US3573672A - Crystal filter - Google Patents

Crystal filter Download PDF

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US3573672A
US3573672A US771843A US3573672DA US3573672A US 3573672 A US3573672 A US 3573672A US 771843 A US771843 A US 771843A US 3573672D A US3573672D A US 3573672DA US 3573672 A US3573672 A US 3573672A
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electrodes
plate means
energy
wafer
frequency
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Irvin E Fair
Edwin C Thompson
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AT&T Corp
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Bell Telephone Laboratories Inc
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    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic elements; Electromechanical resonators
    • H03H9/46—Filters
    • H03H9/54—Filters comprising resonators of piezoelectric or electrostrictive material
    • H03H9/56—Monolithic crystal filters
    • H03H9/566—Electric coupling means therefor
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H3/00—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators
    • H03H3/007—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks
    • H03H3/02—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks for the manufacture of piezoelectric or electrostrictive resonators or networks
    • H03H3/04—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks for the manufacture of piezoelectric or electrostrictive resonators or networks for obtaining desired frequency or temperature coefficient
    • H03H2003/0414—Resonance frequency

Definitions

  • This invention relates to energy transfer devices and particularly to crystal filters.
  • low-loss transmission of energy through an acoustically resonant crystal wafer vibrating in the thickness shear mode is selectively controlled by covering the opposite faces of the wafer with a number of spaced electrode pairs whose masses are sufficient to concentrate the thickness shear vibrations between the electrodes of each pair so that the pairs form separate resonators with the crystal, and by spacing the pairs far enough so that the coupling between any two adjacent resonators is less than a given amount.
  • these capabilities may be exploited to form a filter that controls the passband between an electric source and a resistive load. This is accomplished by vapor depositing two or more pairs of electrodes on opposite faces of a piezoelectric crystal wafer. When one pair is connected to a source capable of exciting thickness shear mode vibration in the wafer, and when another pair is connected to a resistive load, the pairs form successive resonators with the wafer.
  • the passband at the load can be adjustably controlled by varying the masses of the electrodes and the spacing between the respective resonators. Specifically, it requires making the electrodes sufficiently massive and spacing them far enough apart so that the coupling between adjacent resonators is at least small enough to be in what is called herein the controlled-coupling condition. Resonators in this condition have also been called definitively coupled.
  • the controlled-coupling condition becomes evident when the coupling between any adjacent two of the resonators is small enough so that the two short circuit resonant frequencies exhibited by these resonators are close enough in frequency to exclude the antiresonant frequencies caused by each resonator, from between them.
  • the controlled-coupling condition is characterized by a characteristic impedance whose real portion varies with rising frequency from zero to a finite intermediate peak and returns to zero. For determining this condition the two resonators are decoupled from any other resonators.
  • the resonator couplings whose value and number determine the resulting passbands, depend upon many factors, such as mass loading, electrode separation crystal wafer thickness, and electrode dimensions. Photoetching of plating masks and accurate crystal thickness permit reasonably good control over the couplings and resulting passbands.
  • variations from the desired passbancb do exist. Overcoming such variations after the crystal structure is made involves adjustment of the masses of the electrodes in the separate resonators. However, this change in mass loading varies not only the couplings from resonator to resonator, but also the midband frequencies. As a result, while the overall passband and midband frequencies can be controlled within comparatively coarse limits, fine control is difficult.
  • the material is deposited or removed from one side of the wafer between the electrodes of each coupled pair of electrodes to be adjusted.
  • the invention is based in part on the recognition that chang ing the thickness of the region between pairs, just as changing the mass loading, affects both the bandwidth and the midband frequency. However, the rates of change are sufficiently different to permit fine adjustment by alternating the changes.
  • the deposit or removal is in the shape of a spot, or preferably, a strip.
  • the mass of the deposition or removal is regulated alternately with changes in the mass loading.
