Filtering circuit, filter, integrated passive device and electronic device
By designing a combination of multiple bandpass filter circuits and utilizing the combination of inductors and capacitors to form multiple transmission zeros, the problems of poor high-frequency signal filtering characteristics and low integration of traditional filters are solved, achieving miniaturization of the filter and effective filtering effect for high-frequency signal processing.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- BEIJING BOE OPTOELECTRONCIS TECH CO LTD
- Filing Date
- 2022-12-26
- Publication Date
- 2026-07-24
AI Technical Summary
Traditional filters have poor filtering characteristics for high-frequency signals and low integration, making them unable to meet the requirements of miniaturization and high-frequency signals. In particular, in the 5G era, it is difficult to achieve the characteristics of large bandwidth, low loss, fast out-of-band attenuation, and high out-of-band rejection.
A filter circuit including multiple bandpass filter circuits was designed. By combining inductors and capacitors, multiple transmission zeros are formed, improving the out-of-band rejection effect and forming a filter with large bandwidth and high roll-off characteristics.
It achieves filter miniaturization, and features low insertion loss, fast band-edge attenuation, and good out-of-band rejection characteristics, making it suitable for high-frequency signal processing.
Smart Images
Figure CN115842526B_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to the field of electronic technology, and in particular to filter circuits, filters, integrated passive devices, and electronic devices. Background Technology
[0002] Filters are an essential component in communication systems and have a wide range of applications.
[0003] Traditional filters come in many different types, including LC filters and cavity filters. Cavity filters are relatively large and are generally used in base stations and other similar applications. LC filters have low integration levels, commonly have large component sizes, and are mainly used in the low-frequency range, exhibiting poor filtering characteristics for high-frequency signals. Summary of the Invention
[0004] The filtering circuit provided in this embodiment includes: a first port, a second port, a first bandpass filter circuit, a second bandpass filter circuit, and a third bandpass filter circuit;
[0005] The first bandpass filter circuit is connected to the first port and is configured to input a first signal with a frequency not less than a first frequency from the signal input to the first port to the second bandpass filter circuit.
[0006] The second bandpass filter circuit is configured to input a second signal from the first input signal, whose frequency is between the second and third frequencies, into the third bandpass filter circuit.
[0007] The third bandpass filter circuit is configured to input a third signal from the input second signal, whose frequency is between the fourth and fifth frequencies, to the second port;
[0008] Wherein, the first frequency is less than the fourth frequency, and the fourth frequency is less than the third frequency.
[0009] In some possible implementations, the first frequency is greater than the second frequency, and the third frequency is less than the fifth frequency.
[0010] In some possible implementations, the first bandpass filter circuit includes: a first capacitor, a second capacitor, a third capacitor, a first inductor, a second inductor, a third inductor, and a ground terminal;
[0011] The first electrode of the first capacitor is connected to the first port, and the second electrode of the first capacitor is connected to the second bandpass filter circuit;
[0012] The first electrode of the second capacitor is connected to the second electrode of the first inductor, and the second electrode of the second capacitor is connected to the ground terminal;
[0013] The first electrode of the third capacitor is connected to the second electrode of the second inductor, and the second electrode of the third capacitor is connected to the ground terminal;
[0014] The first electrode of the first inductor is connected to the first electrode of the first capacitor;
[0015] The first electrode of the second inductor is connected to the second electrode of the first capacitor;
[0016] The first electrode of the third inductor is connected to the first electrode of the second capacitor, and the second electrode of the third inductor is connected to the second electrode of the second capacitor.
[0017] In some possible implementations, the second bandpass filter circuit includes: a fourth capacitor, a fifth capacitor, a sixth capacitor, a fourth inductor, and a ground terminal;
[0018] The first electrode of the fourth capacitor is connected to the first bandpass filter circuit, and the second electrode of the fourth capacitor is connected to the first electrode of the fifth capacitor.
