JP2011217420A - Surface acoustic wave filter, antenna duplexer, high-frequency module using them, and communication apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact surface acoustic wave filter, along with an antenna duplexer, excelling in in-band characteristics.SOLUTION: This surface acoustic wave filter includes: a piezoelectric substrate; a plurality of IDT electrodes and a plurality of reflector electrodes formed on the piezoelectric substrate; and a first wiring electrode and a second wiring electrode respectively connected to the plurality of IDT electrodes. In the surface acoustic wave filter, the first wiring electrode and the second wiring electrode are structured to three-dimensionally intersect with each other through an insulating layer; at least one of the first wiring electrode and the second wiring electrode is connected to an electrode pad formed on the piezoelectric substrate; a strip line constituting the reflector electrode includes a region with the reflector electrode deleted therefrom by being shortened relative to the intersection width of the IDT electrode; and part of the electrode pad is arranged in the region.

Description

  The present invention relates to a surface acoustic wave filter and an antenna duplexer that are small in size and excellent in in-band characteristics used in communication equipment such as a mobile phone. The present invention also relates to such a surface acoustic wave filter, a high-frequency module having an antenna duplexer, and a communication device.

  In recent years, with the development of communication equipment, high performance and downsizing of devices used for mobile phones are expected. In mobile phones and the like, surface acoustic wave filters are widely used as filters, and in addition to low loss and high attenuation, miniaturization is expected.

  Hereinafter, a conventional surface acoustic wave filter will be described. FIG. 10 shows a configuration of a conventional surface acoustic wave filter. A surface acoustic wave filter 1000 includes a first longitudinal mode filter 1007 in which IDT electrodes 1002, 1003, and 1004 and reflector electrodes 1005 and 1006 are arranged close to each other along a propagation direction of a surface acoustic wave on a piezoelectric substrate 1001. And the IDT electrodes 1008, 1009, 1010 and the reflector electrodes 1011, 1012 are arranged close to each other along the propagation direction of the surface acoustic wave. In the first longitudinal mode filter 1007, one electrode finger of the IDT electrodes 1002, 1003, 1004 is wired to the electrode pads 1014, 1015, 1016 and connected to the ground terminal GND, the input terminal IN, and the ground terminal GND, respectively. The In the second longitudinal mode filter 1013, one electrode finger of the IDT electrodes 1008, 1009, 1010 is wired to the electrode pads 1017, 1018, 1019 and connected to the ground terminal GND, the output terminal OUT, and the ground terminal GND, respectively. The The other electrode finger of the IDT electrode 1002 and the other electrode finger of the IDT electrode 1008 are connected by the wiring electrode 1020, and the other electrode finger of the IDT electrode 1004 and the other electrode finger of the IDT electrode 1010 are connected to the wiring electrode 1021. Connected by The other electrode finger of the IDT electrode 1003 and the other electrode finger of the IDT electrode 1009 are wired to the electrode pad 1022 and connected to the ground terminal GND. With the above configuration, a surface acoustic wave filter 1000 in which the first and second longitudinal mode filters 1007 and 1013 are cascade-connected is configured.

  In addition, a technique for three-dimensionally intersecting part of wiring electrodes with an insulator interposed therebetween is disclosed in order to reduce the size of the surface acoustic wave filter (see, for example, Patent Document 1).

  FIG. 11 shows a configuration 1100 of a conventional surface acoustic wave filter. The first and second longitudinal mode filters 1007 and 1013 are cascade-connected by wiring electrodes 1020 and 1021. Further, insulating layers 1101 and 1102 are provided on the wiring electrodes 1020 and 1021, and the other electrode fingers of the IDT electrodes 1003 and 1009 are connected by the wiring electrode 1103 and further formed on the upper part. By 1104, it is connected to the electrode pads 1105 and 1106 connected to the ground terminal GND. At this time, as shown in the cross-sectional view of A-A ′ in FIG. 12, the wiring electrode 1021 and the wiring electrode 1104 are three-dimensionally crossed with the insulating layer 1102 interposed therebetween. With the above configuration, the surface acoustic wave filter 1100 in which the first and second longitudinal mode filters 1007 and 1013 are cascade-connected is configured.

