Four-quadrant multiplier

[theanimalix]

What does it look like and how does it work? Pls help.

 

[antonio_eda]

There are many four-quadrant multipliers. The most famous is probably a Gilbert 6-BJT current-mode multiplier. In general 4-quadrant cell realizes a function: out=k*in1*in2 where in1 and in2 may be greater or less then 0.

 

[flatulent]

The six transistor circuit was around for years before Gilbert. Gilbert described it in his first paper on multipliers which used FETs.

 

[antonio_eda]

Anyway, it is still so-called Gilbert cell... as well as another 4-quadrant multiplier, so-called Czarnul & Song 4-MOSFET resistive circuit.

 

[flatulent]

It is all a matter of what sort of ethics you have. For instance, Darwin claimed the published work of his grandfather as his own. One shortcoming of human nature is to not admit making a mistake. Academics and journalists are quite famous for suffering from this moral vice.

you might want to visit https://analog-rf.com/mixer.shtml which has more details. I understand that after viewing this presentation the professors at UC Berkley ceased from giving Gilbert the credit for the discovery of the topoligy.

 

[antonio_eda]

Probably I have red these explanations. We can name this extraordinary circuit the 6-pack multiplier. Maybe without Gilbert it could be also as recognizable as today... Anyway, in my humble opinion Gilbert is great educator and his works are worth reading. What about reinvention? Or independent invention? Is it so important who was the first?

 

[flatulent]

honesty is honesty. What if someone claimed that Winston Churchill invented the electron microscope? Have you read George Orwell's 1984 about how history was rewritten in a terrifying society? Or perhaps Gaudy Night by Dorothy L. Sayers which involves academic dishonest? I am reminded of an American who once claimed to be the long term, paid private secretary of C. S. Lewis and also to have an Oxford Ph.D. After two books by Kathryn Lindskoog exposing his claims and the claims of others he was too embarrassed to make such claims.

It is an incompetent excuse for an engineer who does not reinvent the wheel several times per year.

 

[antonio_eda]

I agree with you Actually, I came from a country, where the history has been falsified, especially in 1984 ;-)