[0019] The second electrode of the fifth capacitor is connected to the third bandpass filter circuit;
[0020] The first electrode of the sixth capacitor is connected to the first electrode of the fifth capacitor, and the second electrode of the sixth capacitor is connected to the ground terminal;
[0021] The first electrode of the fourth inductor is connected to the first electrode of the sixth capacitor, and the second electrode of the fourth inductor is connected to the second electrode of the sixth capacitor.
[0022] In some possible implementations, the third bandpass filter circuit includes: a seventh capacitor, an eighth capacitor, a ninth capacitor, a fifth inductor, a sixth inductor, a seventh inductor, and a ground terminal;
[0023] The first electrode of the seventh capacitor is connected to the second bandpass filter circuit, and the second electrode of the seventh capacitor is connected to the second port;
[0024] The first electrode of the eighth capacitor is connected to the second electrode of the fifth inductor, and the second electrode of the eighth capacitor is connected to the ground terminal.
[0025] The first electrode of the ninth capacitor is connected to the second electrode of the sixth inductor, and the second electrode of the ninth capacitor is connected to the ground terminal.
[0026] The first electrode of the fifth inductor is connected to the second electrode of the seventh capacitor;
[0027] The first electrode of the sixth inductor is connected to the first electrode of the seventh capacitor;
[0028] The first electrode of the seventh inductor is connected to the first electrode of the eighth capacitor, and the second electrode of the seventh inductor is connected to the second electrode of the eighth capacitor.
[0029] In some possible implementations, the capacitors in the filter circuit have the same capacitance value.
[0030] In some possible implementations, the capacitance value of the capacitor in the filter circuit ranges from 0.1 to 10 pF.
[0031] In some possible implementations, the inductance values of the inductors in the filter circuit are the same.
[0032] In some possible implementations, the inductance value of the inductor in the filter circuit ranges from 0.1 to 10 nH.
[0033] The filtering circuit provided in this embodiment includes the filtering circuit described above.
[0034] In some possible implementations, the filter is formed on a glass substrate.
[0035] In some possible implementations, the filter is a high-frequency filter.
[0036] The integrated passive device provided in this disclosure includes the filter described above.
[0037] The electronic devices provided in this disclosure include the integrated passive devices described above. Attached Figure Description
[0038] Figure 1 Some schematic diagrams of the filter circuit provided in the embodiments of this disclosure;
[0039] Figure 2 Other schematic diagrams of the filter circuit provided in the embodiments of this disclosure;
[0040] Figure 3 Some graphs provided for embodiments of this disclosure;
[0041] Figure 4 Other graphs provided for embodiments of this disclosure;
[0042] Figure 5 Further graphs provided for embodiments of this disclosure;
[0043] Figure 6 Further graphs provided for embodiments of this disclosure;
[0044] Figure 7 Further graphs provided for embodiments of this disclosure;
[0045] Figure 8 Further graphs provided for embodiments of this disclosure;
[0046] Figure 9 Further graphs provided for embodiments of this disclosure;
[0047] Figure 10 Further graphs are provided for embodiments of this disclosure. Detailed Implementation
[0048] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. Furthermore, the embodiments and features in the embodiments of this disclosure can be combined with each other without conflict. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.
[0049] Unless otherwise defined, the technical or scientific terms used in this disclosure shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as “comprising” or “including” mean that an element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as “connected” or “linked” are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect.
[0050] It should be noted that the dimensions and shapes of the figures in the accompanying drawings do not reflect actual proportions and are intended only to illustrate the content of this disclosure. Furthermore, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout.
[0051] With the development of national technologies such as aerospace, defense, satellite remote sensing, and radar communication, communication technology has advanced rapidly, and the requirements for the performance, size, and reliability of microwave radio frequency devices have become increasingly stringent. Furthermore, the rapid popularization of 5G technology has significantly increased the use of high-speed signals in daily life and industry. Therefore, the development of high-speed signal electronic equipment has become the core of communication technology development.
[0052] Communication systems include many common radio frequency (RF) structures, such as filters, baluns, duplexers, and switches. These structures are typically assembled into a system using a printed circuit board (PCB) along with external circuits and discrete capacitors and inductors. These devices and circuit structures occupy a large portion of the PCB area, exceeding 50%, which severely hinders the miniaturization of communication systems.
