Time-domain signal and noise modelling and analysis of millimetre-wave and THz high electron mobility transistors

This study presents the simultaneous signal and noise modelling and analysis of mm-wave/THz high electron mobility transistors (HEMTs) in the linear regime as stochastic active multi-conductor transmission lines (SAMTLs). For such devices, stochastic inhomogeneous telegrapher equations of SAMTLs are extracted assuming the domination of the quasi-transverse electromagnetic mode. Analytical solutions for these equations do not exist. So a numerical analysis of such equations is introduced here at millimetre-wave and terahertz frequencies. These equations are analysed with a numerical method in the time domain, namely the finite-integration technique. A semi-distributed model in the advanced design system commercial software is used to validate the numerical results. Also, the results of noise figure and scattering parameters (S-parameters) for the metal–semiconductor field-effect transistor transistor, which has the same SAMTLs model as the HEMT transistor, are compared with the measurement reports at microwave frequencies.