Abstract: An apparatus including vertically separated acoustic resonators are disclosed. The apparatus includes a first acoustic resonator on a substrate and a second acoustic resonator vertically separated above the first acoustic resonator. Because the resonators are vertically separated above another, total area required to implement the resonators is reduced thereby savings in die size and cost are realized. The vertically separated resonators are supported by standoffs that are fabricated on the substrate, or on a resonator.

Abstract: The band-pass filter has a stacked pair of film bulk acoustic resonators (FBARs) and an acoustic decoupler between the FBARs. Each of the FBARs has opposed planar electrodes and a layer of piezoelectric material between the electrodes. The acoustic decoupler has a single layer of acoustic decoupling material having a nominal thickness equal to an odd integral multiple of one quarter of the wavelength in the acoustic decoupling material of an acoustic wave having a frequency equal to the center frequency. The acoustic decoupling material comprises plastic. The acoustic decoupler controls the coupling of acoustic energy between the FBARs. Specifically, the acoustic decoupler couples less acoustic energy between the FBARs than would be coupled by direct contact between the FBARs. The reduced acoustic coupling gives the band-pass filter desirable in-band and out-of-band properties.

Abstract: An embodiment of the acoustically-coupled transformer has first and second stacked bulk acoustic resonators (SBARs) each having a stacked pair of film bulk acoustic resonators (FBARs) with an acoustic decoupler between the FBARs. Each FBAR has opposed planar electrodes with piezoelectric material between the electrodes. A first electrical circuit connects one FBARs of the first SBAR to one FBAR of the second SBAR, and a second electrical circuit connects the other FBAR of the first SBAR to the other FBAR of the second SBAR. The c-axis of the piezoelectric material of one of the FBARs is opposite in direction to the c-axes of the piezoelectric materials of the other three FBARs. This arrangement substantially reduces the amplitude of signal-frequency voltages across the acoustic decouplers and significantly improves the common mode rejection of the transformer. This arrangement also allows conductive acoustic decouplers to be used, increasing the available choice of acoustic decoupler materials.

Abstract: The invention relates to a component operating with bulk acoustic waves, which comprises a mount substrate, thin-film resonators and an acoustic mirror, with coupled resonators being arranged jointly on this mirror. At least one mirror layer—a coupling layer—is in the form of an electrically conductive layer. This mirror layer forms coupling capacitances with lower electrodes of the resonators, thus resulting in deliberate capacitive coupling between the resonators which, according to the invention, is used in order to achieve additional pole points in the blocking areas of the filter transfer function. The capacitive coupling of the resonators may, for example, be influenced by partial structuring of the coupling layer in order, in particular, to shift the frequency of the pole points.

Abstract: Disclosed herein is a film bulk acoustic resonator (FBAR), an FBAR based duplexer device, and a manufacturing method thereof, which a plurality of sacrificial layer units are formed on a substrate wafer so as to be spaced apart from one another at regular distances, and device functional portions are formed on the sacrificial layer units, respectively. The device functional portions have a piezoelectric layer unit and a plurality of electrodes. Then, side wall and roof of protective formed by the use of dry film. After hardening the dry film, the wafer is cut into a plurality of the wafer sections so as to contain the device functional portions, respectively.

Abstract: A duplexer comprising a transmit resonator device and a receive resonator device for filtering transmit and receive signals. The resonator device has a first BAW resonator for generating an acoustic wave signal from an input electric signal, a first acoustic delay for delaying the acoustic wave signal, and an intermediate BAW resonator for receiving the delayed acoustic wave signal at one end and converting the delayed acoustic wave signal to an electric signal. Through electrical coupling, the electric signal also appears at another end of the intermediate BAW resonator for generating a further acoustic wave signal at the other end. The resonator further comprises a second delay for delaying the further acoustic wave signal, and a second BAW resonator for producing an output electric signal from the delayed further acoustic wave signal. The duplexer can be used in a transceiver in a mobile phone.

