InP-Based Integrated Circuits on SiC/Si Substrates for Terahertz Communications
Tadao Nagatsuma, Weijie Gao, Yuma Kawamoto, Takahiro Ohara, Hiroshi Itô, Tadao Ishibashi
Abstract
This paper presents our series of research results on devices and circuits that are fabricated using SiC- and Si-substrate-based platforms as practical integration methods to realize high-performance, cost-effective terahertz (THz) systems. The performance of these integrated devices in different 300- GHz-band communications systems is evaluated by packaging them into conventional hollow metallic waveguides or Sidielectric waveguides. The SiC platform-based receiver module has been designed with a waveguide-input direct detector and balanced mixer modules that use Fermi-level managed barrier (FMB) diodes. Waveguide-output uni-traveling-carrier photodiode (UTC-PD) modules on the SiC platform exhibit unsaturated output power of much larger than 1 mW and are successfully applied to the self-heterodyne transmitter at 125 Gbit/s. SiC-UTC-PDs are integrated onto Si-dielectric waveguide platform and demonstrated as the transmitter in a heterodyne communication system at 210 Gbit/s. Finally, waveguide-input IQ homodyne receiver modules are developed using the Si-platform. By combining the IQ receiver with SiC-UTC-PD modules in both the transmitter and receiver, a fully-photonic RF amplifier-less 300-GHz-band wireless link is successfully demonstrated.