⌘K

Contents

Analog Electronics

Semiconductor Physics

Energy Band Theory Intrinsic Semiconductors Extrinsic Semiconductors N-Type Extrinsic Semiconductors P-Type Carrier Concentration Drift Current Diffusion Current Einstein Relation Hall Effect Continuity Equation

Diodes & Applications

BJT Amplifiers

FET Amplifiers

JFET Construction JFET Characteristics JFET Self Bias Enhancement MOSFET Depletion MOSFET MOSFET IV Characteristics MOSFET Biasing Techniques Common Source Amplifier Common Gate Amplifier Common Drain Amplifier MOSFET as Switch CMOS Inverter Basics

Operational Amplifiers

Ideal Op-Amp Op-Amp Practical Parameters Inverting Amplifier Non-Inverting Amplifier Voltage Follower Summing Amplifier Difference Amplifier Instrumentation Amplifier Op-Amp Integrator Op-Amp Differentiator Comparator Schmitt Trigger Log and Antilog Amplifier Precision Rectifier Voltage to Current Converter Current to Voltage Converter Sample and Hold Circuit Active Rectifier

Oscillators & Timers

Barkhausen Criterion RC Phase Shift Oscillator Wien Bridge Oscillator Colpitts Oscillator Hartley Oscillator Clapp Oscillator Crystal Oscillator 555 Timer Astable Mode 555 Timer Monostable Mode Waveform Generators Voltage Controlled Oscillator Phase Locked Loop

Filters

Passive RC Low Pass Filter Passive RC High Pass Filter Active Low Pass Filter Active High Pass Filter Active Band Pass Filter Active Band Stop Filter Butterworth Filter Design Chebyshev Filter Design Bessel Filter Filter Frequency Response

Power Electronics Basics

Linear Voltage Regulator 78xx 79xx Series Adjustable Voltage Regulator LM317 Switching Regulator Basics

Other Topics

Other Subjects

Digital Electronics Signals & Systems Control Systems Electromagnetic Theory Digital Communication Analog Communication Network Analysis Microprocessors VLSI Design Verilog HDL Power Electronics Embedded Systems DSP Electronic Devices

Section Progress75%

9 of 12 articles

Common Gate Amplifier

CG low input impedance, no Miller effect, cascode use.

Updated: 19 March 2026

4 min read

Common Gate Amplifier

Test your understanding of CG amplifier input impedance, gain, and cascode applications.

Question 1 of 3

Q1.What is the approximate small-signal input impedance at the source terminal of a common gate MOSFET amplifier (with ro assumed infinite)?

Related Articles

Common Base Amplifier

CB current gain, high frequency advantage, low input impedance.

8 min read

Common Emitter Amplifier

CE voltage gain, input and output impedance, phase inversion.

8 min read

Common Collector Amplifier

Emitter follower, voltage gain approximately 1, impedance transformation.

8 min read

Cascode Amplifier

CE-CB cascade, improved bandwidth, Miller effect reduction.

8 min read

Differential Amplifier

Difference and common mode gain, CMRR, tail current source.

10 min read

Common Source Amplifier

Common Drain Amplifier