A temperature-compensated surface acoustic wave filter device

Abstract

The present application provides a temperature-compensated surface acoustic wave filter device, comprising at least one series-arm resonator and at least one shunt-arm resonator; both the series-arm resonator and the shunt-arm resonator have a plurality of long finger electrodes, two bus bars, and two load structures; the bus bars include a first bus bar and a second bus bar that are oppositely arranged along a first direction; the plurality of long finger electrodes include a plurality of first long finger electrodes and a plurality of second long finger electrodes, both the first long finger electrodes and the second long finger electrodes extend along a second direction and are arranged along the first direction; the load structures include a first load structure and a second load structure, the coverage range of the first load structure at least includes one side of the effective aperture region close to the first bus bar, and the coverage range of the second load structure at least includes one side of the effective aperture region close to the second bus bar. The present invention can suppress the transverse parasitic mode while coupling it with the long finger electrodes, realize the high rectangularity and high out-of-band rejection of the filter, and achieve low loss in the passband.

Description

Technical Field

[0001] This application relates to the technical field of filters, and particularly to a temperature-compensated surface acoustic wave filter device. Background Art

[0002] In surface acoustic wave filter devices, means such as adjusting the width or thickness of interdigital electrodes are usually adopted to modify the frequency, bandwidth and loss of the filter. In these conventional methods, it is difficult to select a suitable electrode to simultaneously optimize the bandwidth and loss of the filter, and improve the rectangularity and out-of-band rejection.

[0003] Therefore, there is an urgent need for a temperature-compensated surface acoustic wave filter device that can suppress transverse parasitic modes while achieving high rectangularity, high out-of-band rejection and low passband loss of the filter. Summary of the Invention

[0004] This application provides a temperature-compensated surface acoustic wave filter device to solve the problem that effective suppression of transverse parasitic modes and high out-of-band rejection cannot be achieved simultaneously.

[0005] This application provides a temperature-compensated surface acoustic wave filter device, including at least one series-arm resonator and at least one shunt-arm resonator;

[0006] Both the series-arm resonator and the shunt-arm resonator have a plurality of long finger electrodes, two bus bars and two load structures;

[0007] The bus bar includes a first bus bar and a second bus bar oppositely arranged along the first direction X;

[0008] The plurality of long finger electrodes include a plurality of first long finger electrodes and a plurality of second long finger electrodes that are cross-arranged along the second direction Y. The first long finger electrodes and the second long finger electrodes both extend along the second direction Y and are arranged along the first direction X. The first long finger electrode has a first end and a second end, and the first end is connected to the first bus bar. The second long finger electrode has a third end and a fourth end, and the third end is connected to the second bus bar;

[0009] The load structure includes a first load structure and a second load structure. The coverage range of the first load structure at least includes one side of the effective aperture area close to the first bus bar, and the coverage range of the second load structure at least includes one side of the effective aperture area close to the second bus bar;

[0010] Along the first direction X, the distance between the central axes of any two adjacent long finger electrodes is a first distance P, and the first distance P is 0.5 times the surface acoustic wave wavelength λ; along the second direction Y, the maximum dimension of the first load structure is a first length M, and the maximum dimension of the second load structure is a second length N, where P ≤ M ≤ 3P and P ≤ N ≤ 3P;

[0011] The first direction X intersects with the second direction Y.

[0012] Preferably, the orthographic projection of the first load structure and the second load structure in the effective aperture region includes at least one rectangle, and the length of the rectangle is equal to the length of the bus bar along the first direction X. It can be understood that the orthographic projection of the first load structure and the second load structure in the effective aperture region can be multiple rectangles with the length equal to the length of the bus bar along the first direction X, or in addition to the rectangles with the length equal to the length of the bus bar along the first direction X, there are other deformations, such as adding parasitic rectangles. The embodiments of the present invention do not specifically limit the shapes and quantities of the first load structure and the second load structure.

[0013] Preferably, the aperture length of the effective aperture region is a first aperture L, and the relationship between the first aperture L and the first distance P is: 16P ≤ L ≤ 60P.

[0014] Preferably, the relationship between the first length M, the second length N and the first aperture L is: 0.25L ≤ M + N ≤ 0.4L.

