gate current in a HEMT

Thread Starter

jsnx

Joined Mar 17, 2022
21
Hello, I'm trying to understand the use of a HEMT as a power amplifier. I want to design a driver for a power amplifier and so I need to deliver enough current to charge the gate capacitance. I wanted to know if there is any other current I should take into consideration.

For instance, the gate contact is a Schottky one, if forward biased, it will "absorb" some current. How can I know how much current it would absorb?

I've also found this graph ( source : Reliability modeling of high voltage AlGaN/GaN and GaAs field-effect transistors)

1648666483569.png
why is there this decrease in the current close to 14dBm before it increases? What could be the physical explanation for that?

And last, I will be biasing my gate with a DC voltage and once the HEMT is on, the RF signal will be introduced. Will it affect the gate current in some way?


Thank you in advance
 

ronsimpson

Joined Oct 7, 2019
2,063
I think you are making a linear RF amplifier??
What part number?

I use GaN transistors in power supplies where the parts are full on or off and never in the linear region, so I might not be much help.
 
Top