Broadband Circular Polarized Patch Antenna Using Rotated Rod Layers
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Solution Overview
Problem
Existing patch antennas struggle to achieve broadband circular polarization over a wide range of frequencies while maintaining a low axial ratio, as current methods only provide circular polarization over a narrow frequency range.
Innovation Solution
The solution involves a substrate with a conductive ground plane and an emitter, where at least one coupling layer with low dielectric constant spacers and high dielectric constant rods is positioned above the emitter, with successive layers rotated at a calculated angle to enhance circular polarization, improving impedance bandwidth and axial ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If corner trimming and diagonal feed arrangement are used to achieve circular polarization, then circular polarization is obtained, but the bandwidth is narrow
Solution Approach 1:
The patent divides the patch antenna into multiple independent resonant sections by introducing rectangular slots that segment the continuous patch structure. This segmentation creates multiple resonant frequencies that can be tuned to provide broadband circular polarization, resolving the contradiction between achieving circular polarization and maintaining wide bandwidth.
Solution Approach 2:
The patent employs asymmetric slot configurations and non-uniform feed point positioning to create the necessary phase quadrature between orthogonal modes. The asymmetric geometry of the slots and their strategic placement break the symmetry of the traditional patch, enabling circular polarization while the segmented structure provides broadband operation.
2Adaptability or versatility
If broadband operation is achieved through conventional means, then frequency range is extended, but axial ratio performance degrades
Solution Approach 1:
The patent applies different geometric characteristics to different regions of the patch antenna. The rectangular slots are strategically positioned and dimensioned to create local resonant effects that maintain circular polarization quality across the broad frequency range. Each slot's local geometry is optimized to contribute to both bandwidth expansion and axial ratio maintenance.
Solution Approach 2:
The patent utilizes parameter optimization of the rectangular slots (dimensions, positions, orientations) to simultaneously achieve broadband operation and maintain axial ratio performance. By carefully adjusting these geometric parameters, the antenna maintains circular polarization quality across an extended frequency range rather than degrading as bandwidth increases.
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 approach significantly increases the bandwidth and preserves the axial ratio of the antenna, allowing for broader frequency operation without degrading the circular polarization quality, making it suitable for retrofitting existing antennas.
Implementation Method 1
The coupling layer includes a low dielectric constant spacer and one layer of high dielectric constant rods
Data Source
AI summary
An antenna for connection to a feed includes a substrate with a conductive ground plane. An emitter is positioned on the top face of the substrate, and the feed is connected to the emitter and ground plane. A spacer is positioned on the substrate above the emitter and one layer of high dielectric constant rods is positioned above the spacer. The rods are positioned in a single plane, coplanar with the emitter, and parallel to the dominant current distribution when the emitter is active. Further layers of spacers and rods can be positioned at a predetermined angle to the rods beneath. A kit is further provided for application of spacers and rods to preexisting antennas.