JP 2004-282707 A

  However, the conventional technique has a problem in that an electrode pad exists between the first and second surface acoustic wave filters, and the size of the surface acoustic wave filter is increased. Further, when the wiring electrodes are three-dimensionally crossed, there is a problem that capacitive coupling occurs between the wiring electrodes and the passband characteristics deteriorate.

  SUMMARY OF THE INVENTION The present invention solves the above-described conventional problems, and an object thereof is to provide a surface acoustic wave filter and an antenna duplexer that are small in size and excellent in in-band characteristics. Another object of the present invention is to provide a small and high-performance high-frequency module and communication equipment using such a surface acoustic wave filter and antenna duplexer.

  In order to solve the conventional problems, a surface acoustic wave filter according to the present invention includes a piezoelectric substrate, a plurality of IDT electrodes formed on the piezoelectric substrate, a plurality of reflector electrodes, and the plurality of IDT electrodes. A surface acoustic wave filter including a connected first wiring electrode and a second wiring electrode, wherein the first wiring electrode and the second wiring electrode cross three-dimensionally through an insulating layer. And at least one of the first wiring electrode and the second wiring electrode is connected to an electrode pad formed on the piezoelectric substrate, and the reflector electrode is mounted on the piezoelectric substrate. The strip line is configured to have a region where the reflector electrode is removed by being shorter than the crossing width of the IDT electrode, and a part of the electrode pad is disposed in the region.

  With this configuration, a surface acoustic wave filter that is small and has excellent passband characteristics can be realized.

  In the surface acoustic wave filter, it is preferable that at least one of the first wiring electrode and the second wiring electrode is connected to a ground terminal.

  With the above configuration, a surface acoustic wave filter having a small size and excellent passband characteristics can be realized.

  In the surface acoustic wave filter, it is preferable that the plurality of IDT electrodes are arranged close to each other along the propagation direction of the surface acoustic wave.

  With the above configuration, a longitudinal mode type surface acoustic wave filter having a small size and excellent passband characteristics can be realized.

  In the surface acoustic wave filter, the first surface acoustic wave filter in which a plurality of IDT electrodes are arranged close to each other along the propagation direction of the surface acoustic wave, and the plurality of IDT electrodes along the propagation direction of the surface acoustic wave. And a second surface acoustic wave filter disposed in close proximity to each other, and at least one of the first or second wiring electrodes, the IDT electrode in the first surface acoustic wave filter or the second surface acoustic wave filter Is preferably grounded.

  With the above configuration, it is possible to realize a longitudinal mode type surface acoustic wave filter that is small in size and has excellent passband characteristics.

  In the surface acoustic wave filter, it is preferable that a part of the electrode pad is disposed between the first surface acoustic wave filter and the second surface acoustic wave filter.

  With the above configuration, a surface acoustic wave filter having a small size and excellent passband characteristics can be realized.

  The antenna duplexer according to the present invention is an antenna duplexer including a transmission filter and a reception filter, and at least one of the transmission filter and the reception filter is configured by the surface acoustic wave filter according to claim 1. It is an antenna duplexer characterized by the above.

  With the above configuration, a small antenna duplexer having excellent passband characteristics can be realized.

  The high-frequency module of the present invention is a high-frequency module including an antenna duplexer including a transmission filter and a reception filter, and a transmission amplifier or a reception amplifier, and at least one of the transmission filter or the reception filter is claimed. A high-frequency module comprising the surface acoustic wave filter according to Item 1.

  With the above configuration, a small and high-performance high-frequency module can be realized.

  The high-frequency module of the present invention is a high-frequency module including an antenna duplexer including a transmission filter and a reception filter, and a changeover switch, and at least one of the transmission filter or the reception filter is defined in claim 1. An antenna duplexer comprising the surface acoustic wave filter described above.

  With the above configuration, a small and high-performance high-frequency module can be realized.

  The communication device of the present invention is a communication device having a radio circuit including an antenna duplexer including a transmission filter and a reception filter, a transmission amplifier and a transmission circuit, and a reception amplifier and a reception circuit, At least one of the transmission filter and the reception filter is a communication device including the surface acoustic wave filter according to claim 1.

