Transmission filter device, transmission filter circuit, and duplexer circuit

Abstract

The invention discloses a transmission filtering device, a transmission filter circuit and a duplexer circuit. The transmission filter circuit comprises at least one first bimodal surface acoustic wave filter. The bimodal surface acoustic wave filter can be equivalent to at least one series resonator and one parallel resonator. Therefore, by additionally arranging at least one first bimodal surface acoustic wave filter in the circuit, the area occupied by the first bimodal surface acoustic wave filter is smaller than that of an equivalent resonator on the premise of meeting the performance index of the filter, so that the circuit structure can be effectively simplified, and the chip size can be reduced.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a transmission filter device, a transmission filter circuit, and a duplexer circuit. Background Art

[0002] The RF front-end chips of wireless communication devices include power amplifiers, antenna switches, RF filters, multiplexers including duplexers, low noise amplifiers, etc. Among them, RF filters include surface acoustic wave (SAW) filters, bulk acoustic wave (BAW) filters, micro-electro-mechanical system (MEMS) filters, integrated passive devices (IPD) filters, etc.

[0003] As wireless communication technology gradually evolves, more and more frequency bands are used. Faced with the dual pressures of miniaturization of mobile terminal devices and cost reduction, the need to reduce chip size is imminent.

[0004] However, there are still many problems in the circuit design of the filter. Summary of the invention

[0005] The technical problem solved by the present invention is to provide a transmission filter device, a transmission filter circuit and a duplexer circuit to reduce the chip size.

[0006] In order to solve the above problems, the technical solution of the present invention provides a transmission filtering device for signal transmission, comprising: at least one first dual-mode surface acoustic wave filter.

[0007] Optionally, the first dual-mode surface acoustic wave filter includes a substrate and a piezoelectric layer located on the substrate, and the thermal conductivity of the material of the substrate is greater than the thermal conductivity of the material of the piezoelectric layer.

[0008] Optionally, the material of the substrate includes silicon, sapphire, spinel or silicon carbide.

[0009] Optionally, it also includes: a plurality of series resonators, wherein the plurality of series resonators are electrically connected to the first dual-mode surface acoustic wave filter.

[0010] Optionally, it also includes: a plurality of parallel resonators, wherein the plurality of parallel resonators are electrically connected to the first dual-mode surface acoustic wave filter.

[0011] Correspondingly, the technical solution of the present invention also provides a transmission filter circuit for signal transmission, comprising: at least one first dual-mode surface acoustic wave filter.

[0012] Optionally, the first end of the first dual-mode surface acoustic wave filter is electrically connected to the input end, and the second end of the first dual-mode surface acoustic wave filter is electrically connected to the output end.

[0013] Optionally, it also includes: a plurality of series resonators; the first end of the first dual-mode surface acoustic wave filter is electrically connected to one end of the series resonator, and the other end of the series resonator is electrically connected to the input end.

[0014] Optionally, it also includes: a plurality of series resonators; the second end of the first dual-mode surface acoustic wave filter is electrically connected to one end of the series resonator, and the other end of the series resonator is electrically connected to the output end.

[0015] Optionally, it also includes: a plurality of parallel resonators; one end of the parallel resonator is electrically connected to the first end of the first dual-mode surface acoustic wave filter and the input end, and the other end of the parallel resonator is grounded.

[0016] Optionally, it also includes: a plurality of parallel resonators; one end of the parallel resonator is electrically connected to the second end of the first dual-mode surface acoustic wave filter and the output end, and the other end of the parallel resonator is grounded.

[0017] Correspondingly, the technical solution of the present invention further provides a duplexer circuit, comprising: a transmitting filter circuit as described in any one of the technical solutions above.

[0018] Optionally, the duplexer circuit further includes: a receiving filter circuit for signal reception; wherein the transmitting filter circuit is electrically connected between the antenna end and the transmitting end; and the receiving filter circuit is electrically connected between the antenna end and the receiving end.

[0019] Optionally, the receiving filter circuit includes: a second dual-mode surface acoustic wave filter.

