A Novel Verilog-A Nonlinear Equivalent Circuit Model for Carbon Nanotube Multifinger Schottky Barrier Diodes in Sub 6-GHz Tunable Microwave Component Applications

This letter presents a novel Verilog-A behavioral model for simulating the nonlinear electrical characteristics of carbon nanotube (CNT) multifinger Schottky barrier diodes (SBDs). Key parameters, including the ideality factor, junction capacitance, series resistance, nonlinear current–voltage ( $I$ – $V$ ) characteristics, and capacitance–voltage ( $C$ – $V$ ) characteristics, are extracted. Experimental measurements and model simulation results show excellent agreement. Furthermore, the proposed SBD model is applied to the design of a low-frequency wideband bandpass filter with tunable transmission zeros, showing low insertion loss and high selectivity. This work highlights the utility of CNT-based SBDs for modeling and RF design in sub-6-GHz applications.