Doherty Amplifier Circuit With LC Compensation for Reverse Capacitance
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Solution Overview
Problem
Existing amplifying circuits, such as Doherty amplifier circuits, face challenges in improving maximum gain due to the suppression of reverse transfer capacitance in transistors.
Innovation Solution
The proposed amplifying circuit includes a transistor with an inductor connected in parallel between the input and output terminals, and a capacitor connected in parallel to the transistor and in series with the inductor. This configuration compensates for the reverse transfer capacitance, enhancing the circuit's gain and characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If reverse transfer capacitance is suppressed in the transistor, then stability is improved, but maximum gain deteriorates
Solution Approach 1:
An inductor is introduced as an intermediary element connected between the input and output terminals of the transistor. This inductor mediates the interaction between input and output signals, providing a controlled impedance path that compensates for the reverse transfer capacitance effect without directly modifying the transistor's internal capacitance, thereby maintaining stability while improving gain
Solution Approach 2:
The invention changes the electrical parameters of the amplifying circuit by introducing an inductor with specific inductance value. This parameter change creates an inductive reactance that counteracts the capacitive effect of the reverse transfer capacitance, allowing the circuit to achieve higher gain while maintaining stability through proper parameter selection
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
The inclusion of the inductor and capacitor improves the maximum gain at the center frequency of the operation band, resulting in enhanced characteristics of the amplifying circuit and Doherty amplifier circuits.
Implementation Method 1
an inductor connected in parallel to the transistor between the input terminal and the output terminal
Implementation Method 2
the inductor compensates for a reverse transfer capacitance of the transistor
Data Source
AI summary
An amplifying circuit includes a transistor that includes an input terminal receiving a high frequency signal and an output terminal outputting an amplified high frequency signal, an inductor connected in parallel to the transistor between the input terminal and the output terminal, and a capacitor connected in parallel to the transistor and connected in series to the inductor between the input terminal and the output terminal.