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Inductor's output power measurement using spectrum analyzer

  1. Nov 21, 2014 #1

    I have a question about measurement of spectrum analyzer.
    I made some inductor by lithography, evaporator, and lift-off process, and tried to measure using spectrum analyzer. (The probing was GSG type)
    I swept the frequency from 100MHz to 5Ghz, and output power was monitored by spectrum analyzer. (Input was 0dBm)
    Then, the output power increased by incresing the input frequency. (100Mhz -> -60dBm, 1GHz -> -40dBm, 5GHz -> -30dBm...)

    Does this passive element play a role by inductor? (or is it capacitor?)

    Thank you.
  2. jcsd
  3. Nov 21, 2014 #2
    Would you give more details on the inductor? How big it is, how many turns? Inductors parasitic capacity at very high frequency can make it behave more like capacitor than inductor
  4. Nov 22, 2014 #3


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    Gold Member

    I expect you are above the self-resonant frequency of the inductor/test system. Sweep lower and try to find the first resonant peak.
    If there is none detectable, the the parasitic capacitance is predominating.

    Also, you are testing with a 50ohm (probably) analyzer input. Compute how your expected inductance might behave with that load.
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