A Novel Terahertz Ballistic Deflection Transistor Travelling Wave Amplifier System

Abstract

In this brief, an innovative terahertz (THz) ballistic deflection transistor (BDT) travelling wave amplifier (TWA) system is proposed. The BDT is an innovated technology device based on InGaAs/InAlAs/InP, able to operate at THz frequencies. The whole BDT TWA system design is based on a lossless THz transmission line called parallel plate dielectric waveguide with signal line (PPDWS). Parasitics for a single stage BDT amplifier and multiple-stage amplifier are also studied. In this brief a new thinner lossless PPDWS (transmission loss = 1.1 dB/mm) is developed. A new THz coupler applying the new PPDWS topology is also proposed and studied. It is shown that a 48-stage TWA system is able to provide a 15-dB gain at more than 1-THz frequency. Results compensate the low transconductance of the BDT and make the TWA a good choice for future THz amplifiers.