An 85?115 GHz MMIC amplifier using self-designed 90-nm InP PHEMT

An 85-115 GHz three-stage monolithic millimeter-wave integrated circuit (MMIC) amplifier based on 90-nm InAlAs/InGaAs/InP pseudomorphic high electron-mobility transistor (PHEMT) devices has been designed. The PHEMT (0.09×2×25um²)used in this design has a dc transconductance (g_m) of 1640 mS/mm with f_t =247 GHz and f_max=392 GHz. The monolithic three-stage amplifier demonstrates a small-signal gain of 18.7 dB at 105 GHz and greater than 15.5 dB gain from 85 to 115 GHz. This amplifier is designed through schematic simulation and momentum EM co-simulation. In this design, the high-low pass filter structures are used for matching network, edge-coupled lines are selected to block dc voltage, radial stubs are chosen as RF ground and shunt RC networks are included in the bias circuitry to maintain amplifier stability. Ground coplanar waveguide (GCPW) structures are added in input and output port.