Metamorphic 94 GHz power amplifier MMICs

In this paper, we present the development of two 94 GHz power amplifier MMICs for use in high-resolution synthetic aperture radar (SAR) systems. The amplifier circuits have been realized using a 0.1 mu m InAlAs/InGaAs based depletion type metamorphic high electron mobility transistor (MHEMT) technology in combination with coplanar circuit topology and dual-gate transistors, thus leading to an excellent power and gain performance at millimeter-wave frequencies. The realized two-stage driver amplifier (MPA) MMIC exhibited a small-signal gain of 16 dB and a saturated output power of 20.5 dBm at 94 GHz with a total gate width of 0.72 mm in the output stage. The two-stage high power amplifier (HPA) circuit achieved a linear gain of 10 dB and a saturated output power of 23.3 dBm with a total output periphery of 1.44 mm.