Abstract: In an electronic component having a piezo-electric resonator 10 formed on an element substrate 11 and obtaining a signal having a predetermined resonant frequency by a bulk wave propagating within a piezo-electric film 15, a mounting substrate 19 on which the piezo-electric resonator 10 is mounted by face-down bonding through N bumps 18, when a maximum diameter of said N bumps 18 is defined as D ?m, die shear strength of said N bumps 18 is not smaller than ND/6 (g), preferably, not smaller than ND/3.6 (g).

Abstract: The acoustically-coupled transformer includes first and second stacked bulk acoustic resonators (SBARs), each having a stacked pair of film bulk acoustic resonators (FBARs) with an acoustic decoupler between them. In one embodiment, the acoustic decoupler comprises a layer of decoupling material has having a nominal thickness equal to an odd integral multiple of one quarter of the wavelength of an acoustic wave having a frequency equal to the transformer's center frequency. In another embodiment, the acoustic decoupler comprises a Bragg stack. Each FBAR has opposed planar electrodes with piezoelectric material between them. The transformer additionally has first terminals, second terminals, a first electrical circuit connecting one FBARs of the first SBAR to one FBAR of the second SBAR and the first terminals, and a second electrical circuit connecting the other FBAR of the first SBAR to the other FBAR of the second SBAR and the second terminals.

Abstract: A film bulk acoustic resonator may be formed with a piezoelectric film having improved quality. The piezoelectric film may be deposited directly onto a single crystal silicon substrate. That substrate may be removed and selectively replaced with a lower electrode to form the film bulk acoustic resonator.

Abstract: A method for fabricating an apparatus, and an apparatus embodying the same is disclosed. First a device chip having circuit elements is fabricated. Next, a cap with a cap circuit is fabricated. Finally, the cap is placed on the device chip to connect a first contact point with a second contact point using the connector on the cap. The apparatus includes a device chip and a cap. The device chip has the first contact point and a second contact point. The cap has the cap circuit that, when the cap is placed on the device chip, connects the first contact point with the second contact point.

Abstract: A dual mode filter includes a casing substrate on which an input electrode, an output electrode, two ground electrodes, and a relay electrode are provided, first and second filter elements mounted in parallel with each other on the casing substrate, and a cap fixed onto the casing substrate. The first and second filter elements each include a first terminal electrode, a second terminal electrode, a pair of segmented electrodes, a counter electrode, and a third terminal electrode. The first terminal electrode of the first filter element is connected to the input electrode, and the third terminal electrode is connected to one ground electrode. The first terminal electrode of the second filter element is connected to the output electrode, and the third terminal electrode is connected to the other ground electrode. The second terminal electrodes of the first and second filter elements are connected to the relay electrode.

Abstract: An energy-trap piezoelectric filter has a construction such that first and second piezoelectric substrates are laminated with an adhesive sheet therebetween. The elasticity modulus of the adhesive sheet is within the range of about 0.5 MPa to about 3000 MPa. In addition, the adhesive sheet is provided with at least one notch in which a material that is used to form external electrodes is inserted.

Abstract: A piezoelectric oscillator is provided with a container unit in which an upper cavity and a lower cavity are partitioned by a partition wall, a piezoelectric oscillating element accommodated in the upper cavity, an IC chip and electronic components accommodated in the lower cavity and forming an oscillating circuit, and external terminals provided at the periphery of the bottom surface of the container unit and connected with the oscillating circuit. A jitter reducing structure for reducing jitter components of an oscillation wave outputted from the output terminal which is an external terminal electrode is formed in the partition wall of the container unit. There can be provided a small-size piezoelectric oscillator which has an excellent jitter characteristic of an oscillation waveform and can stably and satisfactorily perform high-frequency oscillation utilizing overtone oscillation, and whose characteristic is easily changeable to provide excellent versatility and noise resistance.

Abstract: An electronic device includes a crystal filter device (500) that includes a crystal substrate having a top surface and a bottom surface that substantially opposes the top surface, a plurality of electrodes (502, 504, 506) disposed on the bottom surface. A first electrode (512) disposed on the top surface substantially opposes a first (502) of the plurality of electrodes on the bottom surface to thereby define a first resonator (530) of a plurality of resonators (530, 540, 550) across the crystal substrate. A second electrode (510) disposed on the top surface substantially opposes the remaining electrodes (504, 506) of the plurality of electrodes disposed on the bottom surface to thereby define the remaining resonators (540, 550), other than the first resonator (530), of the plurality of resonators across the crystal substrate. The first electrode (512) and the second electrode (510) disposed on the top surface are electrically coupled together.

