An electronic device and a method of forming the same are disclosed. An emitter resonator and a reception cap cavity are formed on and in a first wafer, and an emitter cap cavity and a reception resonator are formed in and on a second wafer. After bonding together the first and second wafers, an emitter filter is formed in an emission region, and a reception filter is formed in a receiving region. The method provided in the present invention not only can simplify the fabrication process of the device and improve its accuracy and stability, but also facilitates integration of the emitter and receives filters in a same chip, which results in a higher degree of integration of the device and a more compact package size thereof.

A bulk wave piezoelectric resonator operating at a predetermined frequency includes a substrate block, having a plane face, a first thickness and consisting of a first material, a resonant plate having a length, width and second thickness, and consisting of a second piezoelectric material, first and second metal electrodes at least partly covering the resonant plate on each side and partly facing each other. The resonant plate is fixed perpendicularly in the vicinity of the plane face of the substrate block so that the width of the resonant plate and the first thickness of the substrate block have the same direction, and the first material, the second material, the first thickness of the block of substrate, the length, the width, the second thickness of the resonant plate are configured for trapping bulk waves at the operating frequency of the resonator and for producing a plane-plane type bulk wave piezoelectric resonator.

A method of manufacturing an ultrasound transducer is provided. The ultrasound transducer is activated and the activity across the transducer is measured to determine whether the activity at any area does not meet an acceptance criteria. The transducer is then modified so that the area meets the acceptance criteria. The transducer may be modified with a laser which removes material from the area which does not meet the acceptance criteria.