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HMC197B switching rate

Hello,

for an academic research project I need a very fast RF switch with low insertion loss in order to modulate (On/Off keying) a 2.4GHz carrier. The HMC197 switch seems to be a good fit for this job as it shows an IL of 0.4dB and a rise/fall time of 3ns.

However, I am not quite sure what would be the maximum switching rate that can be achieved with this switch. Is it 1/(tON+tOFF) = 50MHz? In addition, there is only a typical value given for the switching speed characteristics.

Also, I wonder whether the maximum input power for hot switching (20dBm) has to be reduced further when it comes to switching with a high rate (say, 20MHz).

Please note that since this is for academic research an not for production, it's OK to push the device to it's limits.

I would be grateful for any advice you might be able to give me.

Best regards,

Martin

  • Hi,

    thank you very much for your answer, it is very helpful.

    Still, I dare to add two more questions:

    I'm a bit puzzled by the datasheets of HMC197B & HMC221B:

    The HMC197B one says:

    • See HMC221B(E) for same performance in an alternate SOT26 pin-out.
    • Insertion loss: DC - 2.5 GHz: 0.4dB (typ) 0.9 (max)

    The HMC221B one says:

    • Insertion loss: 2.5 GHz to 3.0 GHz: 0.8 dB (typ), 1.1 dB (max)
    • But the "typical characteristics" plot clearly shows an IL below .5dB for the full range 2.5 GHz to 3.0 GHz

    These statements don't really go together.

    Since the pinout of HMC221B is actually better suited for my layout, I wonder now whether HMC197B really has the better performance in terms of insertion loss.

    The second question is whether there is a good way to simulate the transient behaviour of the switches, since the S-parameters are probably of no use for may application.

    Again, thanks a lot!