Capacitively Coupled Patch Antenna for GNSS
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing patch antennas are inadequate for receiving multiple constellation GNSS signals due to poor axial ratio and cross-polarization interference, especially in urban environments, and the dual feed architecture is not feasible on small high dielectric substrates without increasing cost and size.
Innovation Solution
A patch antenna configuration with capacitively coupled feed pins that provide a controlled impedance and phase shift, allowing for a compact dual feed structure with improved isolation and bandwidth, using a dielectric substrate sandwiched between a resonant metal plate and a ground plane, and employing an integrated matching network to achieve a 50 ohm impedance without external components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a dual feed architecture is used to improve axial ratio and cross-polarization rejection, then positioning accuracy and signal reception quality improve, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent combines two feed structures into a single integrated dual feed architecture where two feed pins share common grounding and support structures. This merging approach achieves the performance benefits of dual feed (improved axial ratio and cross-polarization rejection) while reducing overall device complexity compared to implementing two separate single feed antennas.
2Manufacturing precision
If external matching components are added to achieve controlled impedance, then impedance matching accuracy improves, but device size and complexity increase
Solution Approach 1:
The antenna structure performs its own impedance matching function through the inherent capacitive coupling between the feed pins and the resonant cavity. The feed pins are positioned to create appropriate capacitive reactance, eliminating the need for external matching components such as capacitors or inductors. This self-service approach achieves precise impedance control while maintaining a compact form factor.
3Ease of manufacture
If feed pins are physically connected to the resonant plate, then electrical connection is simpler, but isolation between feeds and control over capacitive coupling is reduced
Solution Approach 1:
The patent introduces capacitive coupling as an intermediary mechanism between the feed pins and the resonant cavity. Instead of direct physical connection, the feed pins couple to the cavity through controlled capacitive reactance. This intermediary approach provides precise control over the electrical connection characteristics while maintaining manufacturing feasibility through standardized feed pin configurations.
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 enhances the rejection of cross-polarized signals, improves positioning accuracy, and allows for the reception of multiple constellation signals over an extended bandwidth, reducing the need for additional matching components and maintaining a compact size.
Implementation Method 1
The patch is electromagnetically coupled to free space by the fringing fields between the resonant metal plate (10) and ground plane (11)
Implementation Method 2
This structure constitutes two orthogonal high-Q resonant cavities, one along a first major axis (5) and another along the second major axis (6) of the patch
Implementation Method 3
the resonant metal plate is capacitively coupled to each of the two feed pins by a capacitive reactance between the resonant metal plate and each of the two feed pins
Implementation Method 4
a first major surface is metalized as a ground plane (2), and a resonant metal plate is metalized on the second major surface (3)
Data Source
AI summary
Systems and methods relating to patch antennas. A patch antenna has a substrate, a resonant metal plate at one side of the substrate, and a ground plane at the other opposite side of the substrate. Two feed pins are used to couple the antenna to other circuitry. The feed pins pass through the substrate and holes in at the ground plane. The feed pins are physically disconnected from both the resonant metal plate and the ground plane. The feed pins are capacitively coupled to the resonant metal plate to provide an electronic connection between other circuitry and the patch antenna.