Class E Amplifier Frequency Switching for ASK Modulation
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Solution Overview
Problem
Existing amplitude shift keying apparatuses using class E amplifiers suffer from efficiency losses due to load current requirements, limited modulation degree, edge overshooting, and additional component complexity.
Innovation Solution
A class E amplifier apparatus with a switching transistor, where the operating or resonance frequency is switched between two values to achieve a deviation degree for amplitude shift keying, eliminating the need for load current and resistances, and allowing optimal modulation control through frequency adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a variable resistor is switched as a load in the class E amplifier to effect amplitude modulation, then amplitude shift keying is achieved, but efficiency losses occur due to load current requirements
Solution Approach 1:
The invention changes the operating parameter from load resistance modulation to frequency modulation. By switching the operating frequency between two values (f1 and f2) while maintaining a fixed load resistance, the patent achieves amplitude modulation without the efficiency losses associated with variable load current. This parameter change eliminates the need for switched variable resistors and their associated switching transistors and control circuits.
2Ease of operation
If a tri state circuit with variable resistances is used to supply gate voltage, then amplitude modulation is achieved, but circuit complexity increases
Solution Approach 1:
The invention extracts and eliminates the complex tri state circuit with its network of variable resistances from the system. Instead of using this complex gate voltage control mechanism, the patent achieves the same amplitude modulation function by simply switching the operating frequency, thereby removing the unnecessary complex circuitry while preserving the essential modulation capability.
Solution Approach 2:
The invention substitutes a simple frequency switching mechanism for the complex mechanical/electrical tri state circuit system. By replacing the complex variable resistance network with a frequency control mechanism, the patent achieves the same functional result with significantly reduced circuit complexity.
3Adaptability or versatility
If load resistance is used for modulation, then amplitude shift keying is achieved, but the degree of modulation is limited
Solution Approach 1:
The invention changes the modulation parameter from load resistance to operating frequency. By varying the operating frequency between two discrete values, the patent achieves a greater degree of modulation without the efficiency losses inherent in load resistance modulation. This allows for more flexible and adaptable modulation depths while maintaining high efficiency.
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 enhances modulation efficiency, reduces component complexity, and prevents edge overshooting, achieving higher modulation degrees and faster data coding with improved signal quality.
Implementation Method 1
a circuit is provided for switching the operating frequency of the voltage (FT) supplied to the gate of the switching transistor, or the resonance frequency (FR), of the class E amplifier between a first value and a second value, in order to switch a deviation degree between the operating frequency and the resonance frequency
Data Source
AI summary
An apparatus for coding a signal by means of amplitude shift keying comprises a class E amplifier including a switching transistor, to whose gate is supplied a voltage having an operating frequency for operating the class E amplifier. For achieving an amplitude shift keying in the output signal of the class E amplifier, a circuit for switching the operating frequency of the voltage supplied to the gate of the switching transistor, or the resonance frequency of the class E amplifier, between a first value and a second value is provided and in order to switch a deviation degree between the operating frequency and the resonance frequency between a first value and a second value.