[0053] Filters, as essential components in communication systems, have a wide range of applications. Traditional filters come in many different types, including LC filters and cavity filters. Cavity filters are relatively large and are generally used in base stations. LC filters, on the other hand, achieve filtering functions by arranging different numbers of inductors, capacitors, and resistors according to circuit design, and can be used in some small electronic devices. However, traditional LC filters composed of discrete components have low integration levels, commonly large device sizes, and are mainly used in the low-frequency region, exhibiting poor filtering characteristics for high-frequency signals. The technical specifications of filters in use include passband, bandwidth, insertion loss, and out-of-band rejection. In the 5G era, simultaneously achieving large bandwidth, low loss, and fast out-of-band attenuation is a core goal of communication technology development.
[0054] Transmission line filters have a simple structure in the microwave range, but their structure is frequency-dependent and often quite large. In the radio frequency (RF) field, where frequencies are typically in the GHz range, the length of the resonant unit is usually half-wavelength or quarter-wavelength to meet usage requirements, significantly increasing the device size and hindering miniaturization. Traditional LC filters, using discrete components, have low integration, low Q-values, and poor insertion loss, making them incompatible with the high bandwidth, high roll-off, and high out-of-band rejection characteristics required in RF applications. Furthermore, traditional LC circuits are primarily used in lower frequency bands, with limited application in higher frequency domains, and achieving both low in-band insertion loss and high out-of-band rejection simultaneously is very challenging.
[0055] Based on this, the filter circuit provided in this disclosure combines a high-Q inductor with an ultra-thin, small-size, large capacitor in a bandpass filter circuit, effectively achieving low insertion loss in the passband, fast attenuation at the band edge, multiple transmission zeros, and good out-of-band rejection characteristics. Furthermore, the circuit design of this disclosure can be applied to the field of integrated passive technology, effectively achieving the goals of filter miniaturization and low cost.
[0056] The filtering circuit provided in the embodiments of this disclosure, such as Figure 1As shown, the filter includes: a first port A, a second port B, a first bandpass filter circuit 10, a second bandpass filter circuit 20, and a third bandpass filter circuit 30; the first bandpass filter circuit 10 is connected to the first port A and is configured to input a first signal with a frequency not less than a first frequency from the signal input to the first port A to the second bandpass filter circuit; the second bandpass filter circuit 20 is configured to input a second signal with a frequency between a second frequency and a third frequency from the first input signal to the third bandpass filter circuit 30; the third bandpass filter circuit 30 is configured to input a third signal with a frequency between a fourth frequency and a fifth frequency from the second input signal to the second port B; wherein, the first frequency is less than the fourth frequency, and the fourth frequency is less than the third frequency.
[0057] In this embodiment of the present disclosure, the cooperation of the first port, the second port, the first bandpass filter circuit, the second bandpass filter circuit, and the third bandpass filter circuit increases the number of transmission zeros, improves the out-of-band suppression effect, and constitutes a filter with multiple transmission zeros, large bandwidth, high roll-off characteristics, and high out-of-band suppression.
[0058] In this embodiment of the disclosure, the first frequency is greater than the second frequency, and the third frequency is less than the fifth frequency.
[0059] For example, the first frequency is 1.9 GHz, the second frequency is 1 GHz, the third frequency is 6 GHz, the fourth frequency is 2.5 GHz, and the fifth frequency is 7.5 GHz. Of course, in specific implementations, the first to fifth frequencies can be determined according to the actual application requirements, and are not limited here.
