Variable Ground Plane Impedance Compensation for Foldable Antennas
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Solution Overview
Problem
Foldable communication devices face challenges in maintaining antenna performance due to changes in mutual coupling between ground planes and a radiofrequency antenna as the device is folded or unfolded, leading to detuning at certain frequencies.
Innovation Solution
A communications device with a radiofrequency antenna and a ground plane assembly that includes a variable impedance compensation network, which adjusts its impedance to maintain optimal tuning across different physical configurations, ensuring consistent performance across various frequencies by compensating for changes in mutual electromagnetic coupling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the device is folded or unfolded, then the physical configuration changes, but the antenna detunes at certain frequencies due to changes in mutual coupling
Solution Approach 1:
The patent applies dynamics by making the ground plane configuration adjustable rather than fixed. The ground plane can be reconfigured between different physical states (folded/unfolded) while the impedance compensation network dynamically adjusts to maintain antenna performance in each configuration state.
Solution Approach 2:
The patent changes electrical parameters by introducing a variable impedance compensation network that adjusts the ground plane impedance to compensate for detuning effects. This parameter adjustment maintains the antenna's resonant frequency and impedance matching across different physical configurations.
2Reliability
If a variable impedance compensation network is added, then antenna detuning is compensated, but device complexity increases
Solution Approach 1:
The patent introduces an intermediary element - the impedance compensation network - that mediates between the antenna and the variable ground plane. This intermediary compensates for the harmful effects of ground plane reconfiguration on antenna performance without requiring fundamental changes to the antenna structure itself.
Solution Approach 2:
Instead of making the antenna structure physically adjustable, the patent changes electrical parameters through the compensation network. This approach maintains structural simplicity while achieving the desired performance through electrical parameter adjustment.
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 variable impedance compensation network effectively tunes the antenna to maintain a 50-ohm impedance within a desired frequency range (500 MHz to 1.25 GHz) across different device configurations, preventing detuning and ensuring reliable radiofrequency operations.
Implementation Method 1
tune mutual electromagnetic coupling between the ground plane assembly and the radiofrequency antenna
Implementation Method 2
a radiofrequency antenna configured to generate an electromagnetic field
Data Source
Figure 1
Figure 2A~2B
Figure 3A~3B
AI summary
A communications device provides variable ground plane tuning compensation. The communications device includes a radiofrequency antenna configured to generate an electromagnetic field, a ground plane assembly electrically coupled to the radiofrequency antenna, and a variable impedance compensation network electrically connected to the ground plane assembly. The ground plane assembly is configurable between a first physical configuration and a second physical configuration. Each physical configuration presents a different ground plane assembly impedance to the electromagnetic field of the radiofrequency antenna. The variable impedance compensation network provides a compensation impedance for each physical configuration of the ground plane assembly. The compensation impedance of the variable impedance compensation network and the ground plane assembly impedance of each of the physical configurations combine to tune mutual electromagnetic coupling between the ground plane assembly and the radiofrequency antenna to satisfy a predetermined operational tuning condition for the communications device in each physical configuration.