Patch Antenna Metal-Body Layout for Better Low-Elevation Axial Ratio
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Solution Overview
Problem
The axial ratio of patch antennas degrades at low to high elevation angles due to their configuration, affecting their performance.
Innovation Solution
A patch antenna design featuring multiple metal bodies positioned above the radiation element, with distinct areas, improves the axial ratio by optimizing the distance and size of these metal bodies relative to the radiation element.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional patch antenna configuration is used, then the antenna structure is simple, but the axial ratio degrades at low to high elevation angles
Solution Approach 1:
The patent divides the ground plane into multiple separate metal bodies (first metal body, second metal body, third metal body) with different areas. This segmentation allows each metal body to contribute differently to the radiation pattern, improving the axial ratio across elevation angles while maintaining a manageable structural complexity.
Solution Approach 2:
Each metal body is assigned a specific area size (first area, second area, third area) that differs from the others. This local quality variation optimizes the current distribution and radiation characteristics at different elevation angles, thereby improving the overall axial ratio performance without requiring a completely complex antenna structure.
2Reliability
If multiple metal bodies with different areas are added to improve axial ratio, then the axial ratio improves, but the antenna size increases
Solution Approach 1:
The patent combines multiple metal bodies with different areas into a single integrated ground plane structure. This merging approach allows the antenna to achieve improved axial ratio performance through the composite effect of multiple areas while maintaining a compact overall footprint suitable for vehicular applications.
Solution Approach 2:
The patent utilizes the planar dimension of the ground plane to accommodate multiple metal bodies with different areas. By arranging these metal bodies in a two-dimensional configuration rather than extending in the vertical dimension, the antenna achieves improved axial ratio performance without significantly increasing the overall antenna size.
Data Source
AI summary
A patch antenna includes: a radiation element; and n (where n is a natural number of 2 or greater) metal bodies that are positioned above the radiation element, wherein an area of at least one of the n metal bodies is different from an area of any other metal body of the n metal bodies. Further, in the patch antenna, the n is 2 or 3, at least two of the n metal bodies are a first metal body and a second metal body, respectively, the first metal body is provided at a distance equal to or smaller than one-tenth of a wavelength in a desired frequency band, from the radiation element in a direction perpendicular to an upper surface of the radiation element, and the second metal body is arranged at position closest to the first metal body in the direction perpendicular to the upper surface of radiation element.