Multilayer Loop Antenna Structure for Broadband Mobile Devices
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Solution Overview
Problem
Designing an antenna structure for ultra-thin mobile communication devices that effectively utilizes the multilayer circuit board to cover a broad range of frequency bands while minimizing space and near-field electromagnetic fields, as traditional printed antennas fail to efficiently leverage the multilayer structure and often require significant clearance.
Innovation Solution
A printed antenna structure with a loop design on the multilayer circuit board, where the loop structure increases surface currents for improved impedance matching and bandwidth, reduces near-field electromagnetic fields, and allows for integration with an adjacent ground plane, thereby reducing the required clearance area and optimizing space usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a traditional printed antenna is used, then the antenna can be applied to ultra-thin devices, but it cannot effectively use the multilayered structure to cover broad range of multiple bands
Solution Approach 1:
The patent transitions from a traditional planar printed antenna to a three-dimensional folded loop antenna structure that extends across multiple layers of the circuit board. The antenna utilizes conductive traces on different layers connected through vias to form a folded loop configuration, effectively using the vertical dimension and multilayer structure to achieve broad band coverage while maintaining a thin overall profile.
Solution Approach 2:
The folded loop antenna is nested within the multilayer circuit board structure, with the antenna traces embedded in internal layers and connected through vias. This nesting approach allows the antenna to be integrated within the device thickness while utilizing the available space in multiple layers to create a compact yet electrically large structure for multiband operation.
2Area of stationary object
If the antenna structure is printed on the circuit board, then space is saved, but near-field electromagnetic fields require significant clearance area
Solution Approach 1:
The patent strategically positions the folded loop antenna structure and its associated ground planes to convert the near-field electromagnetic fields from a harmful factor into a beneficial one. By carefully designing the ground plane configuration and antenna positioning, the near-fields are contained and utilized to improve impedance matching and bandwidth, while the overall clearance area required is reduced compared to traditional antenna designs.
3Adaptability or versatility
If more functions are added to mobile communication devices, then device functionality increases, but available space for antennas decreases
Solution Approach 1:
The folded loop antenna structure is designed to provide multiband coverage, enabling a single antenna to support multiple communication functions and frequency bands. This multi-functionality allows the device to accommodate various communication standards (e.g., GSM, WCDMA, LTE) without requiring separate antennas for each band, thereby saving space while maintaining comprehensive functionality.
Data Source
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AI summary
A communication device including a multilayer circuit board and an antenna structure therein is provided. The multilayer circuit board has at least a first plane, a second plane, and a third plane. A ground plane is disposed on one of the planes, and the ground plane is in proximity to a clearance region of the multilayer circuit board. An antenna structure is disposed in the clearance region. The antenna structure includes a first metal portion and a second metal portion. The first metal portion is coupled to a signal source through a feeding portion. The second metal portion includes at least a first line segment and a second line segment. The first line segment and the second line segment are disposed respectively on any two planes of the multilayer circuit board. The first metal line and the second metal line forms a loop structure through two conductive vias.