Monolithic microwave integrated circuit

Inputs and outputs on MMIC devices are frequently matched to a characteristic impedance of 50 ohms.

MMICs are dimensionally small (from around 1 mm2 to 10 mm2) and can be mass-produced, which has allowed the proliferation of high-frequency devices such as cellular phones.

It has two fundamental advantages over silicon (Si), the traditional material for IC realisation: device (transistor) speed and a semi-insulating substrate.

Other III-V technologies, such as indium phosphide (InP), have been shown to offer superior performance to GaAs in terms of gain, higher cutoff frequency, and low noise.

Silicon germanium (SiGe) is a Si-based compound semiconductor technology offering higher-speed transistors than conventional Si devices but with similar cost advantages.