A Microwave Nonreciprocal Notch Filter Tunable by a Surface Acoustic Wave in Dynamic Magnonic Crystals

• Published in: Instruments and experimental techniques (New York) 2019, Vol.62 (1), p.42-46
• Main Authors: Kryshtal, R. G., Kundin, A. P., Medved, A. V.
• Format: Article
• Language: English
• Subjects: Electrical Engineering; Electronics and Radio Engineering; Gadolinium; Gallium; Measurement Science and Instrumentation; Microwave filters; Notch filters; Physical Chemistry; Physics; Physics and Astronomy; Rejection; Substrates; Surface acoustic waves; Yttrium; Yttrium-iron garnet
• ISSN: 0020-4412; 1608-3180
• DOI: 10.1134/S0020441219010123

The results of using a dynamic magnonic crystal, which is created by a surface acoustic wave (SAW) in the structure of a film of yttrium iron garnet on a gallium gadolinium garnet substrate, for the development of a tunable nonreciprocal microwave filter are presented. A filter prototype that operates in the range of 3600–4200 MHz at a magnetic bias field of 640 Oe was developed and its main characteristics were measured. At a SAW frequency of 41 MHz and a power of 30 mW, the rejection depth was 23 dB. A SAW-frequency change by 1 MHz shifted the rejection frequency by ~7 MHz. The inversion of the signal-propagation direction in the device resulted in a shift of the rejection frequency by the value of the SAW frequency. The possibilities of the further improvement of the parameters of this device are discussed.