[0015] Preferably, the width of the long finger electrode along the first direction X is a first width K, and the relationship between the first width K and the first distance P is: 0.3 ≤ K / P ≤ 0.8.

[0016] Preferably, along the second direction Y, the length that the long finger electrode extends is a third length J, and the difference between the third length J and the first aperture L is a first difference m, and the relationship between the first difference m and the first distance P is: 0.8P ≤ m ≤ 3P.

[0017] Preferably, the series arm resonator and the shunt arm resonator further include: a reflection grating region, and along the first direction X, the reflection grating region is at least located on one side of the long finger electrode;

[0018] The reflection grating region includes a plurality of reflection gratings, the reflection gratings extend along the second direction Y, and the plurality of reflection gratings are arranged along the first direction X.

[0019] Preferably, at least a part of the positive projection of the load structure on the substrate overlaps with the positive projection of the reflection grating region on the substrate, that is, along the first direction X, both the first load structure and the second load structure can extend to the reflection grating region.

[0020] Preferably, along the first direction X, the end of the load structure is aligned with the boundary of the reflection grating region, that is, both the first load structure and the second load structure can extend to the boundary of the reflection grating region.

[0021] The temperature-compensated surface acoustic wave filter device provided by the embodiment of the present invention includes at least one series-arm resonator and at least one shunt-arm resonator; both the series-arm resonator and the shunt-arm resonator have a plurality of long finger electrodes, two bus bars, and two load structures; the bus bars include a first bus bar and a second bus bar oppositely arranged along the first direction; the plurality of long finger electrodes include a plurality of first long finger electrodes and a plurality of second long finger electrodes cross-arranged along the second direction, and both the first long finger electrodes and the second long finger electrodes extend along the second direction and are arranged along the first direction; the load structures include a first load structure and a second load structure, the coverage range of the first load structure at least includes one side of the effective aperture region close to the first bus bar, and the coverage range of the second load structure at least includes one side of the effective aperture region close to the second bus bar. By providing the first load structure and the second load structure and coupling them with the long finger electrodes, the present invention can suppress the transverse parasitic mode while reducing the bandwidth of the resonator, increasing the out-of-band zeros of the filter, realizing the high rectangularity and high out-of-band suppression of the filter, and realizing low loss in the passband. Description of the Drawings

[0022] In order to more clearly illustrate the technical solutions in the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0023] Figure 1 is the circuit diagram of the temperature-compensated surface acoustic wave filter device provided by Embodiment 1 of the present application;

[0024] Figure 2 is the top view of the first type of elastic wave resonator in the temperature-compensated surface acoustic wave filter device provided by Embodiment 1 of the present application;

[0025] Figure 3 is the top view of the first type of elastic wave resonator in the temperature-compensated surface acoustic wave filter device provided by Embodiment 2 of the present application;

[0026] Figure 4It is a top view of the first type of elastic wave resonator of the temperature-compensated surface acoustic wave filter device provided in Embodiment 3 of the present application;

[0027] Figure 5 It is a top view of the first type of elastic wave resonator of the temperature-compensated surface acoustic wave filter device provided in Embodiment 4 of the present application;

[0028] Figure 6 It is a top view of the first type of elastic wave resonator of the temperature-compensated surface acoustic wave filter device provided in Embodiment 5 of the present application;

[0029] Figure 7 It is a diagram of the resonance characteristics of the surface acoustic wave resonator of the temperature-compensated surface acoustic wave resonator provided in Embodiment 1 of the present application and the reference example of the surface acoustic wave resonator with other loaded structures;

[0030] Figure 8(a) is a diagram of the S32 transmission characteristics of the transmit filter in Embodiment 1 of the present application and the comparative example;

[0031] Figure 8(b) is a diagram showing an enlarged view of the main part of Figure 8(a).

[0032] Symbol description:

[0033] 1: receiving terminal; 2: antenna terminal; 3: common connection point; 4: transmitting terminal; 11: transmit filter; 12: receive filter; S1, S2, S3, S4, S5: series-arm resonators; P1, P2, P3, P4: shunt-arm resonators; S102, S103, S104: series-arm resonators; P105, P106: shunt-arm resonators; 13: long finger electrode; 131: first long finger electrode; 132: second long finger electrode; 14: bus bar; 141: first bus bar; 142: second bus bar; 15: load structure; 151: first load structure; 152: second load structure; 16: reflection grating region. Detailed implementation manners

[0034] To make the objectives, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be clearly and completely described below with reference to the accompanying drawings in the present application. Apparently, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without making creative efforts shall fall within the protection scope of the present application.

