Bandpass filter and electronic device

Abstract

The present invention provides a bandpass filter and an electronic device, the bandpass filter comprises a substrate, a first-order resonator and a second-order resonator arranged inside the substrate, and an input end and an output end respectively arranged at two ends of the substrate; the first-order resonator is located above the second-order resonator in the height direction of the substrate and the first-order resonator and the second-order resonator are partially cross-coupled; the first-order resonator and the second-order resonator both comprise a first compensation stripline, a main resonant stripline and a second compensation stripline, the first compensation stripline, the main resonant stripline and the second compensation stripline are sequentially arranged at intervals along the height direction of the substrate, and the main resonant stripline is U-shaped. Compared with the prior art, the bandpass filter of the present invention can maximize the use of the internal space of the bandpass filter, which is conducive to realizing the miniaturization design of the filter.

Description

Technical Field

[0001] The present invention belongs to the technical field of filters, and more specifically, relates to a bandpass filter and electronic equipment. Background Art

[0002] With the development of informatization in modern society, wireless communication technology has been widely used in all walks of life, and new communication standards and formats have emerged one after another. The application in multiple fields and the increasingly tight spectrum resources have also prompted the continuous innovation of wireless communication technology, and the RF communication system has been developing in the direction of miniaturization and high performance. As a key component in the RF communication system, the size reduction of the filter has always been a research hotspot in modern RF communication systems. However, it is difficult to further miniaturize the existing filters. Summary of the invention

[0003] The purpose of the embodiments of the present invention is to provide a bandpass filter to solve the technical problem in the prior art that the filter is difficult to miniaturize.

[0004] To achieve the above object, the technical solution adopted by the present invention is: to provide a bandpass filter, comprising a substrate, a first-order resonator and a second-order resonator arranged inside the substrate, and an input end and an output end respectively arranged at two ends of the substrate;

[0005] The first-order resonator is located above the second-order resonator in the height direction of the substrate and the first-order resonator and the second-order resonator are partially cross-coupled;

[0006] The first-order resonator and the second-order resonator each include a first compensation stripline, a main resonant stripline and a second compensation stripline, wherein the first compensation stripline, the main resonant stripline and the second compensation stripline are sequentially arranged at intervals along the height direction of the substrate, and the main resonant stripline is U-shaped;

[0007] One end of the first compensation stripline is grounded, and the other end is suspended; both ends of the main resonant stripline are suspended, and the main resonant stripline of the first-order resonator is connected to the input end, and the main resonant stripline of the second-order resonator is connected to the output end; one end of the second compensation stripline is grounded, and the other end is suspended.

[0008] In one embodiment, the main resonant strip line includes a first connecting section, a second connecting section and a third connecting section connected in sequence, and the first connecting section and the third connecting section are parallel to each other;

[0009] The second connection segment of the main resonant stripline of the first-order resonator intersects with the third connection segment of the main resonant stripline of the second-order resonator, and the third connection segment of the main resonant stripline of the first-order resonator intersects with the second connection segment of the main resonant stripline of the second-order resonator.

[0010] In one embodiment, the first-order resonator and the second-order resonator each include two first compensation striplines and two second compensation striplines; in each of the main resonant striplines, the first connecting section and the third connecting section are respectively arranged opposite to the corresponding first compensation stripline, and the first connecting section and the third connecting section are respectively arranged opposite to the corresponding second compensation stripline.

[0011] In one embodiment, a distance between the first compensation stripline and the main resonant stripline is less than or equal to 0.06 mm, and a distance between the second compensation stripline and the main resonant stripline is less than or equal to 0.06 mm.

[0012] In one embodiment, the bandpass filter includes a first tap connecting a main resonant stripline of the first-order resonator to the input end and a second tap connecting a main resonant stripline of the second-order resonator to the output end.

