Non-Linear Dipole Antenna Array for Low-Frequency Direction Finding
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Solution Overview
Problem
Direction finding antenna arrays, particularly at low frequencies, face challenges with sensitivity and cross-polarization isolation due to coupling with mounting structures, leading to inaccurate signal direction determination.
Innovation Solution
A direction finding antenna array comprising multiple dipole elements arranged in a non-linear pattern with specific electrical connections between them, forming a closed structure that improves low-frequency sensitivity, cross-polarization isolation, and immunity to conductive structure coupling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional dipole antenna arrays are used at low frequencies, then the array structure is simple, but the coupling to mounting structures increases causing poor DF sensitivity and cross-polarization isolation
Solution Approach 1:
The antenna array is segmented into multiple dipole elements (at least three) arranged in a non-linear pattern, where each dipole is electrically connected to its neighbors at both ends through multiple electrical connections. This segmentation creates a distributed structure that reduces coupling to mounting structures while maintaining DF sensitivity.
Solution Approach 2:
The dipole elements are arranged in a non-linear pattern rather than a symmetric linear or planar configuration. This asymmetric spatial arrangement, combined with the specific electrical connection topology, disrupts coupling paths to mounting structures and improves cross-polarization isolation.
2Reliability
If dipole elements are arranged in linear or planar patterns, then the array is easier to manufacture, but the low-frequency sensitivity and cross-polarization isolation are insufficient
Solution Approach 1:
The patent employs a non-linear arrangement of dipole elements that breaks the symmetry of conventional linear or planar arrays. This asymmetric configuration improves cross-polarization isolation by reducing unwanted coupling, while the systematic electrical connection method keeps manufacturing feasible.
Solution Approach 2:
Each dipole element is selectively connected to its adjacent neighbors through multiple electrical connections at both ends, creating local redundancy. This local quality enhancement improves overall array performance without requiring complete reconfiguration of the entire array structure.
3Reliability
If each dipole element is connected to adjacent elements at both ends with multiple electrical connections, then the immunity to conductive structure coupling improves, but the device complexity increases
Solution Approach 1:
The electrical connection system is segmented into localized pairs of connections between adjacent dipoles, rather than a single centralized feed. Each dipole connects to its neighbors at both ends through dedicated electrical connections, distributing the complexity across multiple simple, repeatable units.
Solution Approach 2:
The patent combines multiple electrical connections between adjacent dipole elements to create a redundant connection topology. This merging of connection paths provides multiple signal routes that improve immunity to conductive structure coupling while the modular nature keeps overall complexity manageable.
Data Source
AI summary
A direction finding antenna array comprises at least a first dipole antenna element 14, a second dipole antenna element 16 and a third dipole antenna element 18. The dipole elements comprise respective first ends 14.1, 16.1, 18.1, respective second ends 14.2, 16.2, 18.2 and a respective feed-point 14.3, 16.3, 18.3. The first, second and third dipole elements are arranged in spaced relationship relative to one another in a non-linear pattern. In respect of each dipole element in the array (and taking dipole element 14 as an example), the first end 14.1 is connected by first and second electrical connections 24, 26 to the first end of each of two adjacent dipole elements 16, 18 in the array and the second end 14.2 is connected by third and fourth electrical connections 28, 30 to the second end of each of the two adjacent dipole elements 16, 18.