Abstract: A SAW device includes a LiNbO3 single crystal piezoelectric substrate having an orientation defined by Euler angles (?,?,?), with angle ? ranging from ?5° to +5°, angle ? ranging from about ?74° to about ?65°, and angle ? ranging from ?5° to +5°. Electrode patterns on a surface of the substrate form element resonators having a metallization ratio ranging from about 0.3 to about 0.8 and electrode thicknesses ranging from about 12% to about 17.5% of an acoustic wavelength of a strongly coupled non-leaky surface acoustic wave, excited on the surface of the substrate, if Al is used as electrode material, and in a range from about 6% to about 10% of an acoustic wavelength, if Cu is used as electrode material. Such orientations simultaneously combined with an optimized electromechanical coupling of spurious surface acoustic mode provide for improved performance in RF applications with a widened passband.

Abstract: A SAW filter is fabricated at a wafer level for providing desirable temperature characteristics. The filter includes a piezoelectric substrate bonded to a carrier substrate, wherein the coefficient of thermal expansion of the carrier substrate is less than the coefficient of thermal expansion of the piezoelectric substrate. Interdigital transducers are formed on the piezoelectric substrate so as to form a SAW composite die structure. A cap substrate having a coefficient of thermal expansion similar to that of the carrier substrate is bonded to the SAW composite die structure for enclosing the interdigital transducers. Plated vias form signal pad interconnects to input and output pads of the interdigital transducer and a sealing pad formed on the surface of the piezoelectric substrate bonds the SAW composite die structure to the cap substrate.

Abstract: A SAW filter includes a piezoelectric substrate of Lithium Niobate or optionally Lithium Tantalate having a thickness of at least twice an acoustic wavelength. The piezoelectric substrate is bonded to a surrogate substrate of a silicon material. The surrogate substrate is characterized by a resisitivity of at least 100 ohm-cm and an expansion coefficient compatible with the piezoelectric substrate. A catalytic bonding film between the piezoelectric substrate and the surrogate substrate is formed from a first catalytic bonding film deposited onto a surface of the piezoelectric substrate and a second catalytic bonding film deposited onto a surface of the surrogate substrate. The piezoelectric substrate is bonded to the surrogate substrate through a compression force sufficient for providing a bonding at a normal temperature.

Abstract: A miniaturized SAW duplexer includes SAW filters carried on a monolithic piezoelectric chip that is mounted inside a multi-layered ceramic package. A phase matching stripline is embedded diagonally and between two ground layers of the multi-layered ceramic package and is positioned between a wall of vias for significantly minimizing coupling between transmitted and received filters by providing an improved ground shielding of the phase matching stripline. Coupling within the same filter and coupling between the SAW filters are suppressed and thus provide enhanced isolation performance. for the SAW duplexer.