CNTFET Based Fully Differential First Order All Pass Filter

A novel, carbon nanotube field effect transistor (CNTFET) based fully differential first order all pass filter (FDFAPF) circuit configuration is presented. The FDFAPF uses CNTFET based negative transconductors (NTs) and positive transconductors (PTs) in its realization. The proposed circuit topology employs two PTs, two NTs, two resistors and one capacitor. All the passive components of the realized topology are grounded. Active only fully differential first order all pass filter (AO-FDFAPF) topology is also derived from the proposed FDFAPF. The electronic tunability of the AO-FDFAPF is obtained by controlling the employed CNTFET based varactor. A tunabilty of pole frequency in the range of 10.5 to 26 GHz is obtained. Both the circuits are potential candidates for high frequency fully differential analog signal processing applications. As compared to prior state-of-the-art works, both the realized topologies have achieved highest pole frequency and lowest power dissipation. Moreover, they utilize compact circuit structures and suitable for low voltage applications. Moreover, both topologies work equally well in the deep submicron. The proposed filters are analyzed and verified through HPSPICE simulations by utilizing Stanford CNTFET model at 16 nm technology node. It is observed that the proposed circuit simulation outcomes verify the theory.