Magnetostatic Waves, Microwave SAW?

Abstract

The continual demand for increased performance in modern communication and rader systems in terms of increased bandwidths and higher operating frequencies has led to investigation of novel techniques and technologies for analog signal processing. In particular, surface acoustic waves (SAW) have been extensively e xploited with great success to this end, but systems requiring bandwidths greater than 500 MHz and center frequencies greater than 1 GHz have pushed SAW devices near the practical physical limit of the technology. A novel technology promising increased bandwidths at higher frequencies is based on magnetostatic waves (MSW) propagating in epitaxial ferrite films such as Yttrium Iron Garnet (YIG). ploited in devices offering instantaneous bandwidths up to 2.2 GHz at microwave center frequencies from 0.5 to 20 GHz. This MSW signal processing technology, based on transversal filtering concepts used in SAW, has been under extensive investigation for the p ast 8 years. This paper will first discuss physical properties and limits o f magnetostatic waves, and consider similarities and differences with SAW. Next, the state of development of MSW technology in the United States and abroad will be summarized. Finally, some significant remaining problems for device application of MSW will be discussed followed by some projections for MSW technology limits.