Elastic wave device and module including the same

Abstract

The present disclosure provides an elastic wave device and a module including the same. The elastic wave device includes a substrate, a transmission filter disposed on the substrate, a reception filter disposed on the substrate, a transmission ground pad disposed on the transmission filter of the substrate, and a reception ground pad disposed on the reception filter of the substrate. The transmission filter includes a plurality of series resonators and a plurality of parallel resonators. One of the parallel resonators is a first parallel resonator electrically connected to the reception ground pad. The elastic wave device is small in size and has good isolation characteristics.

Description

Technical Field

[0001] This disclosure relates to an elastic wave device and a module comprising the elastic wave device. Background Technology

[0002] An electronic component as shown in Patent Document 1 (Japanese Patent Application Publication No. 2014-120841). According to the electronic component, the isolation characteristics can be improved.

[0003] However, the electronic component described in Patent Document 1 requires additional circuitry for the elastic wave device. Therefore, it is impossible to miniaturize the electronic component. Summary of the Invention

[0004] This disclosure is made to solve the above-mentioned problems. The purpose of this disclosure is to provide a smaller elastic wave device with better isolation characteristics, and a module including said elastic wave device.

[0005] This disclosure discloses an elastic wave device comprising a substrate, a transmitting filter formed on the substrate, a receiving filter formed on the substrate, a transmitting grounding pad of the transmitting filter formed on the substrate, and a receiving grounding pad of the receiving filter formed on the substrate. The transmitting filter includes a plurality of series resonators and a plurality of parallel resonators, one of which is electrically connected to the receiving grounding pad as a first parallel resonator.

[0006] In one embodiment of this disclosure, the first parallel resonator is not electrically connected to the transmitting grounding pad.

[0007] In one embodiment of this disclosure, the first parallel resonator is positioned furthest from the input terminal of the transmitting filter.

[0008] In one embodiment of this disclosure, the first parallel resonator is one of the parallel resonators in which the last segment of the transmitting filter is divided in parallel.

[0009] In one embodiment of this disclosure, the capacitance value of the first parallel resonator is smaller than the average capacitance value of the parallel resonators.

[0010] In one embodiment of this disclosure, the capacitance value of the first parallel resonator is the smallest among the capacitance values ​​of the parallel resonators.

[0011] In one embodiment of this disclosure, the first parallel resonator has a resonant frequency close to the highest frequency of the passband of the receiving filter.

[0012] In one embodiment of this disclosure, the substrate is formed by bonding a piezoelectric substrate to a support substrate formed of one of sapphire, silicon, alumina, spinel, crystal, and glass.

[0013] In one embodiment of this disclosure, the elastic wave device further includes a transmitting ground electrode electrically connected to the transmitting ground pad and a receiving ground electrode electrically connected to the receiving ground pad, wherein the area of ​​the receiving ground electrode is larger than the area of ​​the transmitting ground electrode.

[0014] One embodiment of this disclosure includes a module comprising the elastic wave device.

[0015] The beneficial effects of this disclosure are that it provides a smaller elastic wave device with better isolation characteristics, and a module including the elastic wave device. Attached Figure Description

[0016] Other features and effects of the present invention will be clearly presented in the embodiments with reference to the drawings, wherein:

[0017] Figure 1 This is a cross-sectional view of the elastic wave device in the first embodiment.

[0018] Figures 2(a)-2(d) This is a schematic diagram of the elastic wave device described in the first embodiment.

[0019] Figures 3(a)-3(d) This is a structural schematic diagram of a comparative example of the elastic wave device described in the first embodiment.

[0020] Figure 4 This is a schematic diagram of the elastic wave component of the elastic wave device described in the first embodiment.

[0021] Figure 5 This is a schematic diagram of the transmission band characteristics of the elastic wave device in the first embodiment and the transmitting filter in the comparative example.

[0022] Figure 6 This is a schematic diagram of the passband characteristics of the elastic wave device in the first embodiment and the receiving filter in the comparative example.

[0023] Figure 7 This is a schematic diagram illustrating the isolation characteristics of the elastic wave device in the first embodiment and the comparative example.

