Ferrite devices and materials

Abstract

The development and current status of microwave ferrite technology is reviewed in this paper. An introduction to the physics and fundamentals of key ferrite devices is provided, followed by a historical account of the development of ferrimagnetic spinel and garnet (YIG) materials. Key ferrite components, i.e., circulators and isolators, phase shifters, tunable filters, and nonlinear devices are also discussed separately.

A Magnetic Field Tunable Yttrium Iron Garnet Millimeter-Wave Dielectric Phase Shifter: Theory and Experiment

“…In our experiments, the shift in resonance frequencies f (1) rj − f (2) rj for all cases (see Fig. 2) is less then 0.8 GHz, whereas resonance linewidths are quite different.…”

“…A wide variety of materials and devices based on semiconductors, ferroelectrics, and ferrites has been developed for high frequency applications [4][5][6]. In particular, phase shifters based on ferromagnetic resonance (FMR) or spin wave propagation in yttrium iron garnet (YIG) are attractive because of their planar geometry and magnetic tunability of their operating frequency over a wide range [2]. Yttrium iron garnet has long been used for device applications over 1-10 GHz because of low magnetic and dielectric losses.…”

“…Phase shifters are important elements in phased array radars and for applications in wireless communication, surveillance, sensing and tracking [1,2]. Recently there has been considerable interest in signal processing at frequencies 70 GHz and higher [3].…”

Magnetostatic waves in layered materials and devices

“…The latter is based on the transmission and reception of spin waves in a magnetic film by means of two microwave transmission lines ͑antennas͒ placed on top of it. Originally employed for ferrites, [17][18][19] this approach has been extended to metallic films in recent years in the frequency 6,7 and time domains. 8 The structure ͑Fig.…”

“…An important characteristic of spin wave propagation in magnetic layers is the possibility of nonreciprocal surface wave propagation. Such effects have been studied extensively in ferrite films, [14][15][16][17] and nonreciprocal ferrite-based devices such as microwave isolators and circulators are widely in use today. However, there is little information regarding the nonreciprocal characteristics of spin waves in thin, laterally confined metallic magnetic elements which are currently of increasing technological relevance.…”