[0035] The terms "first", "second", etc. in the description, claims and the above-mentioned drawings of the present application are used to distinguish similar objects and do not necessarily describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances so that the embodiments described herein can be implemented in an order other than that illustrated or described herein.

[0036] As Figure 1 shown is the circuit diagram of the temperature-compensated surface acoustic wave filter device provided in the first embodiment of the present application. The temperature-compensated surface acoustic wave filter device has an antenna terminal 2 connected to an antenna. The antenna terminal 2 is connected to a common connection point 3. A transmit filter 11 is connected between the common connection point 3 and a transmit terminal 4. A receive filter 12 is connected between the common connection point 3 and a receive terminal 1.

[0037] The transmit filter 11 has: a plurality of series-arm resonators S1, S2, S3, S4, S5 and shunt-arm resonators P1, P2, P3, P4.

[0038] The series-arm resonators S1, S2, S3, S4 and series-arm resonator S5 are arranged in sequence from the side of the transmit terminal 4 as Figure 1 shown.

[0039] The shunt-arm resonator P1 is connected between the connection point between the series-arm resonators S1 and S2 and the reference potential, and an inductor may also be connected between the shunt-arm resonator P1 and the reference potential, which is not shown in the drawings.

[0040] The shunt-arm resonator P2 is connected between the connection point between the series-arm resonators S2 and S3 and the reference potential, and an inductor may also be connected between the shunt-arm resonator P2 and the reference potential, which is not shown in the drawings.

[0041] The shunt-arm resonator P3 is connected between the connection point between the series-arm resonators S3 and S4 and the reference potential, and an inductor may also be connected between the shunt-arm resonator P3 and the reference potential, which is not shown in the drawings.

[0042] The shunt-arm resonator P4 is connected between the connection point between the series-arm resonators S4 and S5 and the reference potential, and an inductor may also be connected between the shunt-arm resonator P4 and the reference potential, which is not shown in the drawings.

[0043] The receive filter 12 is not particularly limited, but in this embodiment, it has a longitudinally coupled resonator type surface acoustic wave filter 101, series-arm resonators S102, S103, S104 and shunt-arm resonators P105, P106.

[0044] In the above-mentioned transmission filter 11, the series-arm resonators S1 to S5 and the shunt-arm resonators P1 to P4 are each constituted by an elastic-wave resonator.

[0045] Figure 2 is a top view of a first-type elastic-wave resonator in the temperature-compensated surface acoustic wave filter device provided in the first embodiment of the present application. In Figure 1 Among the series-arm resonators S1 to S5 and the shunt-arm resonators P1 to P4 shown, at least one series-arm resonator is Figure 2 the first-type elastic-wave resonator shown, and at least one shunt-arm resonator is Figure 2 the first-type elastic-wave resonator shown, whereby out-of-band rejection and transverse parasitic mode suppression can be effectively performed.

[0046] The first-type elastic-wave resonator has a plurality of long finger electrodes 13, two bus bars 14, and two load structures 15;

[0047] The bus bar 14 includes a first bus bar 141 and a second bus bar 142 that are oppositely arranged along the first direction X;

[0048] The plurality of long finger electrodes 13 includes a plurality of first long finger electrodes 131 and a plurality of second long finger electrodes 132 that are cross-arranged along the second direction Y. The first long finger electrodes 131 and the second long finger electrodes 132 both extend along the second direction Y and are arranged along the first direction X; the first long finger electrode 131 has a first end and a second end, and the first end is connected to the first bus bar 141; the second long finger electrode 132 has a third end and a fourth end, and the third end is connected to the second bus bar 142;

[0049] The load structure 15 includes a first load structure 151 and a second load structure 152. The coverage range of the first load structure 151 at least includes one side of the effective aperture region close to the first bus bar 141, and the coverage range of the second load structure 152 at least includes one side of the effective aperture region close to the second bus bar 142;

[0050] Along the first direction X, the distance between the central axes of any two adjacent long finger electrodes 13 is a first distance P (those skilled in the art refer to this distance as pitch). The first distance P is 0.5 times the surface acoustic wave wavelength λ; along the second direction Y, the maximum dimension of the first load structure 151 is a first length M, and the maximum dimension of the second load structure 152 is a second length N, where P ≤ M ≤ 3P and P ≤ N ≤ 3P;

[0051] The first direction X intersects with the second direction Y.