[0024] Figure 8 This is a schematic diagram of the antenna impedance of the elastic wave device in the first embodiment and the comparative example.

[0025] Figure 9 This is a schematic diagram of the first example of the electrical resistance of the elastic wave device described in the first embodiment and the comparative example.

[0026] Figure 10This is a second schematic diagram illustrating the electrical resistance of the elastic wave device described in the first embodiment and the comparative example.

[0027] Figure 11 This is a cross-sectional view of the module employing the elastic wave device in the second embodiment. Detailed Implementation

[0028] The following description of the embodiments is based on the accompanying drawings. It should be noted that identical or equivalent parts in each drawing are represented by the same symbol. The descriptions of these identical or equivalent parts will be simplified or omitted as appropriate.

[0029] (First Embodiment)

[0030] Figure 1 This is a cross-sectional view of the elastic wave device 1 in this embodiment.

[0031] Figure 1 An elastic wave device with a duplexer is shown as an example of elastic wave device 1.

[0032] like Figure 1 As shown, the elastic wave device 1 includes a wiring board 3, several external connection terminals 31, several electrode pads 9, several bumps 15, a substrate 5, and a sealing part 17.

[0033] The wiring substrate 3 may, for example, be a multilayer substrate composed of resin. The wiring substrate 3 may, for example, be a low-temperature co-fired ceramic (LTCC) multilayer substrate composed of several dielectric layers.

[0034] The external connection terminal 31 is formed on the lower side of the wiring board 3.

[0035] The electrode pad 9 is formed on the main surface of the wiring substrate 3. The electrode pad 9 is formed, for example, of copper or a copper-containing alloy. The thickness of the electrode pad 9 is, for example, between 10 μm and 20 μm.

[0036] The bumps 15 are formed on the upper side surface of the electrode pads 9. The bumps 15 are, for example, made of gold. The height of the bumps 15 is, for example, between 20 μm and 50 μm.

[0037] The substrate 5 may be, for example, a piezoelectric substrate formed from a piezoelectric single crystal such as lithium tantalate, lithium niobate, or quartz. Alternatively, the substrate 5 may be a piezoelectric substrate formed from piezoelectric ceramic. The substrate 5 may be formed by bonding a piezoelectric substrate to a support substrate. The support substrate may be formed from, for example, sapphire, silicon, alumina, spinel, quartz, or glass.

[0038] The substrate 5 is disposed on the wiring substrate 3 via the bumps 15 using flip-chip bonding technology. The substrate 5 is electrically connected to the electrode pads 9 via the bumps 15.

[0039] The substrate 5 serves as a substrate for mounting functional components. For example, a transmitting filter 201 and a receiving filter 202 are formed on the main surface of the substrate 5.

[0040] The transmitting filter 201 allows electrical signals in the desired frequency band to pass through. The transmitting filter 201 is, for example, a trapezoidal filter composed of several series resonators and several parallel resonators.

[0041] The receiving filter 202 allows electrical signals in the desired frequency band to pass through. The receiving filter 202 is, for example, a trapezoidal filter composed of several series resonators and several parallel resonators.

[0042] The sealing portion 17 is formed in a manner that covers the substrate 5. The sealing portion 17 may be formed using an insulator such as a synthetic resin. The sealing portion 17 may also be formed of metal, for example.

[0043] When the sealing portion 17 is formed of a synthetic resin, the synthetic resin is epoxy resin or polyimide. Preferably, the sealing portion 17 can be epoxy resin, or epoxy resin formed by a low-temperature curing process.

[0044] Next, the structures of the elastic wave device 1 of this disclosure and the comparative example elastic wave device will be described with reference to Figures 2 and 3. Figure 2 is a schematic diagram of the structure of the elastic wave device 1 in the first embodiment. Figure 3 is a schematic diagram of the structure of the comparative example of the elastic wave device 1 in the first embodiment.