  • FIG. I is a partly pictorial schematic diagram of a filter circuit, including a plan view of a filter, embodying features of the invention
  • FIG. 2 is a diagram of the same circuit in FIG. I but showing a cross section of the filter in FIG. I;
  • FIG. 3 is a diagram of a filter circuit utilizing a monolithic crystal filter having two coupled resonators
  • FIGS. 4 and 5 are, respectively, the lattice and ladder equivalent circuits for the filter circuit in FIG. 3;
  • FIG. 6 is a graph illustrating the variation in impedance and reactance with frequency of impedances in FIG. 4 when electrodes in the circuit of FIG. 3 are substantially massless and the coupling between electrode pairs tight;
  • FIG. 7 is a graph illustrating the image impedance, i.e. characteristic impedance, of the circuit of FIGS. 3, 4 and 5 for the conditions illustrated in FIG. 6;
  • FIG. 8 is a graph illustrating the transmission characteristics of the circuit in FIG. 3 when operated under the conditions of FIGS. 6 and 7 when terminated by a low resistance;
  • FIG. 9 is a graph illustrating the variations of impedance and reactance of elements in the circuit of FIG. 4 when the electrode pairs in the filter of FIG. 3 are coupled less than a predetermined amount;
  • FIG. 10 is a graph illustrating the image or characteristic impedance of the filter in FIG. 3 for variations in frequency under the conditions illustrated in FIG. 9;
  • FIG. I l is a graph illustrating the transmission characteristic of the filter of FIG. 3 operating under the conditions of FIGS. 9 and 10 when terminated by a low resistance;
  • FIG. 12 is a circuit diagram illustrating a test circuit for testing the coupling between resonators, that is electrode pairs, on a filter embodying features of the invention
  • FIGS. 13, 14 and I5 are graphs illustrating the parameter relationships for filters such as those of FIGS. 1, 2, 3, 17, I8 and 19 without their interelectrode depositions;
  • FIG. 16 is a graph illustrating the effects of the deposited interelectrode area according to the invention upon the bandwidth and coupling of electrode pairs in FIGS. 1 and 2 and as measured in FIG. 12;
  • FIG. I7 is a diagram illustrating another filter embodying.
  • FIG. 18 is a circuit diagram including another filter embodying features of the invention shown in plan view;
  • FIG. I is a circuit diagram of FIG. 18 wherein the filter is shown as cross section 19-19 on FIG. I8;
  • FIG. 20 is a partially pictorial circuit diagram illustrating another embodiment of the invention.
  • two pairs of electrodes 10, 12 and 14, 16 each have their constituent opposing electrodes vapordeposited or otherwise plated on opposite faces of a rectangular AT-cut quartz crystal wafer 18.
  • the pairs made up of rectangular electrodes whose thicknesses appear exaggerated for clarity, are aligned in this embodiment along the Z crystallographic axis of the crystal wafer.
  • a high frequency source 22 applies a high frequency potential across the electrodes 10 and 12 for piezoelectrically generating thickness shear mode vibrations in wafer 18.
  • the portion of the vibratory energy in the wafer 18 between the electrodes 14 and 16 establishes a varying electric field that the leads 20 apply across a terminating resistor R
  • the two electrode pairs thus form two coupled resonators.
  • a deposition 24 in the shape of a spot, vapor-deposited or otherwise plated between the electrodes and 14 on one side and the wafer 18 in the center of the interelectrode spacing, has smaller dimensions than the rectangular electrodes. Its mass is sufficient to widen the bandwidth of the filter to a desired value.
  • the masses of the electrodes 10, 12, 14 and 16 are sufficiently great and the respective electrode pairs 10, 12 and l4, 16 are spaced from each other so that the resonators formed by the electrode pairs are in what is here termed the controlled-coupling condition. That is to say, the masses of the electrodes 10, 12, 14 and 16 are sufficiently great so as to trap" or concentrate the energy of vibrations in the wafer 18 to the volume of the wafer between the electrodes of each pair and attenuate the energy exponentially with distance away from the pair. This limits the effect of the wafer boundaries upon vibrations within the wafer.