[0020] Compared with the prior art, the technical solution of the present invention has the following advantages:

[0021] In the transmission filter device of the technical solution of the present invention, since the dual-mode surface acoustic wave filter can be equivalent to at least one series resonator and one parallel resonator, by adding at least one of the first dual-mode surface acoustic wave filters in the circuit, under the premise of meeting the filter performance index, the area occupied by the first dual-mode surface acoustic wave filter is smaller than that of the equivalent resonator, so the circuit structure can be effectively simplified and the chip size can be reduced.

[0022] Furthermore, the material of the substrate includes silicon, sapphire, spinel or silicon carbide. Since the power tolerance requirement of the receiving filter is relatively low and the power tolerance requirement of the transmitting filter is relatively high, the existing dual-mode surface acoustic wave filter has relatively low power tolerance and is therefore often used in the receiving filter. In the embodiment of the present invention, by selecting a material with high thermal conductivity for the substrate, the substrate has good heat dissipation, and can effectively dissipate the heat generated in the transmitting filter device, so that the first dual-mode surface acoustic wave filter can be applied to the transmitting filter and has relatively high power tolerance.

[0023] In the transmitting filter circuit of the technical solution of the present invention, since the dual-mode surface acoustic wave filter can be equivalent to at least one series resonator and one parallel resonator, by adding at least one of the first dual-mode surface acoustic wave filters in the circuit, under the premise of meeting the filter performance index, the area occupied by the first dual-mode surface acoustic wave filter is smaller than that of the equivalent resonator, so the circuit structure can be effectively simplified and the chip size can be reduced.

[0024] In the duplexer circuit of the technical solution of the present invention, since the dual-mode surface acoustic wave filter can be equivalent to at least one series resonator and one parallel resonator, by adding at least one of the first dual-mode surface acoustic wave filters in the circuit, under the premise of meeting the filter performance index, the area occupied by the first dual-mode surface acoustic wave filter is smaller than that of the equivalent resonator, so the circuit structure can be effectively simplified and the chip size can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a circuit diagram of a transmit filter circuit;

[0026] Figure 2 is a schematic diagram of the structure of a transmitting filter device;

[0027] Figure 3 is a circuit diagram of a transmitting filter circuit in an embodiment of the present invention;

[0028] Figure 4 is a schematic structural diagram of a transmission filtering device in an embodiment of the present invention;

[0029] Figure 5 is a circuit diagram of a frequency division duplexer circuit in an embodiment of the present invention;

[0030] Figure 6 is a schematic structural diagram of a frequency division duplex device in an embodiment of the present invention;

[0031] Figure 7 is a circuit diagram of a time division duplexer circuit in an embodiment of the present invention;

[0032] Figure 8is a schematic structural diagram of a resonator in an embodiment of the present invention;

[0033] Fig. 9 Schematic diagram of the electrode structure in an embodiment of the present invention. DETAILED DESCRIPTION

[0034] As described in the background art, there are still many problems in the circuit design of the filter, which will be described in detail below with reference to the accompanying drawings.

[0035] Figure 1 is a circuit diagram of a transmit filter circuit; Figure 2 It is a structural diagram of a transmitting filtering device.

[0036] Please refer to Figure 1 and Figure 2 A transmission filter circuit for signal transmission includes: a plurality of series resonators 100 and a plurality of parallel resonators 101, one end of each of the parallel resonators 101 is electrically connected to one end of an adjacent series resonator 100, and the other end of each of the parallel resonators 101 is grounded.

[0037] In this embodiment, the transmission filter circuit adopts a ladder type circuit (Ladder Type), and the transmission filter circuit is composed of single-port resonators connected in series and parallel.

[0038] However, in order to meet the requirements of the transmission filter performance index, the transmission filter circuit usually needs to be composed of multiple stages of series resonators and parallel resonators, so the chip size is relatively large.

[0039] On this basis, the present invention provides a transmission filter device, a transmission filter circuit, and a duplexer circuit, wherein the dual-mode surface acoustic wave filter can be equivalent to at least one series resonator and one parallel resonator. Therefore, by adding at least one of the first dual-mode surface acoustic wave filters in the circuit, the area occupied by the first dual-mode surface acoustic wave filter is smaller than that of the equivalent resonator while meeting the filter performance index, thereby effectively simplifying the circuit structure and reducing the chip size.

