High-Frequency Semiconductor Amplifier Harmonic Impedance Matching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-frequency semiconductor amplifiers face challenges in achieving high power-added efficiency due to difficulties in effectively matching load impedances for fundamental, second harmonic, and third harmonic frequencies, which limits their operational performance in radio communication and radar devices.
Innovation Solution
The design incorporates a microstrip line output matching circuit with specific electrical lengths and characteristic impedances to transform load impedances for fundamental, second harmonic, and third harmonic frequencies, achieving a desired impedance configuration that enables inverse class-F operation, eliminating even harmonics of voltage and odd harmonics of current.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If conventional matching circuits are used to match load impedances for fundamental and harmonic frequencies, then impedance matching is achieved, but power-added efficiency remains limited and device complexity increases
Solution Approach 1:
The matching circuit is divided into multiple independent transmission line segments (first transmission line for fundamental frequency, second transmission line for second harmonic, third transmission line for third harmonic). Each segment is optimized for a specific frequency component, allowing independent control of impedance at different harmonics while maintaining overall circuit simplicity and achieving high power-added efficiency through targeted harmonic management.
2Use of energy by moving object
If multiple transmission lines are added to control harmonic impedances, then power-added efficiency improves, but the circuit size and complexity increase
Solution Approach 1:
Each transmission line segment is designed with specific electrical length and characteristic impedance tailored to its designated frequency function. The first transmission line (λ/4 at fundamental frequency) provides impedance transformation for the fundamental, while the second (λ/8 at second harmonic) and third (λ/12 at third harmonic) lines are optimized for their respective harmonic frequencies. This localized optimization allows efficient power amplification without requiring a uniformly complex circuit structure across all frequencies.
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 enhances power-added efficiency by approximately 5-10% and ensures high-frequency semiconductor amplifiers operate efficiently by matching load impedances to achieve high power-added efficiency.
Implementation Method 1
The design incorporates a microstrip line output matching circuit with specific electrical lengths and characteristic impedances to transform load impedances for fundamental, second harmonic, and third harmonic frequencies
Implementation Method 2
The output matching circuit includes a second transmission line having a fourth electrical length corresponding to one eighth of a wavelength of the second harmonic frequency and a fifth characteristic impedance, and a third transmission line having a sixth electrical length corresponding to one twelfth of a wavelength of the third harmonic frequency and a seventh characteristic impedance
Data Source
Figure 1~2
Figure 3A~3B
Figure 4~5
AI summary
According to one embodiment, a high-frequency semiconductor amplifier (1) includes an input terminal (10), an input matching circuit (12), a high-frequency semiconductor amplifying element (14), an output matching circuit (21) and an output terminal (18). The input terminal (10) is inputted with a fundamental signal. The fundamental signal has a first frequency band and a first center frequency in the first frequency band. The input matching circuit (12) includes an input end and an output end. The input end of the input matching circuit (12) is connected to the input terminal (10). The high-frequency semiconductor amplifying element (14) includes an input end and an output end. The input end of the high-frequency semiconductor amplifying element (14) is connected to the output end of the input matching circuit (12). The high-frequency semiconductor amplifying element (14) is configured to amplify the fundamental signal.