  • the spacing between the electrode pairs combined with the degree of mass loading is such as to couple the pairs only enough so that resonant frequencies f and f exhibited by the coupled resonators are close enough so that neither antiresonant frequency f,,,, nor f exhibited by the respective resonators appears between them.
  • the coupled resonators are coupled to less than one-half of the maximum coupling in the controlled coupled condition. That is, the resonant frequencies are closer to each other than to the nearest antiresonant frequency.
  • FIG. 3 corresponds to FIGS. 1 and 2 without deposition 24.
  • the three capacitors C represent the electrical equivalent of the acoustical coupling between the electrode regions of FIG. 3. According to Bartletts bisection theorem the two circuits are related to each other by the following equations:
  • C1 1B-1 g The values C and L are such that the shear mode fundamental frequency of the crystal wafer 18 is /zrnLQ.
  • the value of L is a function of the crystal body thickness and the geometry of electrodes 10, 12, and 14, 16.
  • C is the static interelectrode capacitance of each pair of electrodes.
  • the image impedance, i.e. the characteristic impedance Z, 1 Z Z where cuited, and Z is the input impedance when the load end is short circuited.
  • the characteristic impedance or image impedance Z for the crystal structure of FIG. 3 and its equivalent circuit in FIG. 4 is equal IOVZAZB- Since the crystal wafer 18 has a large Q, the values Z and 2,, are almost exclusively comprised of their component reactances X A and X,,.
  • the characteristic impedance Z is substantially equal to vX X
  • the values X A and X B can be plotted and the valuesof Z,- determined therefrom for various masses of electrodes 10, 12 and 14, 16.
  • the impedance Z possesses two positive real ranges.
  • One range extends between the resonant frequencies j ⁇ and f,; and has an intermediate maximum R with zero extremes.
  • a second range lies between f and f,,,,. There R, starts at infinity, drops and returns to infinity as the frequency rises.
  • One of the two frequency ranges of FIG. 9 can be rejected by terminating the electrodes 14 and 16 within the resistance range of one resistance R,- but remote from the other. Since in FIG. 10 R closely matches all resistances less than Z the system passes the frequencies between f,, and f,, with little loss.
  • Z is the input impedance when the load end is open-cir- A curve showing the insertion loss for a filter exhibiting these f,,faA fl, fi,, is known as the beforementioned controlledcoupling condition. If f,,f exceeds or is equal to f,, ,-f,,, the condit ons of FIGS. 6, 7 and 8 exist. The coupling coefficient k between these pairs is equal to (f,,f,)/ fBf,. Approximately 15 For practical purposes, in order to make the maximum characteristic resistance value of FIG. 10 between f and f much smaller than the minimum characteristic impedance value between f g flu, the frequency difference f,,f, is generally below (f f,,,,)/2.
  • the electrodes l0, l2, l4 and 16 are in the controlled-coupling condition where f,f,, f,, ,f,,. That is, they follow the rule illustrated in FIGS. 9, 10 and 11. Nof or f exists between f,, and f More specifically, they are such that f,,f,, (f ,,f,, )/2. Thus, f,, and f,; are closer together than to either f,,,, or f,,,,,. This is so both before and after the spot electrode 24 is added.
  • the bandwidth (fl -f of such a filter is a function of several parameters.
  • the graphs of FIGS. 13, 14 and 15 illustrate empirical relationships between the parameters in one such filter. In these graphs the masses of the electrodes are represented not directly, but by how much the masses lower the frequency of each resonator. Such frequency lowering occurs even for a single pair of electrodes on a crystal wafer.
  • the fractional drop (ff,.)/f in the resonant frequency f,, of an uncoupled resonator formed by a single pair of electrodes on a crystal wafer, from the fundamental thickness shear frequency f of the unelectroded crystal body, due to increasing masses of the electrodes is called plateback.
