Band-pass filter based on integrated passive device technology

Abstract

The invention discloses a band-pass filter based on an integrated passive device process. The band-pass filter comprises a first inductor, a first parallel circuit and a second parallel circuit, the first end of the first inductor is connected with one end of the first parallel circuit, the second end of the first inductor is connected with one end of the second parallel circuit, and the other end of the first parallel circuit and the other end of the second parallel circuit are both grounded; each first parallel circuit comprises a resonator, a plurality of capacitors and a plurality of inductors, the resonators are connected with the capacitors and the inductors in series, the out-of-band rejection of the band-pass filter is improved, the capacitors are arranged between the parallel circuits, the circuit inductance value is relieved, signal transmission is optimized, and the band-pass filter is more stable in performance. The band-pass filter provided by the invention can improve insertion loss performance and return loss, has better out-of-band rejection, and is beneficial to miniaturization of a microwave system.

Description

Technical Field

[0001] The invention belongs to the technical field of filter design and simulation in wireless communication systems, and in particular relates to a bandpass filter based on an integrated passive device process. Background Art

[0002] With the rapid development of mobile communications, wireless communications, network communications and other fields, integrated passive device filters have begun to be widely used in various mobile communication devices. They have been developed to meet the increasing demands of microwave communication systems for size and cost. The technology of integrated passive devices has been continuously improved. Traditional bandpass filters occupy a large chip area and have large insertion losses, which cannot meet the demand for device miniaturization. The out-of-band attenuation performance of integrated passive device bandpass filters is low, and they can only be used in large broadband and high frequency bands where the requirements for out-of-band attenuation are not high. In addition, the optimization of return loss, in-band insertion loss and low-frequency out-of-band suppression effect, which is one of the main measurement indicators of filters, is still an unresolved problem. Summary of the invention

[0003] In order to solve the above problems existing in the prior art, the present application provides a bandpass filter based on integrated passive device technology, which improves the insertion loss performance and helps miniaturize the microwave system through the design of the bandpass filter, so as to overcome the shortcomings of the above-mentioned prior art.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] A bandpass filter based on an integrated passive device process, comprising: a first inductor, a first parallel circuit, and a second parallel circuit; used to block input signals outside a frequency band, wherein a first end of the first inductor is connected to one end of the first parallel circuit, a second end of the first inductor is connected to one end of the second parallel circuit, and the other ends of the first parallel circuit and the second parallel circuit are both grounded;

[0006] The first parallel circuit comprises: a first resonator, a first series group and a second series group; the capacitor and the inductor are connected in series with the first resonator, thereby improving the out-of-band suppression of the bandpass filter; the first end of the first inductor is connected to one end of the first resonator through the second series group, and the first end of the first inductor is connected to the other end of the first resonator through the first series group; the first series group and the second series group are both composed of an inductor and a capacitor connected in series, the capacitor connected in series with the first resonator is used to generate a low-frequency out-of-band attenuation zero point, and the inductor connected in series with the first resonator is used to generate a high-frequency out-of-band attenuation zero point;

[0007] The second parallel circuit includes: a second resonator, a third series group and a fourth series group, the second end of the first inductor is connected to one end of the second resonator through the third series group, the second end of the first inductor is connected to the other end of the second resonator through the fourth series group, the third series group and the fourth series group are both composed of an inductor and a capacitor in series, the capacitor connected in series with the second resonator is used to generate a low-frequency out-of-band attenuation zero point, and the inductor connected in series with the second resonator is used to generate a high-frequency out-of-band attenuation zero point.

[0008] Preferably, the first resonator comprises a fourth inductor and a sixth capacitor, the fourth inductor and the sixth capacitor are connected in parallel, and the second resonator comprises a fifth inductor and a seventh capacitor, the fifth inductor and the seventh capacitor are connected in parallel.

[0009] Preferably, it also includes a first capacitor, a second capacitor and a third capacitor, the second end of the first capacitor is connected to one end of the first parallel circuit and the first end of the second capacitor, the second end of the second capacitor is connected to the first end of the first inductor, and the second end of the first inductor is connected to one end of the second parallel circuit and the first end of the third capacitor. The arrangement of the first capacitor, the second capacitor and the third capacitor alleviates the inductance of connecting the first parallel circuit and the second parallel circuit only by wires, optimizes signal transmission, optimizes insertion loss and echo, and improves the performance of the bandpass filter.

