#223: Basics of the Gilbert Cell | Analog Multiplier | Mixer | Modulator
Why Electrical Engineering Stack Exchange recommends it
Electronics Stack Exchange users point people to it as a practical introduction to the Gilbert cell, both when answering multiplier questions and as the reference design people build from in their own circuits.
Recommended by 1 people across 1 different months, 2015 to 2025.
What it is
A 17-minute tutorial by Alan Wolke (w2aew) on how the Gilbert Cell works, a four-quadrant analog multiplier used in variable gain amplifiers, mixers and balanced modulators. It stays light on math and aims for practical intuition, assuming the viewer already understands differential pairs.
What people said
Recommends jippie · 2015-12 · Electrical Engineering Stack Exchange · on “Actual Implementation of a Multiplier”
Take a look at the fundamentals video about the Gilber cell. The only prerequisite is that you understand long tailed pairs of differential amplifiers. [this video]
Cites OnurTR · 2022-02 · Electrical Engineering Stack Exchange · on “BJT type Gilbert cell does not work”
I designed a Gilbert cell for analog multiplication, all the transistors (NPN) are in active region as I checked one by one, however, the result does not seem correct at all. How can I make it better? [LINK] [LINK] In the first picture, red trace and green trace are supposed to be multiplied, but the blue trace which is the multiplication of these two seems to be out of phase. I mean when red signal is highest, I would expect blue trace to make a peak as well. I do not know what is going on. The NPN I use is simple, generic NPN with DC current gain of approximately 100. The tutorial that I followed building the circuit is [this video] [LINK] I think I have to keep frequencies high so that output
Cites Official Pyramid · 2025-06 · Electrical Engineering Stack Exchange · on “Issues with Gilbert Cell Design”
I am using a Gilbert cell multiplier design from [this video] I connected the circuit in LTspice and appear to always get a pretty noisy output with quite a few harmonics. Is this a result of the Gilbert cell design or is there an issue with my circuit design [LINK] [LINK] 50 kHz Carrier 1 kHz message signal [LINK] FTT decibel scale [LINK] FFT Linear Scale What step could I take to reduce the noise and make this circuit work for frequencies up to 10 MHz?