Abstract: A magnetostatic wave device operating within a biasing magnetic field for delaying microwave signals is described including a layer of YIG material having a predetermined thickness, first and second transducers spaced apart for generating and receiving magnetostatic waves in the YIG material and a ground plane having a plurality of spacings from said YIG material, each spacing having a predetermined length along the propagation path between the first and second transducers. The invention further includes first and second layers of YIG material, first and second transducers spaced apart for generating magnetostatic waves in said first material and said first material having a plurality of spacings from said second material, each spacing having a predetermined length along the propagation path from said first to said second transducer. The invention overcomes the problem of undesired phase or group delay variations from a desired linear or quadratic phase variation as a function of frequency.

Abstract: The linearity of group delay versus frequency in magnetostatic wave delay lines is improved by a linear variation of one of three discrete parameters in the region between the two delay line transducers. The parameter variation is applied to magnetostatic wave delay lines that have a ground plane, a magnetic garnet crystal film substrate that is spaced from the ground plane and has transmitting and receiving transducers engaged to it, and a magnetic bias field. The discrete parameters varied are the magnetic bias field; the distance of the substrate from the ground plane; and the thickness of the substrate. Appropriate linear variations of any one of the these parameters provides improved linearity of group delay versus frequency.

Abstract: A magnetostatic wave device is described incorporating a plurality of resistive strips spaced apart from one another and transverse to the propagation path of magnetostatic waves in a material such as a YIG film having a finite width for attenuating selected higher order modes of propagating magnetostatic waves.

Abstract: A magnetostatic wave device having a microstrip transmission line in conjunction with a YIG thin film biased for magnetostatic wave operation at a level where relatively lower power input microwave signals are highly attenuated up to a critical point past which the relative attenuation is greatly reduced. Such devices may be utilized as signal-to-noise enhancers in microwave circuits such as frequency memory loops.

Abstract: A method and apparatus are disclosed for low-dust discharge of particulate material such as grain. The apparatus provides a nozzle having a hollow body with an inlet at the top and an outlet at the bottom. An impeller is mounted inside the body in an outwardly and downwardly flaring region below the inlet. A fluid stream of the particulate material drops through the inlet and impinges on the immpeller which deflects or throws the particles outwardly within the flaring region of the nozzle. The coarser, heavier particles have more outward momentum than the lighter, finer particles and are concentrated toward the wall of the nozzle below the impeller while the lighter, finer particles are concentrated toward the center, so that a rough separation is made and stream density is increased. A compacted downwardly moving mass is accumulated within the nozzle and is discharged through the outlet at controlled rate as a denser, relatively dust-free stream in open air.

Abstract: A magnetostatic wave device for microwave signal processing which includes an input or output transducer finger arrangement which allows shaping of the device response. Two sets of interdigitated fingers are connected to receive the same microwave input signal which is power divided between the two sets. The fingers of one set are substantially parallel to, and in side-by-side relationship with, the fingers of the other set. The device may be used for delay lines, filters, signal correlation, oscillators and numerous other microwave signal processing arrangements.