AnsweredAssumed Answered

DC block between HMC519 and HMC1019

Question asked by AntoineCar on Jan 19, 2018
Latest reply on Mar 9, 2018 by AntoineCar

Hi,

 

Like a lot of people it seems, I have some doubt with my design when I read in datasheets "Blocking capacitors are required if RF line potential is not equal to 0V.".

 

I have 2 configurations in my design for which I assume I don't need DC block capacitors, but I would appreciate a confirmation:

 

   1. I use the following chain: HMC519LC4+HMC1019ALP4E+HMC498LC4

HMC519 and HMC498 are AC coupled on RF ports, but the HMC1019 datasheet says "Blocking capacitors are required if RF line potential is not equal to 0V." Can you confirm in this case that I don't need to use DC block capacitor between the HMC519 and the HMC1019, and between the HMC1019 and the HMC498 ?

 

   2. I use this second chaine too: DC block+Attenuator pad+HMC547ALP3E+HMC1019ALP4E+DC block

The datasheets of both HMC547 and HMC1019 say "Blocking capacitors are required if RF line potential is not equal to 0V." Can you confirm in this case that I don't need to use DC block capacitors (neither between the attenuator pad and the HMC547, nor between the HMC547 and the HMC1019) ?

 

More generally, for a RF port which is specified "Blocking capacitors are required if RF line potential is not equal to 0V.", is it correct to approximate it, from a DC point of view, as a self connected to GND ?

 

Thanks in advance for your help, and best regards,

Antoine

Outcomes