  With the above configuration, a small and high-performance communication device can be realized.

  According to the surface acoustic wave filter of the present invention, a surface acoustic wave filter and an antenna duplexer that are small in size and excellent in passband characteristics can be realized. In addition, by using the surface acoustic wave filter and the antenna duplexer of the present invention, a small and high-performance high-frequency module and communication equipment can be realized.

Configuration diagram of a surface acoustic wave filter according to Embodiment 1 of the present invention. Enlarged view of the broken line in FIG. Passband characteristic diagram of surface acoustic wave filter considering capacitive coupling Another block diagram of the surface acoustic wave filter in Embodiment 1 of the present invention Another block diagram of the surface acoustic wave filter in Embodiment 1 of the present invention Another block diagram of the surface acoustic wave filter in Embodiment 1 of the present invention Configuration diagram of surface acoustic wave filter in Embodiment 2 of the present invention Another block diagram of the surface acoustic wave filter in Embodiment 2 of the present invention Configuration diagram of communication equipment according to Embodiment 3 of the present invention Configuration of conventional surface acoustic wave filter Another configuration diagram of a conventional surface acoustic wave filter Sectional view of A-A 'in FIG. Configuration diagram of surface acoustic wave filter in Embodiment 4 of the present invention Sectional view of B-B 'in FIG. Configuration of conventional surface acoustic wave filter Sectional view of C-C 'in FIG. The figure which shows the characteristic of the surface acoustic wave filter in Embodiment 4 of this invention shown in FIG. 13, and the characteristic of the surface acoustic wave filter in the conventional structure shown in FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is a configuration diagram of a surface acoustic wave filter according to Embodiment 1 of the present invention. In FIG. 1, a surface acoustic wave filter 100 includes a first longitudinal electrode in which IDT electrodes 102, 103, 104 and reflector electrodes 105, 106 are arranged close to each other along a propagation direction of a surface acoustic wave on a piezoelectric substrate 101. The mode filter 107 and the second longitudinal mode filter 113 in which the IDT electrodes 108, 109 and 110 and the reflector electrodes 111 and 112 are arranged close to each other along the propagation direction of the surface acoustic wave. In the first longitudinal mode type filter 107, one electrode finger of the IDT electrodes 102, 103, 104 is wired to the electrode pads 114, 115, 116 and is connected to the ground terminal GND, the input terminal IN, and the ground terminal GND, respectively. The In the second longitudinal mode filter 113, one electrode finger of the IDT electrodes 108, 109, 110 is wired to the electrode pads 117, 118, 119 and connected to the ground terminal GND, the output terminal OUT, and the ground terminal GND, respectively. The The other electrode finger of the IDT electrode 102 and the other electrode finger of the IDT electrode 108 are connected by the wiring electrode 120, and the other electrode finger of the IDT electrode 104 and the other electrode finger of the IDT electrode 110 are connected by the wiring electrode 121. Connected by In addition, insulating layers 122 and 123 are provided on the wiring electrodes 120 and 121, and the other electrode fingers of the IDT electrodes 103 and 109 are connected by the wiring electrode 124 and further formed on the upper portion. Are connected to electrode pads 126 and 127 connected to the ground terminal GND. At this time, as shown in an enlarged view of a portion surrounded by a broken line in FIG. 1, the electrode width of the wiring electrode 125 is a configuration having a region where the electrode width is different in part and through the insulating layer 123. The electrode width d1 corresponding to the three-dimensional intersection of the wiring electrode 121 and the wiring electrode 125 is configured to be smaller than the electrode width d2 of other portions, and the configuration is d1 <d2. With the above configuration, the area of the three-dimensional intersection can be reduced without greatly increasing the resistance of the wiring electrode 125, and the capacitive coupling of the wiring electrode at the three-dimensional intersection can be reduced as compared with the prior art. Can do. FIG. 3 shows the passband characteristics of the surface acoustic wave filter when the capacitance of the wiring electrodes at the three-dimensional intersection is considered in an equivalent circuit. As shown in FIG. 3, when the capacity increases, the surface acoustic wave filter has a reduced pass bandwidth and in-band characteristics. Therefore, by applying the configuration shown in this embodiment and reducing the capacitive coupling between the wiring electrodes at the three-dimensional intersection, the in-band characteristics of the surface acoustic wave filter are improved, and the reduction of the pass bandwidth can be reduced.

