A CNTFET-C first order all pass filter

Abstract

A compact, low voltage, low power and high frequency voltage mode first order all-pass-filter (APF) topology is presented using carbon nanotube field effect transistor (CNTFET) based inverting voltage buffer. The proposed resistor-less APF topology uses only one capacitor and two N-type CNTFETs. Adding one CNTFET based voltage controlled resistor to the proposed first order APF results into an electronically controlled first order APF with a tuneable frequency range between 1.913 and 40.2 GHz. The proposed circuits are potential candidate for low voltage analog applications as it uses only two transistors between its supply rails. Moreover, both the proposed topologies do not have any passive component matching constraint. The realized filter circuit performance is verified with HSPICE simulations, using well known Deng’s CNTFET model at 16 nm technology node with supply voltage of ± 0.7 V. The simulation results substantiate the theoretical predictions.