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51. 发明专利

JPH11112467A RF SIGNAL PROCESSOR FOR CDMA COMMUNICATION USING SAW 失效
公开(公告)号：JPH11112467A
公开(公告)日：1999-04-23
申请号：JP27079897
申请日：1997-10-03
申请人： HITACHI LTD
发明人： HIKITA MITSUTAKA , TAKUBO CHISAKI , ASAI KENGO , SHIBAGAKI NOBUHIKO , OKAZAKI KATSUNORI
IPC分类号： H03H9/42 , H03H9/72 , H04B1/707 , H04B1/708 , H04B1/7093 , H04J13/00
摘要： PROBLEM TO BE SOLVED: To demodulate the spread spectrum signal of high efficiency without requiring a generation circuit, or the like of a replica signal by inputting two high frequency signals to two surface acoustic wave(SAW) delay element, mixing respective output signal by a mixer and taking out the output signal of the frequency of difference. SOLUTION: Concerning a first delay element, a transducer 15 for SAW excitation and transducers 16-1 to 16-N for reception are formed at a piezoelectric substrate 1. Concerning a second delay element, a transducer 18 for SAW excitation and transducers 19-1 to 19-N for reception are formed at a piezoelectric substrate 1. The spread spectrum signal of a frequency fRF is inputted from a first input terminals 14. The nonmodulation continuous waves of a frequency fLO is inputted from a second input terminals 17. Each output signal from each delay element is mixed by mixers 20-1 to 20-N to obtain the output signals O(1) to O(N) of the frequency |fRF-fLO|of difference.

52. 发明专利

JPH10145172A SURFACE ACOUSTIC WAVE RESONATOR COMPOSITE-TYPE FILTER 失效
公开(公告)号：JPH10145172A
公开(公告)日：1998-05-29
申请号：JP30442496
申请日：1996-11-15
申请人： HITACHI LTD
发明人： SHIBAGAKI NOBUHIKO , HIKITA MITSUTAKA , SAKIYAMA KAZUYUKI
IPC分类号： H03H9/145 , H03H9/25 , H03H9/64
摘要： PROBLEM TO BE SOLVED: To manufacture the filter with a sharp and wide band, which is demanded by a vehicle and a portable telephone set by using the change in resonance characteristics, generated by varying the film thickness of electrode thin films in plural surface acoustic wave resonators formed on the same piezoelectric substrate. SOLUTION: Four surface acoustic wave resonators, constituted of electrodes 3-8 and one gap capacitor constituted of electrodes 9 and 19, are provided on a piezoelectric board 1, that can transmit a surface acoustic wave so as to form the composite filter. The electrode 4 is electrically connected to an electrode pattern 10 by bonding wire 11, and matching inductances 23-26 and sound- absorbing materials 31-36 are provided. In such a case, the electrode film thickness h1 and h2 of the electrodes 3-5 and that of the electrodes 6-8 on the board 1 are set to be 900Å and 2700Å, and a filter characteristics is composited by using the difference of the resonance characteristics, which are generated by the difference in film thickness. Thus, a filter of the sharp and wide frequency characteristics, which is requested in digital movable communication, can be obtained.

53. 发明专利

JPH1084245A SURFACE ACOUSTIC WAVE ELEMENT 失效
公开(公告)号：JPH1084245A
公开(公告)日：1998-03-31
申请号：JP23882796
申请日：1996-09-10
申请人： HITACHI LTD
发明人： ISOBE ATSUSHI , HIKITA MITSUTAKA , ASAI KENGO , TAKUBO CHISANORI
IPC分类号： H03H9/25
摘要： PROBLEM TO BE SOLVED: To provide a resonator which has a high transmission speed, a large electromechanical coupling coefficient and a large impedance ratio between the resonance frequency and the anti-resonance frequency by forming a comb- line electrode of specific thickness on a Y-cut surface having a specific rotation frequency of an LiNbO3 single crystal and using a surface acoustic wave of a transmission speed equal to a specific level or higher. SOLUTION: A comb-line electrode 1 is formed on a θ-degree rotation Y-cut surface of an LiNbO3 single crystal 2 by the patterning of a metallic film consisting primarily of Al. Thus, a single openirng resonator is obtained. The electrode 1 is positioned vertical (Z') against an X axis and the surface acoustic wave is transmitted in the Z' direction. Then -20

