Abstract: The diversity SCO digital audio technique (300) provides packet protection through statistical diversity by adding new audio modes (202, 204) that operate within a Bluetooth framework (200). Increased packet protection improves audio intelligibility and data transmission. The combination of a blind or signaled transmission of a redundant packet (202 or 204) in combination with a randomly faded frequency hop for each packet provide for enhanced reliability and link quality.

Abstract: The present invention is directed to a communication system wherein ultrasonic signals can be used as carriers to efficiently produce high fidelity, wide audio bandwidth sound. Exemplary embodiments rely on the airborne transport of an inaudible ultrasonic carrier directly into the ear canal of a user, such that the non-linearities within the ear itself can be exploited to demodulate the ultrasonic carrier without producing audible sounds at the input to the user's ear. The non-linearities of the ear itself, in conjunction with the human brain's perception of audible frequencies generated in response to ultrasonic stimulation, are relied upon to detect audio information. The ultrasound-to-audio-sound conversion in the confined volume of the inner ear appears to be constant pressure, as opposed to constant velocity, such that all frequencies of the audio bandwidth (including low frequency bass signals) are produced with comparable sound intensity.

Abstract: Composite semiconductor structures and methods are provided for communications systems, specifically, those utilizing RF signals. Antenna switches, and amplifiers in receiver and transmitter sections of the communications systems are shown that are fabricated within a compound semiconductor layer of a composite semiconductor structure is integrated with support circuitry in a non-compound semiconductor substrate. Support circuitry that may be integrated include negative voltage generation circuitry, drain current protection circuitry, and voltage regulation circuitry.

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 semiconductor substrate with electronic circuitry (e.g., a transmitter or receiver) formed thereon and including interconnects. A ferrite disk bonded to the substrate so as to interact with the interconnects, when the ferrite disk is activated by a substantially constant magnetic field thereacross, to provide frequency selectivity within the electronic circuitry. A permanent magnet positioned adjacent to the ferrite disk to provide a substantially constant magnetic field across the ferrite disk so that the magnetic field produces resonance in the ferrite disk.

Abstract: A three-terminal resonator device (200) resonant at a resonant frequency has a first terminal (201), a second terminal (202), and a common terminal (203). The resonator includes a surface acoustic wave transducer (290) disposed on a piezoelectric substrate (201). The SAW transducer (290) is comprised of a first sub-transducer (210) and a second sub-transducer (220) which respectively include a first set of electrodes (211,213) and a second set of electrodes (221,223). One of the electrodes of each of the first set and the second set of electrodes respectively provide the first terminal (201) and the second terminal (203). The other terminals of the first and second set of electrodes are connected at the common terminal (203) to provide a serial connection between the first sub-transducer (210), and the second sub-transducer (220).

Abstract: A semiconductor substrate with electronic circuitry (e.g., a transmitter or receiver) formed thereon and including interconnects. A ferrite disk bonded to the substrate so as to interact with the interconnects, when the ferrite disk is activated by a substantially constant magnetic field thereacross, to provide frequency selectivity within the electronic circuitry. A permanent magnet positioned adjacent to the ferrite disk to provide a substantially constant magnetic field across the ferrite disk so that the magnetic field produces resonance in the ferrite disk.

Abstract: A SAW resonator/filter structure (300) includes a transducer portion. The transducer portion includes a plurality of acoustically coupled sub-transducer portions (310 and 312) comprising conductive patterns having interdigitated open-ended fingers. The sub-transducer portions (310 and 312) are electrically coupled to each other in series in order to increase the port impedance of the SAW filter structure (300) while providing the widest bandwidth.

Abstract: A single chip receiver/transmitter section (202) includes an antenna switch (208), a low noise amplifier (210), a power amplifier (212) and a first (214) and second (216) mixers. The antenna switch (206)includes an antenna terminal (256) which is coupled to an off-chip band pass filter (206) which provides all of the selectivity for radio (200). Also described is a transmitter/receiver structure (300) which incorporates a transmission line filter such as band pass filter (206) formed by substrates (304) and (306) and includes the single chip transmitter/receiver section (202) imbedded inside of the structure (300).

Abstract: A tunable oscillator circuit (200) includes surface acoustic wave transducer (303) disposed on a piezoelectric substrate (301) having a high SAW coupling coefficient. The SAW transducer is (303) non-reflective and self-resonant comprising a pair of electrodes with interdigitated fingers. A tuning mechanism, such as a varactor, is coupled across the transducer allowing for output frequency tuning of the oscillator circuit.

Abstract: A programmable electronic product includes a video generator (120) and RF modulator (122) for interfacing with an external video monitor. The programmable electronic product can then be programmed by the product user with the programming information being displayed on the external video monitor.

