Broadband terahertz integrated waveguide transition and its application in the amplifier module

In this paper, a broadband terahertz (THz) monolithically integrated waveguide-to-grounded coplanar waveguide (GCPW) transition, which can be operated in the whole R band (220-325 GHz), is designed for the first time. The WR3 standard waveguide and the radial E-plane probe transition are utilized in our design. A back-to-back transition structure with input and output waveguides is designed for the verification. The simulated results show that the insertion loss is approximate 1.5 dB and the return losses are more than 13 dB from 220 GHz to 325 GHz. Then a single-stage amplifier monolithic microwave integrated circuit (MMIC) with the integral waveguide-to-GCPW transition using 70-nm InP high electron mobility transistor (HEMT) process is designed, which can eliminate the need for wire bonds in the RF signal path. The amplifier can provide more than 1 dB gain at 300 GHz, with the input and output return losses of better than 13 and 20 dB, respectively.