Patch Antenna Impedance Control via Electromagnetic Shield
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Solution Overview
Problem
Conventional patch antennas are limited by feedline configurations that introduce reactance and radiation effects, reducing bandwidth and performance, particularly when patch elements are closer to the ground plane.
Innovation Solution
A patch antenna design incorporating a ground plane, feedline, and electromagnetic shield, where the feedline is routed through openings in the ground plane and electrically coupled to a coaxial cable with a center and outer conductor, allowing for controlled impedance and reduced deleterious effects of conventional feedline configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If patch elements are spaced closer to the ground plane, then the quality factor (Q) increases, but the bandwidth decreases
Solution Approach 1:
A coaxial feed structure is introduced as an intermediary between the patch element and conventional feedline configurations. The coaxial feed includes a center conductor connected to the patch element and an outer conductor that extends to the ground plane, creating a controlled impedance transmission path that maintains high Q-factor while expanding bandwidth by eliminating conventional feedline reactance effects
2Device complexity
If conventional feedline configurations are used, then the antenna structure is simple, but reactance and radiation effects limit performance and bandwidth
Solution Approach 1:
The harmful reactance and radiation effects are extracted and eliminated by replacing conventional feedline configurations with a coaxial feed structure. The outer conductor of the coaxial feed is extended to connect to the ground plane, effectively removing the problematic feedline section that causes performance degradation while maintaining structural simplicity
3Ease of manufacture
If feedline configurations introduce reactance effects, then impedance control becomes difficult, but the antenna can still be manufactured easily
Solution Approach 1:
The impedance control parameter is optimized by changing the feedline configuration to a coaxial structure with extended outer conductor connection to the ground plane. This parameter change provides inherent impedance control through the coaxial geometry, making impedance management more precise while maintaining ease of manufacture through standard coaxial cable and ground plane integration
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 maintains a wide frequency bandwidth and reduces impedance variations, enabling a low-profile, lightweight antenna with improved performance by minimizing reactance and radiation effects while maintaining a good Voltage Standing Wave Ratio (VSWR).
Implementation Method 1
The electromagnetic shield extends, at least partially, between the ground plane and the patch element and is electrically coupled to the ground plane. The electromagnetic shield is configured to control an impedance associated with the feedline between the ground plane and the patch element.
Implementation Method 2
The feedline guides the electromagnetic signal and extends through an opening in the ground plane and to the patch element. The feedline is electrically coupled to the patch element to guide an electromagnetic signal to or from the patch element.
Data Source
AI summary
Embodiments of the present invention include a patch antenna having a patch element, a ground plane, a feedline, and an electromagnetic shield. The patch element transmitting and/or receives electromagnetic signals. The ground plane is spaced at a specified distance from the patch element. The feedline guides the electromagnetic signal and extends through an opening in the ground plane and to the patch element. The feedline is electrically coupled to the patch element to guide an electromagnetic signal to or from the patch element. The electromagnetic shield extends, at least partially, between the ground plane and the patch element and is electrically coupled to the ground plane. The electromagnetic shield is configured to control an impedance associated with the feedline between the ground plane and the patch element.