Coupled Antenna with Nested Radiators for Metal Housing
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Solution Overview
Problem
Metallic enclosures in radio devices act as RF shields, degrading antenna performance, especially when operating in multiple frequency bands, making it challenging to achieve effective RF antenna implementations.
Innovation Solution
A coupled antenna apparatus with a conductive ring-like structure and separate radiator elements, including an outer radiator element with protruding conductive portions, is designed to optimize operating parameters and improve antenna performance within metal housings, using capacitive feeding methods to achieve resonance across desired frequency bands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If a metal housing is used for aesthetic benefits, then the appearance and feel of the device are improved, but the metal housing acts as an RF shield that degrades antenna performance
Solution Approach 1:
The antenna system is divided into multiple separate radiator elements (first radiator element, second radiator element, third radiator element) that can be independently configured and tuned. This segmentation allows each element to be optimized for specific frequency bands while collectively providing multi-band operation capability, resolving the conflict between metal housing aesthetics and antenna performance.
Solution Approach 2:
The patent implements a nested antenna structure where the first radiator element is disposed within the metal housing, the second radiator element is disposed within a cavity formed by the first radiator element, and the third radiator element is disposed within a cavity formed by the second radiator element. This nested configuration allows multiple antenna elements to coexist in a compact space while maintaining their individual radiation characteristics, enabling multi-band operation without compromising the metal housing's aesthetic appearance.
2Device complexity
If typical prior art antenna solutions are used, then the antenna structure is simple, but the antenna performance is inadequate for use with metallic housings and external metallic surfaces
Solution Approach 1:
The patent introduces an intermediary coupling mechanism between the radiator elements and the metal housing. The first radiator element is capacitively coupled to the metal housing, which serves as an intermediary structure that enables RF signal transmission through the metal housing without requiring direct galvanic connection. This intermediary approach allows the antenna system to achieve good performance with metallic housings while maintaining a relatively simple overall structure.
Solution Approach 2:
The patent transitions from traditional planar antenna designs to a three-dimensional nested structure. The radiator elements are arranged in multiple spatial dimensions with varying orientations and positions, creating a volumetric antenna system. This dimensional change allows the antenna to achieve superior performance in metallic housing environments by utilizing spatial diversity and three-dimensional radiation patterns, while the nested configuration keeps the overall device footprint compact.
3Adaptability or versatility
If the antenna is required to operate in several frequency bands, then the versatility of the device is improved, but the metal housing degrades antenna performance across these bands
Solution Approach 1:
Each radiator element is designed with specific local characteristics optimized for particular frequency bands. The first radiator element has a first resonant frequency, the second radiator element has a second resonant frequency, and the third radiator element has a third resonant frequency. By assigning different local qualities (resonant frequencies, geometries, and configurations) to each element, the system achieves broad multi-band coverage while minimizing signal loss in each specific band, overcoming the RF shielding effect of the metal housing.
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 solution enhances antenna efficiency, bandwidth, and polarization performance, allowing for effective operation across multiple frequency bands, including GPS and GLONASS, while minimizing signal loss and interference from metallic enclosures.
Implementation Method 1
using capacitive feeding methods to achieve resonance across desired frequency bands
Implementation Method 2
achieve resonance across desired frequency bands
Data Source
AI summary
The invention concerns an electronic device for personal use and a coupled antenna apparatus for such a device, comprising a top cover and a housing with an opposing back cover configured to form a closed space between said top and back cover that is adapted to receive electronic circuitry and a display unit. A bezel made of a conductive material is forming a rim on top of said housing and is interfacing with the top cover. According to the invention, an elongate strip of a conductive material deposited on a first side of an elongate antenna feed element and is forming a first radiating element and a second elongate strip of a conductive material deposited on a second side of the antenna feed element is forming a second radiating element, whereby the first and second radiating elements are positioned in proximity against the bezel at at least one inner wall portion of the bezel that extends in a direction between the first and second radiating elements and the display unit. The first and second radiating elements are functionally coupled to said bezel to form an antenna system of said electronic device.