Coupled-Line Matching Circuit for Wideband Low-Power Amplifiers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Designing a circuit with a wide operating bandwidth for ultra-high frequency communication systems like 5G and 6G is challenging due to the large size and high power consumption of traditional distributed amplifier structures, which are difficult to apply in small and low power applications.
Innovation Solution
An input/output matching circuit with a coupled line having a low resistance characteristic, utilizing a 4-port coupled line structure with impedance restriction circuits, including resistances connected to through ports and capacitors between coupled lines to control impedance modes, thereby reducing characteristic resistance across a wide frequency band.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a traditional distributed amplifier structure is used to achieve wide operating bandwidth, then the bandwidth is improved, but the device size and power consumption increase
Solution Approach 1:
The patent transforms the narrowband matching circuits into broadband matching circuits by changing the impedance parameters across different frequency bands. The even-mode impedance is restricted in the low frequency band while being transformed in the high frequency band, enabling the circuit to achieve wide bandwidth operation without requiring the extensive transmission lines and transistor stages of traditional distributed amplifiers
2Adaptability or versatility
If a traditional distributed amplifier structure is used to achieve wide operating bandwidth, then the bandwidth is improved, but the device size increases
Solution Approach 1:
The patent achieves broadband operation by dynamically changing impedance parameters across frequency bands rather than using long transmission lines. The coupled line structure with frequency-dependent impedance transformation enables wide bandwidth in a compact area, avoiding the large physical dimensions required by traditional distributed amplifier topologies
3Device complexity
If narrowband input/output matching is used to simplify the circuit, then the device complexity is reduced, but the achieved bandwidth does not meet distributed amplifier requirements
Solution Approach 1:
The matching circuit is segmented into different frequency band handling sections: an even-mode impedance restriction section for the low frequency band and an odd-mode impedance transformation section for the high frequency band. This segmentation allows each section to be optimized for its specific frequency range while working together to achieve broadband operation
Solution Approach 2:
The patent employs parameter changes by transforming the impedance characteristics of the coupled line across different frequency bands. The even-mode impedance is restricted at lower frequencies while the odd-mode impedance provides transformation at higher frequencies, enabling the simplified circuit structure to achieve wide bandwidth performance
Data Source
AI summary
Disclosed are an input/output matching circuit and a broadband amplifier including the same. A matching circuit connected to each of an input terminal and an output terminal of an amplifier includes: a coupled line circuit unit constituted by coupled lines having a 4-port structure, in which the coupled line includes a first metal line and a second metal line; and a first impedance restriction circuit unit connected to a through port among 4 ports of the coupled line, and restricting an even mode impedance in a low frequency band.