  • Adjusting the bandwidth (f,,f,,) of such filters has hitherto been accomplished by adding or removing mass from the respective electrodes. Adding mass tends to reduce coupling between resonators. Adding mass thus moves f and f close together, while removing mass separates them. However, adding the mass also lowers f and f Each absolute decrease in bandwidth is accompanied by a far larger absolute drop in prevailing midband frequency f or (f +f )/2. For example, as shown in FIG. 14, decreasing a 2 kHz. bandwidth at 10 MHZ. to 1.8 kHz. requires a change in plateback from 2.0 percent to 2.1 percent. This constitutes 0.1 percent change in f,, at 10 MHz.
  • the 200 Hz bandwidth drop is accompanied by a 10 kHz. drop in the frequency of f,,, f,; and f
  • the dimensions of the dual-mode resonator in FIG. 3 have to be accurately determined beforehand to achieve an accurate passband at the desired midband frequency.
  • the thickness of the wafer determines the fundamental thickness shear frequency f of the wafer for any particular axial alignment of electrodes.
  • the deposition 24 is used to control the band.
  • the absolute changes in bandwidth and center frequency f in Hz are comparable.
  • the relative frequency change is small for a large bandwidth change. If the small relative frequency change is too large for the filter tolerances, the midband frequencyf may be adjusted back by mass loading the electrodes.
  • the absolute change in midband frequency f is accompanied by almost insignificant changes in bandwidth.
  • FIG. 16 illustrates the increase in bandwidth f,,f as a result of depositing and increasing the mass of the deposition 24 as measured in the circuit shown in FIG. 12.
  • two gold electrodes 0.200 inches by 0. l 20 inches with a 0.l00 inch separation between the longer edges were oriented along the Z axis of a l5-millimeter square quartz I crystal wafer having a fundamental frequency of 8 MHz.
  • the frequency generator 30 applied energy through the measuring resistor 34 to the electrodes 10 and 12.
  • the voltmeter 34 measured the phase angle across the resistor 32.
  • the electrodes 14 and 16 were short-circuited.
  • the plater 36 then applied gold into the interelectrode space to form the deposition 24.
  • the mass loading of the spot-shaped deposition 24 was determined on the basis of plating time. This determination was accomplished by calibrating the amount of mass loading obtained on a similar resonator with the same electrode geometry. Gold was deposited on the electrode at various time intervals and the corresponding bandwidth as well as midband frequency change noted.
  • the percent increase in bandwidth was measured at four intervals, at approximate mass loadings of 0.024, 0.035, 0.064 and 0.077 percent.
  • the percentage increase in bandwidth as shown in FIG. 16 was approximately linear.
  • the short circuit frequencies of resonators f, and f were measured to establish (fl f and (f fO/Z.
  • the bandwidth of the filter as determined by the frequency difference between the frequencies f, and f was 986 Hz.
  • mass was added to the deposition 24, the bandwidth increased in steps until a bandwidth of H34 Hz was achieved for an equivalent mass loading of the plated area of 0.077 percent. This is an increase over the initial bandwidth of 148 cycles, or more than 15 percent.
  • the value (f,,+f.)/2 which is the midband frequency f exhibited by the filter, decreased 193 cycles, or on the order of 0.0022 percent.
  • the absolute increase in bandwidth approximated the absolute decrease in midband frequency f
  • the midband frequency could be returned to its original value by removal of a small amount of plating from the electrodes. This would result in a bandwidth change of only two or three Hz, or 0.4 percent.
  • the coupling, prevailing midband frequency f and band width are measured as shown in FIG. 12 by applying signals from a frequency generator 30 across the electrodes 10 and 12 and short circuiting the electrodes 14 and 16.
  • the voltmeter 32 measures the phase angle across a measuring resistor 34. Maximum voltages measured by the meter 32 indicate the frequencies f,, and f The difference should be less than f,,,,-f so that the resonators are in controlled-coupling condition.
  • the plater 36 applies gold to form the deposition 24 as shown in FIG. 12.
