Abstract: A reflector arrangement for an acoustic wave device comprises an acoustic wave propagating substrate, reflection elements having at least two different widths separated by at least one gap breadth disposed on the acoustic wave propagating substrate. The at least two different widths enhance reflected waves produced by the propagating acoustic wave in such a fashion as to achieve a total acoustic reflectivity which is independent of variations in width of the reflection elements.

Abstract: A low-loss acoustic wave filter includes a piezoelectric substrate, a first strongly unidirectional acoustic wave transducer and a second strongly unidirectional acoustic wave transducer. Each of the first and second strongly unidirectional acoustic wave transducers are acoustically coupled to one another. Each of the first and second strongly unidirectional acoustic wave transducers further comprises an acoustic wave reflector and a weakly unidirectional acoustic wave transducer. The acoustic wave reflector and the weakly unidirectional acoustic wave transducer are coupled to the piezoelectric substrate.

Abstract: An acoustic wave filtering apparatus includes an acoustic wave propagating substrate for supporting propagation of acoustic waves and a plurality of acoustic wave filters for filtering an electrical signal. Each of said plurality further comprises an input for supplying electrical input signals, an input unidirectional acoustic wave transducer for converting electrical signal energy into acoustic energy, an output unidirectional acoustic wave transducer for converting acoustic signals to electrical signals, and an output for combining and delivering electrical output signals to external electrical apparatus.

Abstract: An inductive element for impedance matching comprises an acoustic wave propagating substrate and an acoustic wave transducer coupled to the acoustic wave propagating substrate. The acoustic wave transducer has an effective length L.sub.eff such that Le.sub.eff .gtoreq.C.sub.2 v.sub.a /f.sub.o k.sup.2, where C.sub.2 is a numerical factor such that C.sub.2 .gtoreq.2, v.sub.a represents an acoustic velocity, f.sub.o represents an acoustic wave transducer center frequency and k.sup.2 denotes an acoustic wave propagating substrate electromechanical coupling coefficient. Reflecting elements are provided on the substrate in the principal acoustic propagation directions to form a resonant acoustic cavity. The device exhibits inductive impedance and high Q over a significant frequency range in small physical size.

Abstract: A reflector arrangement for an acoustic wave device comprises an acoustic wave propagating substrate, reflection elements having at least two different widths separated by at least one gap breadth disposed on the acoustic wave propagating substrate. The at least two different widths enhance reflected waves produced by the propagating acoustic wave in such a fashion to as to achieve a total acoustic reflectivity which is independent of variations in width of the reflection elements.

Abstract: In a radio transceiver (100), an IF stage (110) is formed on a single substrate. A balanced or image rejection mixer (204) having two pairs of inputs and a pair of outputs is integrated on an IC substrate (202). Disposed on the IC substrate are SAW transformers (210, 212 and 214) which provide a desired phase transformation. The SAW transformers comprise piezoelectric layers (228) and metallization layers (230) which are suitably patterned to provide the desired phase transformation and frequency selectivity.

Abstract: A surface acoustic wave (SAW) device package for reducing insertion loss and direct RF feedthrough of the SAW device is disclosed. The package provides for extensive shielding of each of the input and output pads. The inputs and outputs to the SAW device are separated by maintaining the inputs on one surface of the substrate and the outputs on the opposite surface of the substrate. The SAW crystal substrate including the SAW devices is bonded to the package substrate and the package is hermetically sealed via a low-temperature glass seal or solder-type sealing, for example.

Abstract: A passivation layer of dielectric material disposed on the top surface of the SAW device prevents the metallized transducer pattern on the piezoelectric substrate from being exposed to chemical attack. This layer also provides for improved metal acousto-migration resistance through the well-known mechanism of grain boundary pinning. The piezoelectric SAW device substrate includes a dielectric layer which is disposed along the surface over the transducer metallization. The piezoelectric substrate includes metallized regions on top of the dielectric layer which is disposed over the substrate surface and the SAW transducers thereon. These metallized regions form capacitors to the transducer busses and capacitively couple electrical input and output signals to the transducers from external electronic apparatus.

