I currently have two setups with the same components and in one of the setups I am experiencing some type of oscillation since these amplifiers do not deliver the typical gain. The only difference between the setups is the layout, distance between components. I was wondering what could be causing oscillations, but also if you guys have a spise type model for the HMC635LC4 so that additional simulation can be done to prevent oscillation in the future.
My setup is using a doubler XX1000QT, HMC899LP4E filter, then two HMC635LC4 with a KAT+6 attenuator in between. It is a little strange that in one of the setups the amplifiers work well over the entire frequency band, but in the second setup the amplifiers oscillate (don't deliver the appropriate gain) from 33.5GHz to 37GHz. We have tried to compare the differences between the setups, but the most obvious is the distance between the components. We don't have additional DC capacitors around HMC635 since it is already built in. Could it be some type of DC leakage into the amplifier?