I am having trouble with the HMC392LC4. I am unsure as to why I am getting a 20 dB Loss at the output of the cascade of these amplifiers instead of a 30 dB gain. The only difference between the eval circuit and the circuit I used for my PC board is the blocking caps I placed at the inputs and output s of the amplifiers. Could this cause the issue, seeing that the amplifiers have internal DC blocks? Any help will be appreciated.
Thank you all.
I've attached SMA coax pigtails to the input and output of the amplifier and biased it using an external PSU. The current was 56 mA (55mA is typical), the response was the same. About 10 dB loss at the peak (No gain). What are the chances that all the HMC392 chips were assembled incorrectly (the RF switches that are connected to the amplifiers on the board are also QFN 4X4 with the same footprint and they function as expected) or the chances that all four chips were damaged due to a low ESD tolerance, or even if the 4 IC's were from a bad batch? The only thing we can come up with, similar to you, is a bad RF path, whether internal or external to the chip. Do you have anymore suggestions or tests that we can do? Thank you for your reply.