Coplanar Coupled-Fed Multiband Antenna for Mobile Devices
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Solution Overview
Problem
Conventional planar inverted-F antennas face challenges in achieving dual-band operation for GSM850/900 frequencies with limited space, and existing designs often fail to cover the required frequency range for GSM850, GSM900, DCS, PCS, and UMTS operations effectively.
Innovation Solution
A coplanar coupled-fed multiband antenna design featuring a dielectric substrate, ground plane, radiating portion, shorting metal portion, and feeding portion, utilizing a dual-resonance characteristic and coplanar coupling feed to reduce inductive reactance and achieve wideband operation, allowing for GSM850/900 coverage while also supporting DCS, PCS, and UMTS frequencies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a conventional planar inverted-F antenna uses a single resonance path, then the antenna structure is simple, but it cannot achieve dual-band operation for GSM850/900 frequencies with limited space
Solution Approach 1:
The radiating element is divided into two separate metal portions (first and second metal portions), each resonating at 1/4-wavelength mode for different frequency bands. The first metal portion excites the upper band while the second metal portion excites the lower band, enabling dual-band operation through structural segmentation.
Solution Approach 2:
A coplanar coupling feed structure is introduced as an intermediary between the feeding portion and the radiating portion. This coupling feed reduces the inductive reactance of the antenna, enabling the lower band to achieve dual-resonance characteristic and cover both GSM850 and GSM900 operations.
2Adaptability or versatility
If the lower band antenna uses single resonance mode, then the antenna design is simple, but it cannot cover both GSM850 and GSM900 operations
Solution Approach 1:
The coplanar coupling feed changes the electrical parameters by reducing the inductive reactance of the antenna. This parameter change enables the lower band to achieve dual-resonance characteristic, transforming the antenna's resonant behavior to cover both GSM850 (824-894 MHz) and GSM900 (890-960 MHz) operations.
3Adaptability or versatility
If the antenna uses coplanar coupling feed to reduce inductive reactance, then the lower band achieves dual-resonance characteristic, but the impedance matching becomes more challenging
Solution Approach 1:
The patent employs iterative optimization of the coplanar coupling feed dimensions and positioning based on impedance matching requirements. By adjusting the coupling feed parameters and observing the resulting input impedance, the design achieves good impedance matching for both resonance frequencies in the lower band.
Solution Approach 2:
The antenna design allows for dynamic adjustment of the coplanar coupling feed structure to optimize performance across different frequency bands. The coupling feed can be tuned to achieve the desired reactance reduction and impedance matching for dual-band operation.
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 antenna effectively covers the required frequency bands with improved impedance matching and reduced inductive reactance, enabling efficient operation for GSM850/900, DCS, PCS, and UMTS systems while maintaining a simple and cost-effective fabrication process.
Implementation Method 1
the coplanar coupling feed to reduce the inductive reactance of the antenna, thereby the former single resonance mode in the lower band can achieve the dual-resonance characteristic
Implementation Method 2
reduce the inductive reactance of the antenna
Implementation Method 3
the radiating portion further comprises a first metal portion and a second metal portion which both resonate at the 1/4-wavelength mode
Data Source
AI summary
The present invention is related to a coplanar coupled-fed multiband antenna for the mobile communication device. The antenna mainly comprises a dielectric substrate, a ground plane located on one surface of the dielectric substrate, and a radiating portion, a shorting metal portion, and a feeding portion, which are all on the same surface of the dielectric substrate near one edge of the ground plane. One end of the shorting metal portion is connected to the radiating portion, and the other end is connected to the ground plane. The feeding portion comprises a first feeding metal portion and a second feeding metal portion. The first feeding metal portion has a feeding point for the antenna. One end of the second feeding metal portion is connected to the radiating portion, and there is a gap between the second feeding metal portion and the first feeding metal portion.