Abstract: A method including to a resonator coupled to at least one support structure on a substrate, the resonator having a resonating frequency in response to a frequency stimulus, modifying the resonating frequency by modifying the at least one support structure. A method including forming a resonator coupled to at least one support structure on a chip-level substrate, the resonator having a resonating frequency; and modifying the resonating frequency of the resonator by modifying the at least one support structure. A method including applying a frequency stimulus to a resonator coupled to at least one support structure on a chip-level substrate determining a resonating frequency; and modifying the resonating frequency of the resonator by modifying the at least one support structure.

Abstract: An anisotropically electroconductive adhesive comprising a thermosetting insulating adhesive mixed with electroconductive particles, the thermosetting insulating adhesive having an intrinsic acoustic impedance of about 1.4 MPa·s/m or less is provided. Piezoelectric resonators are bonded to lands on an insulating substrate using this anisotropically electroconductive adhesive. The piezoelectric resonators are connected in a ladder type to form a ladder filter by pattern electrodes on the insulating substrate. When a filter is prepared using piezoelectric resonators, this anisotropically electroconductive adhesive can provide good filter characteristics without propagating the vibration of the piezoelectric resonators to the insulating substrate.

Abstract: Improved bandwidths and oscillation uniformity is obtained through a rod type BAW TFR structure formed over a semiconductor support. The resonator includes a first and a second electrode and a plurality of distinct elemental piezoelectric structures between the electrodes. Each of the piezoelectric structures has a length, a width and a height, the height being the distance between the electrodes. The height of the piezoelectric structures is at least equal to or more than one of the length or the width, or both. Such resonator is made by forming on a common bottom a plurality of distinct piezoelectric structures each having a length, a width and a height, wherein the height is formed at least equal to the width or the length of the piezoelectric structure, and forming a common top electrode thereover.

Abstract: A radio frequency filter system includes a first acoustic resonator (54, 56) for a first frequency and a second acoustic resonator (54, 56) for a second frequency. An acoustic reflector array (102, 152, 202) is coupled to an electrode of the first acoustic resonator (54, 56) and to an electrode of the second acoustic resonator (54, 56). The acoustic reflector array (102, 152, 202) includes a plurality of reflector layers (112, 152, 210). A first reflector layer (112, 152, 210) is operable to reflect a signal at substantially the first frequency. A second reflector layer (112, 152, 210) is operable to reflect a signal at substantially the second frequency.

Abstract: A multilayer type piezoelectric filter is provided which includes at least two chambers for receiving therewithin resonators, respectively. The chambers are partly defined by a top printed circuit board and an intermediate printed circuit board. The top printed circuit board and the intermediate printed circuit board are formed with communication holes for communicating the chambers with the outside.

Abstract: An energy-trap piezoelectric filter has a construction such that first and second piezoelectric substrates are laminated with an adhesive sheet therebetween. The elasticity modulus of the adhesive sheet is within the range of about 0.5 MPa to about 3000 MPa. In addition, the adhesive sheet is provided with at least one notch in which a material that is used to form external electrodes is inserted.

Abstract: The invention relates to resonator structures of radio communication apparatus, especially bulk acoustic wave filter structures. According to the invention, a bulk acoustic filter structure is constructed with a lattice configuration, in which two of the filters have a different area than other two for creating very steep passband edges in the frequency response of the filter. Preferably, the filter structure further comprises a second lattice structure for increasing the stopband rejection ratio of the filter structure, and for allowing the use of a simple mechanical structure. The cascaded configuration allows the construction of the filter structure in such a way, that the electrodes of the input and output port are at the same layer, thereby removing the need to make vias in the piezoelectric layer, which results in considerable simplification of the manufacturing process.

