Dual-Band PCB MIMO Antenna Layout for Small-Form WLAN Isolation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Designing an on-board wireless local area network (WLAN) MIMO antenna system for ultra-small form factor devices like digital set-top boxes is challenging due to low internal space, high electromagnetic interference (EMI) from components, and blockages like TVs, leading to low antenna efficiency, high mutual coupling, and poor system throughput.
Innovation Solution
A custom-designed dual-band MIMO antenna system with strategically placed antennas at PCB corners, orthogonal orientations, a dual-band decoupler, and visual indicators to minimize EMI, optimizing antenna placement and isolation, and utilizing the PCB space efficiently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If antennas are placed in ultra-small form factor devices, then device size is reduced, but antenna efficiency and isolation deteriorate due to limited space and proximity to EMI components
Solution Approach 1:
The patent positions antennas at opposite corners of the PCB, utilizing the two-dimensional plane of the board to maximize separation between antenna elements. This corner placement strategy effectively uses the available PCB area to achieve optimal antenna spacing and isolation within the constrained ultra-small form factor device volume.
Solution Approach 2:
The patent implements a dual-band decoupler structure specifically positioned between the antenna elements to provide localized EMI filtering and signal isolation. This decoupler is strategically placed at the location where EMI from components like DDR, PCIe, and HDMI ports most significantly affects antenna performance, providing targeted protection without increasing overall device size.
2Productivity
If multiple WLAN antennas are placed in close proximity, then MIMO configuration is achieved, but mutual coupling and EMI from components like DDR, PCIe, and HDMI increase
Solution Approach 1:
The patent introduces a dual-band decoupler as an intermediary component positioned between the antenna elements and the EMI-generating components (DDR, PCIe, HDMI). This decoupler acts as a mediator that filters out harmful electromagnetic interference while allowing the MIMO antenna configuration to maintain high WLAN throughput and productivity.
Solution Approach 2:
The patent segments the device into distinct functional zones: EMI-sensitive antenna regions positioned at PCB corners, EMI-generating components (DDR, PCIe, HDMI) positioned away from corners, and a dual-band decoupler structure positioned between these regions. This spatial segmentation minimizes mutual coupling and EMI while maintaining MIMO performance.
3Ease of operation
If device is mounted behind a TV, then visual placement guidance is needed, but TV screen causes blockage to WLAN signal transmission
Solution Approach 1:
The patent incorporates visual indicators (such as colored markings or LED indicators) on the device housing to guide users on proper placement orientation when mounting behind a TV. These visual cues indicate the optimal orientation that minimizes signal blockage from the TV screen while ensuring the antenna elements are positioned to maximize WLAN reception and transmission.
Data Source
AI summary
A multiple-antenna device including a printed circuit board, a first antenna formed into a first corner of the printed circuit board, a second antenna formed into a second corner of the printed circuit board, and a dual-band decoupler formed in the printed circuit board between the first antenna and the second antenna. The multiple-antenna device includes WLAN circuitry located on the printed circuit board between the first antenna and the decoupler. The first and second antennas have polarizations orthogonal to each other.