Abstract: Integrated circuit fabrication technique for constructing novel MEMS devices, specifically band-pass filter resonators, in a manner compatible with current integrated circuit processing, and completely encapsulated to optimize performance and eliminate environmental corrosion. The final devices may be constructed of single-crystal silicon, eliminating the mechanical problems associated with using polycrystalline or amorphous materials. However, other materials may be used for the resonator. The final MEMS device lies below the substrate surface, enabling further processing of the integrated circuit, without protruding structures. The MEMS device is about the size of a SRAM cell, and may be easily incorporated into existing integrated circuit chips. The natural frequency of the device may be altered with post-processing or electronically controlled using voltages and currents compatible with integrated circuits.

Abstract: Several MEMS-based architectures which utilize vibrating micromechanical resonators in circuits to implement filtering, mixing, frequency reference and amplifying functions are provided. A method and apparatus are provided for upconverting and filtering an information signal utilizing a vibrating micromechanical device based on an AC signal having a desired frequency. One of the primary benefits of the use of such architectures is a savings in power consumption by trading power for high selectivity (i.e., high Q). Consequently, the present invention relies on the use of a large number of micromechanical links in SSI networks to implement signal processing functions with basically zero DC power consumption.

Abstract: A method of adjusting a frequency of an energy-trap type piezoelectric resonance element includes the steps of preparing a piezoelectric resonance element including first and second vibration electrodes formed partially on both of the main surfaces of a piezoelectric plate, the thickness of the first vibration electrode being larger than that of the second vibration electrode, and modifying the first vibration electrode or the second vibration electrode in such a manner that the thicknesses of the first and second vibration electrode electrodes are substantially equal to each other such that the piezoelectric resonance element has a desired frequency.

Abstract: Several MEMS-based methods and architectures which utilize vibrating micromechanical resonators in circuits to implement filtering, mixing, frequency reference and amplifying functions are provided. Apparatus is provided for selecting at least one desired passband or channel in an RF transmitter subsystem utilizing a bank of vibrating micromechanical devices. One of the primary benefits of the use of such architectures is a savings in power consumption by trading power for high selectivity (i.e., high Q). Consequently, the present invention relies on the use of a large number of micromechanical links in SSI networks to implement signal processing functions with basically zero DC power consumption.

Abstract: A filter for electric signals has a substrate, a vibrating body capable of vibrating with at least two antipodes deflected in phase opposition relative to the substrate and has electrodes connected to a signal input and a signal output for electric excitation and for detection of the vibration of the vibrating body. The electrodes for detecting the vibration, each assigned to antipodes deflected in phase opposition, are connected to two separate terminals of the signal output.

Abstract: Integrated circuit fabrication technique for constructing novel MEMS devices, specifically band-pass filter resonators, in a manner compatible with current integrated circuit processing, and completely encapsulated to optimize performance and eliminate environmental corrosion. The final devices may be constructed of single-crystal silicon, eliminating the mechanical problems associated with using polycrystalline or amorphous materials. However, other materials may be used for the resonator. The final MEMS device lies below the substrate surface, enabling further processing of the integrated circuit, without protruding structures. The MEMS device is about the size of a SRAM cell, and may be easily incorporated into existing integrated circuit chips. The natural frequency of the device may be altered with post-processing or electronically controlled using voltages and currents compatible with integrated circuits.

Abstract: A high Q MEMS capacitor that can be continuously tuned with a large tuning ratio or reversibly trimmed using an electrostatic force. The tunable capacitor has a master/slave structure in which a control voltage is applied to the master (control) capacitor to set the capacitance of the slave (signal) capacitor to which an RF signal is applied via a suspended mechanical coupler. The master-slave structure reduces tuning error by reducing the signal capacitor's surface area and increasing its spring constant, and may eliminate the need for discrete blocking inductors by electrically isolating the control and signal capacitors. The trimmable capacitor provides an electrostatic actuator that selectively engages a stopper with teeth on a tunable capacitor structure to fix the trimmed capacitance.

Abstract: A Q-controlled microresonator and devices including such resonators.

Abstract: A microstructure includes a substrate and a movable platform which is tethered by a first cantilever arm to the substrate. The first cantilever arm is comprised of a sandwich of first and second materials, the first and second materials exhibiting either different thermal coefficients of expansion or a piezoelectric layer. A second cantilever arm includes a first end which is tethered to the platform and a free distal end which is positioned to engage the substrate. The second cantilever arm is constructed similarly to the first cantilever arm. A controller enables movement of the platform through application of signals to both the first cantilever arm and the second cantilever arm to cause flexures of both thereof. The second cantilever arm, through engagement of its free end with the substrate, aids the action of the first cantilever arm in moving the platform.