[0013] In one embodiment, a projection of the input end, the first tap, and the first-order resonator in the height direction of the substrate is centrally symmetric to a projection of the output end, the second tap, and the second-order resonator in the height direction of the substrate.

[0014] In one embodiment, the first tap is a single-layer folded stripline, and the second tap is a single-layer folded stripline.

[0015] In one embodiment, the bandpass filter further includes two side grounding plates arranged on the left and right sides of the substrate, one end of the first compensation stripline grounding is connected to the corresponding side grounding plate, and one end of the second compensation stripline grounding is connected to the corresponding side grounding plate.

[0016] In one embodiment, the bandpass filter further comprises an upper ground plate disposed on the upper side of the substrate and a lower ground plate disposed on the lower side of the substrate.

[0017] The present invention also provides an electronic device, comprising the bandpass filter as described above.

[0018] The beneficial effects of the bandpass filter and the electronic device provided by the present invention are as follows: compared with the prior art, the first-order resonator and the second-order resonator of the bandpass filter of the present invention both include a first compensation stripline, a main resonant stripline and a second compensation stripline, and by respectively arranging the first compensation stripline and the second compensation stripline on the upper and lower sides of the main resonant stripline, the parallel plate capacitors formed by the first compensation stripline and the second compensation stripline respectively coupling with the main resonant stripline are equivalently loaded on the main resonant stripline, providing compensation capacitance for the first-order resonator and the second-order resonator, increasing the electrical length of the first-order resonator and the second-order resonator, effectively reducing the physical length of the first-order resonator and the second-order resonator, and realizing the miniaturization design of the filter; in addition, the main resonant stripline is U-shaped, and by arranging the main resonant stripline to be in a bent shape, the physical length of the main resonant stripline can be guaranteed, so that the internal space of the bandpass filter can be maximized, which is conducive to realizing the miniaturization design of the filter.

[0019] The electronic device of the present invention is advantageously designed to be miniaturized by adopting the above-mentioned bandpass filter. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0021] Figure 1 A schematic diagram of a three-dimensional perspective structure of a bandpass filter provided by an embodiment of the present invention;

[0022] Figure 2 A schematic diagram of an exploded perspective structure of a bandpass filter provided by an embodiment of the present invention;

[0023] Figure 3 A schematic diagram of the three-dimensional structure of a first-order resonator provided in an embodiment of the present invention;

[0024] Figure 4 A schematic diagram of the front view structure of a bandpass filter provided by an embodiment of the present invention;

[0025] Figure 5 A schematic diagram of a top view of the structure of a bandpass filter provided by an embodiment of the present invention;

[0026] Figure 6 An equivalent circuit diagram of a bandpass filter provided by an embodiment of the present invention;

[0027] Figure 7 A diagram showing simulation results of a bandpass filter provided in an embodiment of the present invention.

[0028] Among them, the reference numerals in the figure are:

[0029] 100-substrate; 210-first-order resonator; 220-second-order resonator; 230-first compensation stripline; 240-main resonant stripline; 241-first connecting section; 242-second connecting section; 243-third connecting section; 250-second compensation stripline; 310-input end; 320-output end; 410-first tap; 420-second tap; 500-side grounding plate; 610-upper grounding plate; 611-upper notch; 612-upper bonding slot; 620-lower grounding plate; 621-lower notch; 622-lower bonding slot. DETAILED DESCRIPTION

