Propagation of surface magnetostatic waves through a periodic array of parallel metal stripes

A study has been made of the propagation of a surface magnetostatic wave through a YIG film in which the propagation path traverses a periodic structure consisting of several parallel metal stripes. Results are reported for a structure consisting of 20 copper stripes 2 mm long and 1.6 micron thick, with the period of the structure varying from 40 to 120 microns and the width of the stripes varying from 2 to 14 microns. The ratio of the transmitted power to the incident power is shown as a function of the frequency for a YIG film (10 x 2 x 0.006 mm) for a structure period of 93 microns and a stripe width of 7.5 microns. Such an arrangement is shown to result in a single passband which is 3.5 MHz wide at the 3-dB level. The signal loss levels in the passband and the stopband are 12 and 31 dB, respectively. It is concluded that the propagation of magnetostatic waves through a periodic array of metal stripes can be used to develop narrow-band microwave filters.