Terahertz Transceivers for Short Range Multi-Gigabit Wireless Communications

The demand for broadband content and services has been growing at tremendous rates, and predictions indicate that wireless data-rates of multiple tens of gigabits per second (Gbps) will be required by the year 2020, essentially for short-range connectivity. Currently available wireless technology cannot support these future demands, and so there is an urgent need to develop new technology platforms that are cost and energy efficient to enable ubiquitous ultra-broadband wireless communications seamlessly integrated with high-speed fibre-optic networks, paving the way for 100 Gbps data rates in the longer term. The frequency spectrum currently in use is not expected to be suitable to accommodate the predicted future data-rate requirements, and therefore there is a need to embrace higher frequency bands, above 60 GHz and up to 1 THz.
Aims and objectives:
This project aims at developing a novel, low cost, energy-efficient and compact ultra-broadband short-range wireless communication transceiver technology, capable of addressing predicted future network usage requirements. This will be pursued through the exploitation of Resonant Tunnelling Diode (RTD) devices which represent the fastest pure solid-state electronic devices operating at room temperature with reported working frequencies exceeding 1 THz. The project aims at increasing the RTD oscillator output power to over 1 mW at frequencies above 500 GHz through improved circuit design and implementation, and the use of this in basic multi-gigabit wireless communications links.
Novelty of the research methodology:
On this project, we will also seek to develop high power sources at 600 GHz and 1THz. The higher frequencies provide higher (modulation) bandwidth, while the antenna challenge is reduced since the high permittivity substrate can be isolated with a ground plane and a spin-on dielectric such as benzocyclobutane (BCB) used as a substrate for common planar antennas such as patch antennas. The oscillators will be realised in the recently developed polyimide-based microstrip technology which offers the required low inductance values required to realise THz RTD oscillators. The epitaxial layer design and processing will be optimised to reduce the device contact resistances and the peak current voltage to increase both the device bandwidth and circuit efficiency, respectively.
Alignment to EPSRC's strategies and research areas:
The research topic is aligned to EPSRC priority areas of RF and Microwave Devices, Non-CMOS Device Technology and Manufacturing the Future.
Its potential applications and benefits:
The terahertz (THz) frequency range has received considerable attention due to its wide applicability. In particular, high-capacity short-distance wireless communication using the wide bandwidth available in the THz range is an important application. Other important applications include imaging, medicine and forensics. The THz spectrum also contains many spectroscopic modes that are of interest in biochemistry, atmospheric and materials research. There are, however, many unfulfilled opportunities owing to lack of low-cost, compact and easily deployable equipment. The success of this project would result in compact room temperature sources that could be readily deployed in the aforementioned fields. Other systems that will benefit include chemical analysis and THz astronomy. Low cost compact THz sources would also be an enabling technology for portal security screening systems for airports, civil buildings and public places. Safe screening through clothing at video rates for short stand-off distances compatible with portal systems would be possible. They would also be useful for non-destructive testing applications.
Any companies or collaborators involved:
This project contributes to the EU iBROW project (www.ibrow-project.eu) and so has links to a number of partners including Nokia Bell Labs.