Loop Antenna with Segmented Portions for Thin Devices
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Designing low-profile multi-band antenna elements for thin mobile communication devices that can efficiently cover various frequency bands while maintaining a compact form factor is a significant challenge.
Innovation Solution
A communication device with a metal antenna element forming a loop structure and having a gap between its open ends, which extends along the edge of a ground element, featuring a feeding point and two portions of different lengths to achieve reduced height and effective radiation in both vertically and horizontally polarized waves, and utilizing a matching circuit for impedance matching and radiation efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the antenna element uses a conventional full-loop structure to ensure good radiation performance, then the radiation efficiency is improved, but the height of the antenna element increases making it unsuitable for thin devices
Solution Approach 1:
The antenna element is segmented into a first portion and a second portion with different lengths (0.1-0.4 times ratio), where the first portion primarily contributes to vertical polarization and the second portion to horizontal polarization. This segmentation allows each segment to be optimized for specific polarization directions while maintaining overall compact dimensions suitable for thin devices.
Solution Approach 2:
Different portions of the antenna element are designed with different local characteristics - the first portion has optimized geometry for vertical polarization radiation, while the second portion is configured for horizontal polarization. This local quality differentiation enables multi-polarization capability without requiring a larger overall structure.
2Adaptability or versatility
If the antenna element is designed to support multiple frequency bands with adequate bandwidth, then the adaptability is improved, but the device complexity increases
Solution Approach 1:
The antenna element achieves multi-band coverage (704-960 MHz, 1710-2690 MHz) through a unified planar structure with two portions of different lengths. The first portion resonates at lower frequencies while the second portion resonates at higher frequencies, allowing a single antenna structure to serve multiple frequency bands without requiring separate antennas for each band.
Solution Approach 2:
The antenna element uses parameter variation in the form of two portions with different length ratios (0.1-0.4 times) to achieve frequency multiplication. By changing the electrical length of different segments, the antenna can resonate at multiple frequency bands while maintaining a compact physical size, avoiding the need for complex multi-element arrays.
3Ease of operation
If the antenna element uses a larger area to achieve better impedance matching, then the ease of operation is improved, but the area occupied increases reducing space for other components
Solution Approach 1:
The antenna element transitions from traditional planar ground-plane-based impedance matching to a three-dimensional spatial configuration where the two portions extend in different directions from the feeding point. This dimensional approach allows effective impedance matching across multiple bands by utilizing spatial distribution rather than increasing two-dimensional area, thereby saving space for other device components.
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 enables a low-profile, multi-band antenna element that efficiently covers frequencies from 704 MHz to 2690 MHz with improved radiation efficiency and impedance matching, suitable for thin mobile devices like smartphones and tablets.
Implementation Method 1
the excited surface currents of the antenna element has two components which are substantially perpendicular to each other, and hence the vertically-polarized radiation fields of the antenna element is substantially equal to the horizontally-polarized radiation fields thereof
Implementation Method 2
the first portion of the metal element is excited to generate a first resonant mode in the first band, and the second portion of the metal element is excited to generate a second resonant mode in the second band
Data Source
AI summary
A communication device including a ground element and an antenna element is provided. The antenna element includes a metal element. The metal element has a plurality of bends and substantially forms a loop structure with a gap. The gap is between a first open end and a second open end of the metal element. The metal element extends along an edge of the ground element and does not overlap with the ground element. The antenna element has a feeding point. A first portion of the metal element is between the feeding point and the first open end, and a second portion of the metal element is between the feeding point and the second open end. The feeding point, the first open end, and the second open end are all facing or adjacent to the edge of the ground element.