• HMC547 ac coupling question

    I am wondering if I have a fixed attenuator after the HMC547 switch do I need to have AC coupling caps to the attenuator?  I am trying to minimize my component count and want to make sure a coupling cap is or is not required.


  • How can I choose Value of DC block capacitor at HMC547?

         I'm using HMC547 (electric switch).

    It operates from DC to 20GHz.

    From Datasheet, evaluation board has no DC blocking capacitor at input and output port.

    But frequencies I'm interesting are dual band, 3GHz and 9GHz. So I need DC block capacitor…

  • RE: DC block between HMC519 and HMC1019

    Thank you very much s.ilke, I take into account your recommendations, and remove the DC block capacitors between the attenuator pad and the HMC547, and between the HMC547 and the HMC1019.

    You're right, the attenuator pad is equivalent to a pi-pad configuration…

  • RE: 射频开关咨询


  • HMC547ALP3E RFC connected to HMC641ALP4E RFC with no AC coupling cap, weird insertion loss behavior

    I have a fan-out circuit suing a HMC547 (to select src or cap) connected via RFC to a HMC641 to mux out to 4 lines

    The board has AC coupling caps on all the RF inputs but the RFCs are connected together DC coupled (oversight)

    I am getting weird issues…

  • RE: Reliability Information


    Try these URLs.

    HMC547LP3E: http://www.analog.com/media/en/quality/hmc-qtr/QTR_2013-00247.pdf

    HMC641ALP4E: http://www.analog.com/media/en/quality/hmc-qtr/QTR_2013-00285.pdf

    Note that HMC939LP4E and HMC547LP3E are obsolete parts. We recommend you to change…

  • ADRF5020 Video switching Noise

    Please can someone indicate if this switch has similar low Video breakthrough noise compared to the HMC547 as this is a silicon process instead of a the 547's GaAs MESFET process.


     I am using this in a 2-18GHz application and need to know if i need…

  • RE: Board level alternative to HMC-C019


         The HMC-C019 consists of 2 HMC547 die in series.   As long as you optimized the layout for isolation there is no reason a PCB version of the HMC-C019 should not work as well.

    best regards,


  • RE: HMC494 how to prevent self oscillation in differential mode

    Hi Marty, thanks for your reply.

    Yes all the DC blocking caps are broadband caps.

    1) Regarding oscillation. Yes i am driving differential. There is an RF switch is between the PLL output and the HMC494 divider inputs. The differential signal is not always…

  • Impedance related issue with HMC547LP3E


    I've been evaluating the SPDT HMC547LP3E, DC-20GHz as well as an SP4T HMC641, DC-20 GHz switch for use in one of my projects, using the evaluation modules. However, during my testing I noticed that the impedance of the switches jumps to ~65 Ohms…