Submicron Y3Fe5O12 Film Magnetostatic Wave Band Pass Filters

Thin Y3Fe5O12 (YIG) films were pulsed laser deposited onto Gd3Ga5O12 (111) and (001) substrates. Processing conditions were optimized to obtain compressively strained films with a ferromagnetic resonance linewidth at 9 GHz as narrow as 0.9 Oe and high uniaxial magnetic anisotropy Hu=−880 Oe. Several designs of magnetostatic surface wave (MSSW) bandpass filters were fabricated and tested: 0.45 and 0.22 μm thick YIG films lain on transducers alumina board and with microstripe transducers defined directly onto YIG film, with effective antenna areal sizes of 2 and 0.4 mm2. The MSSW filter with 2 mm2 antenna shows, at 7.5 GHz, insertion loss −9 dB and a resonant −3 dB bandwidth as narrow as 12.5 MHz.