[0030] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0031] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0032] It should be understood that the orientation or position relationship indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0033] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0034] See also Figures 1 to 3An embodiment of the present invention provides a bandpass filter, including a substrate 100, a first-order resonator 210, a second-order resonator 220, an input end 310 and an output end 320, wherein the first-order resonator 210 and the second-order resonator 220 are arranged inside the substrate 100, and the input end 310 and the output end 320 are respectively arranged at the input end 310 and the output end 320 at both ends of the substrate 100. Specifically, the first-order resonator 210 is located above the second-order resonator 220 in the height direction of the substrate 100, and the first-order resonator 210 and the second-order resonator 220 are partially cross-coupled; the first-order resonator 210 and the second-order resonator 220 both include a first compensation stripline 230, a main resonant stripline 240 and a second compensation stripline 250, and the first compensation stripline 230, the main resonant stripline 240 and the second compensation stripline 250 are arranged in sequence along the height direction of the substrate 100, and the main resonant stripline 240 is U-shaped; one end of the first compensation stripline 230 is grounded, and the other end is suspended; both ends of the main resonant stripline 240 are suspended, and the main resonant stripline 240 of the first-order resonator 210 is connected to the input end 310, and the main resonant stripline 240 of the second-order resonator 220 is connected to the output end 320; one end of the second compensation stripline 250 is grounded, and the other end is suspended. The bandpass filter of the embodiment of the present invention includes a first-order resonator 210 and a second-order resonator 220, that is, the bandpass filter is a second-order bandpass filter. Of course, according to the actual situation and specific needs, the bandpass filter can also include more resonators, which is not limited here.

[0035] The beneficial effects of the bandpass filter of the embodiment of the present invention are:

[0036] (1) Compared with the prior art, in the bandpass filter of the embodiment of the present invention, the first-order resonator 210 and the second-order resonator 220 both include a first compensation stripline 230, a main resonant stripline 240 and a second compensation stripline 250. By arranging the first compensation stripline 230 and the second compensation stripline 250 on the upper and lower sides of the main resonant stripline 240, respectively, the parallel plate capacitors formed by the first compensation stripline 230 and the second compensation stripline 250 respectively coupling with the main resonant stripline 240 are equivalently loaded on the main resonant stripline 240, providing compensation capacitance for the first-order resonator 210 and the second-order resonator 220, increasing the electrical length of the first-order resonator 210 and the second-order resonator 220, effectively reducing the physical length of the first-order resonator 210 and the second-order resonator 220, and realizing the miniaturization design of the filter;

[0037] (2) The main resonant stripline 240 is U-shaped. By setting the main resonant stripline 240 to a bent shape, the physical length of the main resonant stripline 240 can be guaranteed, so that the internal space of the bandpass filter can be maximized, which is conducive to realizing the miniaturization design of the filter.

[0038] Further, as a specific embodiment of the present invention, in the bandpass filter of the embodiment of the present invention, an upper plane and a lower plane are provided in the substrate 100, wherein the upper plane is located above the lower plane in the height direction of the substrate 100, the first-order resonator 210 is located on the upper plane, the second-order resonator 220 is located on the lower plane, and the first-order resonator 210 and the second-order resonator 220 are arranged at intervals in the height direction of the substrate 100, so that the first-order resonator 210 and the second-order resonator 220 do not intersect in a direction perpendicular to the straight line of the height direction of the substrate 100, and the first-order resonator 210 and the second-order resonator 220 only intersect in the height direction of the substrate 100.

[0039] Further, as a specific embodiment of the present invention, please refer to Figure 3 , while combining Figure 2 The first-order resonator 210 and the second-order resonator 220 have the same structure. The main resonant stripline 240 includes a first connecting section 241, a second connecting section 242 and a third connecting section 243 connected in sequence. The first connecting section 241 and the third connecting section 243 are parallel to each other. The second connecting section 242 of the main resonant stripline 240 of the first-order resonator 210 and the third connecting section 243 of the main resonant stripline 240 of the second-order resonator 220 are intersected, and the third connecting section 243 of the main resonant stripline 240 of the first-order resonator 210 and the second connecting section 242 of the main resonant stripline 240 of the second-order resonator 220 are intersected, so that the first-order resonator 210 and the second-order resonator 220 are partially cross-coupled in the height direction of the substrate 100.