[0040] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0041] Figure 3 is a circuit diagram of a transmitting filter circuit in an embodiment of the present invention; Figure 4 is a schematic structural diagram of a transmission filtering device in an embodiment of the present invention; Figure 8 is a schematic structural diagram of a resonator in an embodiment of the present invention; Fig. 9 Schematic diagram of the electrode structure in an embodiment of the present invention.

[0042] Please refer to Figure 3 and Figure 4 , a transmitting filter circuit for signal transmission, comprising: at least one first dual-mode surface acoustic wave filter 201 (Double Mode SAW, DMS).

[0043] Since the dual-mode surface acoustic wave filter can be equivalent to at least one series resonator and one parallel resonator, by adding at least one of the first dual-mode surface acoustic wave filters 201 in the circuit, under the premise of meeting the filter performance index, the first dual-mode surface acoustic wave filter 201 occupies a smaller area than the equivalent resonator, thereby effectively simplifying the circuit structure and reducing the chip size.

[0044] Please refer to Figure 8 In this embodiment, the first dual-mode surface acoustic wave filter 201 includes a substrate 200 and a piezoelectric layer 204 located on the substrate 200 , and the thermal conductivity of the material of the substrate 200 is greater than the thermal conductivity of the material of the piezoelectric layer 204 .

[0045] In this embodiment, the substrate 200 is made of a material including silicon, sapphire, spinel or silicon carbide.

[0046] Since the power tolerance requirement of the receiving filter is relatively low and the power tolerance requirement of the transmitting filter is relatively high, the existing dual-mode surface acoustic wave filter has relatively low power tolerance and is therefore often used in the receiving filter. In the embodiment of the present invention, by selecting a material with relatively high thermal conductivity for the substrate 200, the substrate 200 has good heat dissipation, and can effectively dissipate the heat generated in the transmitting filter circuit, so that the first dual-mode surface acoustic wave filter 201 can be applied to the transmitting filter and has relatively high power tolerance.

[0047] Please continue to refer to Figure 3 and Figure 4 In this embodiment, the first end of the first dual-mode surface acoustic wave filter 201 is electrically connected to the input end (including direct electrical connection or indirect electrical connection), and the second end of the first dual-mode surface acoustic wave filter 201 is electrically connected to the output end (including direct electrical connection or indirect electrical connection).

[0048] The transmission filter circuit further includes: at least one of a series resonator and a parallel resonator.

[0049] Please continue to refer to Figure 3 and Figure 4In this embodiment, the transmitting filter circuit also includes: a plurality of series resonators 202; the series resonators 202 are connected in series between the first end of the first dual-mode surface acoustic wave filter 201 and the input end, the first end of the first dual-mode surface acoustic wave filter 201 is electrically connected to one end of the series resonator 202, and the other end of the series resonator 202 is electrically connected to the input end; the series resonator 202 is connected in series between the second end of the first dual-mode surface acoustic wave filter 201 and the output end, the second end of the first dual-mode surface acoustic wave filter 201 is electrically connected to one end of the series resonator 202, and the other end of the series resonator 202 is electrically connected to the output end.

[0050] It should be noted that, in this embodiment, some of the series resonators 202 are connected in series between the first end and the input end of the first dual-mode surface acoustic wave filter 201, and another part of the series resonators 202 are connected in series between the second end and the output end of the first dual-mode surface acoustic wave filter 201.

[0051] Please continue to refer to Figure 3 and Figure 4 In this embodiment, the transmitting filter circuit further includes: a plurality of parallel resonators 203; the parallel resonators 203 are connected in parallel between the first end of the first dual-mode surface acoustic wave filter 201 and the input end, one end of the parallel resonator 203 is electrically connected to the first end of the first dual-mode surface acoustic wave filter 201 and the input end, and the other end of the parallel resonator 203 is grounded; the parallel resonator 203 is connected in parallel between the second end of the first dual-mode surface acoustic wave filter 201 and the output end, one end of the parallel resonator 203 is electrically connected to the second end of the first dual-mode surface acoustic wave filter 201 and the output end, and the other end of the parallel resonator 203 is grounded. It should be noted that the parallel resonator 203 can be directly grounded, or can be grounded after being electrically connected to the capacitor / inductor.

