Magnetostatic Wave Notch Filters Frequency Tuned Via a Zero DC Power Magnetic Bias Circuit

This paper presents a miniature (1.7 cm(3)) and zero static power magnetostatic surface wave tunable notch filter with a tuning range from 3.3 GHz - 10.3 GHz. The notch frequency can be directly tuned by transient voltage pulses applied to a magnetic bias circuit, eliminating the need for bulky, power-hungry electromagnets. Aluminium transducers were designed to achieve strong spin wave coupling by direct placement on yttrium iron garnet magnetostatic wave resonators. Low insertion loss was achieved by absorbing the parasitic inductance of the magnetostatic wave resonator transducers into an on-chip LC transmission line. The filter exhibits less than 1.8 dB of insertion and a notch rejection of more than 38 dB.