A 25.5-34.5 GHz Broadband Compact Amplifier in 28 nm CMOS Technology

A compact millimeter-wave (mm-wave) amplifier is presented in this paper. The amplifier consists of three cascode stages with a single-ended configuration and is implemented in a 28 nm CMOS technology. In order to achieve the demonstrated compact core size, the input, output, as well as two inter-stage matching networks of this circuit were all realized with only a single inductor. Without using any other passive components, the core size of this three-stage amplifier is shrunk to $0.29 \mathrm{~mm} \times 0.28 \mathrm{~mm}=0.08 \mathrm{~mm}^{2}$. With a total dc power dissipation of $\mathbf{6 0} \mathrm{mW}$, this amplifier exhibits a peak gain of 15.9 dB at 29.5 GHz with $9 \mathrm{GHz} 3-\mathrm{dB}$ bandwidth (BW) from 25.5 to 34.5 GHz. Meanwhile, the measured maximum output 1 dB compression point (OP1dB) is 2.75 dBm at 29 GHz, and the minimum in-band noise figure (NF) is 6.4 dB at 34 GHz, including around loss of the feeding lines both at the input and output side. Overall good agreement between simulation and measurement is observed.