Abstract: A composite longitudinal vibration mechanical filter for delivering out a supplied high-frequency signal in a predetermined frequency range includes a plurality of vibratable bodies including input and output longitudinal vibratable tuning bars with piezoelectric members superposed thereon, coupling elements by which the longitudinally vibratable tuning bars are coupled to each other, supporting elements projecting respectively from the input and output longitudinally vibratable tuning bars, and a holder to which the supporting elements are attached. At least one resonant frequency adjusting finger is disposed on at least one of the vibrational bodies. Grooves are defined in the longitudinally vibratable tuning bars at the same time that they are fabricated. The grooves extend in the direction in which the longitudinally vibratable tuning bars are longitudinally vibratable, and are shorter than the length of the longitudinally vibratable tuning bars.

Abstract: A method of manufacturing a composite longitudinal vibration mechanical filter that vibrates at a preselected central frequency in a high frequency range. The filter includes a plurality of vibratable bodies including input and output vibratable bodies each having respective piezoelectric members superposed thereon. Coupling elements couple the vibratable bodies to each other. Supporting elements project respectively from the input and output vibratable bodies. A holder is provided to which the supporting elements are attached. The method includes forming an integral body including the plurality of vibratable bodies, the coupling elements, the supporting elements, the holder and a vibration absorbing body holder for eliminating unnecessary vibrations.

Abstract: A tunable electromicromechanical resonator structure incorporates an electrostatic actuator which permits reduction or enhancement of the resonant frequency of the structure. The actuator consists of two sets of opposed electrode fingers, each set having a multiplicity of spaced, parallel fingers. One set is mounted on a movable portion of the resonator structure and one set is mounted on an adjacent fixed base on substrate, with the fingers in opposed relationship and their adjacent ends spaced apart by a gap. An adjustable bias voltage across the sets of electrodes adjusts the resonant frequency of the movable structure.

Abstract: A composite longitudinal vibration mechanical filter for delivering out a supplied high-frequency signal in a predetermined frequency range includes a plurality of vibratable bodies including input and output longitudinal vibratable tuning bars with piezoelectric members superposed thereon, coupling elements by which the longitudinally vibratable tuning bars are coupled to each other, supporting elements projecting respectively from the input and output longitudinally vibratable tuning bars, and a holder to which the supporting elements are attached. At least one resonant frequency adjusting finger is disposed on at least one of the vibratable bodies. Grooves are defined in the longitudinally vibratable tuning bars at the same time that they are fabricated. The grooves extend in the direction in which the longitudinally vibratable tuning bars are longitudinally vibratable, and are shorter than the length of the longitudinally vibratable tuning bars.

Abstract: Resonator systems with controlled quality factors including a resonator having a plurality of ports and a first quality factor greater than the system quality factor, and an amplifier providing negative feedback among the ports to render the system quality factor independent of the resonator quality factor.

Abstract: A low vibration sensitive SAW device includes a first quartz substrate having a pair of opposing surfaces, each surface which supports surface wave propagation. A pair of transducers are coupled to each of said surface wave propagation surfaces providing a pair of surface wave devices on opposing surfaces of the substrate. Each surface wave propagating surface is covered by a matching quartz cover and a glass-frit seal to provide a three piece all-quartz package. The pair of devices are connected together in parallel generally externally from the package, and when the dual device package undergoes vibration in a direction perpendicular to the surface wave propagation surfaces, one surface of the substrate will be subjected to a tensile strain field, whereas the opposite surface of the substrate will be subjected to identical but opposite direction strain field that is compressive.

Abstract: A composite longitudinal vibration mechanical filter for delivering out a supplied high-frequency signal in a predetermined frequency range includes a plurality of vibratable bodies including input and output longitudinal vibratable tuning bars with piezoelectric members superposed thereon, coupling elements by which the longitudinally vibratable tuning bars are coupled to each other, supporting elements projecting respectively from the input and output longitudinally vibratable tuning bars, and a holder to which the supporting elements are attached. Grooves are defined in the longitudinally vibratable tuning bars at the same time that they are fabricated. The grooves extend in the direction in which the longitudinally vibratable tuning bars are longitudinally vibratable, and are shorter than the length of the longitudinally vibratable tuning bars.