  • the bandwidth increases. For example, it may increase a kHz. bandwidth 150 Hz or I5 percent.
  • the midband or center frequency f or (f -l-f )/2 decreases a comparable number of Hz. This is a small proportion of the center frequency and may be insignificant.
  • the filter is completed if the accompanying midband frequency drop is within desired tolerances. If not, additional mass is added to the electrodes 10, 12 and 14, 16 to shift the existing midband frequency (f +fA)/2 to the desired midband frequenc f,,,.
  • This added plateback changes the bandwidth only an insignificant amount because, although the absolute lowering in the number of cycles may be large, it represents but a slight proportionate change in the midband frequency. Such slight changes produce only slight changes in the proportion of the bandwidth and result in even slighter absolute bandwidth changes.
  • the invention thus takes advantage of the differences in the rates of change exhibited by the two methods of changing frequency and bandwidth.
  • FIGS. 18 and 19 illustrate another filter embodying features of the invention.
  • six pairs of electrodes 40, 42; 44, 46; 48, 50; 52, 53; 56, 58; 60, 62 are deposited on an AT-cut quartz crystal wafer 64 along the Z axis.
  • a source 66 supplies energy to the electrode pair 40, 42 and a load 68 receives energy from the electrodes 60, 62.
  • the intermediate pairs of electrodes are short-circuited to each other and grounded.
  • Each adjacent pair of electrodes is in controlled-coupling condition. That is, when other resonators are detuned, any two adjacent resonators exhibit the conditions of FIGS. 9, and 11. More specifically, with other resonators detuned, any two adjacent resonators exhibit the condition f,,j" (f,, -f 4 )/2.
  • the strip-shaped deposition 72 in the interelectrode spacing between the electrodes 40, 44, 48, 52, 56, and 60 compensates for departures from the required electrode dimensions, wafer thickness, and mass loading.
  • the existence of the depositions permits fine adjustment of the bandwidths and subsequent fine adjustment of the midband frequencies with negligible disturbance of the bandwidths. It requires only that the electrodes 40 through 62 be plated back initially less than required. The plates thus introduce vemier adjustments which can be added as necessary between any electrode pairs.
  • thickness shear mode is used as defined in Mc- Graw Hill Encyclopedia of Science and Technology, 1966, Vol. 10, pages 221 et seq. It includes both parallel face motion and circular face motion about a common axis. The latter is sometimes called the thickness twist mode.
  • the crystal structure of FIGS. 18 and 19 is manufactured by first selecting the coupling approximately to (f f,,)/f,, or (f -fn/f between each adjacent electrode pair about a desired midband frequency f,, on the basis of the bandwidths calculated for successive coupled resonators. The couplings are adjusted so that any error in bandwidth appears on the low side.
  • An electrode size and suitable plateback (from 0.3 to 3 percent) are chosen from curves such as those in FIGS. l3, l4 and 15, which have been developed empirically. There 1 is the wafer thickness and r the width of the electrodes r/! is generally made equal to 12 although in practice any value between 6 and 20 is usable.
  • f is slightly higher than the desired midband frequency f, in order to make the midband frequency error appear on the high side.
  • the manufacture starts by first cutting a wafer 16 from a quartz crystal having the desired crystallographic orientation such as an AT-cut. The wafer is then lapped and etched to a thickness 1 corresponding to the desired fundamental shear mode index frequency f. either for parallel or twist motion. Generally, the thickness is inversely proportional to the desired frequency. Masks are placed on each face of the crystal wafer with cutouts for depositing the six electrodes. The geometry of the electrodes is determined by considering the desired bandwidths and the convenient plateback.
  • the proper separation d between the electrodes may be determined from the graphs such as those of FIGS. 13, 14 or 15 which show variations in percent bandwidth for various ratios of electrode separation to plate thickness and for various platebacks. as well as various values of r/t.
  • gold or silver is deposited such as by vacuum vapor plating through the masks so as to make connections possible and achieve about nearly all of the total desired plateback.
