Abstract: According to one embodiment, the present invention includes a method for numerically encoding and representing data that includes providing a representation of data and separating the representation into a scale header and an additional precision packet. Separating the representation includes identifying the location of the highest-order non-zero bit and encoding the location of the highest-order non-zero bit to form the scale header. The balance of the bits following the highest-order non-zero bit, or a truncated set of these bits, is encoded to form the additional precision packet, and a matched representation space (MRS) representation is composed of the paired data structures of a scale header and a corresponding additional precision packet, if any.

Abstract: An anti-reflective acoustic diffusion device is provided by a group of irregularly dimensioned diffusing elements positioned on an acoustic wave substrate end that diffuse the SAW and eliminate unwanted acoustic reflections from the end of the substrate. The irregularly dimensioned diffusing elements are substantially irregular in size, shape, composition, and location and provide the desired diffusion into a nearly uniform distributed acoustic energy with a random phase. The anti-reflective acoustic diffusion device can be used with SAW, BAW or multiple acoustic wave configurations. This invention also encompasses an anti-reflective acoustic diffusion system and methods for diffusing acoustic reflections with anti-reflective acoustic diffusing elements.

Abstract: Programmable SAW filter module are provided to overcome undesirable drawbacks, limitations and shortcomings associated with “in-line” SAW filters, such as insertion loss, propagation loss and strong signal capture effects. The programmable SAW filter modules remove the SAW structure from the primary signal path, adding signal gain to drive the splitter and using the SAW portion of the circuit as a programmable impedance element. The programmable SAW filter module includes an amplifier, an impedance, a surface acoustic wave propagation element, a splitter, input and output IDT electrodes, input and output interdigitated transducers, means for gain control and a combiner to combine or sum the signals received from the output IDT electrodes and form an output signal. The input and output IDT's are fully integrated circuits comprising the power splitter and power combiner functions, the phase shift, and gain functions.

Abstract: A restrained surface wave resonator with reduced or abated acceleration sensitivity is provided with a stiffening layer, adhesive layers and subsurface horizontal indentations on the substrate to achieve reduced acceleration sensitivity, increased structural rigidity, decreased sensitivity to in-plane deformations, a lightweight device and reduced deleterious effects from environmental shocks and vibration. The substrate of the restrained surface wave resonators features multiple subsurface horizontal indentations in one major substrate surface deposited on a stiffening layer to provide improved structural rigidity against flexure caused by normal acceleration based upon the diminished mass and reduced weight resulting from removal of portions of the substrate subsurface through micro-machining, and it also tends to improve excessive sensitivity to other flexural deformations. The present invention encompasses a restrained surface wave resonator device and a restrained surface wave resonator system.

Abstract: A packaging system for piezoelectric devices is provided that substantially reduces and avoids the deleterious effects of environmental vibrations and shocks with gas or fluid-filled chambers that drastically improve the resonator's ability to withstand unwanted disturbances and decrease or eliminate the attendant frequency shifts. The damped piezoelectric resonator packaging system combines a resonator package, a membrane and gas/fluid-filled chambers that dampen dynamic amplification of the resonator and firmly restrain the resonator within the packaging system. The selection of gas or fluid for the chamber depends upon variables such as the type of waves being propagated and interaction with the piezoelectric substrate.

Abstract: Proportional-delayed zero-crossing frequency-drift estimator devices are provided. Given N-number of time samples, the current zero-crossing time estimation technique uses only two zero-crossing time samples for repetition-rate estimation. The term “zero-crossing point” refers to the point where a sinusoidal waveform varies from a positive to a negative value and crosses the zero value in the process. The proportional-delayed zero-crossing frequency-drift estimator devices employ four zero-crossing time samples by utilizing both proportional zero-crossing points for current information and delayed zero-crossing points for past information so that the noises in the time samples will be smoothed out making a less noisy estimation.

Abstract: A multiple function radio bezel interface includes a display screen, a first knob assembly including an outer ring and an inner knob, the outer ring adapted to allow a user to select an application from a multimedia main menu and the inner knob adapted to allow a user to selectively power the radio bezel interface and to adjust the volume of the radio, and a second knob assembly including an outer ring and an inner knob, the outer ring adapted to allow a user to select different application screens corresponding to the application selected from the multimedia main menu and the inner knob being a jog controller.

