An Improved Junctionless Nanowire Field Effect Transistor (I-JL-NWFET) device is proposed in this paper to address the limitations of conventional JL-NWFET. This research paper initially, comprehensively analyzes the impact of channel length (L) and channel thickness (t si ) scaling on the electrical, analog/RF, and linearity performance of I-JL-NWFET and JL-NWFET. The results suggest that the specific design features in I-JL-NWFET contribute to a more robust and less sensitive response to variations in scaling compared to its counterpart, JL-NWFET. Furthermore, an exploration into the impact of temperature on the electrical, analog/RF, and linearity performance is also conducted for both I-JL-NWFET and JL-NWFET. The electrical performance of I-JL-NWFET showcases a significantly reduced temperature sensitivity in parameters like drain current (I D ), Subthreshold Slope (SS) and Drain Induced Barrier Lowering (DIBL) compared to JL-NWFET. Subsequently, analyzing the analog/RF performance in the context of parameters such as transconductance (g m ), Transconductance Gain Factor (TGF), output conductance (g d ), early voltage (V EA ), total gate capacitance (C GG ), and cut-off frequency (f T ) under temperature variation, a lower degree of variability in I-JL-NWFET is observed compared to JL-NWFET. Furthermore, the linearity performance of I-JL-NWFET, assessed through parameters such as second and third-order transconductance (g m2 , g m3 ), second and third-order input voltage intercept points (VIP2, VIP3), and third-order intermodulation distortion (IIP3 and IMD3) is improved at the higher temperature than that of JL-NWFET.