Grant: Discovery Development Grant

Gallium nitride has been used in recent years as a base substrate material to design high frequency power amplifiers. Gallium nitride provides excellent heat dissipation for power amplifiers and is highly resistant to radiation (for space-based applications). For these reasons, most research using gallium nitride (GaN) in the last few years has focused on power amplifiers. Typical communication systems have a power amplifier built on GaN, with other components built using a different substrate, such as gallium arsenide (GaAs). However, gallium nitride also has good noise qualities: its minimum noise figure is quite comparable to gallium arsenide (GaAs). Its high power-handling capabilities reduce the need to have complex protection circuitry. For these reasons, GaN can also be used to design other components of a typical telecommunication system, such as low-noise amplifiers and switches. Most research on gallium nitride has focused on circuits operating at frequencies lower than 20GHz; as the fabrication technology matures, the maximum operating frequency will increase, and more opportunities for research will develop. Higher frequencies bring increased design challenges, but also increased design opportunities. The Canadian Microelectronics Corporation (CMC) has recently started offering fabrication of circuits using a gallium nitride substrate through the Canadian Photonics Fabrication Centre (CPFC). More and more manufacturers have GaN-based circuits for sale, and more and more research is being done with this material. This research project will examine the feasibility of designing these other components in the hopes of realizing complete telecommunication circuits on a single gallium nitride substrate, thereby reducing the cost of these circuits. The circuits I have designed in the last few years are mostly switches and phase shifters in GaN. The switches had good performance, and were used to design compact phase shifters. These lumped-element phase shifters also had good performance, and are much more compact compared to traditional distributed-element phase shifters. As the CPFC manufacturing process matures (a new design kit was released in June 2014), the performance of the phase shifters should increase even more. A major impact of this research program is that it will train highly qualified personnel in the design of an important emerging technology for Canada, in microwave integrated circuit design and testing and in particular GaN-based circuits.  A key impact of this research will be to provide circuit designers with more choices for the design of high frequency integrated circuits, if as expected, GaN proves to be a useful competitive substrate in the design of low-noise amplifiers, switches, mixers and oscillators. Another impact is to train students in the design, layout, manufacturing and testing of millimetre-wave integrated circuits.