3D Antenna Element Layout for MIMO Isolation Without Isolators
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Solution Overview
Problem
Conventional vehicle-mounted antenna devices face challenges in ensuring isolation between multiple antenna elements without using expensive isolators, which affects cost and performance.
Innovation Solution
The antenna device employs a configuration where a first antenna element is positioned between two second antenna elements, arranged in a way that they are not adjacent to each other, with specific positional relationships and shapes to reduce correlation and ensure isolation without the need for isolators, utilizing a support structure to secure the second antenna elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If multiple antenna elements are arranged in a compact space, then the antenna device achieves miniaturization and multi-band functionality, but isolation between antenna elements deteriorates
Solution Approach 1:
The patent transitions from two-dimensional planar arrangement to three-dimensional spatial arrangement by positioning antenna elements at different heights and depths. The first antenna element is placed on the upper surface while second antenna elements are positioned in the lower space, utilizing vertical dimension to achieve both compactness and isolation.
Solution Approach 2:
The patent nests antenna elements within each other's spatial envelope. The first antenna element extends in the longitudinal direction while second antenna elements are positioned below it, creating a nested configuration where elements occupy different spatial layers rather than requiring separate planar areas.
2Volume of moving object
If antenna elements are positioned closer together, then the antenna device achieves compact design, but correlation between antenna elements increases
Solution Approach 1:
The patent resolves correlation issues by moving antenna elements into the third dimension. Instead of arranging elements side-by-side in the same plane, the first antenna element is positioned on the upper surface while second antenna elements are placed in the lower space, creating sufficient spatial separation to reduce correlation while maintaining compact overall dimensions.
3Reliability
If isolators are added to ensure isolation between antenna elements, then antenna performance is improved, but device cost and complexity increase
Solution Approach 1:
The patent extracts the isolation function from separate isolator components and integrates it into the spatial arrangement of antenna elements themselves. By positioning elements in three-dimensional space with sufficient separation, the isolation function is achieved through geometry rather than requiring additional isolator materials or components.
Solution Approach 2:
The antenna elements themselves provide the isolation function through their spatial arrangement. The first antenna element and second antenna elements are positioned such that their physical separation in three-dimensional space creates natural isolation, allowing the structure to serve its own isolation needs without external components.
Data Source
AI summary
An antenna device includes an antenna base having a longitudinal direction, a first antenna element on the antenna base, and a pair of second antenna elements on the antenna base, the pair of second antenna elements being capable of transmitting and receiving radio waves in a higher frequency band than the first antenna element. In a planar view, when the antenna base is divided into four regions by a first line segment along the longitudinal direction and a second line segment orthogonal to the first line segment intersecting each other at the center point of the first antenna element, a region where one of the pair of second antenna elements is located is not adjacent to a region where the other of the pair of second antenna elements is located.