Antenna Matching Circuit for Stable Calling Under User Interference
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Solution Overview
Problem
Wireless communication devices experience reduced signal reception and transmission performance due to interference from a user's hands or head, which shifts the antenna's resonant frequency, negatively affecting calling quality.
Innovation Solution
A sensor detects the proximity of external objects and sends a signal to adjust the resonant frequency of the antenna module through a matching circuit, using a variable capacitance diode and capacitors to stabilize the frequency by shifting it towards a lower frequency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the antenna operates at a fixed resonant frequency, then the device structure is simple, but user's hands or head interfere with the antenna causing frequency shift and reduced signal performance
Solution Approach 1:
The patent applies dynamics by making the antenna system adjustable rather than fixed. A matching circuit with variable capacitance (implemented through switchable capacitors or variable capacitance diodes) is connected to the antenna, allowing the resonant frequency to be dynamically adjusted. The processor detects frequency shifts caused by user interference and controls the matching circuit to compensate, thereby maintaining reliable signal performance despite changing conditions.
Solution Approach 2:
The patent changes the electrical parameters of the antenna system by introducing a matching circuit that modifies the capacitance connected to the antenna. This allows the resonant frequency parameter to be adjusted in response to detected interference, compensating for frequency shifts and maintaining optimal signal reception and transmission performance.
2Reliability
If the resonant frequency is adjusted to compensate for interference, then calling quality is maintained, but the device requires additional components and control mechanisms
Solution Approach 1:
The patent implements feedback by having the processor continuously monitor the antenna's resonant frequency and automatically adjust the matching circuit to compensate for detected shifts. This closed-loop control system maintains calling quality by detecting interference conditions and applying corrective frequency adjustments, though it does increase device complexity through the addition of sensing and control components.
Solution Approach 2:
The matching circuit serves as an intermediary between the antenna and the rest of the communication system. It provides a buffer that can be adjusted to compensate for interference effects, isolating the antenna's frequency variations from the main communication circuitry and maintaining overall system performance.
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 reduces or eliminates frequency shifts caused by user interference, enhancing calling quality by maintaining stable signal reception and transmission.
Implementation Method 1
The matching circuit includes a variable capacitance diode, a first capacitor, a resistor and a second capacitor
Implementation Method 2
the resonant frequency of the antenna may be shifted to a high frequency due to the interference
Data Source
AI summary
A wireless communication device includes a central processing unit (CPU), a sensor electrically connected to the CPU, an antenna module, and a matching circuit electrically connected between the CPU and the antenna module. In response to a call being made by the wireless communication device and in response to detection of an external object within a predetermined range of the wireless communication device by the sensor, the sensor transmits a signal to trigger the CPU to generate a control signal. The matching circuit receives the signal from the CPU and shifts the resonant frequency of the antenna module down.