Abstract: An anisotropically electroconductive adhesive comprising a thermosetting insulating adhesive mixed with electroconductive particles, the thermosetting insulating adhesive having an intrinsic acoustic impedance of about 1.4 MPa·s/m or less is provided. Piezoelectric resonators are bonded to lands on an insulating substrate using this anisotropically electroconductive adhesive. The piezoelectric resonators are connected in a ladder type to form a ladder filter by pattern electrodes on the insulating substrate. When a filter is prepared using piezoelectric resonators, this anisotropically electroconductive adhesive can provide good filter characteristics without propagating the vibration of the piezoelectric resonators to the insulating substrate.

Abstract: A piezoelectric filter which is adapted to reduce its height and to electrically and mechanically protect the resonators thereof, and is easy to manufacture and assemble, wherein a plurality of resonators S1 through S3 and P1 through P3 are surrounded by respective frame-like spacers 2a, 2b, 2c; 22a, 22b, 22c and laid one on the other with intermediary printed circuit boards 3a, 3b; 23a, 23b interposed therebetween, a top printed circuit board 4; 24 are placed on the top, a bottom printed circuit board 5; 25 provided on the lower surface thereof with a plurality of connection electrodes 18a, 18b, 18c, 38a, 38b, 38c are placed on the bottom, the frame-like spacers, the top printed circuit board and the bottom printed circuit board are bonded together along the peripheral edges thereof, and the electrodes of the resonators are electrically connected to respective connection electrodes by way of conduction patterns 13a through 13f; 33a through 33f formed on the respective printed circuit boards to produce an int

Abstract: A piezoelectric filter has a significantly reduced size and a sufficient coupling capacitance while avoiding an uneven outer configuration of an overall shape of the filter. The piezoelectric filter includes a first resonating unit and a second resonating unit and a coupling capacitance unit disposed in a piezoelectric substrate. The coupling capacitance unit is provided with a first coupling capacitance electrode located on an upper surface of the piezoelectric substrate and a second coupling capacitance electrode located on a lower surface thereof and the first and second coupling capacitance electrodes are arranged to extend to side edge surfaces of the piezoelectric substrate.

Abstract: A multi-pole monolithic crystal filter with at least three acoustically coupled resonators (50,52,54) on a piezoelectric blank (56). Each resonator (50,52,54) has associated top and bottom electrodes (70,72,74,76,78,80). An input connection (62) is coupled to the top electrode (70) of a first resonator (50) and a ground connection (64) is coupled to the bottom electrode (72) of the first resonator (50). An output connection (68) is coupled to the bottom electrode (80) of a last resonator (54) and a ground connection (66) is coupled to the top electrode (78) of the last resonator (54). The top and bottom electrodes (74,76) of each of the remaining resonators (52) are coupled to each other.

Abstract: In a multiple-stage-connected multiple-mode piezoelectric filter unit having a single container 1 in which there are connected, in cascade, two multiple-mode piezoelectric filter elements comprising at least one piezoelectric substrate and two electrode groups each comprising a pair of input/output electrodes and a grounding electrode, the electrode pairs being formed on one side of the piezoelectric substrate with a predetermined gap provided and the grounding electrodes being formed on the other side of the piezoelectric substrate at positions respectively opposite to the electrode pairs, it is an object of the present invention to enhance the ability of preventing the two filter elements from being coupled with each other, thus facilitating the final adjustment thereof. Formed in a single container 1 are two piezoelectric substrates 2, 3 on each of which formed are a pair of input/output electrodes and a grounding electrode.

Abstract: A Bulk Acoustic Wave (BAW) filter, comprising at least one resonator structure that is disposed over a substrate, and an acoustic mirror that is disposed over the resonator structure. The acoustic mirror includes a plurality of layers. The acoustic mirror substantially isolates acoustic vibrations produced by the resonator from reaching beyond an upper surface of the acoustic mirror. The acoustic mirror also prevents environmental contaminants from coming into contact with the resonator. Also disclosed are surface-mountable BAW components.

Abstract: A power transformer circuit (100) includes a capacitor (120) and a resonator (140). The resonator (140) is coupled in series with the capacitor (120) and is operable to provide a substantially inductive impedance between its terminals (142,144). Resonator (140) is preferably implemented as a piezoelectric lithium niobate resonator that is operated in a thickness-shear mode. In a preferred embodiment, power transformer circuit (100) is employed as a series resonant output circuit in an electronic ballast (500) for powering at least one gas discharge lamp (30).