  • energy is applied successively to each pair of electrodes while mass is added to the electrodes until the frequency shifts nearly to the desired frequency f,,,.
  • the procedure is repeated for all the electrode pairs. During this procedure for each pair, the others remain opencircuited. However, it may be necessary to obviate the effect of the other pairs by terminating them inductively.
  • the depositions 24 are added to achieve the desired individual couplings as necessary to obtain the desired bandwidth Bw.
  • Mass is then added to the plates 40 to 62 to plate them back further until each pair, when considered alone, resonates at f,,, and the midband frequency of the system is f,,,.
  • the crystal material between electrode pairs is removed, by etching, for accomplishing the vemier adjustment.
  • electrodes 80 as electrode pairs on a crystal wafer 82, form resonators in controlledcoupling condition.
  • Recesses 84 between the electrode pairs serve to decrease the bandwidth while increasing the midband frequency f,, exhibited between any two adjacent pairs when they are considered alone.
  • a deposition 86 corresponding to the deposition 24 serves the same adjusting function as the deposition 24.
  • a source S which energizes the first electrode pair, thereby excites the crystal wafer 82.
  • the last electrode pair energizes a load resistor R While embodiments of the invention have been described in detail, it will be obvious to those skilled in the art that the invention may be embodied otherwise without departing from its spirit and scope.
  • An energy translating device comprising a crystal body, first plate means on said body for interacting with acoustical energy in said body, second plate means on said body and spaced from said first plate means for interacting with acoustical energy in said body, said plate means when said body is excited forming respective mutually coupled resonators together exhibiting interdependent resonant frequencies whereby an energy band may be translated between said resonators, said body having a continuous mass, and material means deposited between said plate means thereby altering the mass of said body.
  • An energy translating device comprising a crystal body, first plate means on said body for interacting with acoustical energy in said body, second plate means on said body and spaced from said first plate means for interacting with acoustical energy in said body, said plate means when said body is excited forming respective mutually coupled resonators together exhibiting interdependent resonant frequencies whereby an energy band may be translated between said resonators, said body having a continuous mass, said body including a wafer, said plate means each including a pair of electrodes on opposite faces of said wafer, said wafer comprising an AT-cut for vibrations in a thickness shear mode, and material means in the shape of a strip deposited on said wafer.
  • An energy translating device comprising a crystal body, first plate means on said body for interacting with acoustical resonators, said body having a continuous mass, and material means in the shape ofa strip deposited on said body thereby to alter the mass of said body whereby translated energy is conformed to a given energy band.

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  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Piezo-Electric Or Mechanical Vibrators, Or Delay Or Filter Circuits (AREA)
US771843A 1968-10-30 1968-10-30 Crystal filter Expired - Lifetime US3573672A (en)

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US (1) US3573672A (fr)
BE (1) BE740969A (fr)
CH (1) CH501340A (fr)
DE (1) DE1953826C2 (fr)
FR (1) FR2021887A1 (fr)
GB (1) GB1287002A (fr)
NL (1) NL155693B (fr)
SE (1) SE365083B (fr)