[0060] In the embodiments disclosed herein, such as Figure 2 Therefore, the first bandpass filter circuit 10 includes: a first capacitor C1, a second capacitor C2, a third capacitor C3, a first inductor L1, a second inductor L2, a third inductor L3, and a ground terminal GND; wherein, the first electrode of the first capacitor C1 is connected to the first port A, and the second electrode of the first capacitor C1 is connected to the second bandpass filter circuit 20; the first electrode of the second capacitor C2 is connected to the second electrode of the first inductor L1, and the second electrode of the second capacitor C2 is connected to the ground terminal GND; the first electrode of the third capacitor C3 is connected to the second electrode of the second inductor L2, and the second electrode of the third capacitor C3 is connected to the ground terminal GND; the first electrode of the first inductor L1 is connected to the first electrode of the first capacitor C1; the first electrode of the second inductor L2 is connected to the second electrode of the first capacitor C1; the first electrode of the third inductor L3 is connected to the first electrode of the second capacitor C2, and the second electrode of the third inductor L3 is connected to the second electrode of the second capacitor C2.
[0061] Specifically, by combining the first capacitor C1, the second capacitor C2, the third capacitor C3, the first inductor L1, the second inductor L2, and the third inductor L3, signals with frequencies lower than the first frequency in the signal input to the first port A are filtered out, and signals with frequencies not lower than the first frequency are retained. The retained signal is then input as the first signal into the second bandpass filter circuit 20.
[0062] The first bandpass filter circuit 10 primarily suppresses out-of-band low frequencies. Around the first capacitor C1, two basic parallel branches are formed: the first inductor L1 and the third inductor L3 connected in series; the third inductor L3 and the second capacitor C2 connected in parallel; and the second inductor L2 and the third capacitor C3 connected in series. The first bandpass filter circuit 10 can create three transmission zeros in the low-frequency out-of-band, and the positions of these zeros can be adjusted by fine-tuning the inductors and capacitors, thus achieving excellent out-of-band low-frequency suppression.
[0063] For example, the first bandpass filter circuit 10 not only generates passband characteristics in 3G, but also generates transmission nulls at 0GHz, 1.9GHz, and 5.2GHz, effectively blocking signals near these three frequency points and providing out-of-band low-frequency suppression. However, the suppression effect of this circuit structure at out-of-band high frequencies is not significant. Figure 3 As shown, the horizontal axis represents frequency, and the vertical axis represents loss. Figure 3 As can be seen, the first bandpass filter circuit 10 can generate additional transmission zeros in the out-of-band low-frequency range. These transmission zeros can effectively suppress transmission loss in the out-of-band low-frequency part and improve suppression.
[0064] For example, the second inductor L2 and the third capacitor C3 primarily generate zeros at 5.2 GHz and near 0 GHz, and their impedance curves are shown below. Figure 4 As shown, the horizontal axis represents frequency and the vertical axis represents amplitude.
[0065] For example, the first inductor L1, the third inductor L3, and the second capacitor C2 are mainly generated at the transmission zero at 1.9 GHz and the pole near 0 GHz, and their impedance curves are as follows: Figure 5 As shown, the horizontal axis represents frequency and the vertical axis represents amplitude.
[0066] For example, when the second capacitor C2, the third capacitor C3, the first inductor L1, the second inductor L2, and the third inductor L3 are combined, the second inductor L2 and the third capacitor C3 play a major role at the zero point near 0 GHz, canceling out the poles formed by the first inductor L1, the third inductor L3, and the second capacitor C2 near 0 GHz, thereby forming a... Figure 3 The graph shown is a graph of the first bandpass filter circuit 10.
[0067] For example, the inductor in the first bandpass filter circuit 10 can be implemented by a 3D glass-based, high-resistivity silicon-based, or ceramic-based wire-wound inductor, or by a 2D wire-wound inductor formed of resin material, without limitation.
[0068] For example, the capacitor in the first bandpass filter circuit 10 can be implemented by an ultra-thin two-layer capacitor structure or by a multi-layer thickened capacitor structure, which is not limited here.
[0069] The dimensions of the inductor and capacitor in the first bandpass filter circuit 10 can be designed according to the device size, so that the device size can be reduced to the millimeter level, which is much smaller than the common centimeter-level devices.