[0040] Further, as a specific embodiment of the present invention, please refer to Figure 3 and Figure 4, the first-order resonator 210 and the second-order resonator 220 each include two first compensation striplines 230 and two second compensation striplines 250; in each main resonant stripline 240, the first connecting section 241 and the third connecting section 243 are respectively arranged opposite to the corresponding first compensation stripline 230, and the first connecting section 241 and the third connecting section 243 are respectively arranged opposite to the corresponding second compensation stripline 250. Through the above arrangement, a parallel plate capacitor equivalently loaded on the main resonant stripline 240 is formed between the first connecting section 241 and the first compensation stripline 230 above it, between the first connecting section 241 and the second compensation stripline 250 below it, between the third connecting section 243 arranged oppositely and the first compensation stripline 230 above it, and between the third connecting section 243 arranged oppositely and the second compensation stripline 250 below it, so as to provide a large-capacitance compensation capacitor for the resonator, increase the electrical length of the resonator, reduce the resonant frequency of the resonator, and greatly reduce the physical size of the resonator, which is conducive to the miniaturization design of the filter.

[0041] Further, as a specific embodiment of the present invention, the width of the first compensation stripline 230 is slightly larger than the width of the main resonant stripline 240. Specifically, the width of the first compensation stripline 230 is slightly larger than the width of the first connecting segment 241 and the width of the third connecting segment 243. With this arrangement, when the first compensation stripline 230 and the first connecting segment 241 are slightly misaligned during the lamination process, the area of ​​the overlapping portion of the first compensation stripline 230 and the first connecting segment 241 remains unchanged; when the first compensation stripline 230 and the third connecting segment 243 are slightly misaligned during the lamination process, the area of ​​the overlapping portion of the first compensation stripline 230 and the third connecting segment 243 remains unchanged, thereby stabilizing the capacitance of the compensation capacitor and improving the filter yield.

[0042] As an optional embodiment of the present invention, in the bandpass filter of the embodiment of the present invention, the widths of the first connecting section 241 and the third connecting section 243 are both 0.02 mm smaller than the width of the first compensating stripline 230. For example, the widths of the first connecting section 241 and the third connecting section 243 are both 0.3 mm, and the width of the first compensating stripline 230 is 0.32 mm. It is understandable that the widths of the first connecting section 241, the third connecting section 243 and the first compensating stripline 230 can be appropriately adjusted according to the actual situation and specific needs, and are not limited to this.

[0043] Further, as a specific embodiment of the present invention, the width of the second compensation stripline 250 is slightly larger than the width of the main resonant stripline 240. Specifically, the width of the second compensation stripline 250 is slightly larger than the width of the first connecting section 241 and the width of the third connecting section 243. In this way, when the second compensation stripline 250 and the first connecting section 241 are slightly misaligned during the lamination process, the area of ​​the overlapping portion of the second compensation stripline 250 and the first connecting section 241 remains unchanged; when the second compensation stripline 250 and the third connecting section 243 are slightly misaligned during the lamination process, the area of ​​the overlapping portion of the second compensation stripline 250 and the third connecting section 243 remains unchanged, thereby stabilizing the capacitance of the compensation capacitor and improving the filter yield.

[0044] As an optional embodiment of the present invention, in the bandpass filter of the embodiment of the present invention, the widths of the first connecting section 241 and the third connecting section 243 are both 0.02 mm smaller than the width of the second compensation stripline 250. For example, the widths of the first connecting section 241 and the third connecting section 243 are both 0.3 mm, and the width of the second compensation stripline 250 is 0.32 mm. It is understandable that the widths of the first connecting section 241, the third connecting section 243 and the second compensation stripline 250 can be appropriately adjusted according to the actual situation and specific needs, and are not limited to this.