Abstract: A piezoelectric resonator having a miniature size and being fabricated at a low cost is used in a ladder-type filter that has a substrate, on the front and back surfaces of which line electrodes are provided. A series resonator includes a substantially rectangular piezoelectric plate vibrating in a length vibration mode and has vibrating electrodes located on a pair of opposite side edge surfaces of the substantially rectangular piezoelectric substrate. A parallel resonator including a substantially rectangular piezoelectric plate vibrating in a length vibration mode has vibrating electrodes located on the front and back major surfaces of the substantially rectangular piezoelectric substrate. The series and parallel resonator are mounted on the substrate in such a manner as to be spaced apart from each other. The vibrating electrodes of the series resonator are connected with the line electrodes, respectively, by using a conductive adhesive agent.

Abstract: In an energy trapping type ceramic filter vibrating in the thickness shear-slide mode, vibrating electrodes are formed on opposite sides of a piezoelectric ceramic substrate, while an input terminal electrode and an output terminal electrode are provided on both end portions of the substrate so that lead terminals are soldered to the terminal electrodes. A distance l.sub.5 between the input terminal electrode and the adjacent vibrating electrode and a distance l.sub.6 between the output terminal electrode and the adjacent vibrating electrode are set within a range of one to three times the thickness of the substrate. Thus, it is possible to suppress undesired vibration other than principal vibration, thereby improving filter characteristics.

Abstract: An electronic device which has piezoelectric resonators and terminals piled in a box-like case. The electronic device has a couple of terminals, each of which has a contact portion and a junction portion extending from the contact portion. In the case, the couple of terminals are integrated by electrically connecting the junction portions.

Abstract: In a piezoelectric filter, two vibrating element parts are arranged on longitudinal side portions of a rectangular flat plate shaped piezoelectric substrate, and a capacitor is arranged therebetween. Each of the vibrating element parts comprises a pair of vibrating electrodes which are arranged on an upper surface of the piezoelectric substrate at a distance, and an opposite electrode which is arranged on a back surface of the piezoelectric substrate to be opposed to the vibrating electrodes. The pair of vibrating electrodes of each Vibrating element part is arranged along an electrode arrangement direction which is inclined with respect to side surfaces of the rectangular piezoelectric substrate. The electrode arrangement direction for the vibrating electrodes is inclined with respect to the side surfaces of the piezoelectric substrate at an angle .theta. of inclination which is preferably in excess of 0.degree. and not more than 45.degree..

Abstract: A multi-pole monolithic crystal filter (100) having at least three asymmetrically acoustically coupled resonators (104) on a piezoelectric blank (102) to provide an improved phase response (302). The resonators (104) are positioned substantially in inverse proportion to predetermined ladder network coupling coefficients to achieve an improved phase response filter. The ladder network coupling coefficients are selected from designs including Bessel, Gaussian, linear phase and equiripple models. In this way, a predetermined improved phase response (302) is obtained monolithically without discrete interstage tuning components.

Abstract: The present invention relates to a low profile monolithic crystal strip filter and filter package. The filter includes an AT-cut rectangular strip of quartz crystal. The filter further includes input, output and ground electrodes which are formed in a symmetrical pattern on the strip. Each electrode is connected to its respective mounting or ground contact by a flag. The electrodes, contacts and flags have a predetermined size and shape, and are arranged in a predetermined configuration on the crystal strip to minimize spurious responses and insertion losses. The crystal strip is mounted to an HC-45 or HC-49 base to minimize production costs. The output signal of the filter has a center frequency of about 4 to 500 MHz, a 3 dB bandwidth of about 3 to 250 kHz, an ultimate of better than 60 dB, standard insertion losses for the number of poles in the filter and commercially acceptable spurious responses.

