The design of a four-stage common-source (CS) 150 GHz amplifier in a 65nm technology is described. Each stage bases on the proposed technique of coupled transmission line (T-line) neutralization to achieve an improved intrinsic gain. Coupled T-line is also used for impedance matching, including both input and output, and inter stage impedance matching. Simulations show that the proposed amplifier circuit achieves a gain of 20 dB along with a 3dB bandwidth of 10GHz at 150GHz band, and a power consumption of 22 mW from a 1.2 V supply.