Design of Sub-THz Low-Power and High-Gain Amplifiers Based on Double-Embedded Technique

This article presents a sub-THz low-power and highgain amplifier design technique based on a double-embedded pseudo-Gmax-core. The implementation of the double-embedded pseudo-Gmax-core adopts an additional linear, lossless, and reciprocal (LLR) network that satisfies the Gmax-condition for any even or odd number of N-stage cascaded transistor-level pseudo- Gmax-cores which have a stability factor and phase delay of 1 and 2mπ/N, respectively. By utilizing the proposed doubleembedded pseudo-Gmax-cores, the amplifiers can achieve a higher gain with a reduced dc power consumption compared to the previously reported double-Gmax core-based amplifier, which can only employ an even number of stages. For proof of concept, two amplifiers are implemented in a 65-nm CMOS process which achieve power gain of 18.2 and 9.3 dB and gain-per-mW of 1.48 and 1.4 dB/mW at 280.2 and 309.2 GHz, respectively.