A scalable compact small-signal mHEMT model accounting for distributed effects in sub-millimeter wave and terahertz applications

In this paper we utilize a new approach for a small signal model which is scalable from very small to rather large transistors in a wide frequency range from 50 MHz up to 500 GHz. We show that with increasing frequency and decreasing transistor size we need to take into account termination effects at the open ends of the transistor electrodes. This new approach is based on a decomposition of the transistor into multiport sections. These sections are simulated individually by an electromagnetic field solver and then parameterized by compact networks. The model is verified by S-parameter measurements up to 450 GHz.