[0052] It should be noted that, in this embodiment, some of the parallel resonators 203 are connected in parallel between the first end and the input end of the first dual-mode surface acoustic wave filter 201, specifically, one end of the parallel resonator 203 is electrically connected between adjacent series resonators 202, and / or one end of the parallel resonator 203 is electrically connected between the series resonator 202 and the first dual-mode surface acoustic wave filter 201, and the other end of the parallel resonator is grounded; another part of the parallel resonators 203 are connected in parallel between the second end and the output end of the first dual-mode surface acoustic wave filter 201, specifically, one end of the parallel resonator 203 is electrically connected between adjacent series resonators 202, and / or one end of the parallel resonator 203 is electrically connected between the series resonator 202 and the first dual-mode surface acoustic wave filter 201, and the other end of the parallel resonator is grounded.

[0053] It should be noted that the series resonator 202 and the parallel resonator 203 are both surface acoustic wave resonators, and the series resonator 202, the parallel resonator 203 and the first dual-mode surface acoustic wave filter 201 are simultaneously formed by a synchronous process.

[0054] Please continue to refer to Figure 8 In this embodiment, the series resonator 202 and the parallel resonator 203 also include the substrate 200 and the piezoelectric layer 204, and the series resonator 202, the parallel resonator 203 and the first dual-mode surface acoustic wave filter 201 also include an intermediate layer 205 and an electrode structure 206. The intermediate layer 205 is located between the piezoelectric layer 204 and the substrate 200, the electrode structure 206 is located on the piezoelectric layer 204, and the piezoelectric layer 204 is located between the intermediate layer 205 and the electrode structure 206.

[0055] In this embodiment, the material of the intermediate layer 205 includes silicon dioxide, glass, silicon oxynitride, tantalum oxide, or a compound obtained by adding fluorine, carbon or boron to silicon dioxide, or any one of the materials having the above materials as main components.

[0056] In this embodiment, the material of the piezoelectric layer 204 includes: lithium tantalate, lithium niobate, lead zirconate titanate, lead magnesium niobate-lead titanate, aluminum nitride, aluminum nitride alloy, gallium nitride or zinc oxide.

[0057] Please refer to Fig. 9In this embodiment, the electrode structure includes: a first bus 2061 and a second bus 2062 arranged in parallel along a first direction X; a plurality of first electrode strips 2063 electrically connected to the first bus 2061, and the plurality of first electrode strips 2063 are arranged in parallel along a second direction Y, and the first direction X is perpendicular to the second direction Y; a plurality of second electrode strips 2064 electrically connected to the second bus 2062, and the plurality of second electrode strips 2064 are arranged in parallel along the second direction Y, the first electrode strips 2063 and the second electrode strips 2064 are staggered, and along the second direction Y, the first electrode strips 2063 and the second electrode strips 2064 have an overlapping area.

[0058] In this embodiment, the material of the electrode structure 206 includes but is not limited to one of the following: molybdenum, tungsten, copper, platinum, rhenium, osmium, iridium, tantalum, gold, and hafnium.

[0059] In other embodiments, the series resonator, the parallel resonator and the first dual-mode surface acoustic wave filter may also each include: a temperature compensation layer located on the piezoelectric layer, and the temperature compensation layer covers the electrode structure.

[0060] In other embodiments, in addition to using the heat dissipation approach of the substrate to meet the heat dissipation requirements of the transmitting filter circuit, the series resonator, the parallel resonator and the first dual-mode surface acoustic wave filter may not have the substrate, and other high-power-resistant structures may be used, with the piezoelectric layer 204 also serving as the substrate.

[0061] It should be noted that the number of the series resonators 202 and the parallel resonators 203 in the transmit filter circuit can be flexibly configured based on the actual application scenario of the chip.

[0062] In other embodiments, the transmit filter circuit may not be configured with the series resonator and the parallel resonator, and may only include at least one of the first dual-mode surface acoustic wave filters.

