Design of Broadband CNFET LNA Based on Extracted I-V Closed-Form Equation

Abstract

A procedure of extracting a closed-form user-friendly I–V equation for short channel carbon nanotube field-effect transistors (CNFET) in the saturation region is presented by employing a relation between CNFET parameters meeting the experimental results. The methodology is based on the Stanford model and ballistic relation of one channel CNFET. In this regard, the ballistic relation is simplified to a closed-form I–V equation, and then, the parameters are estimated through the fitting algorithm by means of ICCAP and least square method, respectively, and the obtained equation is verified by the experimental results given in the literature. Additionally, an extended quantitative noise analysis is performed at the circuit level and the noise sources implemented in Verilog-A are added to the Stanford CNFET HSPICE model. Subsequently, with the accordance to the extracted I–V equation, a CNFET-based inductor-less broadband common-gate low noise amplifier (LNA) is designed theoretically and its results are confirmed in HSPICE based on the Stanford CNFET model, indicating a proper matching between analysis and simulation. The proposed CNFET-based LNA provides very-high-frequency bandwidth and also lower noise figure in comparison with its contemporary CMOS-based LNA, without any passive spiral inductor.