A 120-160 GHz 28 mW LNA in 70-nm GaAs mHEMT Technology

In this paper, a D-band low noise amplifier (LNA) is designed at the operation frequency of 140 GHz in a 70-nm GaAs metamorphic high electron mobility transistor (mHEMT) process. The three-stage cascode and one-stage common-source LNA is proposed to achieve wide bandwidth, low noise and high gain. Impedance matching is designed by using T-shape and dual T-shapes networks in the input, output and interstage matching. Passive devices are electromagnetically characterized at such a high frequency, including series capacitors and bypass networks. The LNA exhibits simulated average gain of 26.7 dB, global noise Figure below 6.1 dB, and bandwidth of 40 GHz. The input and output return loss are better than 13 dB and 9 dB, respectively. The power consumption is only 28 mW. The layout of the circuit occupies the area of $1.85 \times 1.4 mm^{\mathbf{2}}$.