[0010] Further preferably, the first series group specifically includes a fourth capacitor and a second inductor connected in series, the second series group specifically includes a sixth inductor and an eighth capacitor connected in series, the first resonator includes a fourth inductor and a sixth capacitor, the fourth inductor and the sixth capacitor are connected in parallel, the second end of the first capacitor is connected to the first end of the sixth inductor and the first end of the fourth capacitor, the fourth capacitor and the second inductor are connected in series, the second end of the second inductor is connected to one end of the first resonator, the sixth inductor and the eighth capacitor are connected in series, the second end of the eighth capacitor is connected to the other end of the first resonator, and the second end of the eighth capacitor, the second end of the fourth inductor and the second end of the sixth capacitor are all grounded.

[0011] Further preferably, the third series group specifically includes a fifth capacitor and a third inductor connected in series, the fourth series group specifically includes a ninth capacitor and a seventh inductor connected in series, the second resonator includes a fifth inductor and a seventh capacitor, the fifth inductor and the seventh capacitor are connected in parallel, the first end of the third capacitor is connected to the first end of the fifth capacitor and the first end of the ninth capacitor, the fifth capacitor and the third inductor are connected in series, the second end of the third inductor is connected to one end of the second resonator, the ninth capacitor and the seventh inductor are connected in series, the second end of the seventh inductor is connected to the other end of the second resonator, and the second end of the fifth inductor, the second end of the seventh capacitor and the second end of the seventh inductor are all grounded.

[0012] Further preferably, it also includes a first port and a second port, the first port is connected to the first end of the first capacitor for receiving an input signal, and the second port is connected to the second end of the third capacitor for outputting a signal processed by a bandpass filter.

[0013] Further preferably, the first capacitor, the second capacitor, the third capacitor, the capacitor in the first parallel circuit and the capacitor in the second parallel circuit are all MIM capacitors in an integrated passive device process;

[0014] Further preferably, it also includes a substrate for carrying the first port, the second port, the first inductor, the first capacitor, the second capacitor, the third capacitor, the first parallel circuit and the second parallel circuit.

[0015] Preferably, the frequency band range of the bandpass filter is 3.3 GHz-4.2 GHz.

[0016] Preferably, the first inductor, the inductor in the first parallel circuit and the inductor in the second parallel circuit are all laminated inductors designed based on an integrated passive device process, the laminated inductor is composed of two metal layers, and the winding shape of the laminated inductor is an octagon.

[0017] Compared with the prior art, the beneficial results of the present invention are:

[0018] The present invention provides a bandpass filter based on an integrated passive device process. The insertion loss performance is improved by designing the bandpass filter and the microwave system is miniaturized. The series design of the resonator, the capacitor and the inductor can improve the out-of-band suppression of the bandpass filter. A plurality of capacitors are arranged between the parallel circuits to alleviate the circuit inductance and optimize signal transmission. The filter circuit has good out-of-band suppression and return loss. The performance of the filter integrated circuit layout is basically the same as that of the filter principle circuit diagram. The filter has good return loss, insertion loss and out-of-band suppression. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings are included to provide a further understanding of the embodiments and are incorporated into and constitute a part of this specification. The accompanying drawings illustrate the embodiments and together with the description are used to explain the principles of the present invention. Other embodiments and many expected advantages of the embodiments will be readily appreciated as they become better understood by reference to the following detailed description. Other features, objects and advantages of the present application will become more apparent by reading the detailed description of the non-limiting embodiments made with reference to the following drawings:

[0020] Figure 1 is a circuit schematic diagram of a bandpass filter based on an integrated passive device process according to a specific embodiment of the present invention;

[0021] Figure 2 is an electromagnetic simulation S-parameter curve diagram of a circuit schematic diagram according to a specific embodiment of the present invention;

[0022] Figure 3 is a process structure diagram of a bandpass filter based on an integrated passive device process according to a specific embodiment of the present invention;

[0023] Figure 4 is a graph showing a Q value and an inductance value of a multilayer inductor according to a specific embodiment of the present invention;

[0024] Figure 5 is a graph showing a Q value and a capacitance value of a MIM capacitor according to a specific embodiment of the present invention;

[0025] Figure 6 is a bandpass filter integrated circuit layout according to a specific embodiment of the present invention;

[0026] Figure 7 It is an electromagnetic simulation S-parameter curve diagram of a bandpass filter integrated circuit layout according to a specific embodiment of the present invention.

