MEMS DVC Antenna Tuning for Head and Hand Impedance Shift
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The head/hand effect, caused by user interaction, leads to changes in the electrical characteristics of antennas in wireless devices, resulting in performance degradation such as dropped connections and disrupted data traffic.
Innovation Solution
The implementation of a Dynamic Variable Capacitance (DVC) system, utilizing Micro Electro Mechanical Systems (MEMS) technology, allows for real-time adjustment of antenna capacitance to maintain optimal radiation and impedance characteristics despite environmental changes or user interaction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the antenna operates in free space during fabrication and testing, then the antenna achieves ideal electrical characteristics, but the antenna performance degrades when the user interacts with the device
Solution Approach 1:
The patent implements a dynamic tuning system that continuously adjusts antenna electrical characteristics during operation. A tuner circuit with variable capacitors and inductors modifies the antenna impedance in real-time based on feedback from a reflection coefficient measurement, allowing the antenna to adapt to changing environmental conditions and user interaction rather than remaining static
Solution Approach 2:
The system employs a feedback mechanism where the reflection coefficient is measured at the antenna input, processed by a controller, and used to generate tuning commands that adjust the antenna impedance. This closed-loop control continuously compensates for head/hand effects by comparing actual performance against desired characteristics and making real-time corrections
2Adaptability or versatility
If the antenna impedance changes due to user interaction, then the antenna adapts to the environment, but the signal strength and connection reliability deteriorate
Solution Approach 1:
The patent changes the electrical parameters of the antenna system by introducing variable capacitors and inductors that can dynamically adjust capacitance and inductance values. The tuner circuit modifies these parameters in response to measured reflection coefficients, transforming the antenna from a fixed-impedance structure to a variable-impedance system that maintains optimal performance across different operating conditions
3Manufacturing precision
If a traditional tuning method with multiple measurements is used, then comprehensive antenna characteristics are achieved, but the tuning process becomes complex and time-consuming
Solution Approach 1:
The system performs preliminary characterization during fabrication by measuring reflection coefficients at multiple known capacitor values to establish a relationship between capacitance and reflection coefficient. This pre-established model allows the operational tuning process to use simple interpolation algorithms rather than requiring complex real-time measurements and calculations, reducing both complexity and tuning time
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 solution effectively compensates for changes in antenna impedance, maintaining consistent signal strength and reducing performance degradation caused by the head/hand effect, thereby ensuring reliable wireless communication.
Implementation Method 1
a dynamic variable capacitance (DVC) system, utilizing Micro Electro Mechanical Systems (MEMS) technology, allows for real-time adjustment of antenna capacitance
Implementation Method 2
utilizing Micro Electro Mechanical Systems (MEMS) technology
Implementation Method 3
The head/hand effect refers to the change in the electrical characteristics of the antenna of the device, typically caused by capacitive loading of the antenna due to the proximity of the user's human tissue
Data Source
Figure 1~2
Figure 3~4
Figure 5A~5C
AI summary
The present disclosure generally relates to any device capable of wireless communication, such as a mobile telephone or wearable device, having one or more antennas. After measuring reflection coefficients of a device at three different DVC states, the reflection coefficient for all other DVC states can be calculated. Thus, based solely upon three reflection coefficient measurements, the antenna can be tuned to adjust for any changes in impedance at the antenna.