[0070] In the embodiments disclosed herein, such as Figure 2 Therefore, the second bandpass filter circuit 20 includes: a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6, a fourth inductor L4, and a ground terminal GND; wherein, the first electrode of the fourth capacitor C4 is connected to the first bandpass filter circuit 10, and the second electrode of the fourth capacitor C4 is connected to the first electrode of the fifth capacitor C5; the second electrode of the fifth capacitor C5 is connected to the third bandpass filter circuit 30; the first electrode of the sixth capacitor C6 is connected to the first electrode of the fifth capacitor C5, and the second electrode of the sixth capacitor C6 is connected to the ground terminal GND; the first electrode of the fourth inductor L4 is connected to the first electrode of the sixth capacitor C6, and the second electrode of the fourth inductor L4 is connected to the second electrode of the sixth capacitor C6.
[0071] In this circuit, the first electrode of the fourth capacitor C4 in the second bandpass filter circuit 20 is connected to the second electrode of the first capacitor C1 in the first bandpass filter circuit 10.
[0072] Specifically, through the cooperation of the fourth capacitor C4, the fifth capacitor C5, the sixth capacitor C6, and the fourth inductor L4, the first signal input to the first bandpass filter circuit 10 with a frequency outside the second and third frequencies is filtered out, and the first signal with a frequency between the second and third frequencies is retained. The retained first signal is then input as the second signal into the third bandpass filter circuit 30.
[0073] For example, the inductor in the second bandpass filter circuit 20 can be implemented by a 3D glass-based, high-resistivity silicon-based, or ceramic-based wire-wound inductor, or by a 2D wire-wound inductor formed of resin material, without limitation.
[0074] For example, the capacitor in the second bandpass filter circuit 20 can be implemented by an ultra-thin two-layer capacitor structure or by a multi-layer thickened capacitor structure, which is not limited here.
[0075] The dimensions of the inductor and capacitor in the second bandpass filter circuit 20 can be designed according to the device size, so that the device size can be reduced to the millimeter level, which is much smaller than the common centimeter-level devices.
[0076] The second bandpass filter circuit 20 primarily suppresses out-of-band low and high frequencies. It uses relatively few components and can create a null point in the 0-1 GHz low-frequency range, while also suppressing frequencies above 6 GHz. Furthermore, the null point's position can be adjusted by fine-tuning the inductor and capacitor, resulting in excellent out-of-band low-frequency suppression. The second bandpass filter circuit 20 also serves as an impedance matcher between the first bandpass filter circuit 10 and the third bandpass filter circuit 30.
[0077] For example, the second bandpass filter circuit 20 differs from the first bandpass filter circuit 10. The second bandpass filter circuit 20 has a certain suppression effect outside the low-frequency band and outside the high-frequency band, and can connect the impedance matching of the first bandpass filter circuit 10 and the third bandpass filter circuit 30, thus functioning as a bandpass filter. Figure 6 As shown in the figure. The horizontal axis represents frequency, and the vertical axis represents loss. Figure 6 As can be seen, this structure can generate transmission zeros in the out-of-band low-frequency range below 1 GHz. These transmission zeros can effectively suppress transmission losses in the low-frequency part outside the passband, improving suppression. It can also suppress high-frequency frequencies above 6 GHz, but the suppression effect is not significant.
[0078] In the embodiments disclosed herein, such as Figure 2 As shown, the third bandpass filter circuit 30 includes: a seventh capacitor C7, an eighth capacitor C8, a ninth capacitor C9, a fifth inductor L5, a sixth inductor L6, a seventh inductor L7, and a ground terminal GND; wherein, the first electrode of the seventh capacitor C7 is connected to the second bandpass filter circuit 20, and the second electrode of the seventh capacitor C7 is connected to the second port B; the first electrode of the eighth capacitor C8 is connected to the second electrode of the fifth inductor L5, and the second electrode of the eighth capacitor C8 is connected to the ground terminal GND; the first electrode of the ninth capacitor C9 is connected to the second electrode of the sixth inductor L6, and the second electrode of the ninth capacitor C9 is connected to the ground terminal GND; the first electrode of the fifth inductor L5 is connected to the second electrode of the seventh capacitor C7; the first electrode of the sixth inductor L6 is connected to the first electrode of the seventh capacitor C7; the first electrode of the seventh inductor L7 is connected to the first electrode of the eighth capacitor C8, and the second electrode of the seventh inductor L7 is connected to the second electrode of the eighth capacitor C8.