  As described above, by adopting the configuration of the present embodiment, it is possible to reduce the capacitive coupling of the wiring electrodes at the three-dimensional intersection, and to realize a surface acoustic wave filter that is small and has excellent in-band characteristics. .

  In the present embodiment, the surface acoustic wave filter in which longitudinal mode filters are cascade-connected has been described in detail. However, the configuration of the surface acoustic wave filter is not limited to this, and the surface acoustic wave resonance is performed. It may be a ladder type filter in which a vessel is connected to a ladder type, or a lattice type filter connected to a lattice type, and the electrode width of the three-dimensional intersection may be smaller than the others. Moreover, it is also possible to apply to the structure which combined the longitudinal mode type | mold filter and the surface acoustic wave resonator.

  Further, as shown in FIG. 4, it may be applied to the configuration of a one-stage longitudinal mode filter. 4, in the surface acoustic wave filter 400, one electrode finger of the IDT electrodes 401 and 402 is connected to the ground terminal GND via the electrode pad, and the other electrode finger of the IDT electrodes 401 and 402 is connected via the electrode pad. The configuration is connected to the output terminal OUT.

  The surface acoustic wave filter according to the present embodiment is an unbalanced type. This is because the IDT electrode 109 is divided into two IDT electrodes 501 and 502 as shown in FIG. The wave filter 500 may be used. At this time, the IDT electrodes 501 and 502 are connected to the balanced terminals OUT1 and OUT2 via the electrode pads 503 and 504, respectively.

  Furthermore, regarding the wiring electrode, the electrode width at the three-dimensional intersection of the upper wiring electrode 125 is reduced. However, the electrode width of the wiring electrodes 120 and 121 may be reduced. Also, all electrode widths of the wiring electrodes 120, 121, and 125 may be reduced at the three-dimensional intersection. In this case, the area of the three-dimensional intersection can be further reduced, and capacitive coupling can be further suppressed.

The insulating layer may be a material that can ensure insulation, such as SiO ₂ , SiN, or a resin material. In particular, when the material used for the temperature compensation of the surface acoustic wave filter such as SiO ₂ as the insulating layer, as shown in FIG. 6, if configured insulating layer 601 covers, small, band characteristics In addition, the surface acoustic wave filter 600 having excellent temperature characteristics can be realized.

  In addition, regarding the production of the surface acoustic wave filter, a process of increasing the thickness of the pad electrode may be used for mounting on a package. In this case, the wiring electrode 125 is simultaneously formed with the step of increasing the pad electrode, etc. By doing so, the surface acoustic wave filter of the present invention can be realized without increasing the number of process steps.

(Embodiment 2)
Hereinafter, the structure of the surface acoustic wave filter of the present invention will be described with reference to the drawings.

