Abstract: A surface acoustic wave (SAW) device (300) is formed from a leaky wave mode piezoelectric substrate (310) to have substantially reduced surface wave attenuation when operating at a particular frequency. The SAW device (300) includes a SAW pattern (322, 324), disposed on a surface (321) of the piezoelectric substrate, having a free surface portion (324) and a shorted surface portion (322). The SAW pattern (322, 324) is overlaid with a material (330), preferably glass, which has a thickness selected to reduce surface wave attenuation.

Abstract: A monolithic thin film resonator, lattice filter including spaced apart strips of a conductive film positioned on a substrate so as to define a first set of I/O terminals, a layer of piezoelectric material positioned on the conductive film, and spaced apart conductive strips of a conductive film positioned on the piezoelectric layer orthogonal to the first strips to form cross-over areas, each defining a thin film resonator and a second set of I/O terminals. A plurality of portions of a dielectric film are positioned on selected cross-over areas to mass load the thin film resonators so as to lower the resonant frequency.

Abstract: A HACT device employing a thin-film overlay of a more strongly piezoelectric material can operate as a delay line and as a tapped delay line, or transversal filter, while requiring less total power for the SAW clock signal. The increased electrical potential per unit total SAW power thus realized facilitates coupling between the total SAW energy and the mobile charge carriers. Some materials systems, such as a GaAs substrate and a ZnO thin-film overlay, will require an intervening thin-film dielectric layer in between the HACT substrate and epitaxial layers and the thin-film piezoelectric overlay. This may be necessitated by chemical, semiconductor device processing, or adhesion incompatibilities between the substrate material and the thin-film overlay material.

Abstract: A HACT device employing a thin-film overlay of a more strongly piezoelectric material can operate as a delay line and as a tapped delay line, or transversal filter, while requiring less total power for the SAW clock signal. The increased electrical potential per unit total SAW power thus realized facilitates coupling between the total SAW energy and the mobile charge carriers. Some materials systems, such as a GaAs substrate and a ZnO thin-film overlay, will require an intervening thin-film dielectric layer in between the HACT substrate and epitaxial layers and the thin-film piezoelectric overlay. This may be necessitated by chemical, semiconductor device processing, or adhesion incompatibilities between the substrate material and the thin-film overlay material.

Abstract: A bipolar injector structure, similar to a common-base amplifier circuit, is described for use as a unidirectional injector of charge for a charge-transfer device input circuit. This injector structure acts to reduce the input impedance of such devices. A plurality of bipolar injector structures may be implemented on a single ACT device channel, and electrically connected in parallel, to effect a further reduction of input impedance and a further increase in device dynamic range. By employing an input contact structure which allows charge to be injected at more than one point along the length of the channel, without perturbing charge which was injected at some earlier time, a means for forming a transversal filter function can be realized at the input contact structure in addition to that which is achieved at the output contact structure, thus permitting improved ACT device selectivity when operated as a filter.

Abstract: A HACT device employing a thin-film overlay of a more strongly piezoelectric material can operate as a delay line and as a tapped delay line, or transversal filter, while requiring less total power for the SAW clock signal. The increased electrical potential per unit total SAW power thus realized facilitates coupling between the total SAW energy and the mobile charge carriers. Some materials systems, such as a GaAs substrate and a ZnO thin-film overlay, will require an intervening thin-film dielectric layer in between the HACT substrate and epitaxial layers and the thin-film piezoelectric overlay. This may be necessitated by chemical, semiconductor device processing, or adhesion incompatibilities between the substrate material and the thin-film overlay material.

Abstract: An acoustooptic transducer includes a base and cap which may be mated axially along a certain length of an optical fiber. The base and cap each include a semicircular channel fabricated along one axis. A zinc oxide layer is sandwiched between two metal layers in each of the semicircular channels. When the cap and base are mated, each of the semicircular channels of metal and zinc oxide correspond to form coaxial cylindrical channels of zinc oxide sandwiched by layers of metal surrounding the fiber. Under an applied electrical force, to electrodes of the metal layers, the zinc oxide produces focused acoustic waves for coupling to the light transmitted through the optical fiber. In another embodiment of this invention, the layer of zinc oxide sandwiched between the metal layers may be applied directly to a predetermined length of the optical fiber.

Abstract: An apparatus and method is disclosed for providing an optical waveguide that is placed in the same plane as the electrodes, thereby creating a more efficient electro optic interaction that requires less voltage to induce the desired effects on the waveguide. In addition, a superstrate is used to cover the waveguide having an index of refraction slightly less than the index of refraction of the waveguide which reduces the scattering loss inherent in the waveguide.

Abstract: Passivated and low scatter acoustic wave devices comprise surface acoustic wave (SAW) and shallow bulk acoustic wave (SBAW) devices having transducers composed of oxidizable metal and layers of metal oxide on conventional acoustic wave substrates. Passivated transducers are achieved by forming a layer of oxide on an existing transducer. The method may be used to passivate a device packaged in a non-oxidizable package with oxidizable wire leads, thus combining complete protection with efficient manufacturing operations. Low scatter SAW transducers are achieved by forming the transducer and the interstitial insulating layer from a single layer of oxidizable metal by means of masking and oxidation operations.

Abstract: An optical channel waveguide is manufactured by forming an optical isolation pedestal or ridge on a substrate and coating the substrate and pedestal with an optical channel layer. The optical channel waveguide is that portion of the optical channel layer which overlies the pedestal. Cladding layers may be added overlying the optical channel film or the cladding function may be performed by air. The disclosed process requires no high temperature diffusion steps and is thus suitable for manufacturing optical channel waveguides integrated on a semiconductor substrate with semiconductor devices. In addition, the entire process for manufacturing the optical channel waveguide may be carried out during a single pumpdown of a vacuum system.

Abstract: Passivated and low scatter acoustic wave devices comprise surface acoustic wave (SAW) and shallow bulk acoustic wave (SBAW) devices having transducers composed of oxidizable metal and layers of metal oxide on conventional acoustic wave substrates. Passivated transducers are achieved by forming a layer of oxide on an existing transducer. The method may be used to passivate a device packaged in a non-oxidizable package with oxidizable wire leads, thus combining complete protection with efficient manufacturing operations. Low scatter SAW transducers are achieved by forming the transducer and the interstitial insulating layer from a single layer of oxidizable metal by means of masking and oxidation operations.

Abstract: A surface acoustic wave (SAW) structure is disclosed wherein a SAW device is incorporated as an exterior lamina within a composite laminate in order to temperature stabilize the acoustic device. The composite laminate is synthesized to selectively mismatch the thermal expansion characteristics of the piezoelectric material, which is the body of the acoustic device, along the axis of acoustic propagation and simultaneously approximately match the thermal expansion properties along the orthogonal axis. Compressive force is thereby applied to the acoustic device to keep the substrate length constant and thus provide an approximately zero temperature coefficient over a preferred range of temperatures.

Abstract: A HACT device employing a thin-film overlay of a more strongly piezoelectric material can operate as a delay line and as a tapped delay line, or transversal filter, while requiring less total power for the SAW clock signal. The increased electrical potential per unit total SAW power thus realized facilitates coupling between the total SAW energy and the mobile charge carriers. Some materials systems, such as a GaAs substrate and a ZnO thin-film overlay, will require an intervening thin-film dielectric layer in between the HACT substrate and epitaxial layers and the thin-film piezoelectric overlay. This may be necessitated by chemical, semiconductor device processing, or adhesion incompatibilities between the substrate material and the thin-film overlay material.