[0063] Please continue to refer to Figure 3 and Figure 4 In this embodiment, only one of the first dual-mode surface acoustic wave filters 201 is shown to be electrically connected to a plurality of the series resonators 202 .

[0064] In other embodiments, the number of the first dual-mode surface acoustic wave filters may be greater than one. When the number of the first dual-mode surface acoustic wave filters is greater than one, a plurality of the first dual-mode surface acoustic wave filters may be connected in series or in parallel.

[0065] Correspondingly, the embodiment of the present invention further provides a transmission filtering device for signal transmission, please continue to refer to Figure 3 and Figure 4 , including: at least one first dual-mode surface acoustic wave filter 201 (Double Mode SAW, DMS).

[0066] Since the dual-mode surface acoustic wave filter can be equivalent to at least one series resonator and one parallel resonator, by adding at least one of the first dual-mode surface acoustic wave filters 201 in the circuit, under the premise of meeting the filter performance index, the first dual-mode surface acoustic wave filter 201 occupies a smaller area than the equivalent resonator, thereby effectively simplifying the circuit structure and reducing the chip size.

[0067] Please continue to refer to Figure 8 In this embodiment, the first dual-mode surface acoustic wave filter 201 includes a substrate 200 and a piezoelectric layer 204 located on the substrate 200 , and the thermal conductivity of the material of the substrate 200 is greater than the thermal conductivity of the material of the piezoelectric layer 204 .

[0068] In this embodiment, the substrate 200 is made of a material including silicon, sapphire, spinel or silicon carbide.

[0069] Since the power tolerance requirement of the receiving filter is relatively low and the power tolerance requirement of the transmitting filter is relatively high, the existing dual-mode surface acoustic wave filter has relatively low power tolerance and is therefore often used in the receiving filter. In the embodiment of the present invention, by selecting a material with relatively high thermal conductivity for the substrate 200, the substrate 200 has good heat dissipation, and can effectively dissipate the heat generated in the transmitting filter device, so that the first dual-mode surface acoustic wave filter 201 can be applied to the transmitting filter and has relatively high power tolerance.

[0070] Please continue to refer to Figure 3 and Figure 4 In this embodiment, the transmission filter device further includes: a plurality of series resonators 202, which are electrically connected to the first dual-mode surface acoustic wave filter 201; and a plurality of parallel resonators 203, one end of each parallel resonator 203 being electrically connected to the adjacent series resonator 202 or the first dual-mode surface acoustic wave filter 201, and the other end of each parallel resonator 203 being grounded. It should be noted that the parallel resonator 203 can be directly grounded, or can be grounded after being electrically connected to a capacitor / inductor.

[0071] It should be noted that the series resonator 202 and the parallel resonator 203 are both surface acoustic wave resonators, and the series resonator 202, the parallel resonator 203 and the first dual-mode surface acoustic wave filter 201 are simultaneously formed by a synchronous process.

[0072] Please continue to refer to Figure 8 In this embodiment, the series resonator 202 and the parallel resonator 203 also include the substrate 200 and the piezoelectric layer 204, and the series resonator 202, the parallel resonator 203 and the first dual-mode surface acoustic wave filter 201 also include an intermediate layer 205 and an electrode structure 206. The intermediate layer 205 is located between the piezoelectric layer 204 and the substrate 200, the electrode structure 206 is located on the piezoelectric layer 204, and the piezoelectric layer 204 is located between the intermediate layer 205 and the electrode structure 206.

[0073] In this embodiment, the material of the intermediate layer 205 includes silicon dioxide, glass, silicon oxynitride, tantalum oxide, or a compound obtained by adding fluorine, carbon or boron to silicon dioxide, or any one of the materials having the above materials as main components.

[0074] In this embodiment, the material of the piezoelectric layer 204 includes: lithium tantalate, lithium niobate, lead zirconate titanate, lead magnesium niobate-lead titanate, aluminum nitride, aluminum nitride alloy, gallium nitride or zinc oxide.

