Antenna Ground Conductor Tapering for Wireless Device Radiation Efficiency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In electronic devices with wireless communication capabilities, the close proximity of antennas to metal members leads to variations in resonant characteristics, necessitating increased power supply to compensate for degraded radiation, which in turn increases power consumption and heat generation, posing challenges for heat dissipation and costing more.
Innovation Solution
A wireless communication device design featuring an antenna with an open end and a ground conductor connected to a metal member, where the metal member has a projection towards the antenna, and a conductor piece covering the region with maximum electric field intensity, to enhance capacitive coupling and improve radiation efficiency without increasing power supply.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the antenna is arranged close to a metal member to reduce device size, then the device size is reduced, but the resonant characteristics of the antenna vary and radiation efficiency degrades
Solution Approach 1:
The ground conductor is designed with non-uniform width, being wider at the first end (near the open end of the antenna element) and narrower at the second end. This local variation in geometry creates regions with different electrical characteristics, allowing the antenna system to maintain stable resonant characteristics even when positioned close to metal members. The wider first end region provides better grounding near the high-voltage region, while the narrower second end region reduces interference with adjacent metal members.
2Power
If power supplied to the radio element is increased to compensate for radiation degradation, then the radiant quantity of radio waves is increased, but power consumption increases
Solution Approach 1:
The ground conductor's width parameter is varied along its length, creating a tapered structure that optimizes the current distribution and reduces resistive losses. This geometric parameter change improves the radiation efficiency of the antenna system, allowing adequate radiant quantity to be achieved with lower input power to the radio element.
3Power
If power supplied to the radio element is increased to compensate for radiation degradation, then the radiant quantity of radio waves is increased, but heat generation increases
Solution Approach 1:
The ground conductor width variation optimizes the current path and reduces current density peaks that cause resistive heating. By distributing current more evenly through the tapered ground structure, the system achieves the required radiant quantity with lower power dissipation, thereby reducing heat generation in the radio element.
4Ease of manufacture
If the ground conductor width is made uniform, then the manufacturing is simplified, but the radiation efficiency cannot be optimized
Solution Approach 1:
The ground conductor employs a tapered width design where the first end width differs from the second end width. This local geometric variation is designed to match the electromagnetic field distribution, with the wider first end providing better grounding in the high-voltage region near the antenna element's open end. While slightly more complex to manufacture than a uniform conductor, the tapered design can be easily implemented in standard PCB fabrication processes.
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 design improves transmission and reception gains at communication frequencies, reducing power consumption and heat generation while maintaining efficient radiation efficiency, thus addressing the challenges of size, cost, and heat dissipation.
Implementation Method 1
the metal member includes a metal main body, and a projection that projects from the metal main body toward the antenna
Implementation Method 2
increases power supplied to a radio element made of, e.g., a semiconductor package to compensate the amount of degradation in radiant power and increase the radiant quantity of radio waves in a communication frequency
Data Source
AI summary
A wireless communication device includes: an antenna including an antenna element, and a ground conductor; an IC connected to the antenna; and a metal member arranged to face the antenna. The ground conductor includes one end and the other end in the X direction. The metal member includes a metal plate, and a projection protruding from the metal plate toward the antenna. The projection is arranged at a position of overlapping with the end of the ground conductor as viewed in the −Z direction. Such a configuration improves the transmission and reception gains at the communication frequency of a radio element.