[0027] Figure markings: port1-first port; port2-second port; C1-first capacitor; C2-second capacitor; C3-third capacitor; C4-fourth capacitor; C5-fifth capacitor; C6-sixth capacitor; C7-seventh capacitor; C8-eighth capacitor; C9-ninth capacitor; L1-first inductor; L2-second inductor; L3-third inductor; L4-fourth inductor; L5-fifth inductor; L6-sixth inductor; L7-seventh inductor. DETAILED DESCRIPTION

[0028] The present application will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant invention, rather than to limit the invention. It should also be noted that, for ease of description, only the parts related to the relevant invention are shown in the accompanying drawings.

[0029] In the description of the present application, it should be noted that the terms "include", "comprising" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. "First", "second" and other similar terms are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated; the terms "installed", "provided with", "set / connected", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection, a mechanical connection, an electrical connection, a direct connection, an indirect connection through an intermediate medium, or a communication between the two elements. For ordinary technicians in this field, the specific meanings of the above terms in the application can be understood according to the specific circumstances.

[0030] To facilitate understanding by those skilled in the art, the present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0031] Figure 1 FIG. 1 shows a circuit schematic diagram of a bandpass filter based on an integrated passive device process according to a specific embodiment of the present application. Figure 1 As shown, it includes: a first inductor L1, a first parallel circuit and a second parallel circuit; used to block the input signal outside the frequency band range, the first end of the first inductor L1 is connected to one end of the first parallel circuit, the second end of the first inductor L1 is connected to one end of the second parallel circuit, and the other end of the first parallel circuit and the other end of the second parallel circuit are both grounded;

[0032] The first parallel circuit comprises: a first resonator, a first series group and a second series group; the capacitor and the inductor are connected in series with the first resonator, thereby improving the out-of-band suppression of the bandpass filter; the first end of the first inductor L1 is connected to one end of the first resonator through the second series group, and the first end of the first inductor L1 is connected to the other end of the first resonator through the first series group; the first series group and the second series group are both composed of an inductor and a capacitor connected in series; the capacitor connected in series with the first resonator is used to generate a low-frequency out-of-band attenuation zero point, and the inductor connected in series with the first resonator is used to generate a high-frequency out-of-band attenuation zero point;

[0033] The second parallel circuit includes: a second resonator, a third series group and a fourth series group. The capacitor and the inductor are connected in series with the second resonator, which can improve the out-of-band suppression of the bandpass filter. The second end of the first inductor L1 is connected to one end of the second resonator through the third series group, and the second end of the first inductor L1 is connected to the other end of the second resonator through the fourth series group. The third series group and the fourth series group are both composed of inductors and capacitors connected in series. The capacitor connected in series with the second resonator is used to generate a low-frequency out-of-band attenuation zero point and improve the out-of-band suppression of the bandpass filter. The inductor connected in series with the second resonator is used to generate a high-frequency out-of-band attenuation zero point and improve the out-of-band suppression of the bandpass filter.

[0034] In a specific embodiment, it also includes a first capacitor C1, a second capacitor C2 and a third capacitor C3, the second end of the first capacitor C1 is connected to one end of the first parallel circuit and the first end of the second capacitor C2, the second end of the second capacitor C2 is connected to the first end of the first inductor L1, and the second end of the first inductor L1 is connected to one end of the second parallel circuit and the first end of the third capacitor C3. The arrangement of the first capacitor C1, the second capacitor C2 and the third capacitor C3 alleviates the inductance of connecting the first parallel circuit and the second parallel circuit only by wires, optimizes signal transmission, optimizes insertion loss and echo, and improves the performance of the bandpass filter.