[0045] Figure 2(a) illustrates the substrate 5 of the elastic wave device 1 in the first embodiment. Figure 2(b) illustrates the first layer of the wiring substrate 3 of the elastic wave device 1 in the first embodiment. Figure 2(c) illustrates the second layer of the wiring substrate 3 of the elastic wave device 1 in the first embodiment. Figure 2(d) illustrates the external connection terminal 31 of the wiring substrate 3 of the elastic wave device 1 in the first embodiment.

[0046] In Figure 2(a), the substrate 5 includes several elastic wave components 52 and wiring patterns 54.

[0047] The elastic wave component 52 has several series resonators S1a, S1b, S2a, S2b, S3a, S3b, S4, and several parallel resonators P1, P2, P3a, P3b.

[0048] The series resonators S1a, S1b, S2a, S2b, S3a, S3b, and S4, and the parallel resonators P1, P2, P3a, and P3b are configured to function as a transmitting filter 201. Other series resonators and other parallel resonators are configured to function as a receiving filter 202.

[0049] The wiring pattern 54 is formed, for example, by a suitable metal such as silver, aluminum, copper, titanium, palladium, or an alloy thereof. The thickness of the wiring pattern 54 is, for example, between 150 nm and 400 nm.

[0050] The wiring pattern 54 includes an antenna pad ANT, a transmitting pad Tx, a receiving pad Rx, several transmitting ground pads GND-Tx formed on the transmitting filter 201, and several receiving ground pads GND-Rx formed on the receiving filter 202. The wiring pattern 54 is electrically connected to the elastic wave assembly 52.

[0051] In Figure 2(b), the wiring board 3 includes a first antenna electrode 301, a first transmitting electrode 302, a first receiving electrode 303, a first transmitting ground electrode 304, and a first receiving ground electrode 305.

[0052] There is no electrical connection between the first antenna electrode 301, the first transmitting electrode 302, the first receiving electrode 303, the first transmitting ground electrode 304, and the first receiving ground electrode 305.

[0053] In actual installation, the first antenna electrode 301 is electrically connected to the antenna pad ANT. The first transmitting electrode 302 is electrically connected to the transmitting pad Tx. The first receiving electrode 303 is electrically connected to the receiving pad Rx. The first transmitting ground electrode 304 is electrically connected to the transmitting ground pad GND-Tx. The first receiving ground electrode 305 is electrically connected to the receiving ground pad GND-Rx.

[0054] In Figure 2(c), the wiring board 3 further includes a second antenna electrode 401, a second transmitting electrode 402, a second receiving electrode 403, a second transmitting ground electrode 404, and a second receiving ground electrode 405.

[0055] There is no electrical connection between the second antenna electrode 401, the second transmitting electrode 402, the second receiving electrode 403, the second transmitting ground electrode 404, and the second receiving ground electrode 405.

[0056] In actual installation, the second antenna electrode 401 is electrically connected to the first antenna electrode 301. The second transmitting electrode 402 is electrically connected to the first transmitting electrode 302. The second receiving electrode 403 is electrically connected to the first receiving electrode 303. The second transmitting ground electrode 404 is electrically connected to the first transmitting ground electrode 304. The second receiving ground electrode 405 is electrically connected to the first receiving ground electrode 305.

[0057] In Figure 2(d), the external connection terminal 31 includes an antenna terminal 501, a transmitting terminal 502, a receiving terminal 503, several transmitting ground terminals 504, and several receiving ground terminals 505.

[0058] There is no electrical connection between the antenna terminal 501, the transmitting terminal 502, the receiving terminal 503, the transmitting ground terminal 504, and the receiving ground terminal 505.

[0059] In actual installation, the antenna terminal 501 is electrically connected to the second antenna electrode 401. The transmitting terminal 502 is electrically connected to the second transmitting electrode 402. The receiving terminal 503 is electrically connected to the second receiving electrode 403. The transmitting ground terminal 504 is electrically connected to the second transmitting ground electrode 404. The transmitting ground terminal 504 is not electrically connected to the second receiving ground electrode 405. The receiving ground terminal 505 is electrically connected to the second receiving ground electrode 405. The receiving ground terminal 505 is not electrically connected to the second transmitting ground electrode 404.

