I am wondering how the signal gets amplified in ATF-58143 amplifer. I mean why does a signal input at gate gets amplified at drain. From what I understand in a FET a gate voltage is used to control the current flow from source to drain.

Thanks

 

Any amplifier can have voltage gain, current gain, and/or power gain. Rf amplifiers are usually described as having power gain.

 

Just pretend it's a bipolar transistor with a really high base impedance. Wiggles on the base (gate) voltage cause wiggles in the drain current, and that causes voltage wiggles across the drain resistor.

Yes, I invented a new word for "change in".