[0035] In a specific embodiment, the first series group specifically includes a fourth capacitor C4 and a second inductor L2 connected in series, the second series group specifically includes a sixth inductor L6 and an eighth capacitor C8 connected in series, the first parallel circuit specifically includes: a fourth capacitor C4, a second inductor L2, a first resonator, a sixth inductor L6 and an eighth capacitor C8, the first resonator includes a fourth inductor L4 and a sixth capacitor C6, the fourth inductor L4 and the sixth capacitor C6 are connected in parallel, the second end of the first capacitor C1 is connected to the first end of the sixth inductor L6 and the first end of the fourth capacitor C4, the fourth capacitor C4 and the second inductor L2 are connected in series, the second end of the second inductor L2 is connected to one end of the first resonator, the sixth inductor L6 and the eighth capacitor C8 are connected in series, the second end of the eighth capacitor C8 is connected to the other end of the first resonator, and the second end of the eighth capacitor C8, the second end of the fourth inductor L4 and the second end of the sixth capacitor C6 are all grounded. The fourth capacitor C4 and the eighth capacitor C8 are used to generate a low-frequency out-of-band attenuation zero point and improve the out-of-band suppression of the bandpass filter. The second inductor L2 and the sixth inductor L6 are used to generate a high-frequency out-of-band attenuation zero point and improve the out-of-band suppression of the bandpass filter.

[0036] In a specific embodiment, the third series group specifically includes a fifth capacitor C5 and a third inductor L3 connected in series, the fourth series group specifically includes a ninth capacitor C9 and a seventh inductor L7 connected in series, the second parallel circuit specifically includes: a fifth capacitor C5, a third inductor L3, a second resonator, a ninth capacitor C9 and a seventh inductor L7, the second resonator includes a fifth inductor L5 and a seventh capacitor C7, the fifth inductor L5 and the seventh capacitor C7 are connected in parallel, the first end of the third capacitor C3 is connected to the first end of the fifth capacitor C5 and the first end of the ninth capacitor C9, the fifth capacitor C5 and the third inductor L3 are connected in series, the second end of the third inductor L3 is connected to one end of the second resonator, the ninth capacitor C9 and the seventh inductor L7 are connected in series, the second end of the seventh inductor L7 is connected to the other end of the second resonator, and the second end of the fifth inductor L5, the second end of the seventh capacitor C7 and the second end of the seventh inductor L7 are all grounded. The fifth capacitor C5 and the ninth capacitor C9 are used to generate a low-frequency out-of-band attenuation zero point and improve the out-of-band suppression of the bandpass filter. The third inductor L3 and the seventh inductor L7 are used to generate a high-frequency out-of-band attenuation zero point and improve the out-of-band suppression of the bandpass filter.

[0037] In a specific embodiment, it also includes a first port port1 and a second port port2, the first port port1 is connected to the first end of the first capacitor C1 for receiving an input signal, and the second port port2 is connected to the second end of the third capacitor C3 for outputting a signal processed by a bandpass filter.

[0038] In a specific embodiment, the first port port1 is connected to the first end of the first capacitor C1, the second end of the first capacitor C1 is connected to the first end of the sixth inductor L6, the first end of the fourth capacitor C4 and the first end of the second capacitor C2, the second end of the fourth capacitor C4 is connected to the first end of the second inductor L2, the second end of the second inductor L2 is connected to the first end of the fourth inductor L4 and the first end of the sixth inductor L6, the second end of the sixth inductor L6 is connected to the first end of the eighth capacitor C8, the second end of the eighth capacitor C8 is connected to the second end of the fourth inductor L4 and the second end of the sixth capacitor C6 and is grounded; the second end of the second capacitor C2 The second end is connected to the first end of the first inductor L1, the second end of the first inductor L1 is connected to the first end of the fifth capacitor C5, the first end of the ninth capacitor C9 and the first end of the third capacitor C3, the second end of the fifth capacitor C5 is connected to the first end of the third inductor L3, the second end of the third inductor L3 is connected to the first end of the fifth inductor L5 and the first end of the seventh capacitor C7, the second end of the ninth capacitor C9 is connected to the first end of the seventh inductor L7, the second end of the fifth inductor L5, the second end of the seventh capacitor C7 and the second end of the seventh inductor L7 are connected and grounded, and the second end of the third capacitor C3 is connected to the second port port2.

