Tunable Harmonic Termination Circuit for Multi-Mode Power Amplifier
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Solution Overview
Problem
Modern wireless communication devices face challenges in implementing a multiple mode transceiver that can efficiently handle both GSM and EDGE signals using a single power amplifier, as non-linear amplifiers are efficient for GSM but inefficient for EDGE, leading to increased size and cost when both types are integrated.
Innovation Solution
A transceiver with a tunable harmonic termination circuit using a varactor, such as a bipolar transistor or FET, adjusts the resonance frequency of the power amplifier output to provide a non-linear output for GSM and a more linear output for EDGE signals, allowing a single power amplifier to be used for both modes without compromising efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a non-linear power amplifier is used for GSM signals, then power efficiency is improved, but linearity deteriorates making it unsuitable for EDGE signals
Solution Approach 1:
The patent applies dynamics by making the power amplifier's operating characteristics可调 (adjustable). A variable capacitor is introduced into the feedback network of the power amplifier, allowing the amplifier to dynamically switch between non-linear operation (for GSM efficiency) and linear operation (for EDGE signal quality). This dynamic adjustment resolves the contradiction by enabling the same amplifier to adapt its behavior based on the required signal type.
Solution Approach 2:
The patent changes the electrical parameters of the power amplifier circuit by introducing a variable capacitor that can alter the feedback network characteristics. By adjusting the capacitance value, the amplifier's linearity and efficiency parameters are changed to match the requirements of different communication standards (GSM vs EDGE), thus resolving the contradiction between efficiency and linearity.
2Adaptability or versatility
If both non-linear and linear power amplifiers are included in the transceiver, then adaptability for different signal types is improved, but device complexity and size increase
Solution Approach 1:
The patent implements universality by designing a single power amplifier that can perform multiple functions - handling both GSM and EDGE signals. By adding a variable capacitor to the feedback network, the same amplifier circuit can be configured for non-linear operation (GSM) or linear operation (EDGE), eliminating the need for separate amplifiers and reducing overall device complexity.
Solution Approach 2:
The patent merges the functionality of what would traditionally require separate non-linear and linear amplifiers into a single unified power amplifier circuit. The variable capacitor allows one amplifier to combine the capabilities of both types, reducing the number of components and simplifying the integrated circuit design while maintaining multi-mode compatibility.
3Reliability
If a linear power amplifier is used for EDGE signals, then signal linearity is improved, but power efficiency deteriorates
Solution Approach 1:
The patent applies dynamics by enabling the power amplifier to switch between operating modes. The variable capacitor in the feedback network allows the amplifier to be dynamically configured - operating in linear mode when EDGE signals are detected (prioritizing linearity) and switching to non-linear mode for GSM signals (prioritizing efficiency). This dynamic adaptation resolves the contradiction between linearity and efficiency.
Solution Approach 2:
The patent changes the circuit parameters by adjusting the capacitance value in the feedback network. When linear operation is required for EDGE signals, the capacitor is configured to provide the appropriate feedback characteristics for linear amplification. When efficiency is prioritized for GSM signals, the parameter is changed to enable non-linear operation, thus resolving the linearity-efficiency trade-off.
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 enables a single power amplifier to efficiently handle both GSM and EDGE signals, reducing the size and cost of the integrated circuit by dynamically tuning the resonance frequency using a harmonic termination circuit with a varactor, achieving efficient operation for both signal types.
Implementation Method 1
the variable capacitor is capable of adjusting its capacitance in response to the tunable harmonic termination voltage so as to achieve at least two modes of operation
Implementation Method 2
tune the resonance frequency of the power amplifier output when in EDGE mode, and re-tunes the resonance frequency of the power amplifier output when in GSM mode
Data Source
AI summary
A transceiver includes a harmonic termination circuit that receives a tunable harmonic voltage from a power amplifier control. The harmonic termination circuit includes a variable capacitor that is capable of adjusting its capacitance in response to the tunable harmonic termination voltage to achieve at least two modes of operation. The at least two modes of operation may be EDGE mode and GSM mode. In this embodiment, the harmonic termination circuit allows for linearity specifications of EDGE to be met, while not degrading the efficiency of the transceiver when operating in GSM mode. In one embodiment, the harmonic termination circuit further includes an inductive element in series with the variable capacitor.