[0060] The antenna terminal 501 serves as the output terminal of the transmitting filter 201. The antenna terminal 501 also serves as the input terminal of the receiving filter 202. The transmitting terminal 502 serves as the input terminal of the transmitting filter 201. The receiving terminal 503 serves as the output terminal of the receiving filter 202. The transmitting ground terminal 504 serves as the ground terminal of the transmitting filter 201. The receiving ground terminal 505 serves as the ground terminal of the receiving filter 202.

[0061] When an electrical signal is input to the transmitting terminal 502, the signal reaches the transmitting filter 201. The desired frequency band signal passes through the transmitting filter 201. Therefore, the desired frequency band signal is output from the antenna terminal 501.

[0062] When an electrical signal is input to the antenna terminal 501, the signal reaches the receiving filter 202. The desired frequency band signal passes through the receiving filter 202. Therefore, the desired frequency band signal is output from the receiving terminal 503.

[0063] In the first embodiment, the parallel resonator P3b serves as the first parallel resonator and is electrically connected to the receiving grounding pad GND-Rx. The parallel resonator P3b is not electrically connected to the transmitting grounding pad GND-Tx.

[0064] Among the parallel resonators P1, P2, P3a, and P3b, the parallel resonator P3b is located at the position furthest from the transmitting terminal 502.

[0065] The parallel resonator P3b is one of the parallel resonators that are divided in parallel in the final segment of the transmitting filter 201. Specifically, in the transmitting filter 201, the parallel resonators in the final segment are divided in parallel into parallel resonators P3a and P3b.

[0066] The capacitance value of the parallel resonator P3b is smaller than the average capacitance value of the parallel resonators P1, P2, P3a, and P3b. The capacitance value of the parallel resonator P3b is the smallest among the capacitance values ​​of the parallel resonators P1, P2, P3a, and P3b.

[0067] For example, the parallel resonator P3b has a resonant frequency that is close to the highest frequency of the pass band of the receiving filter 202.

[0068] The sum of the area of ​​the first receiving ground electrode 305 and the area of ​​the second receiving ground electrode 405 is greater than the sum of the area of ​​the first transmitting ground electrode 304 and the area of ​​the second transmitting ground electrode 404.

[0069] Figure 3(a) shows the substrate 5' of the elastic wave device in a comparative example of the elastic wave device 1 in the first embodiment. Figure 3(b) shows the first layer of the wiring substrate 3' of the elastic wave device in a comparative example of the elastic wave device 1 in the first embodiment. Figure 3(c) shows the second layer of the wiring substrate 3' of the elastic wave device in a comparative example of the elastic wave device 1 in the first embodiment. Figure 3(d) shows the external connection terminal 31' of the wiring substrate 3' of the elastic wave device in a comparative example of the elastic wave device 1 in the first embodiment.

[0070] In Figure 3(a), the substrate 5' is the same as in Figure 2(a), having multiple elastic wave components 52 and wiring patterns 54. The substrate 3' includes a parallel resonator P1b replacing the parallel resonator P3b. The substrate 3' includes multiple grounding pads GND replacing the transmitting grounding pad GND-Tx and the receiving grounding pad GND-Rx.

[0071] In Figure 3(b), the wiring board 3' is the same as that in Figure 2(b), including the first antenna electrode 301, the first transmitting electrode 302, and the first receiving electrode 303. The wiring board 3' includes a first ground electrode 601 that replaces the first transmitting ground electrode 304 and the first receiving ground electrode 305.

[0072] In actual installation, the first grounding electrode 601 is electrically connected to the grounding pad GND.

[0073] The wiring board 3' shown in FIG. 3(c) is similar to that in FIG. 2(c), including the second antenna electrode 401, the second transmitting electrode 402, and the second receiving electrode 403. The wiring board 3' includes a second ground electrode 701 that replaces the second transmitting ground electrode 404 and the second receiving ground electrode 405.

[0074] In actual installation, the second grounding electrode 701 is electrically connected to the first grounding electrode 601.

