Custom HMC407 board only adds 1 dB to 14dB output

Question

Hi 
 
 I have replicated the HMC407MS8G Evaluation board on a 4 layer PCB and a 2 Layer PCB made from JLCPCB.com 
 Upon testing each PCB with a 12dBm output source, I noticed that the when adding the 4 layer board HMC407 board as an amplifier the output increased only by 1dB. Total output power was 13dBm 
 Upon testing the 2nd design with the 2 layer board HMC407 board the amplifier increased the output by 1.5dB so the total output power was 13.5dBm 
 Can someone please explain to me what the reason is behind this decreased power? I'm more than happy to share the designs. It's not the first time that I try to replicate AD evaluation boards, and my output power is nowhere close to what the datasheets claim. 
 Any help would be appreciated. 
 
 Thanks

enash · Accepted Answer

Are you saying that you made a PCB replica of the HMC407 eval board and you are getting a connector-to-connector gain of 1 dB for one board and 1.5 dB for the other board? Do you have a HMC407 board on hand to check your setup? Is the device getting very hot and is your current consumption about what you would expect. The 2-layer vs 4-layer thing should not make a difference but you should have vias under the exposed pad of the device that go through to the underside of the board. Your input and output traces need to be 50 ohm matched. Do you have a network analyzer on hand so that you can check this?)

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Custom HMC407 board only adds 1 dB to 14dB output