  FIG. 7 is a configuration diagram of a surface acoustic wave filter according to Embodiment 2 of the present invention. In FIG. 7, a surface acoustic wave filter 700 includes a first vertical longitudinal axis formed by placing IDT electrodes 702, 703, and 704 and reflector electrodes 705 and 706 close to each other along a propagation direction of surface acoustic waves on a piezoelectric substrate 701. The mode type filter 707 is composed of a second longitudinal mode type filter 713 in which IDT electrodes 708, 709, and 710 and reflector electrodes 711 and 712 are arranged close to each other along the propagation direction of the surface acoustic wave. In the first longitudinal mode filter 707, one electrode finger of the IDT electrodes 702, 703, 704 is wired to the electrode pads 714, 715, 716 and connected to the ground terminal GND, the input terminal IN, and the ground terminal GND, respectively. The In the second longitudinal mode filter 713, one electrode finger of the IDT electrodes 708, 709, 710 is wired to the electrode pads 717, 718, 719 and connected to the ground terminal GND, the output terminal OUT, and the ground terminal GND, respectively. The The other electrode finger of the IDT electrode 702 and the other electrode finger of the IDT electrode 708 are connected by the wiring electrode 720, and the other electrode finger of the IDT electrode 704 and the other electrode finger of the IDT electrode 710 are connected to the wiring electrode 721. Connected by In addition, insulating layers 722 and 723 are provided on the wiring electrodes 720 and 721, and the other electrode fingers of the IDT electrodes 703 and 709 are connected by the wiring electrode 724 and further formed on the upper side. Are connected to electrode pads 726 and 727 connected to the ground terminal GND. At this time, the electrode width of the wiring electrode 725 is a configuration having a region where the electrode width is partially different, and the electrode width corresponding to the three-dimensional intersection of the wiring electrodes 720 and 721 and the wiring electrode 725 via the insulating layer 723 is It is configured to be smaller than the electrode width of other portions. Further, the reflector electrodes 705, 706, 711, and 712 have a configuration in which the length of the strip line constituting the reflector electrode is not uniform and is cut obliquely in the intersecting width direction. Electrode pads 726 and 727 are disposed in the portion. With the above configuration, the area of the three-dimensional intersection can be reduced without greatly increasing the resistance of the wiring electrode 725, and the capacitive coupling of the wiring electrode at the three-dimensional intersection can be reduced as compared with the prior art. Further, in the reflector electrode, by changing the length of the strip line to provide a region shorter than the crossing width, a part of the electrode pads 726 and 727 is provided between the first and second longitudinal mode filters. Further downsizing can be realized.

  As described above, by adopting the configuration of the present embodiment, it is possible to reduce the capacitive coupling of the wiring electrodes at the three-dimensional intersection, and it is possible to realize a surface acoustic wave filter that is small and has excellent passband characteristics. .

  In the present embodiment, the surface acoustic wave filter in which longitudinal mode filters are cascade-connected has been described in detail. However, the configuration of the surface acoustic wave filter is not limited to this, and the surface acoustic wave resonance is performed. It may be a ladder-type filter with a resonator connected to a ladder type, or a lattice-type filter connected to a lattice type. The electrode width of the three-dimensional intersection is smaller than the others, and the reflection that constitutes the surface acoustic wave resonator The strip electrode may have a configuration in which the stripline is not uniform in length and has a partially cut region, and an electrode pad is disposed in the region. Further, the present invention can be applied to a configuration in which a longitudinal mode filter and a surface acoustic wave resonator are combined, or a one-stage longitudinal mode filter.

  Further, regarding the wiring electrode, the electrode width at the three-dimensional intersection of the upper wiring electrode 725 is reduced, but this may be achieved by reducing the electrode width of the wiring electrodes 720 and 721. Moreover, all electrode widths of the wiring electrodes 720, 721, and 725 may be reduced at the three-dimensional intersection. In this case, the area of the three-dimensional intersection can be further reduced, and capacitive coupling can be further suppressed.

  As for the wiring electrodes, the electrode width at the three-dimensional intersection of the upper wiring electrode 725 is reduced. However, even if the electrode width of the wiring electrode 801 of the surface acoustic wave filter 800 is uniform as shown in FIG. The effect of miniaturization can be obtained.

The insulating layer may be a material that can ensure insulation, such as SiO ₂ , SiN, or a resin material. It is also possible to realize a surface acoustic wave filter having excellent temperature characteristics by using a material used for temperature compensation of a surface acoustic wave filter such as SiO ₂ as an insulating layer.

  Further, regarding the reflector electrode, in the present embodiment, the reflector electrode has a configuration in which the strip line has a region where the length of the strip line is short in the cross width direction, and is configured to be cut obliquely. Other configurations may be applied in consideration of the weighting effect of the reflector, and the effect of miniaturization can be obtained as long as the electrode pad is arranged on the part where the reflector is shaved. It is.

(Embodiment 3)
Hereinafter, configurations of an antenna duplexer, a high-frequency module, and a communication device according to the present invention will be described with reference to the drawings.