[0075] In Figure 3(d), the external connection terminal 31', like in Figure 2(d), includes the antenna terminal 501, the transmitting terminal 502, and the receiving terminal 503. The external connection terminal 31' includes a ground terminal 801 that replaces the transmitting ground terminal 504 and the receiving ground terminal 505.

[0076] In actual installation, the grounding terminal 801 is electrically connected to the second grounding electrode 701.

[0077] Next, in coordination Figure 4 The example illustrates the elastic wave component 52.

[0078] Figure 4 This is a schematic diagram of the elastic wave component 52 of the elastic wave device 1 in the first embodiment.

[0079] like Figure 4 As shown, the main surface of the substrate 5 is formed with an IDT (Interdigital Transducer) 52a and a pair of reflectors 52b. The IDT 52a and the reflectors 52b are configured to excite elastic surface waves.

[0080] For example, IDT 52a and reflector 52b are each formed of an alloy of aluminum and copper. Alternatively, IDT 52a and reflector 52b can be formed of suitable metals such as titanium, palladium, or silver, or alloys thereof. For example, IDT 52a and reflector 52b can be multilayer metal films composed of multiple stacked metal layers. For example, the thickness of IDT 52a and reflector 52b can be between 150 nm and 400 nm.

[0081] The IDT 52a has a pair of comb-shaped electrodes 52c. The comb-shaped electrodes 52c are arranged opposite each other. Each comb-shaped electrode 52c has multiple electrode fingers 52d and a bus bar 52e. The electrode fingers 52d extend longitudinally. The bus bar 52e connects the electrode fingers 52d.

[0082] One of the reflectors 52b is adjacent to one side of the IDT 52a. The other reflector 52b is adjacent to the other side of the IDT 52a.

[0083] Next, in coordination Figure 5 The transmit band characteristics of the transmit filter 201 are explained.

[0084] Figure 5 This is a schematic diagram showing the transmission band characteristics of the transmitting filter 201 of the elastic wave device 1 in the first embodiment and the transmitting filter of the comparative example.

[0085] The solid line represents the passband characteristics of the transmit filter 201 of the first embodiment in a narrow bandwidth. The dashed line represents the passband characteristics of the transmit filter of the comparative example in a narrow bandwidth.

[0086] like Figure 5 As shown, the transmit filter 201 of the first embodiment has improved transmit band characteristics compared to the transmit filter of the comparative example.

[0087] Next, in coordination Figure 6 The passband characteristics of the receiving filter 202 are explained.

[0088] Figure 6 This is a schematic diagram showing the passband characteristics of the receiving filter 202 of the elastic wave device 1 in the first embodiment and the receiving filter of the comparative example.

[0089] The solid line represents the passband characteristics of the receiving filter 202 of the first embodiment in a narrow frequency band. The dashed line represents the passband characteristics of the receiving filter of the comparative example in a narrow frequency band.

[0090] like Figure 6As shown, compared to the passband characteristics of the receiving filter in the comparative example, the passband characteristics of the receiving filter 202 in the first embodiment are improved.

[0091] Next, in coordination Figure 7 Explain the isolation characteristics.

[0092] Figure 7 This is a schematic diagram of the isolation characteristics of the elastic wave device 1 in the first embodiment and the comparative example.

[0093] The solid line represents the isolation characteristics of the first embodiment in a narrow bandwidth. The dashed line represents the isolation characteristics of the comparative example in a narrow bandwidth.

[0094] like Figure 7 As shown, the isolation characteristics of the elastic wave device 1 in the first embodiment are improved compared to those of the comparative example. In particular, the isolation characteristics are improved in the high-frequency region slightly above 960MHz by the arrangement of the parallel resonator P3b.

[0095] Next, in coordination Figure 8 Explain the antenna impedance.

[0096] Figure 8 This is a schematic diagram of the antenna impedance of the elastic wave device 1 in the first embodiment and the comparative example.

[0097] The solid line represents the antenna impedance of the elastic wave device 1 in the first embodiment. The dashed line represents the antenna impedance of the comparative example.

