I am a student and I designed a 77 GHz TRx in which I used ALH509 as LNA and AUH320 as PA. The problem is in biasing and I can't reach the maximum currents as it is mentioned in Datasheets, i.e., 70mA instead of 130mA in AUH320 or 15mA instead of 50mA in ALH509!! I also measured the voltages at the traces very close to the chips and the voltage drop is only around 10mV from the assigned voltage at the power supply. I have the same problem with HMC1144 that I used as PA within the LO path. The current valu that I see is 90mA instead of 320mA.
I don't understand why I can't see more current even with the gate voltage of 0 V!! I'd be very grateful if you could help me with this issue.
Thanks in advance,
I support the HMC1144 and can answer regarding that product, though I support neither the HMC-ALH509 nor the HMC-AUH320 and thus cannot answer for either of those products. The applications engineer(s) who support those products should soon answer.
With respect to the HMC1144, to see Idd=90 mA when using Vgg1=0V does indicate some type of a problem. Whether that problem is caused by a defective or damaged device or instead by a problem with the application and/or the application circuit remains to be determined. I hope that I can help you with this.
So that I can help, would you please provide some additional details such as the following?
Did you follow the bias sequence recommended in the Applications Information section of the data sheet?
Have you mounted the die such that there is minimal voiding between the die and substrate?
Are you using a particular thermal management scheme?