  FIG. 9 is a configuration diagram of a communication device according to Embodiment 3 of the present invention. In FIG. 9, the communication device 900 includes first and second wireless circuits 901 and 902 and a changeover switch 903. The first radio circuit 901 includes an antenna duplexer 906 including a transmission filter 904 and a reception filter 905, a transmission circuit 1, a transmission amplifier 907 that amplifies a transmission signal output from the transmission circuit 1, and a reception signal. Is constituted by a receiving amplifier 908 for amplifying the signal and a receiving circuit 1 to which a received signal is inputted. The second radio circuit 902 includes an antenna duplexer 911 including a transmission filter 909 and a reception filter 910, a transmission circuit 2, a transmission amplifier 912 that amplifies a transmission signal output from the transmission circuit 2, and a reception signal. Is constituted by a receiving amplifier 913 for amplifying the signal and a receiving circuit 2 to which a received signal is inputted. One terminal of the changeover switch is connected to the antenna terminal ANT, and the other two terminals are connected to the antenna duplexers 906 and 911 constituting the first and second radio circuits 901 and 902, respectively. With the above configuration, the communication device 900 has a configuration of a multi-function peripheral having the first and second wireless circuits 901 and 902. Here, in the antenna duplexer 906, by applying the surface acoustic wave filter described in Embodiment 1 or 2 to either the transmission filter 904 or the reception filter 905, the antenna sharing that is small in size and excellent in passband characteristics is performed. A device 906 can be implemented. Further, in the antenna duplexer 911, the surface acoustic wave filter shown in Embodiment 1 or 2 is applied to either the transmission filter 909 or the reception filter 910, so that the antenna duplexer is small and has excellent passband characteristics. 911 can be realized. Furthermore, by configuring the communication device 900 using such an antenna duplexer 906 or 911, a small and high-performance communication device can be realized.

  Note that in this embodiment, the number of wireless circuits and circuit configuration in a communication device are not limited to this.

  Furthermore, if the antenna duplexer in the present embodiment is used, it can be realized as a high-frequency module 914 composed of the antenna duplexer 906 and the transmission amplifier 907. From the antenna duplexers 906 and 911 and the changeover switch 903, The configured high frequency module 915 can be realized, and a small and high performance high frequency module can be realized.

  Note that the device combined with the antenna duplexer in the high-frequency module is not limited to this, and can be combined with a receiving amplifier.

  In the present embodiment, the antenna duplexer is used for the high-frequency module and the communication device. This is a communication device using the surface acoustic wave filter of the first or second embodiment. It doesn't matter.

(Embodiment 4)
Hereinafter, the structure of the surface acoustic wave filter of the present invention will be described with reference to the drawings.

