The paper provides a comprehensive comparison of differential amplifiers designed with CMOS (Complementary Metal-Oxide-Semiconductor) at the 45nm technology node and NCFET (Negative Capacitance Field-Effect Transistor) at the 40nm technology node. With the ongoing advancements in semiconductor technologies, the investigation of innovative transistor structures like NCFETs has become essential due to their potential for improved performance and reduced energy consumption compared to conventional CMOS devices. The performance of CMOS and NCFET-based differential amplifiers is evaluated based on various key parameters, including AC Gain (dB), Phase Margin (degree), Unity gain bandwidth (Hertz), Bandwidth (Hertz), delay (nano seconds), Common-Mode Rejection Ratio (CMRR in dB), Input Common-Mode Range (ICMR+ and ICMR- in volts), Slew Rate (Volts/microseconds), Power Consumption (micro-Watts), and Power Supply Rejection Ratio (PSRR in dB). Significant differences in performance metrics between CMOS and NCFET-based designs are identified and analyzed.