[0098] like Figure 8 As shown in the Smith chart, the antenna impedance of the elastic wave device 1 in the first embodiment is improved compared to the antenna impedance of the comparative example.

[0099] Next, in coordination Figure 9 This is the first example illustrating electrical resistance.

[0100] Figure 9 This is a schematic diagram of the first example of the electrical resistance of the elastic wave device 1 in the first embodiment and the comparative example.

[0101] The solid line represents the electrical withstand capability of the parallel resonator P1 of the elastic wave device 1 in the first embodiment. The dashed line represents the electrical withstand capability of the parallel resonator located at the same position as the parallel resonator P1 in the comparative example.

[0102] like Figure 9 As shown, compared to the electric resistance of the parallel resonator located at the same position as the parallel resonator P1 in the comparative example, the electric resistance of the parallel resonator P1 in the elastic wave device 1 of the first embodiment is improved.

[0103] Next, in coordination Figure 10 This is the second example illustrating electrical resistance.

[0104] Figure 10 This is a second schematic diagram of the electrical resistance of the elastic wave device 1 described in the first embodiment and the comparative example.

[0105] The solid line represents the electrical withstand capability of the parallel resonator P3b of the elastic wave device 1 in the first embodiment. The dashed line represents the electrical withstand capability of the parallel resonator P1b in the comparative example.

[0106] like Figure 10 As shown, the electric resistance of the parallel resonator P3b in the first embodiment is slightly inferior to that of the parallel resonator P1b in the comparative example.

[0107] However, the parallel resonator P3b has sufficient electrical resistance to withstand simultaneous power supply with the series resonator S4. Furthermore, the parallel resonator P3b is positioned furthest from the transmitting terminal 502. Therefore, the parallel resonator P3b is less prone to damage than the parallel resonator P1b.

[0108] According to the first embodiment, the parallel resonator P3b is electrically connected to the receiving grounding pad GND-Rx. Therefore, a smaller elastic wave device 1 with better isolation characteristics can be provided.

[0109] Furthermore, the parallel resonator P3b is not electrically connected to the transmitting grounding pad GND-Tx. Therefore, the elastic wave device 1 can provide better isolation characteristics.

[0110] Furthermore, among the parallel resonators P1, P2, P3a, and P3b, the parallel resonator P3b is located furthest from the transmitting terminal 502. Therefore, the parallel resonator P3b is less prone to damage.

[0111] Furthermore, the parallel resonator P3b is one of the parallel resonators that are divided in parallel in the last segment of the transmitting filter 201. Therefore, the parallel resonator P3b is less prone to damage.

[0112] Furthermore, the capacitance value of the parallel resonator P3b is smaller than the average capacitance value of the parallel resonators P1, P2, P3a, and P3b. Therefore, the insertion loss of the transmitting filter 201 can be reduced.

[0113] Furthermore, the capacitance value of the parallel resonator P3b is the smallest among the capacitance values ​​of the parallel resonators P1, P2, P3a, and P3b. Therefore, the insertion loss of the transmitting filter 201 can be reduced.

[0114] Furthermore, the first parallel resonator P3b has a resonant frequency close to the highest frequency in the passband of the receiving filter 202. Therefore, it can provide an elastic wave device 1 with better isolation characteristics.

[0115] Furthermore, the substrate of the substrate 5 can be formed by bonding a piezoelectric substrate with sapphire, silicon, alumina, spinel, crystal, or glass. Therefore, an elastic wave device 1 with better temperature characteristics can be provided.

[0116] Furthermore, the sum of the areas of the first receiving ground electrode 305 and the second receiving ground electrode 405 is greater than the sum of the areas of the first transmitting ground electrode 304 and the second transmitting ground electrode 404. Therefore, when a Defected Microstrip Structure (DMS) filter is used as the receiving filter 202, the hierarchy of the receiving filter 202 can be appropriately designed.

[0117] (Second Embodiment)

[0118] Figure 11 This is a cross-sectional view of the module employing the elastic wave device 1 in the second embodiment. It should be noted that the same or equivalent parts as in the first embodiment use the same symbols, and descriptions of these same or equivalent parts will be omitted.

