RF applications using field emitter arrays (FEAs)

The concept of vacuum microelectronics covers a very wide area in electron devices, but it centers on the applications to microwave and further high frequency devices due to the advantages of vacuum as a transport medium of electrons. Although the attention for the past several years has been focused on the development of a field emission display, the application to high frequency devices still induces great interest in vacuum microelectronics. The paper describes the current status in development of a fine cathode as a key device in beam electronics and discusses state of the art and future prospects for high frequency devices based on the fine cathodes to explore the tube rebirth.