Abstract: A method for microelectronic device encapsulation is described comprising steps of providing a microelectronic device (e.g., a surface acoustic wave device) having interconnection contacts disposed thereon and depositing a passivation layer over the microelectronic device and the interconnection contacts. The method further comprises steps of providing alternating current coupled electrodes positioned on the passivation layer and over the interconnection contacts, providing a base substrate (including pressure contact electrodes and vias) and bonding the base substrate to the microelectronic device with a bonding agent for providing a mechanical bond between the microelectronic device and the base and for providing a hermetically sealed environment for the microelectronic device. The method further comprises providing electrical coupling between the pressure contact electrodes and the alternating current coupled electrodes.

Abstract: An acoustic wave device comprises an acoustic wave transducer coupled to an acoustic wave propagating substrate. The acoustic wave transducer converts signal energy between electrical and acoustical forms. Acoustic reflectors are placed one on either side of the acoustic wave transducer. The acoustic reflectors are composed of acoustic reflection elements spaced approximately one wavelength apart, and provide enhanced acoustic acoustic reflections together with relaxed fabrication constraints.

Abstract: An acoustic transducer for an acoustic wave device which includes an acoustic wave propagating substrate, the transducer adapted to couple to an electrical load and/or source. The transducer includes at least a pair of comb electrodes formed on the substrate. It includes apparatus for applying an electrical load and/or source across the pair of comb electrodes. The first of the combs has a plurality of electrode fingers. The second comb has at least one electrode finger. The widths of the electrode fingers are the same. Gaps of at least two different widths are disposed between the electrodes.

Abstract: A passivation layer of dielectric material disposed on the top surface of the semiconductor device prevents the metallized patterns on the semiconductor substrate from being exposed to chemical attack. This layer also provides for improved metal electro-migration resistance through the well-known mechanism of grain boundary pinning. The semiconductor device substrate includes a dielectric layer which is disposed along the surface over the electrode metallization. The semiconductor substrate includes metallized regions on top of the dielectric layer which is disposed over the substrate surface and the electrodes thereon. These metallized regions form capacitors to the semiconductor electrodes and capacitively couple electrical input and output signals to the electrodes from external electronic apparatus.

Abstract: A microelectronic device including a passivation layer disposed on the top surface has disposed on a portion of its surface a bonding agent. The resulting structure is inverted and sealed to a package base, forming a hermetically sealed cavity. This protects the microelectronic device from the environment. External electrical connection to other electronic apparatus is effected by means of conductors disposed on the package base surface. Alternating current (AC) capacitive coupling contacts allow electrical coupling to the microelectronic device and prevent violation of the integrity of the passivation layer. This method realizes compact microelectronics device packages which can be mass produced from entire microelectronic device substrates.

Abstract: A SAW transducer eliminates mechanical energy reflections by using one-quarter wavelength electrodes spaced at predetermined intervals. Dummy electrodes are shifted one-quarter wavelength to cancel energy reflections in the active electrodes. A pair of dummy electrodes is required for each active set of electrodes (the active set comprises one positive and two negative electrodes).

Abstract: A magnetostatic wave (MSW) device for performing spectral analysis of an input signal containing signal components of very high frequency, well in excess of 1 GHz (gigahertz). An input transducer array couples the input signal to a magnetostatic propagating medium, such as a film of yttrium-iron-garnet (YIG), in such a manner that the array effectively provides multiple wave sources spaced along a predetermined arc on the propagating medium, and the waves combine constructively at frequency-dependent points in a focal region of the medium, spaced apart from the input array. Output transducers located at these frequency-dependent points generate output signals indicative of various selected frequency components of the input signal.

Abstract: Dynamic variation of the functional properties of a surface acoustic wave (SAW) device is achieved by using photoconductive material on a wave propagating substrate and illuminating the material with changing light patterns. Photoconductive materials, such as lead sulfide or cadmium sulfide, are used that are essentially dielectrics and have substantially no effect on SAW propagation when not illuminated, but under suitable levels of illumination become resistive and interact with the electric fields of the waves to dissipate energy as heat. Scanning control of the areas of illumination may be used to attenuate sidelobes and scattering in a wideband system, while intensity variations may be used to amplitude modulate the waves.