Analysis of tip-sample interaction in microwave impedance microscopy by lumped element model

We present a detailed analysis of tip-sample interaction in microwave impedance microscopy by applying lumped element method in this paper. A lumped element model is proposed and the value for each lumped element component is optimized. We find that reflection coefficient including both magnitude and phase obtained by simulation using this model matches with experimental data measured by microwave impedance microscopy (MIM) quite well. Also, the effect which both capacitance and resistance variation have on the tip-sample interaction is discussed. After that, sensitivity of this lumped element model to the electrical parameters is analyzed in this paper.