[0039] In a specific embodiment, the present application adopts an N77 bandpass filter with a frequency band range of 3.3 GHz-4.2 GHz.

[0040] Figure 2 The electromagnetic simulation S parameter curve diagram of the circuit schematic diagram of a specific embodiment of the present application is shown as follows: Figure 2 As shown, the insertion loss is above 1.342dB within 3.3GHz-4.2GHz; at 2.500GHz (i.e. m1), the low-frequency out-of-band suppression is 36.956dB; wherein, m2 is the center frequency point, at 3.750GHz (i.e. m2), there is an out-of-band suppression of 1.342dB; at 5.150GHz (i.e. m3), there is a high-frequency out-of-band suppression of 20.719dB; at 1.710GHz (i.e. m5), there is a low-frequency out-of-band suppression of 49.157dB. It can be seen that the bandpass filter circuit based on the integrated passive device process of this embodiment has good out-of-band suppression and return loss.

[0041] Figure 3 A process structure diagram of a bandpass filter based on an integrated passive device process of a specific embodiment of the present application is shown, including a substrate for carrying the first port port1, the second port port2, the first inductor L1, the first capacitor C1, the second capacitor C2, the third capacitor C3, the first parallel circuit and the second parallel circuit, and vias connecting the metals.

[0042] In a specific embodiment, the first capacitor C1, the second capacitor C2, the third capacitor C3, the capacitor in the first parallel circuit and the capacitor in the second parallel circuit are all MIM (Metal-Insulator-Metal) capacitors in the integrated passive device process, such as Figure 3 As shown, MIM is the capacitor dielectric layer, TM1 is the capacitor upper plate, and M1 is the capacitor lower plate.

[0043] In a specific embodiment, the first inductor L1, the inductor in the first parallel circuit and the inductor in the second parallel circuit are all laminated inductors designed based on an integrated passive device process, and the laminated inductor is composed of two metal layers, such as Figure 3 As shown, the stacked inductor is wound using metal layers TM1 and TM2.

[0044] In a specific embodiment, the winding shape of the stacked inductor is an octagon.

[0045] In a specific embodiment, a multi-layer substrate is used to adapt to the flip chip technology used in subsequent packaging.

[0046] Figure 4FIG. 4 shows a Q value and inductance value curve of a multilayer inductor according to a specific embodiment of the present application. Figure 5 FIG. 2 shows a Q value and capacitance value curve of a MIM capacitor of a specific embodiment of the present application. Figure 4 As shown, the Q value of the stacked inductor reaches 34.816 at 3.760GHz, and the inductance value is 4.507nH; Figure 5 As shown, the Q value of the MIM capacitor reaches 17.339 and the capacitance value is 7.904pF at 3.750GHz. It can be seen that the MIM capacitor and the laminated inductor used in this application have a higher Q value and can provide a smaller bandpass filter volume, which is helpful for miniaturization of microwave systems.

[0047] Figure 6 The integrated circuit layout of a bandpass filter of a specific embodiment of the present invention is shown. The inductor and capacitor components are placed starting from the first port port1, and the schematic-layout joint simulation is performed. Due to the existence of parasitic effects, the frequency point will shift, and it is necessary to optimize the inductor and capacitor components, and simulate all component layouts as a whole, considering the influence between area and inductance, and optimize the capacitor design through joint simulation, so that the bandpass filter based on the integrated passive device process meets the performance indicators.

[0048] In a specific embodiment, the area of ​​the bandpass filter integrated circuit layout based on the integrated passive device process is 1.5 mm*0.7 mm.