Abstract: This invention discloses a monolithic multipole stacked crystal filter comprised of a series of cascaded 2-port semiconductor bulk acoustic resonator stacked crystal filters electrically cascaded and a shunt inductor connected between each of the 2-port filters. Each of the 2-port filters including a first and second piezoelectric layer, typically aluminum nitride. A first input electrode is positioned on a top surface of one of the piezoelectric layers and a second output electrode is positioned on a bottom surface of the other of the piezoelectric layers. A ground electrode is positioned between the piezoelectric layers. In this regard, the piezoelectric layers will resonate at a resonant frequency and provide bandpass filter characteristics. The complete monolithic multipole filter provides control of the passband shape which yields highly desirable filter characteristics.

Abstract: An antenna utilizing an overmoded configuration for coupling energy in a predetermined frequency band between an electrical circuit and a propagating medium. The antenna includes a first thin film resonator having a first pair of electrodes and a first thin film piezoelectric element interposed between the first pair of electrodes, with the first thin film resonator coupled to the electrical circuit. A second thin film resonator includes a second pair of electrodes and a second thin film piezoelectric element interposed between the second pair of electrodes, the second thin film resonator being operable for interfacing between the antenna and the propagating medium. A delay element interposed between the first and second thin film resonators has a thickness substantially equal to a multiple of one-half wavelength of a desired frequency in the predetermined frequency band for acoustically coupling energy in the predetermined frequency band between the first and second thin film resonators.

Abstract: An IF crystal filter for a VHF receiver including:a crystal filter (18) having an input (22) and an output (24)a reactive impedance means (26) coupled across the crystal filter input and output for changing the selectivity characteristics of the crystal filter by a predetermined amount; andswitching means (32) having a control input responsive to a control voltage, and coupled to said reactive impedance means for selectively shunting the reactive impedance means to ground, whereby to change the selectivity of the filter.

Abstract: A plurality of piezoelectric resonators (10,32,37,57,62,66,79,88,93) are utilized to form a bandpass filter (31,56,78). The resonators (10,32,37,57,62,66,79,88,93) are connected in parallel to form a plurality of parallel paths between an input (43,73,81) and an output (47,74,82) of the filter (31,56,78). A predetermined number of the piezoelectric resonators (10,32,37,57,62,66,79,88,93) provide a phase shift of approximately 180 degrees. Each parallel path has a passband and center frequency that is displaced from the passband and center frequency of other paths. Consequently, the passband of each parallel path algebraically sums and creates a filter passband that is wider than the passband of each of the filter's individual parallel paths.

Abstract: A surface mountable piezoelectric device that includes an in situ finish plate mask is mounted on a substrate (20) that includes feedthrough holes (26, 28, and 30) to conduct signals from a piezoelectric element (40) that may include multiple resonator stages (48, 46, 50, and 56). A metallic support structure that includes windows or holes therethrough (72, 74 and 76) permits tuning of the piezoelectric device by mass loading during manufacturing, compliantly supports the piezoelectric element (40), provides RF shielding for the resonators, and is an in situ finish plate mask.

Abstract: A piezoelectric resonator which comprises a piezoelectric resonance element in which electrodes are formed on a pair of side surfaces, which are opposed to each other, of a piezoelectric substrate. The electrodes are opposed to each other while being separated by the piezoelectric substrate in the center of the piezoelectric substrate to form a vibrating portion of an energy-trapped type utilizing a thickness shear vibration mode in the center of the piezoelectric substrate. Spacers are respectively fixed to the side surfaces of the piezoelectric substrate with gaps being provided between the spacers and the above-mentioned vibrating portion, and a pair of cover sheets are respectively affixed to both major surfaces of a structure comprising the spacers and the piezoelectric resonance element so as to form gaps on top of and beneath the vibrating portion in the piezoelectric resonance element.

Abstract: In a trap circuit a plurality of cascade-connected three-terminal piezoelectric ceramic resonators having different resonance frequencies, an inductor is connected between input and output terminals of only the resonator having the lowest resonance frequency, and a resistor is connected between input and output terminals of each remaining resonator, so that large attenuation is attained at the respective resonance frequencies and a large attenuation is attained in intermediate regions between the resonance frequencies. Thus, unwanted signals can be eliminated over a large bandwidth.