[0045] As an optional embodiment of the present invention, the spacing between the first compensation stripline 230 and the main resonant stripline 240 is less than or equal to 0.06 mm, and the spacing between the second compensation stripline 250 and the main resonant stripline 240 is less than or equal to 0.06 mm, thereby effectively ensuring that the first compensation stripline 230 and the second compensation stripline 250 respectively form compensation capacitances with the main resonant stripline 240. It should be noted that the above spacing refers to the distance in the height direction of the substrate 100. Of course, according to the actual selection and specific needs, the spacing between the first compensation stripline 230 and the main resonant stripline 240 and the spacing between the second compensation stripline 250 and the main resonant stripline 240 can be appropriately adjusted, and are not limited to the only ones here.

[0046] As an optional embodiment of the present invention, the spacing between the first compensation stripline 230 and the main resonant stripline 240 is equal to the spacing between the second compensation stripline 250 and the main resonant stripline 240, that is, the first compensation stripline 230 and the second compensation stripline 250 are arranged in a mirror-symmetrical manner with respect to the main resonant stripline 240. Such an arrangement can ensure the symmetry of the first-order resonator 210 and the second-order resonator 220, and reduce the passband insertion loss. In this embodiment, the main resonant stripline 240 of the first-order resonator 210 is located in the upper plane, the main resonant stripline 240 of the second-order resonator 220 is located in the lower plane, and the first compensation stripline 230 of the first-order resonator 210 is located below the second compensation stripline 250 of the second-order resonator 220 in the height direction of the substrate 100.

[0047] Further, as a specific embodiment of the present invention, Figure 1 , Figure 2 and Figure 4 As shown, the bandpass filter includes a first tap 410 connecting the main resonant stripline 240 of the first-order resonator 210 to the input end 310 and a second tap 420 connecting the main resonant stripline 240 of the second-order resonator 220 to the output end 320. In this embodiment, the first connecting section 241 of the main resonant stripline 240 of the first-order resonator 210 is connected to the input end 310 through the first tap 410, and the first connecting section 241 of the main resonant stripline 240 of the second-order resonator 220 is connected to the output end 320 through the second tap 420.

[0048] As an optional embodiment of the present invention, the first tap 410 is a single-layer folded stripline, and the second tap 420 is a single-layer folded stripline, which can ensure the reliability of the connection and reduce the influence of parasitic parameters. In this embodiment, the first tap 410 and the main resonant stripline 240 of the first-order resonator 210 are located in the same plane, and the second tap 420 and the main resonant stripline 240 of the second-order resonator 220 are located in the same plane, which can further ensure the reliability of the connection.

[0049] Further, as a specific embodiment of the present invention, Figure 4 and Figure 5 As shown, the projections of the input end 310 , the first tap 410 and the first-order resonator 210 in the height direction of the substrate 100 are centrally symmetric with the projections of the output end 320 , the second tap 420 and the second-order resonator 220 in the height direction of the substrate 100 . Figure 6 is an equivalent circuit diagram of a bandpass filter according to an embodiment of the present invention, wherein Z0 is the characteristic impedance of the transmission line, C eis the coupling capacitance between the two resonators, θ1 and θ2 are electrical lengths, specifically, the first-order resonator 210 is divided into two parts of electrical length θ1 and θ2 by the first tap 410, and the second-order resonator 220 is divided into two parts of electrical length θ1 and θ2 by the second tap 420, and the electrical lengths of the two transmission lines separated by the first tap 410 and the second tap 420 are exactly the same. By analyzing the transmission matrix of the equivalent circuit prototype, it can be known that at the corresponding frequency points of θ1≈π / 2 and θ2≈π / 2, transmission zeros will be generated, which are located in the upper and lower sidebands of the bandpass filter respectively. It can be seen that through the above settings, the electrical lengths of the two transmission paths separated by the first tap 410 and the second tap 420 are the same, and the phase difference generated is zero, realizing the zero-degree feeding transmission characteristics, and generating a transmission zero in the upper and lower sidebands without adding any additional electrodes and without affecting the passband frequency response, thereby improving the rectangular coefficient and passband selectivity of the bandpass filter.

