Patch Antenna Layout for Circular Polarization Stability
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Solution Overview
Problem
The arrangement of capacitance loading elements above patch antennas in antenna devices leads to decreased reception performance for circularly polarized waves from broadcast or communication satellites due to increased axial ratio and reduced average gain.
Innovation Solution
The capacitance loading elements are arranged separately in a predetermined direction, with equal electrical lengths in the predetermined and orthogonal directions, and connected by a high-impedance filter, or feature slit-like cutouts to reduce electromagnetic interference and maintain performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the capacitance loading element is arranged above the patch antenna to reduce device size, then the antenna device achieves compact dimensions, but the axial ratio increases and reception performance for circularly polarized waves decreases
Solution Approach 1:
The capacitance loading element is divided into multiple separate capacitance loading elements arranged in the vertical direction. This segmentation reduces the axial ratio increase caused by the loading element while maintaining the compact form factor, thereby resolving the contradiction between device size and reception performance.
Solution Approach 2:
The capacitance loading elements are arranged in the vertical dimension above the patch antenna rather than expanding the antenna footprint horizontally. This dimensional arrangement allows compact device size while controlling the impact on axial ratio and reception performance through proper vertical spacing and configuration.
2Device complexity
If the capacitance loading element is placed above the patch antenna, then the antenna structure is simplified and down-sized, but the average gain decreases
Solution Approach 1:
Dividing the capacitance loading element into multiple smaller elements reduces their individual and collective impact on the patch antenna's radiation pattern and gain characteristics, while still achieving the desired size reduction and structural simplification.
3Volume of moving object
If the capacitance loading element is arranged above the patch antenna, then compact integration is achieved, but transmission and reception of circularly polarized waves is adversely affected
Solution Approach 1:
The segmented capacitance loading elements are configured with specific spacing and orientations that minimize their interference with circularly polarized wave transmission and reception, allowing compact integration while maintaining operational effectiveness.
Solution Approach 2:
The multiple capacitance loading elements are arranged with asymmetric positioning and orientations relative to the patch antenna, which helps cancel out their detrimental effects on circular polarization while maintaining compact dimensions.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration allows for satisfactory transmission and reception of circularly polarized waves by the patch antenna, reducing axial ratio and maintaining average gain, even with the presence of capacitance loading elements above the patch antenna.
Implementation Method 1
a capacitance loading element 40 and a helical element (coil) 70... The capacitance loading element 40 is, for example, a conductive metal plate
Implementation Method 2
an antenna 30 for AM/FM broadcast reception serving as a second antenna including a capacitance loading element 40 and a helical element (coil) 70
Data Source
AI summary
An antenna device includes a patch antenna serving as a first antenna; and a second antenna including capacitance loading elements, the capacitance loading elements being located above the patch antenna and also arranged separately in a predetermined direction. Also, an antenna device includes a patch antenna serving as a first antenna; and a second antenna including capacitance loading elements, the capacitance loading elements being located above the patch antenna, and a slit-like cutout part in a predetermined direction being formed in at least one of side edges of the capacitance loading elements.