Abstract: A phase equalizer with a pair of ceramic resonators with different resonant frequencies than each other provides convex group delay time characteristics, which compensates for the concave group delay time characteristics of a ceramic filter. Thus, the flat group delay time characteristics in the combination of a ceramic filter and a phase equalizer is obtained, and excellent speech quality in analog signal transmission and/or excellent error rate in data transmission is obtained, while keeping excellent selectivity in a wireless communication system.

Abstract: A complex circuit component for a video signal circuit in a television receiver set has a single substrate, on which a first ceramic trap for removing speech carrier wave together with an inductor for that trap, a second trap for removing color subcarrier wave, and a delay circuit coupled with output of said second trap are mounted. The capacitors for those circuits are implemented by a pair of conductive patterns deposited on front surface and rear surface of the substrate. The capacitor for said first ceramic trap is subject to trimming so that the characteristics of the trap is adjustable.

Abstract: A mechanical filter having as its major part at least one longitudinal vibration mode vibrator, includes a piezoelectric ceramic plate an electrode pair attached to top and bottom surfaces thereof. The piezoelectric ceramic plate is polarized in its thickness direction to form at least two polarized regions, the polarization directions being different from each other.

Abstract: A piezoelectric filter of the energy-trapped type which utilizes thickness shear mode is disclosed, wherein first and second resonator units are connected in a cascade manner. Each of the resonator units includes a piezoelectric plate which has a slit formed therein and a pair of front electrodes on the front thereof and a pair of back electrodes on the back thereof, with the slit lying between each pair of the electrodes. The pair of back electrodes of the second resonator unit are electrically connected to each other. The first and second resonator units are positioned so that the back electrodes of one of the two units face against those of the other, and then mechanically coupled together through the use of an electrically nonconductive adhesive. The back electrodes of the first and second resonator units are led commonly outwardly, while the pair of the front electrodes of the first resonator unit form an input electrode and an output electrode.

Abstract: A wireless superheterodyne receiver is provided having an antenna for receiving wireless transmissions, a preamplifier having an input connected to the antenna and an output, a crystal filter having an input connected to the output of the preamplifier and an output, a demodulator having an input connected to the output of the filter, the demodulator having a single mixer, an oscillator having a second crystal connected to the single mixer of the demodulator wherein the demodulator supplies at an output a demodulated signal based upon the wireless transmissions.

Abstract: A multi-resonator crystal body is physically supported by electrical lead wires extending from a support substrate having individual shaped electrical conductors thereon which are thus connected to each resonator on the crystal body such that the individual resonator electrodes can be selectively short-circuited, or open-circuited, or displayed to an external electrical network to facilitate final finishing of the resonator electrodes. Predetermined electrical circuits (e.g. a short-circuit effected by conductive cement or paint) are thereafter connected across some of the resonator electrodes via the shaped conductive areas on the support substrate before the entire assembly is encapsulated in a standard pin connector housing arrangement. Besides greatly facilitating the tuning of individual crystal resonators to desired frequencies during the finishing operation, this mounting arrangement is also believed to provide improved temperature characteristics and/or shock mounting of the crystal body.

Abstract: A crystal filter structure and fabrication method therefor. The crystal filter is constructed as a thick film circuit on a ceramic substrate. The coupling capacitors are painted on the ceramic substrate as part of the thick film circuit. The capacitors are laser trimmed to precise tolerance in order to provide a crystal filter having precise characteristics.

Abstract: A symmetrical two pole monolithic crystal filter is combined with appropriate value fixed capacitors and cascaded with other similar filter elements to provide a high order filter with symmetrical transmission zeros and low passband ripple. The filter includes a piezoelectric resonating element having first and second opposite sides with first and second pairs of electrodes thereon. A first capacitor is coupled to an electrode of the first pair located on the first side and a second capacitor is coupled to an electrode of the second pair of the electrodes located on the first side. A shunting capacitor is used between the electrodes of the first and second pairs located on the first side. A fourth capacitor is coupled from both of the first and second electrodes located on the second side.

Abstract: A multi-resonator crystal filter is provided having a reduced number of electrical connecting pins. The monolithic crystal filter includes at least four resonators, namely, an input resonator, an output resonator and electrically coupled center resonators. A single electrical pin connection is made to the electrically coupled together center resonators thus avoiding the need for an individual connecting pin for each resonator.