[0079] In this circuit, the first electrode of the seventh capacitor C7 in the third bandpass filter circuit 30 is connected to the second electrode of the fifth capacitor C5 in the second bandpass filter circuit 20.
[0080] Specifically, through the cooperation of the seventh capacitor C7, the eighth capacitor C8, the ninth capacitor C9, the fifth inductor L5, the sixth inductor L6, and the seventh inductor L7, the second signal input to the second bandpass filter circuit 20 with a frequency outside the fourth and fifth frequencies is filtered out, and the second signal with a frequency between the fourth and fifth frequencies is retained. The retained second signal is then input as the third signal to the second port B.
[0081] For example, the inductor in the third bandpass filter circuit 30 can be implemented by a 3D glass-based, high-resistivity silicon-based, or ceramic-based wire-wound inductor, or by a 2D wire-wound inductor formed of resin material, without limitation.
[0082] For example, the capacitor in the third bandpass filter circuit 30 can be implemented by an ultra-thin two-layer capacitor structure or by a multi-layer thickened capacitor structure, which is not limited here.
[0083] The dimensions of the inductor and capacitor in the third bandpass filter circuit 30 can be designed according to the device size, so that the device size can be reduced to the millimeter level, which is much smaller than the common centimeter-level devices.
[0084] The third bandpass filter circuit 30 mainly suppresses out-of-band high and low frequencies. It uses relatively few components and can form three transmission zeros at 0 GHz, 2.5 GHz, and 7.5 GHz in the high-frequency out-of-band. The position of the zeros can also be adjusted by fine-tuning the inductor and capacitor, thus playing a good role in suppressing out-of-band high frequencies.
[0085] For example, the third bandpass filter circuit 30 plays a different role than the first bandpass filter circuit 10 and the second bandpass filter circuit 20. The third bandpass filter circuit 30 not only suppresses low frequencies but also suppresses high-frequency out-of-band signals. It can also generate transmission nulls at 0 GHz, 2.5 GHz, and 7.5 GHz, effectively blocking signals near these three frequency points and thus providing out-of-band suppression. Its suppression effect on low and high frequencies outside the band is relatively large. Figure 7 As shown in the figure. The horizontal axis represents frequency, and the vertical axis represents loss. Figure 7 As can be seen, this structure can generate additional transmission zeros in the out-of-band high and low frequency ranges. These transmission zeros can effectively suppress transmission losses in the out-of-band high and low frequency ranges, thus improving suppression.
[0086] For example, the sixth inductor L6 and the ninth capacitor C9 are primarily generated at the propagation zero at 2.5 GHz, while simultaneously generating poles near 0 GHz, as shown in their impedance curves. Figure 8 As shown, the horizontal axis represents frequency and the vertical axis represents amplitude.
[0087] For example, the fifth inductor L5, the seventh inductor L7, and the eighth capacitor C8 primarily generate a zero at 7.5 GHz, while also generating a zero near 0 GHz, as shown in their impedance curves. Figure 9 As shown, the horizontal axis represents frequency and the vertical axis represents amplitude.
[0088] When the eighth capacitor C8, the ninth capacitor C9, the fifth inductor L5, the sixth inductor L6, and the seventh inductor L7 are combined, the zeros near 0 GHz of the fifth inductor L5, the seventh inductor L7, and the eighth capacitor C8 play a major role, canceling out the poles formed by the sixth inductor L6 and the ninth capacitor C9 near 0 GHz, thus forming a... Figure 7 The graph shown is a graph of the third bandpass filter circuit 30.
