Tunable VHF Transconductor Using Double-Gate Carbon Nanotube Field Effect Transistors (DG-CNTFETs) and its Application in Gm-C Filters

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.

کلیدواژه ها:

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