Abstract: A semiconductor bulk acoustic resonator (SBAR) with improved passband insertion loss and phase performance characteristics making it suitable for use in a wider variety of narrowband filtering applications. The SBAR is configured to suppress lateral propagating acoustical wave mode. The lateral acoustical wave modes are controlled by varying the lateral dimension of the resonator electrodes and or utilizing a viscous acoustic damping material, such as a viscoelastic material, such as polyimide, along at least~a portion of the perimeter of the electrodes to attenuate reflections of the lateral acoustic modes at the electrode edges back into the electrode region.

Abstract: A semiconductor bulk acoustic resonator (SBAR) with improved passband insertion loss and phase performance characteristics is suitable for use in a wide variety of narrowband filtering applications. The SBAR is configured to suppress lateral propagating acoustical wave modes. The lateral acoustical wave modes are controlled by varying the lateral dimension of the resonator electrodes and or utilizing a viscous acoustic damping material, such as a viscoelastic material, such as polyimide, applied along at least a portion of the perimeter of the electrodes to attenuate reflections of the lateral acoustic modes at the electrode edges back into the electrode region.

Abstract: Disclosed is a thin film voltage-tuned semiconductor bulk acoustic resonator (SBAR). A piezoelectric film is positioned between a first electrode and a second electrode and positioned adjacent a semiconductor substrate containing a via hole. A variable voltage source applies a DC bias voltage to the electrodes which causes an electric field to be created between the electrodes within the piezoelectric film. The resulting electric field causes the piezoelectric film to resonate at a frequency different than its unbiased resonant frequency. By adjusting the variable voltage source to change the DC bias voltage, the resonant frequency from the thin film semiconductor bulk acoustic resonator (SBAR) can be varied.

Abstract: This invention discloses a monolithic multipole stacked crystal filter comprised of a series of cascaded 2-port semiconductor bulk acoustic resonator stacked crystal filters electrically cascaded and a shunt inductor connected between each of the 2-port filters. Each of the 2-port filters including a first and second piezoelectric layer, typically aluminum nitride. A first input electrode is positioned on a top surface of one of the piezoelectric layers and a second output electrode is positioned on a bottom surface of the other of the piezoelectric layers. A ground electrode is positioned between the piezoelectric layers. In this regard, the piezoelectric layers will resonate at a resonant frequency and provide bandpass filter characteristics. The complete monolithic multipole filter provides control of the passband shape which yields highly desirable filter characteristics.

Abstract: A one-piece wire guard device formed of non-metallic material for use in wells includes an inner ring having a split therein defining an opening and having a portion of reduced thickness defining a hinge. Arcuate sections are disposed concentrically outwardly of the inner ring and are connected to the latter by ribs. The ribs, arcuate sections and inner ring cooperate with each other to define openings for accommodating electric wires, ropes and the like therethrough. A guard device may be flexed about its hinge from a normally closed condition to an open position to permit a drop pipe to be inserted through the opening defined by the split. Releasably locking means lock the guard device upon the drop pipe. Spacer tabs extend outwardly from the arcuate sections and engage a well casing to space the drop pipe from the casing and thereby prevent damage to the drop pipe, electrical wires, safety ropes and the like extending through the guard device.