface and having an operating wavelength λ, the UWB antenna comprising: an array of electrically cooperating antennas emanating outward from a base region to respective locations of an outer surface region conforming to the doubly curved surface, the area of the outer surface region being divided in accordance with a mesh of unit cells defining thereby a plurality of edges, each of the unit cells having a unit cell minimum area selected in accordance with a desired array gain; wherein for each antenna the respective location of the outer surface region to which the antenna extends is associated with a respective one of the plurality of edges defined by the mesh of unit cells.