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HMC788ALP2E - DC feed question

Question asked by JUST_ANOTHER_RF_GUY on Feb 4, 2015
Latest reply on Feb 5, 2015 by JUST_ANOTHER_RF_GUY

Hello all,

 

  In looking at the evaluation board information included in the datasheet for the HMC788ALP2E device (pages 7 and 8) it seems pretty obvious to me that the conical inductor feeding the DC voltage to the device was a very purposeful decision.  Given that I do not see any noticeable structures in the output trace from the device, my assumption is that the designer of the evaluation board wanted to make a very nice broadband DC feed... but we all know what happens when you assume. In my application I do not need an extremely broadband match and simply cannot afford the space required to put the same conical inductor in the design.  Does anybody have experience using this part with an alternate DC feed network?  Alternatively, if any of the Hittite design or apps engineers are reading this, I would greatly appreciate your suggestions.  Right now my plan is to start a simulation with the S2P file from Hittite and add my proposed biasing structure to the output to see if I notice any significant changes in insertion loss and return loss.  In this application, the output power we be +15 dBm at the absolute maximum, so I am not too worried about affecting the P1dB performance of the part. 

 

Thanks in advance for the help!!  

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