MICs are commonly used in cell phones.
Microwave integrated circuits, or MICs, are a type of microchip semiconductor designed to operate specifically at microwave frequencies, usually at 1 gigahertz (GHz) or more. The specific ability to transmit over microwaves is often what sets MICs apart from other types of integrated circuits. MICs are widely used in small electronic devices that work via electronic and electromagnetic frequencies, such as cell phones, GPS devices, remote control systems, and imaging devices. Their small size allows them to be used in various handheld wireless devices, and the nature of the MIC is such that a chip can operate as a standalone device, using just a single semiconductor wafer.
MICs were first designed in the 1940s and evolved from the basic microwave circuit as demand and technologies of the time allowed advances in wafer-based circuit manufacturing. Since then, microwave integrated circuits have matured from simple, single-function circuits to complex, multi-function circuits of increasingly smaller sizes and complex capabilities. They form the root of the microwave and semiconductor manufacturing industries, and many types of MICs can be mass-produced inexpensively and efficiently for use in consumer electronics, science, and industry.
Specialized types of MICs have different benefits and applications, which are often determined by their manufacturing method. Hybrid microwave integrated circuits (HMICs) are made by placing discrete components on a circuit board, known as a substrate. The individual components can be capacitors, resistors, transistors or other chips. Together they form the entire MIC. Materials used in manufacturing and soldering components can affect frequency, electrical properties, and overall circuit performance.
Monolithic microwave integrated circuits, also known as MMICs, require a more complex design where the entire circuit is designed as a single chip and all components are manufactured on the semiconductor substrate. MMICs are often used in satellite systems that require small, inexpensive circuits that still deliver high speed and performance. These circuits operate in the 300 megahertz (MHz) to 300 GHz bands and are capable of multiple frequency and power manipulation functions.
Many users find that MMICs offer significant advantages over hybrid circuits due to differences in design and performance features. The modern microwave integrated circuit concept often refers to the MMIC – which is considered an improvement over the original, larger, heavier MIC – despite the MMIC’s limitations, which may include functional inflexibility after initial fabrication. For more robust, scalable, and flexible circuit designs, many integrate multi-purpose MMICs that specialize in larger, more complex microwave integrated circuits.