[0089] In summary, the first bandpass filter circuit 10, the second bandpass filter circuit 20, and the third bandpass filter circuit 30 can all form the characteristics of a simple bandpass filter. However, the first bandpass filter circuit 10 mainly suppresses low-frequency out-of-band frequencies, while the second bandpass filter circuit 20 can suppress both low frequencies (0-1 GHz) and high frequencies (above 6 GHz), and also serves as a bridge between the first bandpass filter circuit 10 and the third bandpass filter circuit 30. The third bandpass filter circuit 30 suppresses both out-of-band high and low frequencies. Combining the first bandpass filter circuit 10, the second bandpass filter circuit 20, and the third bandpass filter circuit 30 forms the final filter, and the filter curve is shown in Figure 10. Figure 10 As shown, the filter has good out-of-band suppression in both low and high frequencies, and the standing wave ratio in the passband is also good, which is beneficial to the tolerance consistency of manufacturing.
[0090] For example, the capacitance values of the capacitors in the filter circuit provided in this disclosure embodiment can be set to the same value. This reduces the design complexity. Of course, the capacitance values of these capacitors can also be set differently, so that different capacitors are specifically designed with their capacitance values according to their functions.
[0091] For example, the inductance values of the inductors in the filter circuit provided in this disclosure embodiment can be set to the same value. This can reduce the design complexity. Of course, the inductance values of these inductors can also be set differently, so that the inductance values of different inductors are specifically designed according to their functions.
[0092] For example, the capacitance value of the capacitor in the filter circuit provided in this embodiment of the present disclosure ranges from 0.1 to 10 pF.
[0093] For example, the inductance value of the inductor in the filter circuit provided in this embodiment of the present disclosure ranges from 0.1 to 10 nH.
[0094] Based on the same inventive concept, embodiments of this disclosure also provide a filter, including the filtering circuit described above. The principle by which this filter solves the problem is similar to that of the aforementioned filtering circuit; therefore, the implementation of this filter can refer to the implementation of the aforementioned filtering circuit, and repeated details will not be described here.
[0095] For example, the filter provided in this disclosure is formed on a glass substrate.
[0096] The filter in this embodiment is a high-frequency filter used to eliminate interference noise signals and obtain a pure high-frequency signal by filtering the input or output signal.
[0097] Based on the same inventive concept, embodiments of this disclosure also provide an integrated passive device, including the filter described above in embodiments of this disclosure. The principle by which this integrated passive device solves the problem is similar to that of the aforementioned filter; therefore, the implementation of this integrated passive device can refer to the implementation of the aforementioned filter, and the repetitions will not be repeated here.
[0098] Based on the same inventive concept, embodiments of this disclosure also provide an electronic device, including the aforementioned integrated passive device provided in embodiments of this disclosure. The principle by which this electronic device solves the problem is similar to that of the aforementioned integrated passive device; therefore, the implementation of this electronic device can refer to the implementation of the aforementioned integrated passive device, and the repetitions will not be repeated here.
[0099] For example, the electronic device can be a radio frequency device.
[0100] Although preferred embodiments of this disclosure have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this disclosure.
[0101] Obviously, those skilled in the art can make various modifications and variations to the embodiments of this disclosure without departing from the spirit and scope of the embodiments of this disclosure. Therefore, if these modifications and variations to the embodiments of this disclosure fall within the scope of the claims of this disclosure and their equivalents, this disclosure is also intended to include these modifications and variations.
Claims
1. A filter circuit, characterized in that, The filtering circuit includes: a first port, a second port, a first bandpass filter circuit, a second bandpass filter circuit, and a third bandpass filter circuit; The first bandpass filter circuit is connected to the first port and is configured to input a first signal with a frequency not less than a first frequency from the signal input to the first port to the second bandpass filter circuit; the first bandpass filter circuit is also configured to suppress low-frequency out-of-band signals; the first bandpass filter circuit includes: a first capacitor, a second capacitor, a third capacitor, a first inductor, a second inductor, and a third inductor; The second bandpass filter circuit is configured to input a second signal from the first input signal, whose frequency is between the second and third frequencies, to the third bandpass filter circuit; the second bandpass filter circuit is further configured to suppress low-frequency out-of-band signals and high-frequency out-of-band signals, and to perform impedance matching between the first bandpass filter circuit and the third bandpass filter circuit; the second bandpass filter circuit includes: a fourth capacitor, a fifth capacitor, a sixth capacitor, and a fourth inductor; The third bandpass filter circuit is configured to input a third signal with a frequency between the fourth and fifth frequencies from the second input signal to the second port; the third bandpass filter circuit is configured to suppress high-frequency out-of-band signals and low-frequency out-of-band signals; the third bandpass filter circuit includes: a seventh capacitor, an eighth capacitor, a ninth capacitor, a fifth inductor, a sixth inductor, and a seventh inductor; Wherein, the first frequency is less than the fourth frequency, and the fourth frequency is less than the third frequency.
