Determining the reference impedance of on-wafer TLR calibrations on lossy substrates

This paper presents an efficient reference impedance determination method, which is applicable to TLR calibrations performed on a wide variety of substrates, including those consisting of low resistivity material. The method is shown to be valid up to 40 GHz. It is based on the comparison of DC-resistance and scattering-parameter measurements of a resistor, a short and an open.