Department of Microelectronics and Nanoelectronics
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The Department of Microelectronics and Nanoelectronics is responsible for the research and the lecturing in the following fields:
Analogue and Mixed Mode ASIC Design,
RF CMOS Circuits,
Micro-Electro-Mechanical Systems (MEMS),
Modules are currently being offered in the B.Sc. (Hons) ICT and the Electrical Engineering B.Eng. (Hons).
Analogue and Mixed Mode ASIC Design:
This is one of the areas where significant expertise has already been built up in low-voltage, low-power designs, using a number of techniques including switched capacitor architecture, switched current topology. Circuits that have been designed, sent for fabrication and tested include a 1 V second-order sigma-delta modulator, a ±0.9 V switched-capacitor CMOS multiplier with rail-to-rail input, a low-voltage high-speed fully differential CMOS op amp, a low-voltage high-resolution pipelined incremental ADC, analogue neural network circuits for phoneme recognition, log-domain audio processing front-end.
RF CMOS Circuits:
Here the objective is the design of building blocks of RF systems, such as LNAs, VCOs, low-phase noise quadrature VCOs, multipliers. The technology used here has changed from silicon CMOS 0.6 µm, to 0.35 µm, to SiGe 0.25 µm, 0.18 µm. These technologies are available through our participation in EUROPRACTICE.
This deals with the design of digital circuits which starts from a high-level description using a hardware description language such as VHDL, followed by synthesis to gate-level, and then followed by silicon layout. In order to carry out digital signal processing on the chip itself, thus creating the possibility for a smart microsystem, it is preferable to have an embedded signal processing core in the digital chip itself.
The idea here is to design both the biochip that senses electronically a specific biochemical or biotechnological process, e.g. DNA hybridization, as well as the signal processing, such as amplification, filtering, required to obtain the desired output. If both the biochip and the ASIC can be designed with the same technology then a fully integrated system would result. Otherwise, if the biochip detection process entails a different technology from standard ASIC technology, system-in-package technology can be used to still get a lab-on-chip package. An example application would be the development of integrated, portable, battery-operated silicon bioprofilers with specific applications to gene expression profiling and to metabolic profiling. The new Department already collaborates with other University of Malta entities in the area of molecular biology, and in the area of neuroscience. Suitable software packages include BioChip Developer, and Dispensing Developer which form part of the CoventorWare suite available through EUROPRACTICE.
Micro-Electro-Mechanical Systems (MEMS):
The availability of MEMS software and design kits will allow us to design innovative microstructures such as capacitive sensors, electrostatic actuators, high Q resonating structures, energy scavengers, microfluidic test structures. MEMS are particularly useful in multi-standard applications which require the tuning of circuitry in order to suit different frequency bands. Typical applications include the input and output tuning of LNAs, multi-standard VCOs and output matching networks of variable-power power amplifiers. For these applications high quality tunable inductors and/or switches are required. These types of MEMS require some electrically-controlled actuator mechanism in order to provide tuning. MEMS, having no electrically activated actuators, can also be useful for the implementation of fixed-value inductors and capacitors having high quality factors, which are crucial components in the design of low phase-noise, low power VCOs.
This area looks at the design of nanostructures where quantum properties are investigated and both electronic and optical applications can be developed. Some work on the optical properties of quantum well structures has already been carried out in previous years, with a number of publications. This work is of interest and can be resumed since nanostructures of course very often entail quantum properties.
System-in-Package and System-on-Chip:
System-in-Package refers to the packaging of MEMS/ASICS in a single package, where different technologies need to be used for the MEMS, Sensor and for the ASIC carrying out the required signal processing. System-on-chip refers to the design of both analogue and digital modules on the same piece of silicon, thus utilising one specific technology. In particular, the integration of MEMS devices with the active circuitry in RF applications is an important issue: the interconnect parasitics have to be accurately modelled and controlled in order to achieve the required circuit performance. This area needs to be developed practically from scratch.