I have an active antenna used for GPS. I need to supply the conductor of the RF cable with 5V DC. It consumes around 20mA. This antenna connects to a PCB where I inject the DC bias onto the RF line through an inductor.

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I would like to also have the ability to be able to open the RF line to able to simulate when the antenna is not connected to the SMA connector. All of the RF switches I have seen require DC block capacitors at their inputs, so that rules them out (the 5V bias must reach my active antenna.)

I also looked at using a PIN diode, but was unsure of the best approach. Does anybody know a good solution?

  • \$\begingroup\$ Use an RF relay. \$\endgroup\$
    – Andy aka
    Commented Dec 6, 2022 at 11:49
  • \$\begingroup\$ or add the 5V after the switch. (need to actually take care to achieve desired isolation) \$\endgroup\$ Commented Dec 6, 2022 at 12:27
  • \$\begingroup\$ Marcus I need to achieve the effect of creating an open condition to the antenna, it can be on the core or the shield. How about simply placing a N-FET in series with the shield of the SMA and the GND of my PCB? An RF switch that requires blocking caps will not work \$\endgroup\$
    – Engo
    Commented Dec 6, 2022 at 12:40


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