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3676805A (en) * 1970-10-12 1972-07-11 Bell Telephone Labor Inc Monolithic crystal filter with auxiliary filter shorting tabs
US3697788A (en) * 1970-09-30 1972-10-10 Motorola Inc Piezoelectric resonating device
US3699484A (en) * 1970-06-24 1972-10-17 Vernitron Corp Width extensional resonator and coupled mode filter
US3732510A (en) * 1970-10-12 1973-05-08 Bell Telephone Labor Inc Multisection precision-tuned monolithic crystal filters
US3866155A (en) * 1972-09-20 1975-02-11 Oki Electric Ind Co Ltd Attenuation pole type monolithic crystal filter
US4112147A (en) * 1977-05-13 1978-09-05 Western Electric Company, Inc. Method of manufacturing a monolithic crystal filter
DE2823540A1 (de) * 1977-06-08 1978-12-14 Kinsekisha Lab Ltd Piezoelektrischer schwinger
US4329666A (en) * 1980-08-11 1982-05-11 Motorola, Inc. Two-pole monolithic crystal filter
US4627379A (en) * 1984-11-29 1986-12-09 General Electric Company Shutter apparatus for fine-tuning a coupled-dual resonator crystal
US4676993A (en) * 1984-11-29 1987-06-30 General Electric Company Method and apparatus for selectively fine-tuning a coupled-dual resonator crystal and crystal manufactured thereby
US4833430A (en) * 1984-11-29 1989-05-23 General Electric Company Coupled-dual resonator crystal
US4839618A (en) * 1987-05-26 1989-06-13 General Electric Company Monolithic crystal filter with wide bandwidth and method of making same
WO1992019043A1 (fr) * 1991-04-22 1992-10-29 Motorola, Inc. Dispositif piezoelectrique montable en surface a masque sous forme de plaque de finition in situ
US5757104A (en) * 1994-10-10 1998-05-26 Endress + Hauser Gmbh + Co. Method of operating an ultransonic piezoelectric transducer and circuit arrangement for performing the method
US6020797A (en) * 1998-08-21 2000-02-01 Cts Corporation Electrode connection configuration and method for a multi-pole monolithic crystal filter
US6236140B1 (en) * 1996-07-31 2001-05-22 Daishinku Corporation Piezoelectric vibration device
US20080180193A1 (en) * 2007-01-25 2008-07-31 Matsushita Electric Industrial Co., Ltd. Dual mode piezoelectric filter, method of manufacturing the same, high frequency circuit component and communication device using the same
US20100096951A1 (en) * 2007-02-26 2010-04-22 Epson Toyocom Corporation Contour resonator and method for adjusting contour resonator
WO2012049126A1 (fr) * 2010-10-15 2012-04-19 Commissariat A L'energie Atomique Et Aux Energies Alternatives Filtre baw a couplage lateral utilisant des cristaux phononiques

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2345491A (en) * 1941-11-25 1944-03-28 Bell Telephone Labor Inc Wave transmission network
US2859346A (en) * 1954-07-28 1958-11-04 Motorola Inc Crystal oscillator
US2956184A (en) * 1954-11-01 1960-10-11 Honeywell Regulator Co Transducer
US3264585A (en) * 1961-06-20 1966-08-02 Siemens Ag Dual electrostrictive drivers bonded to and driving opposite sides of mechanical resonator
US3271704A (en) * 1963-03-25 1966-09-06 Bell Telephone Labor Inc Ultrasonic delay device
US3382381A (en) * 1965-05-27 1968-05-07 Piezo Technology Inc Tab plateback

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1274675B (de) * 1964-09-24 1968-08-08 Telefunken Patent Piezoelektrische Resonatoranordnung
FR1523518A (fr) * 1966-04-11 1968-05-03 Western Electric Co Dispositif acoustique servant à transmettre de l'énergie entre deux circuits d'énergie

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2345491A (en) * 1941-11-25 1944-03-28 Bell Telephone Labor Inc Wave transmission network
US2859346A (en) * 1954-07-28 1958-11-04 Motorola Inc Crystal oscillator
US2956184A (en) * 1954-11-01 1960-10-11 Honeywell Regulator Co Transducer
US3264585A (en) * 1961-06-20 1966-08-02 Siemens Ag Dual electrostrictive drivers bonded to and driving opposite sides of mechanical resonator
