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Question about PCB design of HMC788A and HMC408LP3E

Question asked by Se-woong on Nov 30, 2017
Latest reply on Dec 12, 2017 by kkaya



My customer are considering to use HMC408LP3E and HMC788ALP2E.

And they have some issues to darw PCB artwork related desiding size of pattern.


Please refer below questions and let me know your opinions.


1. HMC408E


  As Page 9 of HMC408LP3.pdf, below TL1 (0.2 inch)  & TL2 (0.1 inch) value are optimized for 5.7 ~ 5.9 GHz operation.

Q1-1)  If  size of TL1 and TL2 are reduced, which specification or performance of HMC408E are changed?


Q1-2) Would you provide your data (or test result) about changed values of HMC408E specificartion?


Q1-3) If they use this device at 5.4GHz to 5.9GHz, would you recommend values of TL1 & TL2?


2. HMC788ALP2E

At page 8 of HMC788ALP2E.pdf , inductance value of L1 is recommded as "Conical 6.35uH.

Q2-1) Why do you use L1 inductor in your evaluation board?

          Is it for supporting wide band coverage?

Q2-2) If they use this device for 5 to 6GHz band only, would you suggest your recommended inductor?



Please advise me.