Low-noise Si/Si0.5Ge0.5 SOI junctionless TeraFET for designing sub-0.5 dB ultra-broadband LNA in 6G applications

Impurity scattering in junctionless transistors reduces electron velocity in the channel, so the performance of analog/RF at high frequencies degrades. For the first time, this study offers shell-doped channel along with a stacked layer in the source region to optimize analog/RF figure of merits and high-frequency noise performance of heterostructure silicon on insulator-junctionless transistor (HH-SOI-JLT). The suggested idea causes increasing gate control in the maximum current path and decreases impurity scattering. Therefore, current density and mobility of electrons in the channel enhance, and transconductance remarkably increases. The proposed structure named shell-doped channel HH-SOI-JLT (SDCh-HH-SOI-JLT) attains gmmax = 25 mS/µm (transconductance), (f_{{ ext{T}}}) = 3.5 THz (unity gain cut-off frequency), NFmin = 0.07 dB (minimum noise figure), and Gma = 26.8 dB (maximum available gain). The gmmax, (f_{{ ext{T}}}), NFmin, and Gma are modified by 150%, 110%, 100%, and 23% compared to HH-SOI-JLT, respectively. A low-noise amplifier (LNA) using SDCh-HH-SOI-JLT designed for F-Band 6G. An s2p model is developed for the proposed device and incorporated into the ADS software in circuit simulation. The LNA with NF < 0.3 dB and nearly flat S21 (≈ 15 dB) were achieved. Thus, the SDCh-HH-SOI-JLT is considered a reasonable candidate for 6G mobile communication systems and radars. Graphical abstract