State of the art in design and technology of MSW devices (invited)

Abstract

Electronic warfare and telecom systems demands for increased bandwidths and operating frequencies for analog signal processing could be satisfied in the near future by the emergence of a novel technology based on magnetostatic waves (MSW) propagating in single crystal magnetic films such as the epitaxial yttrium iron garnet (YIG). Offering bandwidths up to 2 GHz at operating frequencies ranging from 0.5 to 20 GHz, MSW is, at the present time, the only available technology for analog signal processing directly at microwave frequencies. This paper will present an overview of the various techniques involved in the MSW area and of the possible device applications. In a first section, the growth of epitaxial YIG film, the propagation characteristics, the transduction, terminations, and temperature stability are briefly reviewed. Next, periodic structures obtained by ion beam milling, metal deposit, or ion implantation are considered. The following section is devoted to dispersive and nondispersive delay lines. Finally, the last part describes several major MSW devices with a particular emphasis on tunable MSW oscillators, a very promising application of MSW technology.