Broadband Power Amplifier Matching With Open Stub Harmonic Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional power amplifiers face challenges in miniaturization and high transmission loss due to increased circuit area for broad band operation and harmonic control, particularly with the use of trap circuits.
Innovation Solution
The power amplifier incorporates multiple transmission lines with different characteristic impedances and open stubs, where the length of each open stub is shorter than the transmission line, allowing for harmonic impedance control without the need for trap circuits or short circuits, thereby enabling a compact and efficient matching circuit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a trap circuit or short circuit is added to control harmonics in a broad band power amplifier, then harmonic impedance control is improved, but the circuit area increases and miniaturization becomes difficult
Solution Approach 1:
The patent combines the harmonic control function with the output matching circuit by integrating open stubs directly into the transmission lines. This merging eliminates the need for separate trap circuits or short circuits, achieving both harmonic impedance control and circuit miniaturization simultaneously.
Solution Approach 2:
The open stubs integrated into the transmission lines serve multiple functions: they provide harmonic control for both class F and inverse class F operations, maintain broadband matching, and enable circuit compactness. This multi-functionality resolves the contradiction by making the same circuit structure serve multiple purposes.
2Area of stationary object
If a trap circuit is used for harmonic control, then the circuit can be configured in a compact size, but transmission loss becomes relatively large
Solution Approach 1:
The patent uses open stubs instead of traditional trap circuits, which are simpler in structure and have lower transmission loss. The open stub configuration provides effective harmonic control with minimal energy loss, resolving the contradiction between compact size and low transmission loss.
3Use of energy by moving object
If odd harmonics are set to open impedance for class F operation or even harmonics are set to open impedance for inverse class F operation, then power-added efficiency is enhanced, but the circuit complexity increases for broadband operation
Solution Approach 1:
The patent changes the impedance parameters of the transmission lines and open stubs to achieve the desired harmonic control. By adjusting the characteristic impedances and lengths of the transmission lines, the circuit achieves both high efficiency and broadband operation without increasing complexity.
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 high efficiency operation across a broad band by effectively matching harmonic impedance to open, eliminating the need for additional circuits and reducing transmission loss, resulting in a compact and efficient power amplifier design.
Implementation Method 1
by providing the open stubs in the plurality of transmission lines respectively, the impedance of harmonics of the power amplifier can be gathered to open
Data Source
AI summary
A plurality of transmission lines (3b,3c) are connected to a transistor (1) and have different characteristic impedances. A plurality of open stubs (4a,4b) are connected to the plurality of transmission lines (3b,3c) respectively. A length of each open stub (4a,4b) is shorter than a length of each transmission line (3b,3c).