  FIG. 13 is a configuration diagram of a surface acoustic wave filter according to Embodiment 4 of the present invention. In FIG. 13, a surface acoustic wave filter 1300 is a one-stage vertical surface formed by arranging IDT electrodes 1302, 1303, and 1304 and reflector electrodes 1305 and 1306 close to each other along a propagation direction of surface acoustic waves on a piezoelectric substrate 1301. It is composed of mode filters. In the longitudinal mode filter, one electrode finger of the IDT electrodes 1302, 1303, and 1304 is wired to the electrode pads 1314, 1315, and 1316 and connected to the ground terminal GND, the input terminal IN, and the ground terminal GND, respectively. The other electrode finger of the IDT electrode 1303 is connected to the electrode pads 1317 and 1318 connected to the ground terminal GND without contacting the second wiring electrode through the first wiring electrode 1309. The other electrode fingers of the IDT electrodes 1302 and 1304 are connected to the second wiring electrodes 1310 and 1313 through the first wiring electrodes 1307 and 1308, respectively, and are connected to the output terminal OUT through the electrode pad 1319. It becomes composition. In addition, insulating layers 1311 and 1312 are provided on the first wiring electrode 1309, and second wiring electrodes 1310 and 1313 are formed thereon. At this time, the electrode widths of the second wiring electrodes 1310 and 1313 are partially configured to have regions having different electrode widths, and electrodes that are three-dimensionally intersected with the first wiring electrode 1309 via the insulating layers 1311 and 1312. The width is configured to be smaller than the electrode width of other portions. Here, FIG. 14 shows a cross-sectional view between FIGS. A surface acoustic wave filter as in the embodiment of the present invention is formed by two-stage sputtering in which a first wiring electrode is formed and then a second wiring electrode is formed. Therefore, as shown in FIG. 14, contact resistance is generated between the first wiring electrode 1308 and the second wiring electrode 1313 due to the degree of adhesion. In the configuration according to this embodiment, the contact resistance 1400 is generated on a signal line connected to the output terminal OUT of the IDT electrodes 1302 and 1304. On the other hand, FIG. 15 shows a configuration diagram of a conventional surface acoustic wave filter. FIG. 16 is a cross-sectional view taken along the line C-C ′ in FIG. According to the configuration of the conventional surface acoustic wave filter, as shown in FIG. 16, the contact resistance 1600 between the first wiring electrode 1506 and the second wiring electrode 1508 is transferred to the ground terminal GND of the IDT electrode 1503 in FIG. Occurs on connected lines. For this reason, when the contact resistance 1400 in the fourth embodiment of the present invention and the contact resistance 1600 in the conventional configuration have the same resistance component, in the embodiment of the present invention, a resistance is formed on the signal line to the output terminal OUT. Compared with the case where a component is generated and is generated on the line to the ground terminal GND, loss deterioration of the surface acoustic wave filter can be reduced. FIG. 17 shows a comparison between the characteristics of the surface acoustic wave filter in the embodiment of the present invention shown in FIG. 13 and the characteristics of the surface acoustic wave filter in the conventional configuration shown in FIG.

  As described above, by adopting the configuration of the present embodiment, the influence of the contact resistance between the wiring electrodes can be reduced, and a surface acoustic wave filter having a small size and excellent passband characteristics can be realized.

  Note that in this embodiment, the second wiring electrodes 1310 and 1313 have a structure in which the electrode widths of the second wiring electrodes 1310 and 1313 are partially different from each other. The effect of reducing deterioration can be obtained similarly.

  Further, in the present embodiment, the wiring electrode has a reduced electrode width at the three-dimensional intersection of the upper wiring electrodes 1310 and 1313, but this may reduce the electrode width of the wiring electrode 1309. Further, all the electrode widths of the wiring electrodes 1310, 1313, and 1309 may be reduced at the three-dimensional intersection. In this case, the area of the three-dimensional intersection can be further reduced, and capacitive coupling can be further suppressed.

The insulating layer may be a material that can ensure insulation, such as SiO ₂ , SiN, or a resin material. It is also possible to realize a surface acoustic wave filter having excellent temperature characteristics by using a material used for temperature compensation of a surface acoustic wave filter such as SiO ₂ as an insulating layer.

  In addition, regarding the reflector electrode, in the present embodiment, the reflector electrode has a uniform intersection width. However, the present invention is not limited to this configuration, and the reflector electrode has a stripline length. It is possible to apply a configuration that has a short region in the cross width direction and is scraped obliquely, or another configuration that takes into account the effect of weighting of the reflector, and is small as long as the electrode pad is placed on the portion where the reflector is shaved. The effect of conversion is obtained similarly.

  The surface acoustic wave filter according to the present invention is useful as an antenna duplexer having a small size and excellent passband characteristics. It can also be applied to applications such as high-frequency modules and communication equipment.

