A 300 GHz High-Pass Distributed Amplifier using a Quasi High-Pass Transmission Line Topology

This paper presents a H-band high-pass distributed amplifier consisting of two cascaded amplifiers, which is used as pre-amplifier to drive subsequent high-power amplifier. The first stage is a high-pass distributed amplifier with four parallel gain cells as driver amplifier. The second stage consists of two parallel high-pass distributed amplifiers, connected using a Wilkinson power dividers. Both stages use RF-grounded shunt stubs at gate- and drain-line in order to design high-pass artificial transmission lines. A 3-dB-bandwidth of more than 80 GHz is achieved with a maximum gain of up to 15 dB and a saturated output power of 3 dBm. The maximum measured power added efficiency exceeds 4.5 %. The amplifier is fabricated in a 35 nm InGaAs mHEMT technology