[0049] In a specific embodiment, Figure 6As shown, the first port port1 is connected to the first end of the first capacitor C1, the second end of the first capacitor C1 is connected to the first end of the sixth inductor L6, the first end of the fourth capacitor C4 and the first end of the second capacitor C2, the second end of the fourth capacitor C4 is connected to the first end of the second inductor L2, the second end of the second inductor L2 is connected to the first end of the fourth inductor L4 and the first end of the sixth inductor L6, the second end of the sixth inductor L6 is connected to the first end of the eighth capacitor C8, the second end of the eighth capacitor C8 is connected to the second end of the fourth inductor L4 and the second end of the sixth capacitor C6 and is grounded; the second end of the second capacitor C2 The first end of the first inductor L1 is connected, the second end of the first inductor L1 is connected to the first end of the fifth capacitor C5, the first end of the ninth capacitor C9 and the first end of the third capacitor C3, the second end of the fifth capacitor C5 is connected to the first end of the third inductor L3, the second end of the third inductor L3 is connected to the first end of the fifth inductor L5 and the first end of the seventh capacitor C7, the second end of the ninth capacitor C9 is connected to the first end of the seventh inductor L7, the second end of the fifth inductor L5, the second end of the seventh capacitor C7 and the second end of the seventh inductor L7 are connected and grounded, and the second end of the third capacitor C3 is connected to the second port port2. The first port port1 is used to receive an input signal, and the second port port2 is used to output a signal processed by a bandpass filter. The fourth capacitor C4, the eighth capacitor C8, the fifth capacitor C5 and the ninth capacitor C9 are used to generate a low-frequency out-of-band attenuation zero point and improve the out-of-band suppression of the bandpass filter, and the second inductor L2, the sixth inductor L6, the third inductor L3 and the seventh inductor L7 are used to generate a high-frequency out-of-band attenuation zero point and improve the out-of-band suppression of the bandpass filter. The configuration of the first capacitor C1, the second capacitor C2 and the third capacitor C3 alleviates the inductance of connecting the first parallel circuit and the second parallel circuit only by wires, optimizes signal transmission, optimizes insertion loss and echo, and improves the performance of the bandpass filter.

[0050] In a specific embodiment, it also includes a substrate for supporting the first port port1, the second port port2, the first inductor L1, the first capacitor C1, the second capacitor C2, the third capacitor C3, the first parallel circuit and the second parallel circuit.

[0051] In a specific embodiment, the first capacitor C1, the second capacitor C2, the third capacitor C3, the fourth capacitor C4, the fifth capacitor C5, the sixth capacitor C6, the seventh capacitor C7, the eighth capacitor C8 and the ninth capacitor C9 in the integrated circuit layout are all MIM capacitors in the integrated passive device process. The above capacitors are all generated on the substrate using the integrated passive device process, and are composed of a top metal, a bottom metal and an intermediate insulating layer added between the two. The capacitance value of the above capacitor is mainly determined by the area of ​​the insulating layer, which facilitates the drawing of the above capacitor. The capacitors processed by the integrated passive device process have a high degree of integration, which reduces the volume of the capacitor, thereby reducing the size of the bandpass filter.

[0052] Figure 7 An electromagnetic simulation S-parameter curve of a bandpass filter integrated circuit layout of a specific embodiment of the present application is shown. In the range of 3.3 GHz to 4.2 GHz (i.e., between m1 and m2), the insertion loss is between 1.654 dB and 1.983 dB; at 2.500 GHz (i.e., m4), the low-frequency out-of-band suppression is 27.480 dB; at 5.373 GHz (i.e., m3), the high-frequency out-of-band suppression is 21.349 dB; at 1.980 GHz (i.e., m5), the low-frequency out-of-band suppression is 41.101 dB. It can be seen that the performance of the filter integrated circuit layout is basically the same as that of the filter principle circuit diagram, and the filter has good performance in terms of return loss, insertion loss and out-of-band suppression.

[0053] It should be noted that G1 and G2 in the figure represent ground terminals.

[0054] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the above invention concept. For example, the above features are replaced with the technical features with similar functions disclosed in this application (but not limited to) by each other to form a technical solution.

