OICC Press Signal Processing and Renewable Energy (SPRE) 2588-7335 10 1 2026 03 31 A Low-Power CNTFET-Based Optical Communication Receiver for 40 Gbps Applications 10.57647/spre.2026.1001.02 EN Nazanin Zamani Department Engineering, Na.C., Islamic Azad University, Najafabad, Iran Mehdi Amoon Department Engineering, Na.C., Islamic Azad University, Najafabad, Iran; Digital Processing and Machine Vision Research Center, Na.C., Islamic Azad University, Najafabad, Iran https://orcid.org/0000-0001-9751-278X Zahra Alaie Department Engineering, Na.C., Islamic Azad University, Najafabad, Iran; Digital Processing and Machine Vision Research Center, Na.C., Islamic Azad University, Najafabad, Iran Mahmoud Daneshvar Farzanegan Department Engineering, Na.C., Islamic Azad University, Najafabad, Iran; Digital Processing and Machine Vision Research Center, Na.C., Islamic Azad University, Najafabad, Iran Journal Article 2026 03 31 This paper presents an optical receiver system for 40 Gbps communication applications in 32 nm carbon nanotube field-effect transistor (CNTFET) technology. The architecture consists of a modified regulated cascode (MRGC)-based transimpedance amplifier (TIA), followed by limiting amplifiers (LAs). The TIA is designed using the  methodology to optimize performance and power efficiency.    Simulation results indicate that the modified TIA achieves a transimpedance gain of 56.6 dBΩ, a −3 dB bandwidth of 28 GHz, an input-referred noise current of 14 pA/√Hz, and a power consumption of only 177 µW. The TIA is fully transistor-based and occupies a compact 2240 nm × 1216 nm chip area. The LA stage provides a voltage gain of 10.3 dB, a bandwidth of −3 dB at 32 GHz, and power consumption of 382 µW, in an area of 11.14 µm². The optical receiver system demonstrates a transimpedance gain of 86.9 dBΩ, a −3 dB bandwidth of 34.2 GHz, total power consumption of 1387 µW, and occupies a chip area of 48.40 µm². All simulations are performed at a supply voltage of ±0.45 V, with the photodiode and load capacitors set to 10 fF. The gain, bandwidth, and input-referred noise characteristics of the TIA are derived analytically and discussed using the  design methodology. Both analytical and simulation results confirm the suitability of the topology as a low-power optical receiver for next-generation communication systems.