Hi, I used the HMC981LP3E for controlling bias on the HMC460LC5 Follow the circuit recommended by AN-1363，But HMC981 has no correct output.
The test results are as following：
1.VDD is 8.75V and VDIG is 5V.
2.VNEG =+0.8V，VGATE=+0.7V（The output of VGATE is a negative voltage bewteen -2 to 0V theoretically）
3.VDRIN has no output .（In fact, its test value is equal to +0.15V）
Did I do something wrong,or was there something I ignored?
Hi ckl1009,
There may be a problem with your LNA but there are some issues I notice. One issue I see is that R60 should see .3V less than R59. You can use the a calculator that is on our wiki (link below) to determine passive values in the circuit. For example: R60 = 867Kohms and R59 = 1.6Mohms. Just to make sure, the correct bias sequencing is below.
https://wiki.analog.com/resources/eval/user-guides/active-bias-controllers/hmc981
Thanks,
DanO
