14 March 2014

UCL and Chalmers report widest-band amplifier

A research collaboration between the University College London (UCL) in the UK and Chalmers University of Technology in Gothenburg, Sweden has resulted in the design and testing of what is reckoned to be the widest-band amplifier circuit ever reported.

The work was led by professor Herbert Zirath (head of the Microwave Electronics Laboratory at the Department of Microtechnology and Nanoscience at Chalmers) and professor Izzat Darwazeh (head of the Communications and Information Systems Group in UCL’s Department of Electronic and Electrical Engineering).

Zirath and Darwazeh started on the joint project in summer 2012, aiming to design circuits suitable for communication at frequencies approaching the terahertz (THz) region. A set of amplifier circuits was designed by PhD student Klas Eriksson, manufactured by Teledyne in the USA, and measured at Chalmers a few months ago. However, the circuit builds on previous research and design work reported by Zirath and Darwazeh over the past two decades.

Picture: Microphotograph of two-stage 235GHz amplifier MMIC (1.12mm x 0.48mm).

The new monolithic microwave integrated circuit (MMIC) amplifiers achieved results close to design predictions: exceptionally wide broadband operation (from low GHz frequencies to frequencies exceeding 235GHz) and gain exceeding 15dB translate to a gain bandwidth product of about 1.5THz. The design team believes that this amplifier is at least twice as fast (in terms of bandwidth) as the fastest amplifier reported to-date.

“This achievement was possible both because of excellent technological advances in nanotechnology and state-of-the-art design processes and techniques,” says Darwazeh. “This technology will help make ultrafast broadband possible for widespread use not only for communication systems but also for different scientific and test & measurement instrumentation,” he adds.

“This result is of considerable interest for the development of new products within the area of communication and instrumentation such as fast oscilloscopes, pulse amplifiers and fast fiber-optic receivers,” reckons Zirath.
Details of the work will be reported at the IEEE Microwave Theory and Techniques Society’s (MTT-S) 2014 International Microwave Symposium (IMS) in Tampa Bay, FL, USA (1-6 June).

Tags: MMIC

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