Terahertz communications with Resonant Tunnelling Diodes: status and perspectives

This chapter aims to provide a description of the state-of-the-art of the rapidly developing solid-state electronics for terahertz (THz) communications with a focus on the resonant tunnelling diode (RTD) technology. The other key technologies include those that are transistor-based, the so-called THz monolithic integrated circuits (TMICs), and photonics-based solutions, which utilise the uni-travelling carrier photodiode (UTC-PD) for generating the THz signal through photo-mixing. Only an overview of these other technologies will be provided. The chapter will present the status of THz RTD oscillator sources, which are the key component in RTD-based THz transmitters (Tx) and receivers (Rx). An overview of the technical challenges is provided and possible strategies for future progress of the technology are discussed