[0075] Please continue to refer to Fig. 9 In this embodiment, the electrode structure includes: a first bus 2061 and a second bus 2062 arranged in parallel along a first direction X; a plurality of first electrode strips 2063 electrically connected to the first bus 2061, and the plurality of first electrode strips 2063 are arranged in parallel along a second direction Y, and the first direction X is perpendicular to the second direction Y; a plurality of second electrode strips 2064 electrically connected to the second bus 2062, and the plurality of second electrode strips 2064 are arranged in parallel along the second direction Y, the first electrode strips 2063 and the second electrode strips 2064 are staggered, and along the second direction Y, the first electrode strips 2063 and the second electrode strips 2064 have an overlapping area.

[0076] In this embodiment, the material of the electrode structure 206 includes but is not limited to one of the following: molybdenum, tungsten, copper, platinum, rhenium, osmium, iridium, tantalum, gold, and hafnium.

[0077] In other embodiments, the series resonator, the parallel resonator and the first dual-mode surface acoustic wave filter may also each include: a temperature compensation layer located on the piezoelectric layer, and the temperature compensation layer covers the electrode structure.

[0078] In other embodiments, in addition to using the heat dissipation approach of the substrate to meet the heat dissipation requirements of the transmitting filter device, the series resonator, the parallel resonator and the first dual-mode surface acoustic wave filter may not have the substrate, and other high-power-resistant structures may be used, with the piezoelectric layer 204 also serving as the substrate.

[0079] It should be noted that the number of the series resonators 202 and the parallel resonators 203 in the transmitting filter device can be flexibly configured based on the actual application scenario of the chip.

[0080] In other embodiments, the transmission filtering device may also only include: a plurality of series resonators, and the plurality of series resonators are electrically connected to the first dual-mode surface acoustic wave filter.

[0081] In other embodiments, the transmission filtering device may also only include: a plurality of parallel resonators, and the plurality of parallel resonators are electrically connected to the first dual-mode surface acoustic wave filter.

[0082] In other embodiments, the transmission filtering device may not be configured with the series resonator and the parallel resonator, and only includes at least one of the first dual-mode surface acoustic wave filters.

[0083] Please continue to refer to Figure 3 and Figure 4 In this embodiment, only one of the first dual-mode surface acoustic wave filters 201 is shown to be electrically connected to a plurality of the series resonators 202 .

[0084] In other embodiments, the number of the first dual-mode surface acoustic wave filters may be greater than one. When the number of the first dual-mode surface acoustic wave filters is greater than one, a plurality of the first dual-mode surface acoustic wave filters may be connected in series or in parallel.

[0085] Figure 5 is a circuit diagram of a frequency division duplexer circuit in an embodiment of the present invention; Figure 6 is a schematic structural diagram of a frequency division duplex device in an embodiment of the present invention; Figure 7 is a circuit diagram of a time division duplexer circuit in an embodiment of the present invention.

[0086] Accordingly, the present invention also provides a duplexer circuit and a duplexer device, please continue to refer to Figure 3 and Figure 4 The duplexer circuit includes a transmitting filter circuit as described in any one of the above embodiments, and the duplexer device includes a transmitting filter device as described in any one of the above embodiments.

[0087] Since the dual-mode surface acoustic wave filter can be equivalent to at least one series resonator and one parallel resonator, by adding at least one of the first dual-mode surface acoustic wave filters 201 in the circuit, under the premise of meeting the filter performance index, the first dual-mode surface acoustic wave filter 201 occupies a smaller area than the equivalent resonator, thereby effectively simplifying the circuit structure and reducing the chip size.

[0088] Please continue to refer to Figure 8 In this embodiment, the first dual-mode surface acoustic wave filter 201 includes a substrate 200 and a piezoelectric layer 204 located on the substrate 200 , and the thermal conductivity of the material of the substrate 200 is greater than the thermal conductivity of the material of the piezoelectric layer 204 .

[0089] In this embodiment, the substrate 200 is made of a material including silicon, sapphire, spinel or silicon carbide.

