teleko7
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Hi all.
Regarding S parameters and their measurement with modern VNAs, most of the times reference impedance is 50ohm, as is the characteristic impedance of the waveguides that connect the VNA and the DUT. This way, TRL calibrations (that set the value of Zref) are consistent and the VNA measures the traveling waves with generator and load, no reflected wave in the load port of the DUT.
Is there any real-life situation where one wanted to set a reference impedance different from the characteristic impedance of the VNA waveguides, and different from 50 ohms? I can only think of CAD EM simulations, where modal waveguide ports measure generalized S parameters that can then be"normalized" to 50 ohms.
Regards.
Iban
Regarding S parameters and their measurement with modern VNAs, most of the times reference impedance is 50ohm, as is the characteristic impedance of the waveguides that connect the VNA and the DUT. This way, TRL calibrations (that set the value of Zref) are consistent and the VNA measures the traveling waves with generator and load, no reflected wave in the load port of the DUT.
Is there any real-life situation where one wanted to set a reference impedance different from the characteristic impedance of the VNA waveguides, and different from 50 ohms? I can only think of CAD EM simulations, where modal waveguide ports measure generalized S parameters that can then be"normalized" to 50 ohms.
Regards.
Iban