Claims

1. A bandpass filter based on an integrated passive device process, characterized in that: include: A first inductor, a first parallel circuit, and a second parallel circuit; a first end of the first inductor is connected to one end of the first parallel circuit, a second end of the first inductor is connected to one end of the second parallel circuit, and the other end of the first parallel circuit and the other end of the second parallel circuit are both grounded; The first parallel circuit includes: a first resonator, a first series group and a second series group; the first end of the first inductor is connected to one end of the first resonator through the second series group, and the first end of the first inductor is connected to the other end of the first resonator through the first series group; the first series group and the second series group are both composed of an inductor and a capacitor connected in series; The second parallel circuit includes: a second resonator, a third series group and a fourth series group, the second end of the first inductor is connected to one end of the second resonator through the third series group, the second end of the first inductor is connected to the other end of the second resonator through the fourth series group, and the third series group and the fourth series group are both composed of an inductor and a capacitor in series.

2. A bandpass filter based on integrated passive device technology according to claim 1, characterized in that: The first resonator includes a fourth inductor and a sixth capacitor, the fourth inductor and the sixth capacitor are connected in parallel, and the second resonator includes a fifth inductor and a seventh capacitor, the fifth inductor and the seventh capacitor are connected in parallel.

3. A bandpass filter based on integrated passive device technology according to claim 1, characterized in that: It also includes a first capacitor, a second capacitor and a third capacitor, wherein the second end of the first capacitor is connected to one end of the first parallel circuit and the first end of the second capacitor, the second end of the second capacitor is connected to the first end of the first inductor, and the second end of the first inductor is connected to one end of the second parallel circuit and the first end of the third capacitor.

4. A bandpass filter based on integrated passive device technology according to claim 3, characterized in that: The first series group specifically includes a fourth capacitor and a second inductor connected in series, the second series group specifically includes a sixth inductor and an eighth capacitor connected in series, the first resonator includes a fourth inductor and a sixth capacitor, the fourth inductor and the sixth capacitor are connected in parallel, the second end of the first capacitor is connected to the first end of the sixth inductor and the first end of the fourth capacitor, the fourth capacitor and the second inductor are connected in series, the second end of the second inductor is connected to one end of the first resonator, the sixth inductor and the eighth capacitor are connected in series, the second end of the eighth capacitor is connected to the other end of the first resonator, and the second end of the eighth capacitor, the second end of the fourth inductor and the second end of the sixth capacitor are all grounded.

5. The bandpass filter based on integrated passive device technology according to claim 3, characterized in that: The third series group specifically includes a fifth capacitor and a third inductor connected in series, the fourth series group specifically includes a ninth capacitor and a seventh inductor connected in series, the second resonator includes a fifth inductor and a seventh capacitor, the fifth inductor and the seventh capacitor are connected in parallel, the first end of the third capacitor is connected to the first end of the fifth capacitor and the first end of the ninth capacitor, the fifth capacitor and the third inductor are connected in series, the second end of the third inductor is connected to one end of the second resonator, the ninth capacitor and the seventh inductor are connected in series, the second end of the seventh inductor is connected to the other end of the second resonator, and the second end of the fifth inductor, the second end of the seventh capacitor and the second end of the seventh inductor are all grounded.

6. The bandpass filter based on integrated passive device technology according to claim 3, characterized in that: It also includes a first port and a second port, the first port is connected to the first end of the first capacitor, and the second port is connected to the second end of the third capacitor.

7. The bandpass filter based on integrated passive device technology according to claim 3, characterized in that: The first capacitor, the second capacitor, the third capacitor, the capacitor in the first parallel circuit, and the capacitor in the second parallel circuit are all MIM capacitors in an integrated passive device process.

8. The bandpass filter based on integrated passive device technology according to claim 6, characterized in that: The invention also includes a substrate for supporting the first port, the second port, the first inductor, the first capacitor, the second capacitor, the third capacitor, the first parallel circuit and the second parallel circuit.

9. The bandpass filter based on integrated passive device technology according to claim 1, characterized in that: The frequency band range of the bandpass filter is 3.3 GHz-4.2 GHz.

10. The bandpass filter based on integrated passive device technology according to claim 1, characterized in that: The first inductor, the inductor in the first parallel circuit and the inductor in the second parallel circuit all adopt a stacked inductor designed based on an integrated passive device process. The stacked inductor is composed of two metal layers and has an octagonal winding shape.

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