Abstract: An acceleration insensitive piezo-microresonator provides substantially reduced acceleration sensitivity with a plano—plano piezo-microresonator, upper gap and lower gap embedded in a rigid structural supporting member holding major surfaces of the piezo-microresonator firm and steady. The piezo-microresonator has neither electrodes on its surfaces nor contacts with any electrodes. Electrodes are doped regions incorporated into the support member. The upper and lower gaps are adjacent to the major surfaces of the piezo-microresonator, permitting it to vibrate freely. The support member surrounds and supports the plano—plano piezo-microresonator plate, upper gap and lower gap, maintaining a constant upper gap height and lower gap height. The electrodes provide a thickness-directed electrical field exciting the piezo-microresonator. A method of desensitizing a resonant frequency of a piezo-microresonator to acceleration stresses is also provided.

Abstract: RF programmable SAW filters achieve selectable filter performance by providing tunable input and output interdigital (IDTs) with different synchronous frequencies and substantially reduce electromagnetic interference (EMI) associated with RF signals not of interest. The RF programmable SAW filter includes tunable input and output IDT's, with the input and output IDT's having different input and output IDT synchronous frequencies. The input signal is divided into multiple output signals along multiple signal paths that are applied to an input tap weight network wherein the amplitude of each output signal may be varied individually. The individually weighted signal paths are then applied one each to individual IDT input electrode fingers in a means for IDT input, which is characterized by a synchronous frequency Fin. The IDT input means generates an acoustic wave that propagates to a means for IDT output, which is characterized by a synchronous frequency Fout, where Fin and Fout are not the same.

Abstract: Fiber Bragg gratings (FBG) seismic activity sensors coupled in sensor arrays provide increased sensitivity to seismic activities, lower strain values and an absence of EMI allowing detection of troop and vehicle movements based on ground vibrations generating seismic signals. The FBG sensor head features a spring-mass configuration with a head surface, fiber optic cable and the FBG sensor attached to a spring that stretches during the acceleration of the mass. Waves propagating inside the earth and along the ground arriving at the sensor locations cause movement of the seismic activity sensors embedded in the ground and this movement induces an acceleration-dependent change in the FBG gratings placed on the sensors. In multiple sensor configurations, the cable will be connected to the other sensors in the network. FBG sensors, sensor arrays and sensor methods are provided in several embodiments.

Abstract: Reliable piezoelectric restraint mechanisms are provided that substantially reduce the ill effects of acceleration sensitivity through an increasingly rigid and precise orientation system. The piezoelectric resonator stress relief apparatus, devices and systems of the present invention resolve the long-standing disadvantages, limitations and shortcomings of acceleration sensitive resonators by stacking a number of rigid plates, layers and spring cushions around the piezoelectric resonator by means of a mounting structure that provides in-plane stress relief and precise definition of the mounting plane. The piezoelectric resonator stress relief apparatus, device and system can essentially eliminate any deformation or may include precisely defined features to tailor the allowed deformation of the piezoelectric resonator, without suffering from the long-standing disadvantages, limitations and shortcomings of prior art acceleration sensitive resonators.

Abstract: The present invention provides a radio system for portable use. The radio system includes a radio tuner, a display, and a touch pad. The radio tuner is configured to receive radio transmissions. The display is in communication with the radio tuner to display transmission information, radio commands, or input from the touch pad. The touch pad is configured to sense gestures on the surface of the touch pad. Further, the radio tuner is capable of executing radio control commands in response to each of the gestures.

Abstract: A novel programmable SAW filter with switchable multi-element interdigital transducers (IDTs) controlled by a microprocessor or a computer is provided that realizes the tunability of both center frequency and bandwidth of the SAW filter. The filter possesses the feature of the programmability of both center frequency and 3 dB bandwidth. As an example design, the center frequency of the SAW filter ranges from 126.8 MHz to 199.1 MHz while the 3 dB bandwidth ranges from 18.8 MHz to 58.9 MHz. The multi-input configuration increases the programmability of the device and improves insertion loss. A matching network for the programmable SAW filter further improves insertion loss level and stopband attenuation. A resistance weighting method has been applied to improve in band ripple with the passband ripple being reduced from 6.44 dB to 1.37 dB after resistance weighting.