Abstract: A multilayer circuit board (200) providing a feedthrough filter having metallized via (234) having input and output ports (232, 226) which are coupled to metallized areas (206, 214). Each of the metallized areas (206, 214) being opposed by ground planes (202, 210, and 218) which are separated from the metallized areas (206, 214) by dielectric layers (204, 208, 212, and 216) forming a reactive coupling between the metallized areas (206, 214) and the ground planes (202, 210, and 218). The multilayer circuit board as employed in the present invention, may be advantageously utilized in a variety of applications where multilayer circuit boards require attenuation of unwanted RF signals.

Abstract: A crystal oscillator circuit for use with overtone crystals restricts its resonant frequency to either fundamental or overtone frequencies. An inverting amplifier, which provides 180 degrees of phase shift by inverting an input signal, includes components which effectively provide another 180 degree phase shift at a particular frequency by adding a time delay. The 180 degree phase shift by a signal inverting amplifier, with the included 180 degree phase shift provided by the time delay comprises an oscillator by the addition of a crystal with a resonant frequency equal to the particular frequency determined by the time delay. Suppression of unwanted oscillation frequencies is accomplished by adjusting a current source, which changes time delay, without using inductors or other reactive components.

Abstract: A stripline structure has a stabilized resonant frequency against temperature variations. It includes a lower and an upper substrate of ceramic materials, each substrate having opposing inner and outer surfaces. Each of the outer surfaces are covered with a layer of conductive material constituting ground planes. Resonator strips of conductive material are situated on each of the inner surfaces, and each have one end connected to the ground, while the opposite end is an open circuit. The upper and lower substrates are bonded together along the length of their respective resonator strips, thereby producing the stripline structure. The length of the resonator determines the resonant frequency of the stripline structure. The two substrates are made of materials having opposite dielectric temperature coefficient.

Abstract: A stripline filter resonator structure is provided which exhibits high Q and results in a filter with low insertion loss. The dielectric consists of two sections of dielectric material. A groove shaped as half an ellipse is formed in each of the sections. The surface of the grooves are covered with electrically conductive material. The two grooves are aligned and filled with adhesive material to hold the two dielectric sections together. An elliptically shaped resonator is thus formed in the center of the dielectric sandwich. Ground plane layers are respectively situated on the outer layers of the dielectric sandwich thus forming a stripline resonator structure. This unique resonator structure results in a more uniform current density around the periphery and thus undesired current bunching is correspondingly decreased.

Abstract: An electrically variable three terminal monomorphic piezoelectric capacitor is manufactured with thick or thin film hybrid microelectronic circuit technology. A first capacitor plate and a ridge, which substantially surrounds and extends above the first capacitor plate, are formed on the surface of a substrate. A monomorphic piezoelectric wafer having a control plate and a second capacitor plate on opposing surfaces is bonded to the upper surface of the ridge. During bonding, a force is applied at the center of the wafer which fixes a permanent bow in the wafer in the direction of the first capacitor plate. A four terminal monomorphic embodiment and three and four terminal bimorphic embodiments are also described.

Abstract: An electrically variable three terminal monomorphic piezoelectric capacitor is manufactured with thick or thin film hybrid microelectronic circuit technology. A first capacitor plate and a ridge, which substantially surrounds and extends above the first capacitor plate, are formed on the surface of a substrate. A monomorphic piezoelectric wafer having a control plate and a second capacitor plate on opposing surfaces is bonded to the upper surface of the ridge. During bonding, a force is applied at the center of the wafer which fixes a permanent bow in the wafer in the direction of the first capacitor plate. A four terminal monomorphic embodiment and three and four terminal bimorphic embodiments are also described.

Abstract: An improved ceramic stripline filter assembly is disclosed which provides optimized performance characteristics by careful control of the gap thickness between the filter halves during the assembly process. The filter arrangement utilizes paddle leads which include central cavities or pocket holes to accept any excess solder during filter assemblage. Close tolerances are thereby obtained regarding the referenced gap thicknesses from filter to filter.The method of fabricating the stripline filter assembly contemplates the use of a leadframe with the leads extending laterally from a unitary support structure. The leads are then cut or otherwise separated from this integral support after attachment of the leads to the filter body connection points. They may be pre-formed to any predetermined pattern after such separation.

Abstract: Piezoelectric filter includes a piezoelectric substrate having an upper and lower opposed major surfaces. A plurality of N coupled resonators where N is an integer greater than two exposed on the surface of the substrate. A plurality of mounting pedestals are utilized to couple the resonators to ground in a manner such that no two non-adjacent resonators are coupled to any one pedestal. This mounting scheme suppresses undesired spurious attenuation poles and improves the selectivity of the piezoelectric filter.

Abstract: A hybrid filter comprising a plurality of removably mountable resonator modules, each constructed of nmicrostrip, and mounted parallel to each other and perpendicular to the substrate so as to isolate the resonators for single mode operation; the inter-resonator coupling is provided by adjustable capacitor coupling gaps on the host substrate.