Passive Components

The Passive Components are used to help user during the bench sizing (Receivers attenuation calculation), the calibration (Source Power Offset) and the measurement de-embedding step (Input & Output Fixtures).

  • Receivers attenuation calculation

    Depending on the power level expected, some attenuators have to be added between the couplers and the VNA’s receivers. During the full power sweep used to characterize the DUT, the power seen by the input VNA’s receivers must be compliant with the maximum power than can be provided to the VNA’s receivers, minus a certain amount of power in order to use these receivers in their linear operating conditions.

    For example, Keysight PNA-X N5242A will be used for Power characterization. The absolute maximum power which can be sent to the receivers is +15dBm. Nevertheless, VNA receivers must see a power lower than -5dBm. If not, the measurements will be done in receivers nonlinear measurement conditions, and therefore will not be accurate. ideally, a maximum power of -20dBm seen by the receivers is advised to meet high measurement accuracy. If not, the power at will lead the receivers in saturation. In order to find the best trade-off between the noise floor and the saturated region of the receivers, a power budget has to be done to define the appropriate attenuators on each VNA's receiver.

    Filling up DUT, Output Coupler, Input Coupler hardware, IQSTAR will indicate on the schematic the recommended attenuation values to be added between the couplers and the VNA receivers taking into account a maximum power of -20dBm seen by the receivers:



  • Raw Power Offset

    Filling up Driver Amplifier hardware, IQSTAR will apply an offset value on each raw (source) power level defined during the calibration and measurement steps. Driver Amplifier information provides a fast method of compensating port power for added attenuation or amplification in the source path. It's an alternative of the Raw Power Calibration:

    • For amplification, use positive offset
    • For attenuation, use negative offset


  • Input & Output Fixtures

    The fixtures files can be used when the reference plane of the calibration and the one for the desired data is not the same. In this case, the fixtures can be used to directly de-embed the power waves during the measurements by using the corresponding S2P block files filled in Input Coupler.