Abstract: The operational flexibility of programmable transversal filters is enhanced by incorporating switch arrays to permit passage for a plurality of tap voltages or signals to particular amplifiers in amplifier arrays. Fixed gain amplifiers may be incorporated to overcome the need to calibrate variable gain amplifiers and to reduced the number of amplifiers required.

Abstract: A programmable SAW transversal filter utilizing a finger array and phase shifters to implement unidirectional transducers for providing low insertion loss and reduced or suppressed triple transient echo. A piezoelectric substrate has an input unidirectional transducer and an output unidirectional transducer formed thereon. A surface acoustic wave is transmitted between the input unidirectional transducer and the output unidirectional transducer. Programmable gain devices and phase shifters are coupled to the respective input unidirectional transducer fingers and the output unidirectional transducer fingers forming multi-phase unidirectional transducers. The present invention may be utilized as a transversal filter in many communication devices, and in particular a multi format personal communication system.

Abstract: A novel programmable SAW filter with switchable multi-element interdigital transducers (IDTs) controlled by a microprocessor or a computer is provided that realizes the tunability of both center frequency and bandwidth of the SAW filter. The filter possesses the feature of the programmability of both center frequency and 3 dB bandwidth. As an example design, the center frequency of the SAW filter ranges from 126.8 MHz to 199.1 MHz while the 3 dB bandwidth ranges from 18.8 MHz to 58.9 MHz. The multi-input configuration increases the programmability of the device and improves insertion loss. A matching network for the programmable SAW filter further improves insertion loss level and stopband attenuation. A resistance weighting method has been applied to improve in band ripple with the passband ripple being reduced from 6.44 dB to 1.37 dB after resistance weighting.

Abstract: Piezoelectric resonator structures and circuits therefor are provided to p the energy available for vibrational deformation in a resonator, between the driving electrodes of the resonator structure. Field trapping electrodes are disposed to enclosed the driving electrodes in the resonator structures which are arranged in circuits to derive electric fields between the field trapping electrodes in an opposite direction to that of an electric field between the driving electrodes.

Abstract: Mounting arrangements are provided for crystals, which greatly reduces or iminates the effect of the force which develops on the crystal when acceleration is encountered. In these arrangements, flexible bushings are incorporated to absorb energy during periods of acceleration and collars are incorporated between which portions of the crystal are gripped to stiffen the structural characteristics thereof.

Abstract: The invention is directed to resonators and more particularly to an MMIC-compatible resonator which can be fabricated on an MMIC chip using MMIC processing techniques. The MMIC-compatible resonator has a substrate approximately 100 microns thick made of semi-insulating GaAs and/or AlGaAs. The substrate flanks an air via on which is fabricated a thin film piezoelectric semi-insulating GaAs film, comprising the piezoelectrically active element. The piezoelectrically active element is flanked either laterally or from the top to bottom thereof by a pair of electrodes which serve to excite the thickness shear or thickness extensional mode of the thin film piezoelectrically active element. There are a number of III-V and II-VI binary compounds and ternary, and other piezoelectric semiconductor alloys, which can be used for the purposes of the invention. The thin film measures approximately 5 microns or less in thickness and is fabricated on the semi-insulating GaAs, on the ?110!, ?111! or ?100! axis thereof.

Abstract: A microcircuit package with an integrated acoustic isolator made up of a stacked acoustic filter. The package includes a rigid, electrically conductive housing with a IC module mounted therein. The acoustic filter includes two electroacoustic transducers mounted on opposite sides of a common wall of the package, one inside the package and the other outside. An a.c. power source is connected to the transducer that is mounted on the outside of the package. Electrical energy from the power source is converted by the outside transducer into acoustic energy which is conducted through the package wall to the inside transducer which reconverts the acoustic energy into electrical energy. The package wall has a significant thickness in comparison to the acoustic wavelength of the filter passband and is preferably equal to an integer number of one-half acoustic wavelengths.