Hybrid Class Amplifier Harmonic Impedance Switching
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Solution Overview
Problem
Traditional power amplifiers face challenges in combining high efficiency at medium output amplitudes with high maximum output power, as the narrow current pulses of class C operation interact negatively with the high harmonic impedances required for class F or inverse F operation, leading to efficiency degradation and potential transistor breakdown.
Innovation Solution
A power amplifier is configured to generate impedances at harmonic frequencies, allowing it to operate in class C mode at low output amplitudes and in class F or inverse class F mode at high output amplitudes, using a combination of parallel and series resonators to manage harmonic impedances and reduce voltage overshoots.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the amplifier operates in class C mode with narrow current pulses, then efficiency at medium output amplitudes is improved, but voltage overshoots and transistor breakdown risk increase at high output amplitudes
Solution Approach 1:
The amplifier dynamically switches between class C mode (for medium output amplitudes) and class F or inverse class F mode (for high output amplitudes). This dynamic operation mode allows the amplifier to optimize efficiency at medium power while preventing voltage overshoots and transistor breakdown at high power levels.
Solution Approach 2:
The amplifier changes the impedance parameters at harmonic frequencies based on the output amplitude level. At medium amplitudes, the circuit allows narrow current pulses for high efficiency, while at high amplitudes, it transforms the impedance to reduce voltage overshoots and prevent transistor breakdown.
2Power
If the amplifier operates in class F or inverse class F mode with high harmonic impedances, then maximum output power is improved, but efficiency at medium output amplitudes degrades due to interaction with narrow current pulses
Solution Approach 1:
The amplifier dynamically adjusts the impedance at harmonic frequencies based on the output amplitude. At high output amplitudes, high harmonic impedances are maintained to achieve maximum output power, while at medium amplitudes, the impedance is adjusted to work effectively with narrow current pulses for high efficiency.
Solution Approach 2:
The amplifier changes the operating mode between class C, class F, and inverse class F based on output amplitude levels. This parameter change allows the amplifier to achieve high maximum output power when needed while maintaining high efficiency at medium power levels.
3Stability of the object's composition
If traditional linear amplifier circuits are used, then linearity is improved, but efficiency and power consumption worsen
Solution Approach 1:
The amplifier dynamically switches between linear operation modes (class A, AB, B) and non-linear operation modes (class C, F, inverse F) based on the required output amplitude and signal characteristics. This allows the amplifier to maintain signal linearity when required while achieving high efficiency through non-linear modes during normal operation.
Solution Approach 2:
The amplifier changes the conduction angle and operating class based on signal requirements. By adjusting these parameters dynamically, the amplifier achieves a balance between linearity and efficiency, using linear modes only when necessary for signal fidelity.
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 configuration achieves higher average efficiency and increased output power compared to traditional amplifiers, while maintaining robustness and avoiding transistor saturation, particularly beneficial for multi-carrier radio signals.
Implementation Method 1
A power amplifier is configured to generate impedances at harmonic frequencies, allowing it to operate in class C mode at low output amplitudes and in class F or inverse class F mode at high output amplitudes, using a combination of parallel and series resonators to manage harmonic impedances
Data Source
Figure 1A~1B
Figure 2
Figure 3
AI summary
A power amplifier (10) configured to generate impedances at harmonic frequencies such that the power amplifier (10) operates in a class C mode in a low output amplitude range and in a class F or inverse F mode in a high output amplitude range.