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.