Abstract: A nonreciprocal microwave phase shifter or circulator includes a substrate, a transducer on a surface of the substrate and configured to reciprocally convert between electrical signals to acoustic waves, a first piezoelectric material configured to generate and transport acoustic waves from a signal applied to the transducer, and a thin film magnetic material configured to couple to acoustic waves through magnetoelastic coupling so as to have nonreciprocal magnetoelastic coupled acoustic wave transport. Phase shifts of acoustic waves through the thin film magnetic material in directions toward and away the transducer have significantly different magnitudes.

Abstract: A nonreciprocal microwave transmission device includes a substrate, a transducer on a surface of the substrate and configured to reciprocally convert between electrical signals to acoustic waves, a first piezoelectric material configured to generates and transports acoustic waves from a signal applied to the transducer, and a thin film magnetic material configured to couple to acoustic waves through magnetoelastic coupling so as to have non-reciprocal magnetoelastic coupled acoustic wave transport. Transmission of acoustic waves through the thin film magnetic material is in a direction toward the transducer has a first magnitude and transmission of acoustic waves through the thin film magnetic material in a direction away from the transducer has a second magnitude, the first and second magnitude being significantly different.

Abstract: A photodetector array readout and dynamic multiplexing method for reducing the overall channel count in a PET scanner system is disclosed. A PET system includes detector modules mounted on a ring-shaped gantry, each module including an array of M×N pixelated scintillators with photosensors attached to each pixelated scintillator on at least one of the top and the bottom surfaces. The multiplexer includes row and column summing, pulse shaping, and dynamic switching circuits multiplexing M×N inputs to a single output representing the energy and timing of the detected radiation. A position encoder is configured to receive outputs from the N+M summing circuits, and determine which pixelated scintillator had a gamma ray interaction. When photosensors are attached on both surfaces, the depth of interaction is determined as well based on the relative strength of the top and bottom surface readouts.

Abstract: A photodetector array readout and dynamic multiplexing method for reducing the overall channel count in a PET scanner system is disclosed. A PET system includes detector modules mounted on a ring-shaped gantry, each module including an array of M×N pixelated scintillators with photosensors attached to each pixelated scintillator on at least one of the top and the bottom surfaces. The multiplexer includes row and column summing, pulse shaping, and dynamic switching circuits multiplexing M×N inputs to a single output representing the energy and timing of the detected radiation. A position encoder is configured to receive outputs from the N+M summing circuits, and determine which pixelated scintillator had a gamma ray interaction. When photosensors are attached on both surfaces, the depth of interaction is determined as well based on the relative strength of the top and bottom surface readouts.

Abstract: A PET scanning system includes a plurality of detector modules, each having an array of pixelated scintillators, the array having N rows of pixelated scintillators, and M columns of pixelated scintillators. Each detector module includes a first set of N light guides optically coupled to the top surface that accumulate optical signals, and a second set of M light guides optically coupled to the bottom surface that accumulate optical signals. Each light guide is coupled to a light sensor which converts optical signals into analog electrical outputs. A processor is coupled to outputs from the first set and the second set, the processor configured to determine which pixelated scintillator within the array had a gamma ray interact therewith, and its depth of interaction, based on the outputs. Thus, gamma ray detection in an array of M×N scintillator pixels is accomplished using only M+N channels.

Abstract: An ultrasonic transducer assembly for use in sensing the location of objects in proximity to the transducer. The ultrasonic transducer assembly includes a substrate member, a piezoceramic resonator plate supported on a planar surface of the substrate member adjacent to a peripheral edge of the substrate member, and a coupler connected to a surface of the resonator plate for acoustically coupling the resonator plate to a medium in contact with the coupler.

Abstract: An ultrasonic transducer assembly for use in sensing the location of objects in proximity to the transducer. The ultrasonic transducer assembly includes a substrate member, a piezoceramic resonator plate supported on a planar surface of the substrate member adjacent to a peripheral edge of the substrate member, and a coupler connected to a surface of the resonator plate for acoustically coupling the resonator plate to a medium in contact with the coupler.