Antenna Module With Nested Ground Portion For ISM Band Miniaturization
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Solution Overview
Problem
The existing antenna modules for the Industry-Science-Medical (ISM) band face challenges in miniaturization due to size limitations, particularly for frequencies like 2.4 GHz, where reducing size affects frequency deviation and resonant frequency requirements.
Innovation Solution
A small-sized antenna module design featuring a ground portion with a lower and upper ground plane, a dielectric layer, and an antenna portion with a patch layer and antenna layer that includes a Hilbert curve structure, allowing for capacitive coupling and inductive loading, which facilitates frequency variation and efficient radiation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the antenna length is reduced to miniaturize the antenna module, then the size is reduced, but the resonant frequency requirement for 2.4 GHz ISM band cannot be secured
Solution Approach 1:
The patent implements a nested structure where the antenna layer is placed within the ground portion, specifically positioning the antenna layer inside the cavity formed by the lower ground plane and upper ground plane. This nested arrangement allows the antenna to achieve the required electrical length for 2.4 GHz resonance while being compactly housed within a small module volume, resolving the contradiction between miniaturization and resonant frequency requirements.
Solution Approach 2:
The patent transitions from a planar two-dimensional antenna layout to a three-dimensional structure by stacking the antenna layer within the ground portion cavity. This vertical dimensionality change enables the antenna to achieve the necessary electrical length for resonance without increasing the horizontal footprint, thus miniaturizing the overall module while maintaining frequency stability.
2Volume of moving object
If the antenna size is reduced using bottom surface utilization, then the size is reduced to 20 mm by 11 mm, but frequency deviation is influenced by permittivity
Solution Approach 1:
The patent applies local quality by creating a dedicated cavity structure within the ground portion that provides a controlled electromagnetic environment for the antenna layer. This localized structural modification isolates the antenna from external permittivity variations, maintaining frequency stability while achieving compact dimensions through efficient space utilization.
Solution Approach 2:
The patent employs a composite structure combining the antenna layer with the ground portion cavity and dielectric layers. This composite design integrates multiple functional elements that work together to maintain resonant frequency stability while achieving miniaturization, overcoming the frequency deviation issues associated with simple bottom-surface utilization designs.
3Reliability
If a wiring space for antenna length corresponding to wavelength of λ/4 is secured, then resonant frequency for 2.4 GHz is achieved, but the antenna size cannot be reduced further
Solution Approach 1:
The patent places the antenna layer inside the ground portion cavity, nesting the radiating element within the ground structure. This allows the antenna to achieve the required λ/4 electrical length for 2.4 GHz resonance while the overall module size is reduced because the antenna is integrated within the existing ground structure rather than occupying separate space.
Solution Approach 2:
The patent utilizes the vertical dimension by stacking the antenna layer within the ground portion cavity depth. This three-dimensional arrangement allows the antenna to achieve the necessary electrical length for resonance without increasing the horizontal dimensions, thus reducing the overall module size while maintaining frequency performance.
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 a compact size while maintaining high radiation efficiency and frequency stability, with S11 reflectivity of -25 dB or less and omnidirectional radiation patterns, suitable for the ISM band.
Implementation Method 1
The ground portion may be coupled to the antenna portion by capacitive coupling.
Implementation Method 2
An inductive loading may be caused by the antenna layer.
Data Source
AI summary
An antenna module is provided. The antenna module according to one embodiment of the present invention includes a ground portion which has a lower ground plane, a dielectric layer disposed on the lower ground plane, and an upper ground plane disposed on the dielectric layer, and an antenna portion disposed at an adjoining surface of the ground portion and configured to have a patch layer, a dielectric layer disposed on the patch layer, and an antenna layer disposed on the dielectric layer, and having a plurality of unit patterns which continuously repeat.