Stacked Patch Antenna Structure for Lower-Frequency Operation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current stacked patch antenna designs are limited in achieving lower frequency operation without increasing the antenna size, as the resonant frequency of the lower patch element is constrained by the dimensions of the ground plane metallization on the upper patch element, limiting the independence of resonant frequencies and requiring larger antenna dimensions for lower frequency performance.
Innovation Solution
Incorporating a dielectric spacer with a lower dielectric constant between the upper and lower patch antenna elements, allowing the castellated periphery of the lower patch antenna to extend under the upper patch, decoupling the microwave signals and enabling the lower patch antenna to operate at lower frequencies without increasing the antenna size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the ground plane metallization on the upper patch element is reduced in size to allow lower frequency operation of the lower patch, then the resonant frequency of the lower patch can be reduced, but the ground plane becomes too small to provide adequate grounding and signal reference
Solution Approach 1:
The invention extends the ground plane metallization vertically into the third dimension by having it pass through the upper patch element's dielectric substrate and extend below the upper patch. This allows the ground plane to provide adequate grounding area for the lower patch's lower frequency operation while not being constrained by the upper patch's footprint, thus resolving the contradiction between achieving lower resonant frequency and maintaining reliable grounding.
2Measurement precision
If the antenna size is increased to achieve lower frequency operation of the lower patch, then the resonant frequency can be reduced, but the overall antenna footprint and volume increase
Solution Approach 1:
The invention utilizes the vertical dimension by extending the ground plane below the upper patch element and employing a spacer to position the lower patch at an optimized distance. This three-dimensional configuration allows the lower patch to achieve lower resonant frequencies through increased electrical path length and adjusted coupling, without requiring an increase in the horizontal footprint of the antenna.
3Reliability
If the ground plane metallization on the upper patch is made large to provide good grounding, then the grounding quality improves, but the castellated periphery of the lower patch cannot extend under the upper patch to achieve lower resonant frequencies
Solution Approach 1:
The invention resolves this contradiction by extending the ground plane metallization into the vertical dimension, allowing it to pass through the upper patch's dielectric substrate and provide adequate grounding area below the upper patch. This enables the castellated periphery of the lower patch to extend horizontally beyond the upper patch's footprint and couple with the extended ground plane, achieving both good grounding quality and lower resonant frequencies through the combined three-dimensional configuration.
4Adaptability or versatility
If the distance between the upper and lower patch elements is increased to reduce coupling and allow independent frequency operation, then the frequency independence improves, but the overall antenna height and volume increase
Solution Approach 1:
The invention employs a spacer with a specific dielectric constant and thickness to precisely control the coupling between the upper and lower patch elements. By selecting appropriate spacer material properties and dimensions, the invention optimizes the distance to achieve sufficient frequency independence for separate operation while minimizing the overall antenna volume. The extended ground plane configuration also contributes to frequency independence through improved grounding, allowing for compact spacing.
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 lower frequency operation of the lower patch antenna while maintaining the same footprint, reducing the size of the antenna and enhancing frequency flexibility without compromising the independence of resonant frequencies.
Implementation Method 1
Incorporating a dielectric spacer with a lower dielectric constant between the upper and lower patch antenna elements, allowing the castellated periphery of the lower patch antenna to extend under the upper patch, decoupling the microwave signals
Implementation Method 2
Patch antenna elements are typically square or circular blocks of very low loss dielectric material having a first lower surface fully metalized so as to provide a ground plane, and a second upper surface at least partially metalized, so as to provide a resonant cavity within the dielectric block
Implementation Method 3
The element provides for reception or transmission of signals at frequencies at or close to the resonant frequency of the cavity by virtue of fringing fields between the resonant metallization and the ground metallization at the perimeter of the patch antenna element
Implementation Method 4
For stacked patch structures wherein the electrical feed pins are connected to the upper surface metallization of the upper patch antenna element only, coupling to the lower patch antenna element is achieved through near field electromagnetic coupling of the two patch antenna elements
Data Source
AI summary
A stacked patch antenna comprises two or more patch antennas physically disposed in a stack to provide a multi-frequency or broad band antenna. However, independence of the resonant response frequencies of the lower and upper patches of each stacked patch antenna pair ground requires metallization dimensions for the upper patch's lower surface be contained within the perimeter of the lower patch's resonant metallization. Accordingly, composite stacked patch element dimensions are limited by the desired resonant frequency of the lower patch. The inventors have established an alternate physical structure where the resonant patch geometry of the lower patch element's upper metallization is not limited by the lower surface ground plane metallization of the first upper patch element. The inventors have also established design solutions allowing the lower frequency performance of the first, lower patch within a stacked patch antenna to be lowered without compromising footprint of the resulting antenna.