[0052] By providing the first load structure 151 and the second load structure 152 and coupling them with the long finger electrode 13, the present invention can reduce the bandwidth of the resonator while suppressing the lateral parasitic mode, increase the out-of-band zeros of the filter, achieve high rectangularity and high out-of-band rejection of the filter, and achieve low loss in the passband.

[0053] Preferably, the orthographic projections of the first load structure 151 and the second load structure 152 in the effective aperture region include two rectangles, and the length of the rectangle is equal to the length of the bus bar 14 along the first direction X. In this way, on the one hand, the setting method is simple, and on the other hand, the out-of-band rejection and the suppression of the lateral parasitic mode can be enhanced.

[0054] Preferably, the aperture length of the effective aperture region is the first aperture L, and the relationship between the first aperture L and the first distance P is: 16P ≤ L ≤ 60P, whereby effective out-of-band rejection and suppression of the lateral parasitic mode can be achieved.

[0055] Preferably, the relationship between the first length M, the second length N and the first aperture L is: 0.25L ≤ M + N ≤ 0.4L, whereby effective out-of-band rejection and suppression of the lateral parasitic mode can be achieved.

[0056] Preferably, the width of the long finger electrode 13 along the first direction X is the first width K, and the relationship between the first width K and the first distance P is: 0.3 ≤ K / P ≤ 0.8, whereby effective out-of-band rejection and suppression of the lateral parasitic mode can be achieved.

[0057] Preferably, along the second direction Y, the length of the long finger electrode 13 extending is the third length J, and the difference between the third length J and the first aperture L is the first difference m. The relationship between the first difference m and the first distance P is: 0.8P ≤ m ≤ 3P, whereby effective out-of-band rejection and suppression of the lateral parasitic mode can be achieved.

[0058] Preferably, the series arm resonator and the shunt arm resonator further include: a reflection grating region, which is at least located on one side of the long finger electrode 13 along the first direction X;

[0059] The reflection grating region 16 includes a plurality of reflection gratings. The reflection gratings extend along the second direction Y, and the plurality of reflection gratings are arranged along the first direction X. Increasing the reflection gratings can enhance the selectivity of the filter, expand the bandwidth of the filter, reduce the size of the filter, and improve the stability of the filter.

[0060] Preferably, at least a part of the positive projection of the load structure 15 on the substrate 1 overlaps with the positive projection of the reflection grating region 16 on the substrate 1, that is, along the first direction X, both the first load structure 151 and the second load structure 152 can extend to the reflection grating region 16. In this way, on the one hand, the setting method is simple, and on the other hand, the out-of-band suppression and the suppression of the transverse parasitic mode can be enhanced.

[0061] Preferably, along the first direction X, the end of the load structure 15 is aligned with the boundary of the reflection grating region 16. In this way, on the one hand, the setting method is simple, and on the other hand, the out-of-band suppression and the suppression of the transverse parasitic mode can be enhanced.

[0062] By providing the first load structure 151 and the second load structure 152, the present invention can achieve high rectangularity and high out-of-band suppression of the filter while suppressing the transverse parasitic mode, and achieve low loss in the passband.

