A 280 GHz 30 GHz Bandwidth Cascaded Amplifier Using Flexible Interstage Matching Strategy in 130 nm SiGe Technology

This paper presents a 280 GHz amplifier design strategy for a robust multistage amplifier in a sub-Terahertz (sub-THz) regime in 130 nm SiGe technology. The presented 280 GHz amplifier consists of 14 stages of the cascaded common emitter (CE) amplifier which offers a compact and improved-noise design due to the absence of the area-expensive and lossy baluns at such high frequencies. The interstage-matching network was flexibly constructed with two separate resonant tanks using metal–insulator–metal (MIM) capacitors and microstrip transmission lines (MSTLs) between each stage. The measured amplifier achieved a peak power gain of 10.9 dB at 283 GHz and a 3 dB gain of bandwidth of 30 GHz between 270 and 300 GHz. The peak output power of the amplifier was 0.8 dBm with an output of 1 dB gain compression point (OP1dB) of −3.6 dBm in simulation. The 14-stage amplifier consumes an area of 0.213 mm², including all the pads. With the proposed interstage matching approach, a well-balanced 280 GHz amplifier has been demonstrated. The proposed design strategy is widely applicable to sub-THz receivers for future wireless communication systems.