Abstract: There is disclosed an improved electromechanical resonator for use in multiresonator mechanical bandpass filters. The resonator is constructed using two resonator rods attached to a ceramic transducer which is substantially centrally located. The thus-formed electromechanical resonator resonates at the desired frequency in the third torsional mode, which is characterized by three motional nodes. Support pins are attached at the two outer nodes to provide physical support, and are also used for signal and ground connections, while the ceramic is positioned on or near the center node, which maximizes the achievable electromechanical coupling. Multiresonator mechanical bandpass filters which use such third-mode electromechanical resonators in conjunction with second-mode interior resonators have improved spurious rejection.

Abstract: By exchanging the position of the input and output resonator means relative to other resonator elements in a mechanical filter, the lengths of the bridging wires used to control the steepness of the bandpass characteristic of the filter can be reduced. Reducing the length of the bridging wires reduces both flexural spurious mode problems and extensional coupling variation problems.

Abstract: A mechanical bandpass filter of the cascaded flexure mode resonator bar type is provided with a coupling structure improving strength an reducing rigid-body spurious modes. Coupling wires are provided on both the top and bottom surfaces of the resonator bars, not just in a single plane.

Abstract: A multimode piezoelectric mechanical filter using edge-mode piezoelectric transducers, each comprising a semi-infinite or long piezoelectric plate polarized in the thickness direction, and a pair of exciting electrodes formed on the plate at an end portion thereof. Input and output edge-mode transducers are supported at their other ends together with optional resonator elements. The transducer and/or resonator elements are mechanically coupled with one another by a coupling rod at their end portions opposite the support to transmit the edge-mode vibration from one to the other. All of the transducers and resonator elements may be disposed in a common plane and may be integrally formed by punching a single piezoelectric plate to form a monolithic type mechanical filter. In such monolithic type filter, coupling rods are also integrally formed with the transducers and resonators.

Abstract: An H-type ceramic resonator having two resonating leaves, a connecting leaf for bridging the two resonating leaves to form an H-shape, and electrodes disposed on at least both surfaces of the resonating leaves. The resonator has a dimensional relationship which falls within the following equities:B.sub.2 /B.sub.3 =4 to 6,B.sub.1 /B.sub.3 =2 to 4, andL/B.sub.1 =5 to 6wherein L is a length of each of the resonating leaves, B.sub.1 is a width of each of the resonating leaves, B.sub.2 is a distance between the two resonating leaves, and B.sub.3 is a width of the connecting leaf.

Abstract: An electromechanical band pass filter includes a plurality of cells in cascade. Each cell comprises two parallel cylindrical bars forming longitudinally vibrating resonators and a flexurally vibrating cylindrical coupler connected between the two resonators.

Abstract: Each cell includes two longitudinally vibrating cylindrical resonators and a flexurally vibrating coupler connected between the two resonators. The diameter of the coupler is defined by the expression: ##EQU1## wherein: d.sub.r is the diameter of the resonatorsl.sub.c is the length of the coupler.OMEGA..sup.+ =f.sup.+ /f.sub.o is the upper relative of the band of frequencies to be transmitted, f.sup.+ the uper frequency of said band and f.sub.o the tuning frequency of the resonators ##EQU2## with l.sub.o the length of the coupler corresponding to a quarter wave effectd.sub.r.sup.+ =2.pi.n.sub.r m.OMEGA..sup.+where m is the order of the vibration mode of the resonators and n.sub.r =l.sub.r /.lambda..sub.o with l.sub.r the length of the resonators and .lambda..sub.o the wavelength at the tuning frequency of the resonators in longitudinal vibration.

Abstract: A carrier frequency communication transmission system has a premodulation band above the transmission position of the base primary group of 60-108 kHz and utilizes mechanical filters as channel filters and also a common group filter in order to filter out the primary group band. Bending resonators having longitudinal coupling are utilized as the mechanical filters. The frequency range of the premodulation band at its lower limit is determined by a frequency spacing of at least 4 kHz from the upper band limit of the primary group band and the upper limit of the frequency range is determined in that the interfering natural oscillations, inasmuch as they occur in the lower stop band of the channel filter, lie at least 12 kHz below the lower limit of the primary group band. Highly stabilized piezo ceramics is used as the electromechanical transducer material.

Abstract: A mechanical filter having at least a pair of mechanical vibrators which are arrayed approximately in parallel with each other in regard to their longitudinal axes, and two couplers which are coupled to the pair of mechanical vibrators. According to the mechanical filter one of the pair of mechanical vibrators undergoes the vibration of the order of an odd number and the other one undergoes the vibration of the order of an even number in the same vibration mode, or both of them undergo the vibration of the order of an odd number or even number in the same vibration mode. Furthermore, these mechanical vibrators have such a mechanical size that they will vibrate at their required order of vibration and at their respective resonance frequencies, and the two couplers are so constructed that they will be differentially coupled to the pair of mechanical vibrators approximately at right angles therewith.