[0063] Figure 3 It is a top view of the first type of elastic wave resonator of the temperature-compensated surface acoustic wave filter device provided in the second embodiment of the present application. The difference between the second embodiment and the first embodiment is that the positive projections of the first load structure 151 and the second load structure 152 in the effective aperture region include two regular rectangles and multiple parasitic rectangles. The length of the regular rectangle is equal to the length of the bus bar 14 along the first direction X. The parasitic rectangle overlaps with the positive projection of the bus bar 14 in the effective aperture region. The number of parasitic rectangles is twice the number of the long finger electrodes 13. The width of the parasitic rectangle along the first direction X is equal to the first width K. The regular rectangle close to the first bus bar 141 is the first regular rectangle. The sum of the lengths of the first regular rectangle and the parasitic rectangle along the second direction Y is the first length M. The regular rectangle close to the second bus bar 142 is the second regular rectangle. The sum of the lengths of the second regular rectangle and the parasitic rectangle along the second direction Y is the first length N. By adjusting the dimensions of the first load structure and the second load structure along the first direction X, the coupling degree between the first load structure and the second load structure and the long finger electrodes can be adjusted, so that the performance of the filter can be further improved, the bandwidth of the resonator can be reduced, the out-of-band zeros of the filter can be increased, and low loss, high rectangularity, and high out-of-band suppression can be achieved.

[0064] Figure 4It is a top view of the first type of elastic wave resonator of the temperature compensation type surface acoustic wave filter device provided in Embodiment 3 of the present application. The difference between Embodiment 3 and Embodiment 2 is that along the second direction Y, the parasitic rectangles are on both sides of the regular rectangle, and the number of parasitic rectangles is four times the number of the long finger electrodes 13. By adjusting the dimensions of the first load structure and the second load structure along the first direction X, the coupling degree between the first load structure and the second load structure and the long finger electrodes can be adjusted, so that the performance of the filter can be further improved, the bandwidth of the resonator can be reduced, the out-of-band zeros of the filter can be increased, and low loss, high rectangularity, and high out-of-band suppression can be achieved.

[0065] Figure 5 It is a top view of the first type of elastic wave resonator of the temperature compensation type surface acoustic wave filter device provided in Embodiment 4 of the present application. The difference between Embodiment 4 and Embodiment 1 is that along the first direction X, both the first load structure 151 and the second load structure 152 extend to the reflection grating region 16, and at least a part of the positive projection of the load structure 15 on the substrate 1 overlaps with the positive projection of the reflection grating region 16 on the substrate 1.

[0066] Figure 6 It is a top view of the first type of elastic wave resonator of the temperature compensation type surface acoustic wave filter device provided in Embodiment 5 of the present application. The difference between Embodiment 5 and Embodiment 2 is that along the first direction X, the ends of the load structure 15 are aligned with the boundaries of the reflection grating region 16, that is, both the first load structure 151 and the second load structure 152 extend to the boundaries of the reflection grating region 16.

[0067] Figure 7 It is a diagram of the resonance characteristics of the surface acoustic wave resonator of the temperature compensation type surface acoustic wave resonator provided in Embodiment 1 of the present application and the surface acoustic wave resonator of a reference example with other load structures loaded. Refer to Figure 7 , Figure 7 in which the abscissa represents frequency, Figure 7 and the ordinate represents admittance. The red curve represents the admittance curve of the surface acoustic wave resonator in the prior art, and the purple and blue curves represent the admittance curves of the surface acoustic wave resonator provided in this embodiment. Among them, in the embodiment represented by the purple curve, the dimensions of the first load structure and the second load structure along the second direction are larger than those in the embodiment represented by the blue curve. The left peak of the three curves is the resonance point, and the right peak is the anti-resonance point. From Figure 7It can be seen that the red curve is very smooth between the resonance point and the anti-resonance point, and only has the suppression effect on the transverse parasitic mode. In addition to the suppression effect on the transverse parasitic mode, the bandwidth of the resonator decreases as the sizes of the first load structure and the second load structure increase along the second direction, and additional zeros are generated near the resonance point, having a good out-of-band suppression effect.

[0068] FIG. 8(a) is a diagram of the S32 transmission characteristics of the transmit filter according to the first embodiment of the present application and the comparative example.

[0069] FIG. 8(b) is a diagram showing an enlarged view of the main part of FIG. 8(a). Referring to FIG. 8(b), the abscissa in FIG. 8(b) represents frequency, and the ordinate in FIG. 8(b) represents admittance. The red curve represents the admittance curve of the surface acoustic wave resonator in the prior art, and the blue curve represents the admittance curve of the surface acoustic wave resonator provided in this embodiment. The left peak in the red curve and the blue curve is the resonance point, and the right peak is the anti-resonance point. It can be seen from FIG. 8(b) that there are obvious transverse mode clutter between the resonance point and the anti-resonance point in the admittance curve of the surface acoustic wave resonator provided in the prior art, while the admittance curve obtained by using the surface acoustic wave resonator provided in this embodiment is very smooth between the resonance point and the anti-resonance point, and the transverse mode suppression effect is obvious, and there are obvious improvements in the margin of the left isolation degree and the overall suppression level.

