Device modelling Centre for Communications Technology

System simulation and modelling

Current research activity involves software modelling of:

• optical components and systems
• signal processing systems
• analogue behavioural models of digital functional blocks and systems

Quite Universal Circuit Simulator (Qucs) is an open-source circuit simulator developed by a international group of scientists and engineers under the GNU General Public License. You can download both binary and source code versions of the package here.

Versions are available for most of the popular computer operating systems, including GNU/Linux, FreeBSD, Solaris, MacOS, Windows and Cygwin.

Qucs is a circuit and system simulator with a graphical user interface that supports schematic capture, analysis control and simulation post-processing using equations. It currently supports the following analogue analysis types:

• DC, AC
• AC noise
• S-parameter
• S-parameter noise and transient

Qucs is multilingual; currently it has been translated into fifteen languages. Qucs uses FreeHDL and Icarus Verilog for VHDL and Verilog digital simulation. The Analogue Device Model Synthesis (ADMS) package is interfaced to Qucs allowing Verilog-A compact device and circuit macromodelling.

Measurement techniques, instrumentation and control

The QUCS development team is taking part in the MOS Modelling and Extraction Working Group (MOS-AK) Verilog-A standardisation initiative.

This work deals with sensors and associated instrumentation for applications such as colour detection, optical communication, antenna arrays for radio mobile communications and electrical power systems. Existing research activities include:

• theoretical analysis and development of a novel optical microphone
• investigation and development of a novel high-speed sensory system for colour recognition of frequency-tuned materials
• novel measurement techniques for investigation of noise in laser diodes
• application of amorphous semiconductors in optical process tomography
• fuzzy control and optimisation in electrical power system
• power inverse autocorrelation and inverse partial autocorrelation techniques for power spectral estimation

Signal processing

Work in this area is focused on:

• signal and image processing: mathematical algorithms and applications
• fourier/wavelet transforms and applications

Current research activity includes:

• application of the analysis of non-linearity to earthquake signal
• statistical signal processing and non-linear systems analysis
• independent research in applications of wavelets in signal/image processing
• schemes for multidimensional non-band limited signals