Dual-Antenna Portable Device Radiation Pattern Control
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Solution Overview
Problem
Portable wireless communication device antennas often have radiation patterns that point towards the terrain, particularly in certain operating positions, leading to degraded communication performance and increased infrastructure costs due to the need for denser antenna tower deployments to maintain reliable RF coverage.
Innovation Solution
A portable wireless communication device with a dual-antenna configuration, where a first antenna element is located at the top and a second antenna element at the bottom, electrically coupled via an RF transmission line, allowing for controlled radiation patterns by adjusting the relative magnitude and phase differences of the RF signals fed to each antenna to optimize gain directions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If a quarter-wavelength monopole antenna is used in a portable wireless communication device, then the physical size of the antenna is reduced, but the radiation pattern points towards the terrain which degrades communication performance
Solution Approach 1:
The antenna system is divided into multiple antenna elements (first antenna element and second antenna element) positioned at different locations on the device. This segmentation allows each element to contribute to the overall radiation pattern, enabling the system to achieve horizon-oriented gain while maintaining a compact form factor suitable for portable devices.
Solution Approach 2:
Multiple antenna elements are combined to form a collaborative radiation system. The first antenna element and second antenna element work together with their respective feed networks to produce a composite radiation pattern that achieves median azimuth gain towards the horizon, resolving the contradiction between compact size and communication performance.
2Reliability
If a half-wavelength monopole antenna is used to improve gain towards the horizon, then the communication performance is improved, but the antenna becomes twice as physically long which is less convenient
Solution Approach 1:
Instead of using a single long half-wavelength antenna, the system segments the radiating function across multiple shorter antenna elements. The first antenna element and second antenna element are each positioned and fed to collectively achieve the radiation characteristics of a longer antenna while maintaining a compact overall device form factor.
Solution Approach 2:
The antenna elements are arranged in a spatial configuration that utilizes different dimensions and positions on the device housing. By strategically positioning elements and controlling their phase relationships through the feed networks, the system achieves horizon-oriented radiation patterns without requiring increased antenna length in any single dimension.
3Device complexity
If the radiation pattern points towards the terrain, then the antenna structure is simple, but the communication performance degrades requiring denser infrastructure deployment
Solution Approach 1:
The antenna system incorporates dynamic control through independent feed networks that can adjust the phase and amplitude of signals to each antenna element. This dynamic capability allows the system to adaptively control the radiation pattern to achieve median azimuth gain towards the horizon, improving communication performance without significantly increasing structural complexity.
Solution Approach 2:
The system changes the radiation pattern parameters by controlling the phase and amplitude relationships between multiple antenna elements through the feed networks. By adjusting these parameters, the radiation pattern is transformed from terrain-oriented to horizon-oriented, achieving better communication performance while maintaining a relatively simple antenna structure.
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
This configuration enhances median azimuth gain by up to 3 dB compared to standard quarter-wavelength antennas without requiring longer half-wavelength antennas, improving communication performance and reducing infrastructure costs by optimizing radiation patterns towards the horizon.
Implementation Method 1
A portable wireless communication device with a dual-antenna configuration, where a first antenna element is located at the top and a second antenna element at the bottom, electrically coupled via an RF transmission line, allowing for controlled radiation patterns by adjusting the relative magnitude and phase differences of the RF signals fed to each antenna to optimize gain directions.
Data Source
AI summary
A portable wireless communication device comprises a housing, a ground reference mass, a first antenna element, and a second antenna element. The first antenna element and the second antenna element are located at different sides of the housing. A radio-frequency (RF) port is electrically coupled to the first antenna element. An RF transmission line is located between the RF port and the second antenna element. The ground reference mass comprises a ground structure of the RF transmission line. An RF transceiver is electrically coupled to the first antenna element. The RF transceiver is further electrically coupled to the RF port to further electrically couple the RF transceiver to the second antenna element via the RF transmission line.