Dynamic Antenna Match Linearity Control for Intermodulation
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Solution Overview
Problem
In wireless communication devices with multiple transceivers, concurrent signal transmissions often result in significant intermodulation in match tuning circuits, leading to receiver desensitization or blocking, especially when using PIN diode-based match tuners, which are inexpensive but have low linearity, while more linear solutions are complex and power-hungry.
Innovation Solution
Implementing a linearity controller that dynamically adjusts the bias current applied to the PIN diode in the antenna match circuit based on operational modes of the transceivers to increase linearity only when needed, thereby mitigating intermodulation distortion and conserving power.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If PIN diode-based match tuning circuits are used, then device cost and complexity are reduced, but linearity deteriorates causing significant intermodulation distortion
Solution Approach 1:
The patent applies dynamics by making the match tuning circuit's linearity adjustable rather than fixed. A linearity controller dynamically changes the operating state of the match tuning circuit between a first state (lower linearity, lower power) and a second state (higher linearity, higher power) based on detected transmission conditions. This allows the system to adapt the circuit's characteristics to match the operational requirements, using higher linearity only when intermodulation is likely to occur.
Solution Approach 2:
The patent changes the operating parameters of the match tuning circuit by adjusting the bias current applied to the PIN diode. The linearity controller modifies the bias current level to transition the circuit between different operational states, thereby changing its linearity characteristic. This parameter adjustment enables the circuit to achieve high linearity when needed while maintaining lower power consumption during normal operation.
2Reliability
If match tuning circuit linearity is increased to reduce intermodulation, then receiver desensitization is prevented, but power consumption increases
Solution Approach 1:
The system dynamically adjusts the match tuning circuit's linearity based on real-time detection of transmission conditions. The linearity controller monitors whether concurrent transmissions are occurring and transitions the circuit between low-power/low-linearity and high-power/high-linearity states accordingly. This dynamic adaptation ensures high receiver sensitivity is maintained only when necessary, while power consumption is minimized during normal single-transmitter operation.
Solution Approach 2:
The linearity controller periodically or continuously monitors transmission conditions and adjusts the match tuning circuit state accordingly. By detecting when concurrent transmissions occur and switching to high-linearity mode only during these periods, the system provides periodic protection against intermodulation while avoiding continuous high power consumption. The circuit returns to low-power mode when transmission conditions normalize.
3Object-generated harmful factors
If higher linearity components are used instead of PIN diodes, then intermodulation distortion is reduced, but device cost and current consumption increase
Solution Approach 1:
The patent uses inexpensive PIN diode-based match tuning circuits that can be easily replaced or reconfigured, rather than investing in expensive high-linearity components. The system accepts that the PIN diode circuit will have lower inherent linearity but compensates through dynamic control and only activates high-linearity mode when necessary. This approach prioritizes cost-effectiveness while maintaining adequate performance through intelligent operation rather than expensive hardware.
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 approach effectively reduces intermodulation distortion, prevents receiver desensitization, and conserves power by increasing linearity of the antenna match circuit during multi-transmitter operations without the need for complex or power-intensive components.
Implementation Method 1
a linearity controller to adjust a bias current applied to a PIN diode of the antenna match circuit
Data Source
AI summary
In embodiments of variable antenna match linearity, a wireless device includes a first transceiver and a second transceiver, an antenna via which signals are received, and a linearity controller that varies a linearity of an antenna match circuit associated with the antenna. The linearity controller can determine whether a frequency of an intermodulated signal that includes transmissions from the first and second transceivers is within one of a respective receive band of the first transceiver or the second transceiver. The linearity controller can increase a linearity of the antenna match circuit to mitigate an amplitude of the intermodulated signal in the receive band.