The development of frequency multipliers has a long history. The low intrinsic carrier concentration of GaN allows its use under very high ambient or junction temperature, without being affected by thermally generated carriers. This chapter discusses the design aspects of GaN Schottky diodes. Based on the current –voltage/charge–voltage relationship, the frequency multiplication performance of Schottky diodes can be evaluated. The chapter addresses the design aspects of GaN-based Schottky multiplier diodes. GaN materials have been demonstrated to be excellent candidates for high power high temperature applications. The chapter describes the various steps involved in GaN diode fabrication using E-beam lithography technology. Three different technologies are possible for diode multiplier technology: dielectric bridge, optical air-bridge, and E-beam air-bridge. The chapter presents the DC and small-signal characteristics of GaN Schottky diodes, and explores the intrinsic elements, that is, junction capacitance and junction resistance. It also discusses the use of GaN Schottky diode in frequency multipliers for signal generation.
