On the de-embedding of small value millimeter-wave CMOS inductor measurements

In radio frequency integrated circuits using a low resistivity silicon substrate, spiral inductors show advantages in performance and size with respect to transmission lines, even at frequencies as high as 60 GHz. In order to verify simulation results and build accurate models, test inductors need to be fabricated and characterized very accurately. This implies the precise determination of the effective quality factor Q_eff and the measurement of the inductance L within a few pico-Henrys. This paper reviews suitable on-chip calibration and deembedding techniques and proposes a technique that uses distributed and lumped elements to model the error two-ports. These elements also take into account the contact impedance. The results obtained by this novel de-embedding approach are compared to results of the other discussed methods and to simulation results. The obtained agreement proves the suitability of the proposed method for characterization of millimeter-wave inductors.