I. Introduction
MICROWAVE and millimeter-wave integrated circuits have experienced a tremendous growth over the last 50 years. Circuits have become smaller, highly integrated, lower cost, and have found extensive applications in radar, electronic warfare, and the commercial field. This historical review is divided into three sections: microwave integrated circuits (MICs), monolithic microwave integrated circuits (MMICs), and MIC and millimeter-wave integrated-circuit applications authored, respectively, by Bahl, Pucel, and Niehenke.