High frequency solid state devices [microwave and mm-wave devices]

In this paper are described solid state devices which have wide applications as RF sources and amplifiers in microwave and millimeter-wave systems. Active devices can be fabricated using a variety of diode and transistor structures, and these devices are widely used in a variety of commercial and military applications. Device development has been closely linked to advances in semiconductor materials growth and processing technology and many devices for mm-wave application are only possible due to the precise nanoscale dimension control afforded by advanced materials growth technology, such as molecular-beam epitaxy (MBE) and organo-metallic chemical vapor deposition (OMCVD). Fine line lithography techniques, such as electron-beam lithography, permit the definition of nanoscale device dimensions. Advanced materials technology has also provided the ability to fabricate heterostructures that permit the advantages of multiple material layers to be optimized for device applications. High performance diodes and transistors are now available for use from UHF into the mm-wave spectrum, approaching THz frequencies.