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DC bias design with HMC981

Question asked by judy2350013 on Jul 28, 2016
Latest reply on Aug 11, 2016 by kkaya

Hi all,


I am considering Active Bias Controller like HMC981 to improve biasing of RF MMIC assembly. Here is all the bias voltages I need listed below.



I would like to use one HMC981 for each color then total should be three HMC981.


For the blue part, use one HMC981 provide Vdrain as VD2, Vgate as VG2 and VNEG as VG1. I would like to connect VD1 and VD2 together then use Vdrain to provide 2V with 30mA current. So here might have two problems come up. 

1. Is that possible to supply a MMIC with a drain voltage of +2V which is lower than the minimum specified (+4V)?

2. The datasheet shows that VNEG default should be -2.5V but stated it is possible to change through factory. Is that possible to change to VG2 (-0.6V)? Or any suggestions for this?


For the red part, use one HMC981 provide Vdrain as Vd_amp, Vgate as Vg_amp and VNEG as Vg_mix. Also need to change VNEG to Vg_mix (-0.8V).


For the orange part, Vdrain as Vd_x, Vgate as Vg_x3 and VNEG as Vg_x2. Also need to change VNEG to Vg_x2 (-0.8V).


I would be appreciated for your suggestions. Thanks in advance for your response.