DESCRIPTION OF SYMBOLS 100 Surface acoustic wave filter 101 Piezoelectric substrate 102,103,104 IDT electrode 105,106 Reflector electrode 107 1st longitudinal mode type filter 108,109,110 IDT electrode 111,112 Reflector electrode 113 2nd longitudinal mode type filter 114, 115, 116, 117, 118, 119 Electrode pad 120, 121 Wiring electrode 122, 123 Insulating layer 125 Wiring electrode 126, 127 Electrode pad 400 Surface acoustic wave filter 401, 402 IDT electrode 500 Surface acoustic wave filter 501, 502 IDT Electrode 503, 504 Electrode pad 600 Surface acoustic wave filter 601 Insulating layer 700 Surface acoustic wave filter 701 Piezoelectric substrate 702, 703, 704 IDT electrode 705, 706 Reflector electrode 707 First longitudinal mode type filter 708 709, 710 IDT electrode 711, 712 Reflector electrode 713 Second longitudinal mode filter 714, 715, 716, 717, 718, 719 Electrode pad 720, 721 Wiring electrode 722, 723 Insulating layer 725 Wiring electrode 726, 727 Electrode pad 800 surface acoustic wave filter 801 wiring electrode 900 communication device 901 first radio circuit 902 second radio circuit 903 changeover switch 904 transmission filter 905 reception filter 906 antenna duplexer 907 transmission amplifier 908 reception amplifier 909 transmission filter 910 reception filter 911 antenna Duplexer 912 Transmission amplifier 913 Reception amplifier 914, 915 High frequency module 1300 Surface acoustic wave filter 1301 Piezoelectric substrate 1302, 1303, 1304 IDT electrode 1305, 1306 Reflector electrode 1307, 1308, 1309 First wiring electrode 1310, 1313 Second wiring electrode 1311, 1312 Insulating layer 1314, 1315, 1316, 1317, 1318, 1319 Electrode pad 1400 Contact resistance 1500 Surface acoustic wave filter 1501 Piezoelectric substrate 1502, 1503, 1504 IDT electrodes 1505, 1506, 1507, 1511 First wiring electrode 1508 Second wiring electrode 1509, 1510 Insulating layer 1600 Contact resistance

Claims (9)

A piezoelectric substrate;
A plurality of IDT electrodes and a plurality of reflector electrodes formed on the piezoelectric substrate;
A surface acoustic wave filter comprising a first wiring electrode and a second wiring electrode respectively connected to the plurality of IDT electrodes,
The first wiring electrode and the second wiring electrode are configured to cross three-dimensionally through an insulating layer,
At least one of the first wiring electrode or the second wiring electrode is connected to an electrode pad formed on the piezoelectric substrate,
On the piezoelectric substrate, the strip line constituting the reflector electrode has a region where the reflector electrode is deleted by being shorter than the crossing width of the IDT electrode,
A surface acoustic wave filter, wherein a part of the electrode pad is disposed in the region. 2. The surface acoustic wave filter according to claim 1, wherein at least one of the first wiring electrode or the second wiring electrode is connected to a ground terminal. The surface acoustic wave filter according to claim 1, wherein the plurality of IDT electrodes are arranged close to each other along a propagation direction of the surface acoustic wave. A first surface acoustic wave filter in which a plurality of IDT electrodes are arranged close to each other along the propagation direction of the surface acoustic wave;
A plurality of IDT electrodes, and a second surface acoustic wave filter in which the IDT electrodes are arranged close to each other along the propagation direction of the surface acoustic wave,
2. The elastic device according to claim 1, wherein an IDT electrode in the first surface acoustic wave filter or the second surface acoustic wave filter is grounded by at least one of the first or second wiring electrode. 3. Surface wave filter. The surface acoustic wave filter according to claim 4, wherein a part of the electrode pad is disposed between the first surface acoustic wave filter and the second surface acoustic wave filter. An antenna duplexer having a transmission filter and a reception filter,
The antenna duplexer, wherein at least one of the transmission filter and the reception filter is configured by the surface acoustic wave filter according to claim 1. An antenna duplexer having a transmission filter and a reception filter;
A high frequency module comprising a transmission amplifier or a reception amplifier,
The high-frequency module, wherein at least one of the transmission filter and the reception filter is configured by the surface acoustic wave filter according to claim 1. An antenna duplexer having a transmission filter and a reception filter;
A high-frequency module comprising a changeover switch,
The high-frequency module, wherein at least one of the transmission filter and the reception filter is configured by the surface acoustic wave filter according to claim 1. An antenna duplexer having a transmission filter and a reception filter;
A communication device having a radio circuit including a transmission amplifier, a transmission circuit, and a reception amplifier and a reception circuit, wherein at least one of the transmission filter and the reception filter is configured by the surface acoustic wave filter according to claim 1. Communication equipment characterized by that.

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