High-Frequency Response of MOSFET Common-Source Amplifier (1): Intro

High-Frequency Response of MOSFET Common-Source Amplifier (1): Intro

by Vincent Chang

Formal & Physical Sciences Engineering & Technology TJFElectronics engineeringTJFCElectronics: circuits and components
🎙 Vincent Chang 👥 2K 📅 March 3, 2021 ⏱ 11 min 👁 684 📄 tutorial 🧭 2026-08-17
Available in: English (current) Français

Keywords

MOSFETcommon-source amplifierhigh-frequency responseMiller theoremtime constant method

Summary

This video is the first in a series on the frequency response of MOSFET common-source amplifiers, focusing on high-frequency analysis. The instructor, Vincent Chang, begins by reviewing the three frequency bands (low, mid, high) and defines the 3dB bandwidth. He explains that high-frequency behavior is dominated by internal capacitances, while low-frequency behavior is affected by external coupling and bypass capacitors. The general transfer function is presented as a product of midband gain and low- and high-frequency functions. The midband analysis is briefly reviewed using the small-signal model. The high-frequency equivalent circuit is introduced, considering the gate-source capacitance (Cgs) and gate-drain capacitance (Cgd), with justification for neglecting other parasitic capacitances. The instructor then outlines three methodologies to analyze high-frequency behavior: the open-circuit time constant method, Miller’s theorem, and exact transfer function derivation. He emphasizes the importance of understanding the exact derivation for a solid foundation. The video concludes by previewing upcoming lectures that will apply each method.

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Critical Evaluation

Value of the Information & Strength of the Argument

The video provides a clear and logical introduction to the high-frequency analysis of a common-source amplifier. It effectively explains the need for a high-frequency model and justifies the inclusion of only two capacitances (Cgs and Cgd) by referencing the common-source configuration and Miller’s theorem. The argumentation is sound, building from the general frequency response concept to the specific high-frequency model. The instructor’s teaching experience is evident in the structured presentation and the emphasis on understanding the foundational transfer function derivation before using shortcuts.

Scientific Rigor, Source Quality, Title Accuracy

The scientific rigor is high for an educational video: the content is accurate and follows standard textbook approaches. However, no external sources or references are cited, which is typical for a tutorial. The title accurately reflects the content, as it is indeed an introduction to the high-frequency response of a common-source amplifier. The video’s pedagogical approach is rigorous, encouraging a deep understanding of the underlying mathematics.

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Title / Content Match

The title accurately reflects the content: an introduction to the high-frequency response of a common-source amplifier.

Quality & Reliability

8/10

The content is a well-structured introductory lecture by an experienced educator (Ph.D. in EE, 30 years teaching). It clearly explains the high-frequency model of MOSFET and outlines three analysis methods. The video is focused and pedagogically sound, though it does not provide citations or references.

Key Moments

Markers derived by PSI from the transcript: the creator did not define chapters.

Contribution & Novelties

This video serves as a foundational introduction to high-frequency analysis of MOSFET amplifiers, clearly outlining the key concepts and methodologies. It does not present new research but offers a structured pedagogical approach that is valuable for learners.

Pour aller plus loin :

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Radar Profile

The radar profile shows balanced scores across information quantity, quality, technical level, and reliability, indicating a well-rounded educational video. The high technical level and reliability scores reflect the instructor's expertise and the accurate content.

Reliability 8/10