Technology, circuit design and applications of GaAs MMICs

Gallium arsenide monolithic microwave integrated circuits (GaAs MMICs) are a means of utilising the high-mobility, high-frequency aspects of the GaAs MESFET together with the semi-insulating properties of gallium arsenide to form a low-loss integrated circuit with active elements. Novel semiconductor growth structures allow devices with cut-off frequencies well into the millimetre wave ranges to be fabricated, with dramatic improvements in gain and noise figure. Multilevel structures also permit very high circuit densities, so complete receivers and phased-array radar multifunction circuits can be made with high repeatability in a few square millimetres. The authors discuss various aspects of the production process including process control and reliability. The materials used for GaAs MMICs and the fabrication technology used are discussed as are their applications. Future MMIC technology developments are also discussed