Scaling of InP HEMT Cascode Integrated Circuits to THz Frequencies

In this paper, we demonstrate that the cascode amplifier topology can be extended to operating frequencies >500 GHz. Two packaged cascode amplifiers are reported, including a broadband 3 stage amplifier with ~17 dB gain and 8.3 dB packaged noise figure at 300 GHz and a narrowband amplifier with 10 dB gain at 0.55 THz measured in package. Both of these amplifiers use 30 nm InP HEMT transistors, are realized in coplanar waveguide on a 1-Mil thick InP substrate and use a monolithically integrated electromagnetic transition for coupling energy from the chip to the waveguide package.