Abstract: An electromechanical filter having mechanical resonators which is used as a channel filter for a mobile radio communication receiver and a carrier telephone. The electromechanical filter is provided with exciter means, each of which is composed of a transducer and an exciter formed as a unitary structure and has the both functions. Each exciter means is a bar-shaped piezoelectric ceramic having a pair of electrodes deposited on its opposing surfaces and subjected to polarization treatment. The exciter means are mechanically coupled by mechanical coupling means with the mechanical resonators.

Abstract: A mechanical bandpass filter has a first resonator which is designed to resonate at a first frequency and a second resonator which is designed to resonate at a second frequency. The two resonators are electrically connected together and the input signal is applied to the first resonator and the filtered signal is removed from an electrical connection to the second resonator.

Abstract: A flexural electromechanical transducer composed of a constant-modulus alloy material and a piezoelectric ceramic material having a high electromechanical coupling coefficient. In the transducer, the piezoelectric ceramic material is polarized in one direction and a specified frequency signal is applied to the piezoelectric ceramic material in a direction parallel to the residual polarization direction of the piezoelectric material for obtaining a thickness-shear vibration. The thickness-shear vibration of the piezoelectric material in turn causes the flexural vibration of the transducer. The transducer achieves a high quality factor Q, a low capacitance ratio r, good spurious characteristics, and low impedance.

Abstract: In an electromechanical filter, poles are obtained by interconnecting an electrical reactance between the input and output of the filter. It is shown that this impedance behaves as a mechanical bridge.

Abstract: An electromechanical filter having minimum attenuation deviation in the pass band frequency range. The filter includes a plurality of mechanical resonators arranged substantially parallel to each other in one plane and mechanical couplers of longitudinal resonance characteristics which are disposed substantially transverse to the plurality of resonators for coupling the resonators together. The couplers have lengths which are between the first and second, and second and third oscillation modes of the longitudinal resonance characteristics. By virtue of the above structure, the couplers can be formed in a single mechanical coupling wire.

Abstract: An electro-mechanical filter comprises an inlet electro-mechanical transducer (12) an outlet electro-mechanical transducer (14) and a mechanical filter constituted by a series connection of resonator bars (1 to 11) which are interconnected by couplers (20 to 29). The bars are half a wavelength long at the central frequency of the pass-band while the couplers are one-quarter of a wavelength long. Instead of being connected to the ends of the bars, the couplers are connected to recessed stepped flats (40) located near the ends of the bars. The positions of the flats (40) are determined to be close to nodes in the first few orders of partials in bending mode vibration of the bars. This has the effect of greatly attenuating the excitation of such parasitic bending modes of vibration. Clearance to enable the couplers to reach the flat (40) is provided by a more deeply stepped positioned flat (41) extending to the end of the rod. Such filters may be used in terminals for analogue transmission systems.

Abstract: An electromechanical filter having two transducers and a mechanical filter vibrating in longitudinal mode, which includes a plurality of resonators connected to each other by coupling rods. The resonators are arranged in two sections and staggered, and the coupling rods connecting two resonators are welded on flat portions provided at the ends of the resonators, each end resonator is connected to the respective transducer through a coupling rod secured to the end face of said resonator adjacent the flat portion, at a point located in the symmetry plane of the resonator, and the coupling rod which connects the end resonator to the next resonator is secured on the flat portion so that the middle of its welded length lies in said symmetry plane.

Abstract: An electromechanical bandpass filter includes at least one real pole consisting of vibrating resonators and couplers between adjacent resonators arranged as filter cells connected in parallel. Each cell includes a coupler and a half of each of the adjacent resonators. At least one bridge extends over at least one resonator and the image mobility of the cells which are spanned by the bridge is equal to the image mobility of the cells in an unbridged electromechanical filter of the same type and having the same passband.

Abstract: A pass-band electromechanical filter, comprising a mechanical unit vibrating in the longitudinal mode mounted between two electromechanical transducers, said unit comprising a plurality of half wave resonators mounted in series and coupling rods connecting the consecutive resonators, the resonators being distributed into two groups of which one comprises the resonators of odd rank and the other the resonators of even rank, the filter comprising moreover at least a bridging coupling rod connecting a resonator of rank k to a resonator of rank k+(2p+1) (p being a positive integer different from zero), said bridging coupling rod having its ends fixed at a certain distance from the end faces of the resonators, at least the bridging coupling rod on the one hand, or the coupling rod placed between the resonator of rank k and that of rank k+(2p+1) on the other hand, having a length which is respectively different from a three quarter wave or different from a quarter wave.