Abstract: A BAW resonator includes: a piezoelectric film array, including multiple piezoelectric films between a substrate of a chip and a capping layer on the top, where multiple first cavities are provided between adjacent piezoelectric films in a vertical direction, between the piezoelectric films and the capping layer, and between the piezoelectric films and the substrate, second cavities are shared between adjacent piezoelectric films in a first direction in a horizontal plane, and third cavities are shared between adjacent piezoelectric films in a second direction in the horizontal plane; multiple electrode layers, covering at least the top surface and bottom surface of each of the piezoelectric films; and multiple electrode interconnection layers, connected to the electrode layers on the bottom surfaces of the piezoelectric films along sidewalls of the third cavities.

Abstract: A level includes a frame defining a web, a flange, and a gauging surface for placement on a workpiece. A magnetic retainer arrangement is secured to the frame laterally of the web and above the flange, and applies a magnetic force to a magnetically attractive workpiece through the laterally extending member. The web includes a lip that cooperates with the web and the flange to define a channel a facing in a direction opposite the gauging surface. The magnetic retainer arrangement includes one or more magnetic members engaged within the channel. The magnetic members are operable to maintain the level in engagement with a magnetically attractive workpiece, by virtue of a magnetic field that passes through the laterally extending member and that applies a magnetic force that acts on the magnetically attractive workpiece to maintain the gauging surface of the level on the workpiece.

Abstract: A level with magnetic device relates to a measuring instrument. That level includes a case body and a bubble cell on the case body, and it is characterized in that the cross section of the bottom of the case body, being the location of the reference plane, has a profiled shape, and furthermore by this is constituted a profiled slot on the bottom of the case body, a magnet is placed inside the profiled slot on the bottom of said case body, an elastic retaining bracket is pressed on top of the magnet, and the shapes of that elastic retaining bracket and the profiled slot are complementarily matched. That level solves the problem of instability of precision of the contemporary level with magnetic device, and it is widely applicable in the level industry.