2. The filter circuit as described in claim 1, characterized in that, The first frequency is greater than the second frequency, and the third frequency is less than the fifth frequency.
3. The filter circuit as described in claim 1 or 2, characterized in that, The first bandpass filter circuit further includes: a ground terminal; The first electrode of the first capacitor is connected to the first port, and the second electrode of the first capacitor is connected to the second bandpass filter circuit; The first electrode of the second capacitor is connected to the second electrode of the first inductor, and the second electrode of the second capacitor is connected to the ground terminal; The first electrode of the third capacitor is connected to the second electrode of the second inductor, and the second electrode of the third capacitor is connected to the ground terminal; The first electrode of the first inductor is connected to the first electrode of the first capacitor; The first electrode of the second inductor is connected to the second electrode of the first capacitor; The first electrode of the third inductor is connected to the first electrode of the second capacitor, and the second electrode of the third inductor is connected to the second electrode of the second capacitor.
4. The filter circuit as described in claim 1 or 2, characterized in that, The second bandpass filter circuit further includes: a ground terminal; The first electrode of the fourth capacitor is connected to the first bandpass filter circuit, and the second electrode of the fourth capacitor is connected to the first electrode of the fifth capacitor. The second electrode of the fifth capacitor is connected to the third bandpass filter circuit; The first electrode of the sixth capacitor is connected to the first electrode of the fifth capacitor, and the second electrode of the sixth capacitor is connected to the ground terminal; The first electrode of the fourth inductor is connected to the first electrode of the sixth capacitor, and the second electrode of the fourth inductor is connected to the second electrode of the sixth capacitor.
5. The filter circuit as described in claim 1 or 2, characterized in that, The third bandpass filter circuit further includes: a ground terminal; The first electrode of the seventh capacitor is connected to the second bandpass filter circuit, and the second electrode of the seventh capacitor is connected to the second port; The first electrode of the eighth capacitor is connected to the second electrode of the fifth inductor, and the second electrode of the eighth capacitor is connected to the ground terminal. The first electrode of the ninth capacitor is connected to the second electrode of the sixth inductor, and the second electrode of the ninth capacitor is connected to the ground terminal. The first electrode of the fifth inductor is connected to the second electrode of the seventh capacitor; The first electrode of the sixth inductor is connected to the first electrode of the seventh capacitor; The first electrode of the seventh inductor is connected to the first electrode of the eighth capacitor, and the second electrode of the seventh inductor is connected to the second electrode of the eighth capacitor.
6. The filter circuit as described in claim 1 or 2, characterized in that, The capacitors in the filter circuit have the same capacitance value.
7. The filter circuit as described in claim 6, characterized in that, The capacitance value of the capacitor in the filter circuit ranges from 0.1 to 10 pF.
8. The filter circuit as described in claim 1 or 2, characterized in that, The inductance values of the inductors in the filter circuit are the same.
9. The filter circuit as described in claim 8, characterized in that, The inductance value of the inductor in the filter circuit ranges from 0.1 to 10 nH.
10. A filter, characterized in that, Includes the filter circuit as described in any one of claims 1-9.
11. The filter as claimed in claim 10, characterized in that, The filter is formed on a glass substrate.
12. The filter as described in claim 10 or 11, characterized in that, The filter is a high-frequency filter.
13. An integrated passive device, characterized in that, Includes the filter as described in any one of claims 10-12.
14. An electronic device, characterized in that, Including the integrated passive device as described in claim 13.