[0119] exist Figure 11 In the module 100, there are wiring board 130, several external connection terminals 131, integrated circuit component IC, elastic wave device 1, inductor 111, and sealing part 117.

[0120] The wiring substrate 130 is the same as the wiring substrate 3 in the first embodiment.

[0121] The external connection terminal 131 is formed on the lower side of the wiring substrate 130. The external connection terminal 131 is mounted on the main printed circuit board of a preset mobile communication terminal.

[0122] Not shown in the figure, the integrated circuit component IC is mounted inside the wiring substrate 130. The integrated circuit component IC includes switching circuitry and a low-noise amplifier.

[0123] The elastic wave device 1 is installed on the main surface of the wiring board 130.

[0124] The inductor 111 is mounted on the main surface of the wiring board 130. The inductor 111 is configured for impedance matching. The inductor 111 is, for example, an integrated passive device (IPD).

[0125] The sealing part 117 seals several electronic components, including the elastic wave device 1.

[0126] According to the second embodiment, the module 100 includes the elastic wave device 1. Therefore, a smaller module 100 with better isolation characteristics can be provided.

[0127] While at least one embodiment has been described above, it should be understood that various changes, modifications, or improvements will readily occur to those skilled in the art. Such changes, modifications, or improvements are intended to be part of this disclosure and are intended to fall within the scope of this disclosure.

[0128] It should be understood that the embodiments of the methods or apparatus described herein are not limited to the structure and arrangement of the constituent components described above or shown in the accompanying drawings. The methods and apparatus can be installed or performed in other embodiments.

[0129] The embodiments given herein are for illustrative purposes only and are not intended to be limiting.

[0130] The wording and terminology used in this disclosure are for illustrative purposes and should not be construed as limiting. The terms “comprising,” “possessing,” “having,” “including,” and variations thereof, as used herein, are intended to include the items listed below, their equivalents, and additional items.

[0131] A reference to “or” is that any term described using “or” can be interpreted as referring to one, more than one, or all of the terms described.

[0132] References to the elements in all directions (front, back, left, right, top, bottom, up, down, horizontal, vertical, table, inside) are for ease of description. These references are not intended to limit the position or spatial orientation of any component of this disclosure. Therefore, the above description and accompanying drawings are merely exemplary.

Claims

1. An elastic wave device, characterized in that: The elastic wave device includes a substrate, a transmitting filter formed on the substrate, a receiving filter formed on the substrate, a transmitting grounding pad of the transmitting filter formed on the substrate, and a receiving grounding pad of the receiving filter formed on the substrate. The transmitting filter includes a plurality of series resonators and a plurality of parallel resonators. One of the parallel resonators is electrically connected to the receiving grounding pad as a first parallel resonator. The first parallel resonator is one of the parallel resonators that are divided in parallel in the last section of the transmitting filter, and the first parallel resonator is located at the position farthest from the input terminal of the transmitting filter.

2. The elastic wave device according to claim 1, characterized in that: The first parallel resonator is not electrically connected to the transmitting grounding pad.

3. The elastic wave device according to claim 1, characterized in that: The capacitance value of the first parallel resonator is smaller than the average capacitance value of the parallel resonators.

4. The elastic wave device according to claim 1, characterized in that: The capacitance value of the first parallel resonator is the smallest among the capacitance values ​​of the parallel resonators.

5. The elastic wave device according to claim 1, characterized in that: The first parallel resonator has a resonant frequency that is close to the highest frequency of the passband of the receiving filter.

6. The elastic wave device according to claim 1, characterized in that: The substrate is formed by bonding a piezoelectric substrate with a support substrate made of one of sapphire, silicon, alumina, spinel, crystal and glass.

7. The elastic wave device according to claim 1, characterized in that: The elastic wave device further includes a transmitting ground electrode electrically connected to the transmitting ground pad and a receiving ground electrode electrically connected to the receiving ground pad, wherein the area of ​​the receiving ground electrode is larger than the area of ​​the transmitting ground electrode.

8. A module comprising the elastic wave device according to any one of claims 1 to 7.

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