[0070] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A temperature-compensated surface acoustic wave filter device, characterized in that: comprising at least one series arm resonator and at least one parallel arm resonator; The series arm resonator and the parallel arm resonator each have a plurality of long finger electrodes, two bus bars and two load structures; The bus bar comprises a first bus bar and a second bus bar which are arranged opposite to each other along a first direction X; The plurality of long finger electrodes include a plurality of first long finger electrodes and a plurality of second long finger electrodes arranged crosswise along a second direction Y, the first long finger electrodes and the second long finger electrodes both extend along the second direction Y and are arranged along the first direction X; the first long finger electrode has a first end and a second end, the first end is connected to the first bus bar; the second long finger electrode has a third end and a fourth end, the third end is connected to the second bus bar; The load structure includes a first load structure and a second load structure, the coverage of the first load structure at least includes a side of the effective aperture area close to the first bus bar, and the coverage of the second load structure at least includes a side of the effective aperture area close to the second bus bar; Along the first direction X, the distance between the central axes of any two adjacent long finger electrodes is a first distance P, and the first distance P is 0.5 times the wavelength λ of the surface acoustic wave; Along the second direction Y, the maximum dimension of the first load structure is a first length M, and the maximum dimension of the second load structure is a second length N, wherein P≤M≤3P, P≤N≤3P; The orthographic projections of the first load structure and the second load structure in the effective aperture region include two regular rectangles and a plurality of parasitic rectangles, wherein: The length of the conventional rectangle is equal to the length of the bus bar along the first direction X, the parasitic rectangle overlaps with the orthographic projection of the bus bar in the effective aperture area, and the number of the parasitic rectangles is twice the number of the long finger electrodes; or, Along the second direction Y, the parasitic rectangles are distributed on both sides of the conventional rectangle, and the number of the parasitic rectangles is four times the number of the long finger electrodes; The first direction X and the second direction Y intersect.

2. The temperature-compensated surface acoustic wave filter device according to claim 1, wherein: The orthographic projections of the first load structure and the second load structure in the effective aperture area at least include a rectangle, and the length of the rectangle is equal to the length of the bus bar along the first direction X.

3. The temperature-compensated surface acoustic wave filter device according to claim 1, wherein: The aperture length of the effective aperture area is a first aperture L, and the relationship between the first aperture L and the first distance P is: 16P≤L≤60P.

4. The temperature-compensated surface acoustic wave filter device according to claim 3, wherein: The relationship between the first length M, the second length N and the first aperture L is: 0.25L≤M+N≤0.4L.

5. The temperature-compensated surface acoustic wave filter device according to claim 1, wherein: The width of the long finger electrode along the first direction X is a first width K, and the relationship between the first width K and the first distance P is: 0.3≤K / P≤0.

8.

6. The temperature-compensated surface acoustic wave filter device according to claim 3, wherein: Along the second direction Y, the elongated length of the long finger electrode is a third length J, the difference between the third length J and the first aperture L is a first difference m, and the relationship between the first difference m and the first distance P is: 0.8P≤m≤3P.

7. The temperature-compensated surface acoustic wave filter device according to claim 1, wherein: The series arm resonator and the parallel arm resonator further include: a reflection grating region, along the first direction X, the reflection grating region is at least located on one side of the long finger electrode; The reflection grating region includes a plurality of reflection gratings, the reflection gratings extend along the second direction Y, and the plurality of reflection gratings are arranged along the first direction X.

8. The temperature-compensated surface acoustic wave filter device according to claim 7, wherein: A substrate is also included, and at least a portion of the orthographic projection of the load structure on the substrate overlaps with the orthographic projection of the reflective gate region on the substrate.

9. The temperature-compensated surface acoustic wave filter device according to claim 8, wherein: Along the first direction X, the end of the load structure is aligned with the boundary of the reflective grid region.

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