US3271704A (en) * 1963-03-25 1966-09-06 Bell Telephone Labor Inc Ultrasonic delay device
US3382381A (en) * 1965-05-27 1968-05-07 Piezo Technology Inc Tab plateback

Cited By (24)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3699484A (en) * 1970-06-24 1972-10-17 Vernitron Corp Width extensional resonator and coupled mode filter
US3697788A (en) * 1970-09-30 1972-10-10 Motorola Inc Piezoelectric resonating device
US3676805A (en) * 1970-10-12 1972-07-11 Bell Telephone Labor Inc Monolithic crystal filter with auxiliary filter shorting tabs
US3732510A (en) * 1970-10-12 1973-05-08 Bell Telephone Labor Inc Multisection precision-tuned monolithic crystal filters
US3866155A (en) * 1972-09-20 1975-02-11 Oki Electric Ind Co Ltd Attenuation pole type monolithic crystal filter
US4112147A (en) * 1977-05-13 1978-09-05 Western Electric Company, Inc. Method of manufacturing a monolithic crystal filter
DE2823540A1 (de) * 1977-06-08 1978-12-14 Kinsekisha Lab Ltd Piezoelektrischer schwinger
US4329666A (en) * 1980-08-11 1982-05-11 Motorola, Inc. Two-pole monolithic crystal filter
US4627379A (en) * 1984-11-29 1986-12-09 General Electric Company Shutter apparatus for fine-tuning a coupled-dual resonator crystal
US4676993A (en) * 1984-11-29 1987-06-30 General Electric Company Method and apparatus for selectively fine-tuning a coupled-dual resonator crystal and crystal manufactured thereby
US4833430A (en) * 1984-11-29 1989-05-23 General Electric Company Coupled-dual resonator crystal
US4839618A (en) * 1987-05-26 1989-06-13 General Electric Company Monolithic crystal filter with wide bandwidth and method of making same
WO1992019043A1 (fr) * 1991-04-22 1992-10-29 Motorola, Inc. Dispositif piezoelectrique montable en surface a masque sous forme de plaque de finition in situ
US5281935A (en) * 1991-04-22 1994-01-25 Motorola, Inc. Surface mountable piezoelectric device using a metallic support structure with in situ finish plate mask
US5757104A (en) * 1994-10-10 1998-05-26 Endress + Hauser Gmbh + Co. Method of operating an ultransonic piezoelectric transducer and circuit arrangement for performing the method
US6236140B1 (en) * 1996-07-31 2001-05-22 Daishinku Corporation Piezoelectric vibration device
US6020797A (en) * 1998-08-21 2000-02-01 Cts Corporation Electrode connection configuration and method for a multi-pole monolithic crystal filter
WO2000011782A1 (fr) * 1998-08-21 2000-03-02 Cts Corporation Configuration et technique de branchement d'electrodes pour un filtre a quartz monolithique multi-pole
US20080180193A1 (en) * 2007-01-25 2008-07-31 Matsushita Electric Industrial Co., Ltd. Dual mode piezoelectric filter, method of manufacturing the same, high frequency circuit component and communication device using the same
US7719390B2 (en) * 2007-01-25 2010-05-18 Panasonic Corporation Dual mode piezoelectric filter, method of manufacturing the same, high frequency circuit component and communication device using the same
US20100096951A1 (en) * 2007-02-26 2010-04-22 Epson Toyocom Corporation Contour resonator and method for adjusting contour resonator
US8242666B2 (en) * 2007-02-26 2012-08-14 Seiko Epson Corporation Contour resonator and method for adjusting contour resonator
WO2012049126A1 (fr) * 2010-10-15 2012-04-19 Commissariat A L'energie Atomique Et Aux Energies Alternatives Filtre baw a couplage lateral utilisant des cristaux phononiques
US9325293B2 (en) 2010-10-15 2016-04-26 Energies Alternatives Laterally coupled BAW filter employing phononic crystals

Also Published As

Publication number Publication date
NL6916084A (fr) 1970-05-04
BE740969A (fr) 1970-04-01
FR2021887A1 (fr) 1970-07-24
DE1953826C2 (de) 1985-02-14
DE1953826A1 (de) 1970-05-21
GB1287002A (en) 1972-08-31
SE365083B (fr) 1974-03-11
CH501340A (de) 1970-12-31
NL155693B (nl) 1978-01-16

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