Coplanar RFID Patch Antenna with Floating Grounds
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Solution Overview
Problem
Traditional patch antennas for UHF RFID applications face challenges in achieving uniform UHF signal emission without null zones and require multiple layers, leading to increased thickness and fabrication costs, which complicates installation and aesthetics in smart shelving and similar applications.
Innovation Solution
A low-cost, low-thickness patch antenna design with the radiating element and reference ground in the same geometric plane, utilizing floating ground conductors to enhance bandwidth and radiation efficiency, allowing for even field distribution and simplified feed cable attachment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional multi-layer patch antenna design is used, then antenna gain and bandwidth can be improved, but antenna thickness and fabrication complexity increase
Solution Approach 1:
The patent merges the radiating element and reference ground into the same geometric plane, eliminating the need for separate layers. This coplanar integration maintains antenna gain while reducing thickness by consolidating functions that traditionally required multiple layers into a single planar structure.
Solution Approach 2:
The patent transitions from a multi-layer three-dimensional structure to a coplanar two-dimensional structure. By redistributing antenna functions across the planar dimension rather than stacking layers, the design achieves comparable performance with reduced thickness.
2Reliability
If traditional multi-layer patch antenna design is used, then antenna performance can be improved, but fabrication cost and complexity increase
Solution Approach 1:
The coplanar design combines multiple antenna functions into a single planar structure, reducing the number of fabrication layers and steps. This integration simplifies the manufacturing process while maintaining the bandwidth performance through optimized in-plane geometry.
Solution Approach 2:
The patent optimizes geometric parameters within the coplanar structure, such as the arrangement and dimensions of radiating elements and ground patterns, to achieve desired bandwidth characteristics without requiring additional layers or complex fabrication processes.
3Length of stationary object
If coplanar reference ground design is used, then antenna thickness is reduced, but uniform signal emission without null zones becomes more difficult to achieve
Solution Approach 1:
The patent applies local quality optimization by strategically positioning floating ground conductors and adjusting the geometry of radiating elements at specific locations within the coplanar structure. This localized optimization ensures uniform signal emission across the radiation pattern while maintaining the thin profile.
Solution Approach 2:
The floating ground conductors serve as intermediary elements that mediate between the radiating elements and the reference ground. These intermediate structures help distribute the electromagnetic field uniformly in the radiation zone, eliminating null zones while preserving the coplanar thin design.
4Reliability
If floating ground conductors are added, then bandwidth and radiation efficiency are enhanced, but device complexity increases
Solution Approach 1:
The floating ground conductors are integrated into the same coplanar structure as the radiating elements, merging the grounding function with the radiating structure rather than requiring separate grounding layers. This integration enhances radiation efficiency while minimizing the increase in overall structural complexity.
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
The design achieves superior antenna gain, bandwidth, and tuning robustness, providing a uniform UHF emission zone above the antenna surface, reducing dead zones, and allowing for thinner, more cost-effective antennas that can read RFID tags with improved spatial resolution and orientation independence.
Implementation Method 1
a low-cost, low thickness, compact, wideband patch antenna with radiating element and reference ground conductor in the same geometric plane or closely spaced parallel planes
Implementation Method 2
including floating ground conductors in the same geometric plane or closely spaced parallel planes
Data Source
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AI summary
The invention describes an antenna in which the main radiating element (110) is placed in a common geometric plane, or substantially the same plane, with the reference ground element (120), or in which the main radiative element and reference ground element are placed in two parallel, closely spaced planes separated by a dialectric laminate (100), with little or no overlap between the main radiative element and the reference ground element. A floating ground plane, or planes (130) may be implemented in addition to the reference ground element.