[0050] Further, as a specific embodiment of the present invention, Figure 1 , Figure 2 as well as Figure 3 As shown, the bandpass filter also includes two side grounding plates 500 arranged on the left and right sides of the substrate 100. The side grounding plates 500 can be, but are not limited to, metal parts. One end of the first compensation stripline 230 that is grounded is connected to the corresponding side grounding plate 500, and one end of the second compensation stripline 250 that is grounded is connected to the corresponding side grounding plate 500, so that one end of the first compensation stripline 230 and one end of the second compensation stripline 250 are grounded.

[0051] Further, as a specific embodiment of the present invention, Figure 1 and Figure 2 As shown, the bandpass filter also includes an upper grounding plate 610 disposed on the upper side of the substrate 100 and a lower grounding plate 620 disposed on the lower side of the substrate 100. The upper grounding plate 610 and the lower grounding plate 620 can be, but are not limited to, metal parts. The upper grounding plate 610, the lower grounding plate 620 and the two side grounding plates 500 are arranged so as to enclose a cavity structure. The first-order resonator 210, the second-order resonator 220, the first tap 410 and the second tap 420 are all located in the cavity structure, which can reduce electromagnetic radiation loss and weaken the influence of external electromagnetic interference signals on the performance of the bandpass filter. In this embodiment, the upper grounding plate 610 is connected to the side grounding plate 500, and the lower grounding plate 620 is connected to the side grounding plate 500.

[0052] Further, as a specific embodiment of the present invention, Figure 1 , Figure 2 as well as Figure 5As shown, upper notches 611 for forming a dielectric area are respectively provided at the edges of the upper grounding plate 610 corresponding to the input terminal 310 and the output terminal 320, and lower notches 621 for forming a dielectric area are respectively provided at the edges of the lower grounding plate 620 corresponding to the input terminal 310 and the output terminal 320. The input terminal 310 corresponds to an upper notch 611 and a lower notch 621, and the output terminal 320 corresponds to an upper notch 611 and a lower notch 621, thereby reducing the capacitance of the input terminal 310 / output terminal 320 to the ground and achieving the purpose of impedance matching.

[0053] Further, as a specific embodiment of the present invention, Figure 1 , Figure 2 as well as Figure 5 As shown, the upper grounding plate 610 is provided with one or more upper bonding grooves 612 at the edge corresponding to the side grounding plate 500, and the lower grounding plate 620 is provided with one or more lower bonding grooves 622 at the edge corresponding to the side grounding plate 500. The functions of the upper bonding grooves 612 and the lower bonding grooves 622 are to enable the upper and lower ceramic sheets to be better bonded together during the lamination process of the LTCC process, and to prevent the large-area printed metal electrode layer from cracking during the sintering process.

[0054] As an optional embodiment of the present invention, the substrate 100 may be a ceramic medium, specifically but not limited to, a ceramic powder having a dielectric constant of 11 to 15 and a dielectric loss factor tanα≤0.0005. For example, the substrate 100 may be made of ULF140 ceramic powder having a dielectric constant of 13.3. Of course, the material of the substrate 100 may be appropriately modified according to the actual situation and specific needs, and is not limited to this.

[0055] As an optional embodiment of the present invention, the substrate 100 may be a rectangular cube with an overall size of 4 mm×3.6 mm×2 mm. Of course, the shape and specific size of the substrate 100 may be appropriately modified according to actual selection and specific needs, and are not limited here.

[0056] Further, Figure 7The simulation result diagram of the bandpass filter of the embodiment of the present invention is shown in FIG. S11 is the return loss curve at each frequency in the simulation; S21 is the insertion loss curve at each frequency in the simulation; from the simulation results, it can be seen that the center frequency of the bandpass filter is 2.08GHz, the 3-dB bandwidth is about 160MHz, the insertion loss in the passband is less than 1.1dB, the return loss in the band is greater than 23dB, there is a transmission zero at 1.79GHz and 2.84GHz, and it has good sideband selectivity. In this embodiment, the total length of the main resonant stripline 240 is 6.6mm, which is only one-sixth of the wavelength of the dielectric electromagnetic wave corresponding to the filter center frequency 2.08GHz, which is much smaller than the half-wavelength resonator length of the traditional stripline.

