This article presents a high-gain and wide band D-band low-noise amplifier (LNA) adopting a proposed wideband pseudo-simultaneous noise-and input-matched (p-SNIM) dual-peak (DP) maximum achievable gain (G(ma)x)-core. For a transmission line (TL)-based DP G(max)-core, the p-SNIM condition is satisfied by adjusting the stability factor (K-f) without requiring additional components. Comprehensive analysis of the DP Gmax-core is performed to investigate the unique behaviors of input admittance for simultaneous conjugate matching (Y-in(& lowast;)) and optimal admittance for minimum noise figure (NF) (Y-nopt) as a function of K-f, which is fully exploited to implement the wideband p-SNIM DP G(max)-core. Moreover, we present the design procedure of a proposed dual-frequency inter-stage matching network that enables the wideband multistage LNA implementation. Implemented in a 40-nm CMOS technology, the D-band three-stage LNA achieves a peak power gain of 16.3 dB, a 3-dB bandwidth of 24 GHz, and a minimum NF of 4.9 dB while dissipating only 16.1 mW.