Duty-Cycle Tuned Switching Amplifier for Wide-Range Efficiency
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Solution Overview
Problem
Class E power amplifiers face efficiency issues at output powers lower than maximum due to pre-set component values, which are not dynamically adjustable, leading to reduced performance across varying duty cycles and frequencies.
Innovation Solution
Incorporating a variable component with adjustable imaginary impedance, controlled by a controller to match the duty cycle of the pulse width modulated input signal, allowing dynamic tuning of the circuit for improved efficiency across a range of operating conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If pre-set component values are used in Class E power amplifiers, then the amplifier can be manufactured with fixed parameters, but the efficiency decreases at output powers lower than maximum due to inability to adapt to varying duty cycles
Solution Approach 1:
The patent applies the Dynamics principle by replacing fixed component values with dynamically adjustable components. Specifically, variable capacitors are used in the output matching network to adjust the imaginary impedance according to the duty cycle of the PWM signal. This allows the amplifier to maintain optimal efficiency across a wide range of output powers by adapting the circuit parameters in real-time, directly resolving the contradiction between fixed manufacturing and dynamic performance requirements.
Solution Approach 2:
The patent implements Parameter changes by varying the capacitance values of the output matching network components based on the duty cycle. The controller modifies the capacitance parameters dynamically to maintain the Class E operating conditions across different power levels. This parameter adaptation enables the amplifier to achieve high efficiency at both maximum and reduced output powers, solving the efficiency degradation problem associated with fixed component values.
2Device complexity
If fixed component values are used in the output matching circuit, then the circuit design is simplified, but the amplifier cannot maintain high efficiency across a large dynamic range of output powers
Solution Approach 1:
The patent applies the Dynamics principle by introducing variable capacitors controlled by a duty cycle detection circuit. The controller adjusts the capacitance values in the output matching network dynamically, enabling the circuit to adapt to different operating conditions. This dynamic adjustment maintains high efficiency across a large dynamic range of output powers while managing the increased circuit complexity through automated control.
Solution Approach 2:
The patent implements Feedback by using the PWM duty cycle as a control parameter to adjust the output matching network. The controller detects the duty cycle and automatically modifies the capacitance values accordingly, creating a closed-loop system that maintains optimal performance. This feedback mechanism enables the amplifier to adapt to varying output power requirements while keeping the circuit design manageable through systematic control.
3Stability of the object's composition
If the amplifier operates at reduced output power with fixed components, then the hardware configuration remains constant, but the efficiency drops significantly below maximum levels
Solution Approach 1:
The patent applies the Dynamics principle by maintaining constant hardware configuration while enabling dynamic parameter adjustment through variable capacitors. The physical circuit structure remains stable, but the electrical parameters (capacitance values) are dynamically modified based on the duty cycle. This approach allows the amplifier to maintain high efficiency at reduced power levels without changing the hardware configuration, resolving the contradiction between structural stability and performance adaptability.
Data Source
AI summary
A switching amplifier (200; 300; 400; 500) comprising: a switch (202; 302) configured to electrically connect and disconnect a first pin (202a; 302a) of the switch (202; 302) to a second pin (202b; 302b) of the switch (202; 302) in accordance with a pulse width modulated input signal (216; 316; 516). The second pin (202b; 302b) is connected to a ground connector (204; 304). The switching amplifier also comprises a feed inductor (206; 306; 406) connected between a voltage supply connector (208; 308) and the first pin (202a; 302a) of the switch (202; 302), and a circuit (210; 310; 522) comprising a variable component having a variable imaginary impedance. The circuit (210; 310; 522) is connected between the first pin (202a; 302a) of the switch (202; 302) and an output connector of the amplifier (212; 312. The switching amplifier further comprising a controller (214; 314; 514) configured to generate a control signal (315; 515) for the circuit (210; 310; 522) such that the variable component of the circuit is adjustable in accordance with the duty cycle of the pulse width modulated input signal (216; 316; 516).