[0090] Since the power tolerance requirement of the receiving filter is relatively low and the power tolerance requirement of the transmitting filter is relatively high, the existing dual-mode surface acoustic wave filter has relatively low power tolerance and is therefore often used in the receiving filter. In the embodiment of the present invention, by selecting a material with relatively high thermal conductivity for the substrate 200, the substrate 200 has good heat dissipation, and can effectively dissipate the heat generated in the transmitting filter device, so that the first dual-mode surface acoustic wave filter 201 can be applied to the transmitting filter and has relatively high power tolerance.

[0091] Please refer to Figure 5 In one embodiment, the duplexer circuit is a frequency division duplexer circuit, a transmitting frequency band and a receiving frequency band in the frequency division duplexer circuit are in different ranges, and the transmitting filter circuit is used for signal transmission.

[0092] Please refer to Figure 6 In one embodiment, the duplex device is a frequency division duplex device, including a transmitting filter device I, the transmitting frequency band and the receiving frequency band in the frequency division duplex device are different in range, and the transmitting filter device I is used for signal transmission.

[0093] Please continue to refer to Figure 5 In this embodiment, the frequency division duplexer circuit also includes: a receiving filter circuit, which is used to receive signals; wherein the transmitting filter circuit is electrically connected between the antenna terminal ANT and the transmitting terminal Tx, wherein the input end of the transmitting filter circuit is electrically connected to the transmitting terminal Tx, and the output end of the transmitting filter circuit is electrically connected to the antenna terminal ANT; the receiving filter circuit is electrically connected between the antenna terminal ANT and the receiving terminal Rx.

[0094] Please continue to refer to Figure 6In this embodiment, the frequency division duplex device also includes: a receiving filter device II, and the receiving filter device II is used to receive signals; wherein the transmitting filter device I is electrically connected between the antenna terminal ANT (not shown) and the transmitting terminal Tx (not shown); the receiving filter device II is electrically connected between the antenna terminal ANT and the receiving terminal Rx.

[0095] Please continue to refer to Figure 5 and Figure 6 In this embodiment, the receiving filter circuit includes: at least one second dual-mode surface acoustic wave filter 300.

[0096] Please continue to refer to Figure 5 and Figure 6 In this embodiment, the receiving filter circuit further includes: a plurality of receiving series resonators 301, which are electrically connected to the second dual-mode surface acoustic wave filter 300; and a plurality of receiving parallel resonators 302, one end of each receiving parallel resonator 302 is electrically connected to the adjacent receiving series resonator 301 or the second dual-mode surface acoustic wave filter 300, and the other end of each receiving parallel resonator 302 is grounded. It should be noted that the receiving parallel resonator 302 can be directly grounded, or can be grounded after being electrically connected to a capacitor / inductor.

[0097] It should be noted that the receiving series resonator 301 and the receiving parallel resonator 302 are both surface acoustic wave resonators, and the receiving series resonator 301, the receiving parallel resonator 302 and the second dual-mode surface acoustic wave filter 300 are simultaneously formed using a synchronous process.

[0098] In this embodiment, the receiving series resonator 301, the receiving parallel resonator 302 and the second dual-mode surface acoustic wave filter 300 also include the substrate 200, the intermediate layer 205, the piezoelectric layer 204, and the electrode structure 206. For details, please refer to Figure 8 and Fig. 9 And related instructions will not be repeated here.

[0099] In other embodiments, in addition to using the heat dissipation approach of the substrate to meet the heat dissipation requirements of the transmitting filter circuit, the receiving series resonator, the receiving parallel resonator, the first dual-mode surface acoustic wave filter, the receiving series resonator, the receiving parallel resonator and the second dual-mode surface acoustic wave filter may not have the substrate, and use other high-power-resistant structures, with the piezoelectric layer 204 also serving as the substrate.

[0100] It should be noted that the number of the receiving series resonators 301 and the receiving parallel resonators 302 in the receiving filter circuit can be flexibly configured based on the actual application scenario of the chip.

[0101] In other embodiments, the receiving filter circuit may also only include: a plurality of receiving series resonators, and the plurality of receiving series resonators are electrically connected to the second dual-mode surface acoustic wave filter.

