We are prototyping a low noise amplifier based on the combination of an HMC-ALH476 and HMC981LP3E. We are using the HMC981LP3E to set the gate voltage to control the drain current, using component values suggested on P18 of the HMC981LP3e data sheet. On investigation, it looks like the HMC981LP3E may be incompatible with the HMC-ALH476 - the absolute gate voltage range on the HMC-ALH476 is -1v to +0.3v, and the HMC981LP3e applies -2.5v initially. Could you confirm if the HMC981LP3e can be used with the HMC-ALH476, and if -2.5 v applied to the gate of HMC-ALH476 would cause failure.
Yes you can use HMC981LP3E to bias HMC-ALH476. In order to change the default Vgate and Vneg threshold values you need to use external resistors. R4 and R6 resistors, at the attached circuit, change the -2.5V value to -1V for this application. Circuit is based on the die part but idea and the resistor values are same for the LP3 packaged HMC981LP3.