[0057] An embodiment of the present invention further provides an electronic device, comprising the bandpass filter as described above, which is conducive to realizing a miniaturized design of the electronic device.

[0058] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A bandpass filter, characterized in that: The device comprises a substrate, a first-order resonator and a second-order resonator arranged inside the substrate, and an input end and an output end respectively arranged at two ends of the substrate; The first-order resonator is located above the second-order resonator in the height direction of the substrate and the first-order resonator and the second-order resonator are partially cross-coupled; The first-order resonator and the second-order resonator each include a first compensation stripline, a main resonant stripline and a second compensation stripline, wherein the first compensation stripline, the main resonant stripline and the second compensation stripline are sequentially arranged at intervals along the height direction of the substrate, and the main resonant stripline is U-shaped; One end of the first compensation stripline is grounded, and the other end is suspended; both ends of the main resonant stripline are suspended, and the main resonant stripline of the first-order resonator is connected to the input end, and the main resonant stripline of the second-order resonator is connected to the output end; one end of the second compensation stripline is grounded, and the other end is suspended; An upper plane and a lower plane are provided in the base, the upper plane is located above the lower plane in the height direction of the base, the first-order resonator is located on the upper plane, the second-order resonator is located on the lower plane, and the first-order resonator and the second-order resonator are spaced apart in the height direction of the base.

2. The bandpass filter according to claim 1, characterized in that The main resonant strip line comprises a first connecting section, a second connecting section and a third connecting section connected in sequence, and the first connecting section and the third connecting section are parallel to each other; The second connection segment of the main resonant stripline of the first-order resonator intersects with the third connection segment of the main resonant stripline of the second-order resonator, and the third connection segment of the main resonant stripline of the first-order resonator intersects with the second connection segment of the main resonant stripline of the second-order resonator.

3. The bandpass filter according to claim 2, characterized in that The first-order resonator and the second-order resonator each include two first compensation striplines and two second compensation striplines; in each of the main resonant striplines, the first connecting segment and the third connecting segment are respectively arranged opposite to the corresponding first compensation stripline, and the first connecting segment and the third connecting segment are respectively arranged opposite to the corresponding second compensation stripline.

4. The bandpass filter according to claim 1, wherein: The distance between the first compensation stripline and the main resonant stripline is less than or equal to 0.06 mm, and the distance between the second compensation stripline and the main resonant stripline is less than or equal to 0.06 mm.

5. The bandpass filter according to claim 1, wherein: The bandpass filter includes a first tap connecting a main resonant stripline of the first-order resonator to the input end and a second tap connecting a main resonant stripline of the second-order resonator to the output end.

6. The bandpass filter according to claim 5, characterized in that The projections of the input end, the first tap, and the first-order resonator in the height direction of the substrate are centrally symmetric with the projections of the output end, the second tap, and the second-order resonator in the height direction of the substrate.

7. The bandpass filter according to claim 5, characterized in that The first tap is a single-layer folded stripline, and the second tap is a single-layer folded stripline.

8. The bandpass filter according to any one of claims 1 to 7, characterized in that: The bandpass filter also includes two side grounding plates arranged on the left and right sides of the substrate, one end of the first compensation stripline grounding is connected to the corresponding side grounding plate, and one end of the second compensation stripline grounding is connected to the corresponding side grounding plate.

9. The bandpass filter according to claim 8, characterized in that The bandpass filter further includes an upper ground plate disposed on the upper side of the substrate and a lower ground plate disposed on the lower side of the substrate.

10. An electronic device, characterized in that: Comprising the bandpass filter as claimed in any one of claims 1 to 9.

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