Microwave signal processing using dipole-exchange spin waves

A microwave signal processor using short (wave number k∼104 cm−1) phase-conjugated dipole-exchange spin waves (DESWs) propagating in yttrium–iron–garnet films has been developed. A DESW pulse having low group velocity (νg∼103 cm/s) and low relaxation parameter (effective linewidth ΔH=0.2 Oe) was excited by a narrow (W=10 μm) strip-line transducer, experienced wave front reversal in a parametric interaction with a double-frequency pumping field created by a dielectric resonator, and was received again at the input transducer. As a result, a controlled delay of an input microwave pulse of more than 1 μs with insertion loss of 40 dB/μs was achieved.