Magnetostatic wave devices and applications (invited)

Microwave magnetics technology is faced with two challenges: the development of an analog signal processing capability directly at microwave frequencies, and development of electronically tunable nanosecond time delays for phased array antennas. The focus is on these two problems from the point of view of magnetostatic wave (MSW) technology in thin films such as liquid phase epitaxy yttrium iron garnet. An assessment is made of MSW devices, their role in realizing wideband phased arrays, and how MSW stacks up against competing technologies. Important devices include oscillators, signal to noise enhancers, frequency separators, filters, tunable time delays, and compressive receivers. One MSW device, a simultaneous pulse separator, is now scheduled to be incorporated into an existing system. This is a first for MSW. Although it is encouraging, much work remains in the areas of materials research, dispersion control, nonuniform biasing fields, and improved theory. The largest payoff may well be in phased array antennas due to the large number of elements involved. Some of the requirements for phased array antennas, including solid state transmit/receive modules and adaptive antennas, are addressed.