There are two types of similar microwave integrated circuits. Microwave integrated circuits ( MIC) and monolithic microwave circuits ( MMIC) sometimes get confused. A typical MIC is a hybrid device with one layer of metallization for conductors and transmission lines, with discrete components (resistors, capacitors, integrated circuit chips, transistors, diodes, etc.) placed and bonded to a substrate which can be a high performance PCB or Alumina.

Some of the simpler components can be deposited on the substrate. MICs were originally developed in the 1960s, and even now deliver a very cost-effective solution. Monolithic microwave integrated circuits (MMIC) on the other hand, are a semiconductor integrated circuit technique, where the active and passive circuit elements are implemented on a semiconductor substrate. Typically Bipolar, SiGe, GaAs, GAN substrates are used.