Amir Baghi Rahin - Department of Electrical Engineering, Sardroud Branch, IAUT, Tabriz, Iran
Amirsaeed Alijanpour - Department of Electrical Engineering, Babol Noshirvani University of Technology, Babol, Iran
Mohammad Hossein Akhtarzadeh - Department of Electrical Engineering, Babol Noshirvani University of Technology, Babol, Iran
Afshin Kadivarian - Department of Electrical Engineering, Science and Research Branch, IAUT, Tehran, Iran
Vahid Baghi Rahin - Department of Electrical Engineering, Sardroud Branch, IAUT, Tabriz, Iran

This paper presents a new tunable Operational Transconductance Amplifier (OTA) based on double-gate carbon nanotube field effect transistor (DG-CNTFET). The inverter-based OTA works with low supply voltage (۱.۰ V) and it is suitable for continuous-time filters in the VHF range. The tunability of this OTA is easily achieved by the control voltages of the DG-CNTFET’s back gates. The proposed OTA has no internal nodes and allows rail-to-rail input voltage swing. Based on the results of HSPICE simulations in the ۳۲ nm process, the OTA has a dc gain of ۸۱ dB. unity gain frequency (UGF) of the proposed OTA is ۱.۱۲ GHz and its phase margin is ۹۰°. As a sample application, a second-order filter with low-pass and band-pass outputs was implemented based on the proposed OTA. Based on the simulation results, the DG-CNTFET-based filter can provide a frequency range of ۶۸ kHz to ۱۴۳ MHz with a tuning range greater than ۱۶۰ times for low-pass response. The power consumption of the filter in the tuning range can vary from ۰.۱۷ μW to ۹.۷ mW depending on the required filtering range.

Operational Transconductance Amplifier (OTA), Double-Gate Carbon Nanotube Field Effect Transistor (DG-CNTFET), VHF Transconductor, Gm-C Filters