A 220 GHz metamorphic HEMT amplifier MMIC

We present the development of two 220 GHz low-noise amplifier (LNA) MMIC's for use in high-resolution active and passive millimeter-wave imaging systems. The amplifier circuits have been realized using a 0.1 /spl mu/m InAlAs/InGaAs based depletion-type metamorphic high electron mobility transistor (MHEMT) technology in combination with coplanar circuit topology and cascode transistors, thus leading to a compact chip-size and excellent gain performance. The realized single-stage cascode LNA exhibited a small-signal gain of 5 dB at 220 GHz and a maximum gain of 7 dB at 215 GHz with an over-all chip-size of 1 /spl times/ 1 mm . The four-stage amplifier circuit achieved a linear gain of 20 dB at the frequency of operation and more than 10 dB over the bandwidth from 180 to 225 GHz while covering a chip-area of 1 /spl times/ 2.5 mm/sup 2/.