[0102] In other embodiments, the receiving filter circuit may also only include: a plurality of receiving parallel resonators, and the plurality of receiving parallel resonators are electrically connected to the second dual-mode surface acoustic wave filter.

[0103] In other embodiments, the receiving filter circuit may not be configured with the receiving series resonator and the receiving parallel resonator, and only includes at least one of the second dual-mode surface acoustic wave filters.

[0104] Please continue to refer to Figure 5 and Figure 6 In this embodiment, only one of the second dual-mode surface acoustic wave filters is shown to be electrically connected to a plurality of the receiving series resonators.

[0105] In other embodiments, the number of the second dual-mode surface acoustic wave filters may be greater than one. When the number of the second dual-mode surface acoustic wave filters is greater than one, a plurality of the second dual-mode surface acoustic wave filters may be connected in series or in parallel.

[0106] Please refer to Figure 7 In one embodiment, the duplexer circuit is a time division duplexer circuit, a transmitting frequency band and a receiving frequency band in the time division duplexer circuit are in the same range, and the transmitting filter circuit is used for receiving signals and transmitting signals.

[0107] Please continue to refer to Figure 4 In one embodiment, the duplex device is a time division duplex device, the transmitting frequency band and the receiving frequency band in the time division duplex device are in the same range, and the transmitting filter device I is used for receiving signals and transmitting signals.

[0108] Please continue to refer to Figure 7 In this embodiment, the transmitting filter circuit includes an input terminal IN and an output terminal OUT.

[0109] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A transmission filtering device, used for signal transmission, characterized in that: include: At least one first dual-mode surface acoustic wave filter.

2. The transmission filter device according to claim 1, characterized in that: The first dual-mode surface acoustic wave filter includes a substrate and a piezoelectric layer located on the substrate, and the thermal conductivity of the material of the substrate is greater than the thermal conductivity of the material of the piezoelectric layer.

3. The transmission filter device according to claim 2, characterized in that: The material of the substrate includes silicon, sapphire, spinel or silicon carbide.

4. The transmission filter device according to claim 1, characterized in that: Also includes: A plurality of series resonators are electrically connected to the first dual-mode surface acoustic wave filter.

5. The transmission filter device according to claim 1, characterized in that: Also includes: A plurality of parallel resonators are electrically connected to the first dual-mode surface acoustic wave filter.

6. A transmission filter circuit for signal transmission, characterized in that: include: At least one first dual-mode surface acoustic wave filter.

7. The transmission filter circuit according to claim 6, wherein: The first end of the first dual-mode surface acoustic wave filter is electrically connected to the input end, and the second end of the first dual-mode surface acoustic wave filter is electrically connected to the output end.

8. The transmission filter circuit according to claim 7, wherein: Also includes: A plurality of series resonators; a first end of the first dual-mode surface acoustic wave filter is electrically connected to one end of the series resonator, and the other end of the series resonator is electrically connected to the input end.

9. The transmission filter circuit according to claim 7, wherein: Also includes: A plurality of series resonators; the second end of the first dual-mode surface acoustic wave filter is electrically connected to one end of the series resonator, and the other end of the series resonator is electrically connected to the output end.

10. The transmission filter circuit according to claim 7, wherein: Also includes: A plurality of parallel resonators; one end of the parallel resonator is electrically connected to the first end of the first dual-mode surface acoustic wave filter and the input end, and the other end of the parallel resonator is grounded.

11. The transmission filter circuit according to claim 7, wherein: Also includes: A plurality of parallel resonators; one end of the parallel resonator is electrically connected to the second end of the first dual-mode surface acoustic wave filter and the output end, and the other end of the parallel resonator is grounded.

12. A duplexer circuit, characterized in that: include: A transmission filter circuit as claimed in any one of claims 6 to 11.

13. The duplexer circuit according to claim 12, wherein: The duplexer circuit further includes: a receiving filter circuit for signal reception; wherein the transmitting filter circuit is electrically connected between the antenna end and the transmitting end; and the receiving filter circuit is electrically connected between the antenna end and the receiving end.

14. The duplexer circuit according to claim 13, wherein: The receiving filter circuit includes: a second dual-mode surface acoustic wave filter.

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