54. 发明专利

JPH0758586A HIGH FREQUENCY CIRCUIT DEVICE 失效
公开(公告)号：JPH0758586A
公开(公告)日：1995-03-03
申请号：JP20491693
申请日：1993-08-19
申请人： HITACHI LTD
发明人： SHIBAGAKI NOBUHIKO , HIKITA MITSUTAKA , KUSANO TADASHIROU
IPC分类号： H03H9/25 , H03H9/64
摘要： PURPOSE:To reduce a chip area of an active element at low cost the as a whole by integrating a high frequency filter element and the active element. CONSTITUTION:A piezoelectric substrate 17 is packaged in a package 16 of metal or ceramic, and an inductance to match the impedance of an FET with external impedance, surface acoustic resonators 9, 10 which comprise a high frequency filter, and a gap capacitance 11 which comprises the high frequency filter are formed on the piezoelectric substrate 17. Furthermore, a semiconductor 18 is packaged at a non-pattern part on the piezoelectric substrate 17 i.e., an area where a surface acoustic wave is excited and propagated and a part other than an electrode pad, and a capacitance 4 to match the impedance of the FET with the external impedance, resistors 6, 7 which comprise the bias circuit of the FET, and capacitance 8 which forms the bias circuit of the FET are formed on the semiconductor substrate 18.

55. 发明专利

JPH06164305A SURFACE ACOUSTIC WAVE DEVICE 失效
公开(公告)号：JPH06164305A
公开(公告)日：1994-06-10
申请号：JP30674992
申请日：1992-11-17
申请人： HITACHI LTD
发明人： ISOBE ATSUSHI , HIKITA MITSUTAKA , ASAI KENGO
IPC分类号： H03H9/25
摘要： PURPOSE:To provide a low-loss filter and a filter whose attenuation amount is large by specifying the rotation angle of a cut surface measured from a Y axis and an angle between a surface acoustic wave propagating direction and an X axis. CONSTITUTION:In a surface acoustic wave device using Love wave type surface acoustic waves for not emitting energy to the inside of a substrate constituted of a rotation Y cut crystal piezoelectric substrate for which the rotation angle of the cut surface measured from the Y axis is (theta+90 deg.) and an electrode formed on its surface by a metallic film, when the angle between the surface acoustic wave propagating direction and the X axis is psi, it is defined as 20 deg. can be enlarged but also transmission/reception is facilitated by the electrode present on the substrate surface. Thus, energy loss can be reduced and the small high-performance surface acoustic wave device can be obtained since the spurious components of the Rayleigh waves are small.

56. 发明专利

JPH05129878A SURFACE ACOUSTIC WAVE DEVICE 失效
公开(公告)号：JPH05129878A
公开(公告)日：1993-05-25
申请号：JP28836591
申请日：1991-11-05
申请人： HITACHI LTD
发明人： ISOBE ATSUSHI , HIKITA MITSUTAKA , ASAI KENGO
IPC分类号： H03H9/25 , H03H9/64
摘要： PURPOSE:To provide the small sized surface acoustic wave device with a low loss, a zero temperature characteristic by using a crystal substrate whose angles theta, phi have a specific relation, where PHI is an angle with respect to the X axis in the surface acoustic wave propagation direction in the theta+90 deg. rotation Y-cut crystal substrate and the electrode made of gold or silver on the surface of the substrate. CONSTITUTION:Angles theta, phi are selected to have a relation in equation I, where phiis the surface acoustic wave propagation direction measured from the X axis by using a crystal Love wave and theta+90 deg. is a rotation angle of a cut face measured from the Y axis. The device is made of the crystal substrate whose angles theta, phi have a specific relation and of the metallic thin film electrode formed on the surface of the crystal substrate. Thus, the characteristic of a low loss and a high Q is realized. Furthermore, since gold with a large reflection coefficient is employed for the electrode, a very high Q (=1000) is obtained with a few electrode finger logarithum and the element is made smaller than a conventional element by using it.

57. 发明专利

JPH0563498A SURFACE ACOUSTIC WAVE DEVICE 失效
公开(公告)号：JPH0563498A
公开(公告)日：1993-03-12
申请号：JP22564391
申请日：1991-09-05
申请人： HITACHI LTD
发明人： ISOBE ATSUSHI , HOSHINA YOSHINORI , ASAI KENGO , IMURA AKIRA , HIKITA MITSUTAKA
IPC分类号： H03H9/25
摘要： PURPOSE:To easily obtain the surface acoustic wave device reducing a temperature characteristic and a change with the passage of time by fixing a piezoelectric substrate to a stem or a substrate by sandwiching the piezoelectric substrate between two solids. CONSTITUTION:A leaf spring 4 is put under a piezoelectric substrate 1, the piezoelectric substrate 1 is sandwiched by pawls 5 from the upside, the piezoelectric substrate 1 is pressed to the leaf spring 4 by fastening screws 6, and the piezoelectric substrate 1 is fixed by utilizing this elasticity. Thus, since the piezoelectric substrate 1 is fixed to a stem 2 by sandwiching the piezoelectric substrate 1 with the two solids 4 from the surface and the back or from both side faces, etc., any adhesive agent as a gas generating source is not used. Since metal generates no gas differently from silicone resin, no change is generated with the passage of time, and the thermal expansion of the piezoelectric substrate 1 is not blocked by using the elasticity. Further, since the solid springs 4 are utilized in place of the adhesive agent, the device can be easily realized by improving the stem 2 a little. In this case, non-metal such as plastic or ceramic, etc., not to generate gas can be used in place of metal.

