Low-noise amplifiers in D-band using 100 nm and 50 nm mHEMT technology

This paper presents two low-noise amplifiers in D-band (110-170 GHz) using metamorphic high electron mobility transistor (mHEMT) technology with gate lengths of 100 nm and 50 nm for applications in passive millimeter-wave imaging. Both amplifiers consist of four transistor stages with a gate width of 2 × 15 μm, each. The chip sizes are 1.0 × 2.0 mm². The circuit design and the impedance matching networks are described in detail and the simulations of the scattering parameters and the noise figure are compared to D-band measurements. A small signal gain of 18-21 dB over a bandwidth of 30 GHz and 20-26 dB in a narrowband design was achieved. Both amplifiers demonstrated a measured noise figure of well below 4 dB.