Frequency sorting based on planar YIG resonators

An approach for an integrated microwave channelizer is introduced. This planar channelizer is basically a contiguous bank of filters, fabricated on one substrate and realized using MSW (magnetostatic wave) resonators. Due to their low magnetic losses, epitaxially grown single-crystal yttrium iron garnet (YIG) films have been used for MSW propagation. Experimental results showing the characteristics of the resonators are presented. An important feature is their tunability with a linear frequency-bias-field characteristic. A theoretical analysis gave good agreement with the experimental results. To increase the bandwidth and improve the filter response of each channel, magnetically coupled MSW resonators of different dimensions, which are used to realize different channels, have been investigated. This approach to frequency sorting requires no gradient in the bias magnetic field. A three-channel device is demonstrated