w2aew | #223: Basics of the Gilbert Cell | Analog Multiplier | Mixer | Modulator @w2aew | Uploaded December 2015 | Updated October 2024, 3 hours ago.
A short tutorial on the basics of the Gilbert Cell - a very popular analog four-quadrant multiplier circuit that has a wide variety of applications ranging from variable gain amplifiers to mixers and balanced modulators. The video is light on the math, focusing mainly on delivering a practical, intuitive understanding of how the circuit operates. It is highly recommended that the viewer be familiar with the basic operation of a differential-pair. Video #193 (linked below) would be a good thing to review to freshen up on the diff-pair operation.

Lecture on Translinear Circuits by Barrie Gilbert himself:
youtu.be/LQNJVtcFrCc?si=m0jPHERL1K-krhL8

Differential Pair video:
youtube.com/watch?v=mejPNuPAHBY

Show notes for this video:
qsl.net/w2aew/youtube/GilbertCell.pdf