Highly Linear and Low Noise Shell Doped GaN Junctionless Nanotube TeraFET for the Design of Ultra-Wideband LNA in 6G Communications

The evolution trend of wireless communication systems tends to ultra-high data rate, ultra-low latency, and high bandwidth systems. It is foreseen that 6G wireless communication systems will be developed in the range of 100-300 GHz (upper mmWave band) and 300-3000 GHz (terahertz band). In such frequencies, the performance of junctionless field effective transistors is limited due to the reduction of carrier mobility in the device channel. In this paper, for the first time, a shell doped device is proposed to improve RF merit parameters and high-frequency noise performance of GaN junctionless double surrounding nanotube FET device with dual material outer gate (SD-GaN-JNFET). Simulation results show that the doping engineering in the proposed device reduces scattering caused by phonon and doping and increases electron mobility significantly. Parameters gmmax and ƒT of the SD-GaN-JNFET device in channel length of 15 nm are 666 μS and 8.47 THz, respectively, and NFmin<0.025 dB is satisfied in the frequency range of 0-500 GHz. The effect of shell doped area on the linearity performance is evaluated. Moreover, the device shows excellent reliability in terms of trap charges. A non-quasi-static small signal model is developed for the device and incorporated into a low noise amplifier (LNA) design. The LNA with S21 = 22.10 dB and NF = 0.032 dB in central band frequency (140 GHz) was attained. This article opens up an opportunity to achieve high-performance LNA for D-Band 6G applications with the reliable SD-GaN-JNFET device.