A terahertz ring hybrid coupler based on parallel plate dielectric waveguide with signal line for a ballistic deflection transistor travelling wave amplifier

In this paper, a new design of Terahertz (THz) Ring Hybrid Coupler Based on Parallel Plate Dielectric Waveguide with Signal Line inserted (PPDWS) is proposed. The PPDWS is a simple transmission line, easy to fabricate, with a low average loss of 0.45dB/mm at 1–1.4THz, and designed to be implemented into the THz Ring Hybrid Coupler Design. We employ (3N+1.5)λ for the circumference of the Ring Hybrid Coupler for a fundamental mode of TE10. ANSYS HFSS simulations show S21=S41=−4.5dB, S31< −20dB, S11<-20dB at 1.022THz. We obtain an excellent isolation between split ports for signal transmission, and a very good signal cancellation on port3. The coupler and PPDWS line are planned for use in the Terahertz Ballistic Deflection Transistor Travelling Wave Amplifier; however, the design is also capable of being applied to other very high frequency applications.