58. 发明专利

JPH04192611A SURFACE ACOUSTIC WAVE DEVICE 失效
公开(公告)号：JPH04192611A
公开(公告)日：1992-07-10
申请号：JP17521090
申请日：1990-07-04
申请人： HITACHI LTD
发明人： ISOBE ATSUSHI , HIKITA MITSUTAKA , IMURA AKIRA , HOSHINA YOSHINORI , SAKIYAMA KAZUYUKI
IPC分类号： H03H9/145 , H03H9/25
摘要： PURPOSE:To realize a surface acoustic wave device with an excellent temperature characteristic by making a rate of a change in a propagation speed of a surface acoustic wave with respect to a temperature substantially equal to a thermal expansion rate of a piezoelectric substrate. CONSTITUTION:The device is provided with a piezoelectric substrate 1 through which a surface acoustic wave is propagated, and metallic films 2, 3 to stimulate, to receive or to reflect the surface acoustic wave on the piezoelectric substrate 1. Then a sum of a rate of a chance in a propagation speed of a surface acoustic wave with respect to a temperature while the metallic films 2, 3 are provided onto the piezoelectric substrate 1 and a thermal expansion rate of the piezoelectric substrate 1 is selected smaller than a sum of a rate of a change in a propagation speed of a surface acoustic wave with respect to a temperature while the metallic films 2, 3 are not provided onto the piezoelectric substrate 1 and a thermal expansion rate of the piezoelectric substrate 1. Thus, the temperature characteristic of the amplitude or phase of a surface acoustic wade while the metallic films 2, 3 for an aluminum electrode or the like are provided is improved.

59. 发明专利

JPH03129914A SURFACE ACOUSTIC WAVE RESONATOR COMPOSITE TYPE FILTER 失效
公开(公告)号：JPH03129914A
公开(公告)日：1991-06-03
申请号：JP26612689
申请日：1989-10-16
申请人： HITACHI LTD
发明人： SHIBAGAKI NOBUHIKO , HIKITA MITSUTAKA , TABUCHI TOYOJI , HIRASHIMA TETSUYA
IPC分类号： H03H9/145
摘要： PURPOSE:To miniaturize a capacity element, to easily set an arbitrary capacity value, and also, to extend a service life of the element by forming the capacity element for constituting the surface acoustic wave resonator composite filter by an inter digital filter electrode. CONSTITUTION:An inter-electrode capacity C0 of an inter digital filter electrode can be derived by C0=CsXNXW. Cs denotes an intrinsic value determined by a dielectric constant of a piezoelectric body 1 for forming inter digital filter electrodes 3, 4 and a ratio (a/b) of electrode width and a period of electrode repetition, and N and W denote the number of electrode repetitions and electrode cross width, respectively. At the time of (a/b)=1/4, Cs becomes 514.93pF/m, and when the number of repetitions of the electrode and the electrode cross width are designed to 200 pairs and 70mum, respectively, the inter-electrode capacity becomes about 7.2pF. In this case, when electrode width (a) is set to '1', the electrode repetition period becomes 4mu, and a pattern size of the capacity element becomes 70mumX800mum.

60. 发明专利

JPH01260911A COMPOSITE FILTER FOR SURFACE ACOUSTIC WAVE RESONATOR 失效
公开(公告)号：JPH01260911A
公开(公告)日：1989-10-18
申请号：JP8738088
申请日：1988-04-11
申请人： HITACHI LTD
发明人： HIKITA MITSUTAKA , TABUCHI TOYOJI , KUROSAWA KAZUHITO , SHIBAGAKI NOBUHIKO
IPC分类号： H03H9/145 , H03H3/08 , H03H9/02 , H03H9/25 , H03H9/64
摘要： PURPOSE:To realize a steep leading/trailing characteristic with respect to frequency by providing plural number of propagation lines having a specified length at least being 1/2 of the wavelength of a surface acoustic wave or over in the inside of a resonator of a surface acoustic wave composite filter comprising plural one-opening surface acoustic wave resonators. CONSTITUTION:A series arm resonator and a shunt arm resonator at the input side both have plural propagation lines having a specified electric length over 1/2 of the wavelength of a surface acoustic wave able to be propagated in the passing band frequency of the filter or over in the inside of the resonator. In general, the realization of a steep leading/trailing frequency characteristic depends it on how much poles f2, f3 and fe2', f3' closest to the pass band are to be approached to the pass band without giving effect on the pass band characteristic. Then the corresponding poles f2, f3 are formed close to the filter pass band thereby reducing sufficiently the effect on the filter pass band characteristic. Thus, the filter having a very steep leading/trailing frequency characteristic is obtained.

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