A 194-GHz Three-Stage Differential Driver Amplifier Utilizing a Three-Element Embedded Core at Near-TEXPRESERVE0 Frequencies in 65-Nm CMOS

In this letter, we introduce a 194-GHz three-stage differential driver amplifier operating at near- $f_{\mathrm{max}}$ frequencies. To address practical considerations associated with implementing on-chip embedding elements within the sub-THz frequency range, we employ a three-element embedded core consisting of three types of embedding networks. This design approach offers greater flexibility in selecting the required embedding elements. Based on the proposed embedded core, a three-stage drive amplifier is implemented in the 65-nm CMOS process. The measurement results indicate that the proposed amplifier exhibits a small signal gain of 20.4 dB, a $P_{\mathrm{sat}}$ of $-$ 2.1 dBm, and a peak PAE of 2.2% at 194 GHz.