CN114584093A - Filter circuit, filter and multiplexer - Google Patents
Filter circuit, filter and multiplexer Download PDFInfo
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- CN114584093A CN114584093A CN202210220194.0A CN202210220194A CN114584093A CN 114584093 A CN114584093 A CN 114584093A CN 202210220194 A CN202210220194 A CN 202210220194A CN 114584093 A CN114584093 A CN 114584093A
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H7/00—Multiple-port networks comprising only passive electrical elements as network components
- H03H7/004—Capacitive coupling circuits not otherwise provided for
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H5/00—One-port networks comprising only passive electrical elements as network components
Abstract
The invention discloses a filter circuit, a filter and a multiplexer. The filter circuit comprises at least two capacitors connected in series, wherein the at least two capacitors connected in series comprise a first capacitor and a second capacitor; the first capacitor comprises a first capacitor plate, and the second capacitor comprises a second capacitor plate; in a first direction, a vertical projection of the first capacitor plate at least partially overlaps a vertical projection of the second capacitor plate; wherein, first direction is first capacitor plate thickness direction, can be so that first capacitor plate and second capacitor plate form new electric capacity, on the basis that does not additionally set up the electric capacity, the electric capacity quantity in the filter circuit has been increased, the capacitance value in the filter circuit has been increased simultaneously, thereby can improve filter circuit's performance on the basis that does not increase filter circuit occupation space, perhaps can reduce filter circuit's occupation space on the basis of guaranteeing filter circuit performance, be favorable to improving filter circuit's integrated level.
Description
Technical Field
The embodiment of the invention relates to the technical field of signal processing, in particular to a filter circuit, a filter and a multiplexer.
Background
Filter circuits are widely used in integrated circuits, for example, in filters, multiplexers, and the like of integrated circuits. In modern communications, the need for low insertion loss, small size filter circuits is increasing. The filter circuit in the conventional integrated circuit has the following problems: the space for placing the filter circuit in the integrated circuit is limited, so that the performance of the filter circuit is difficult to improve. For example, the filter circuit includes a capacitor, and the occupied area of the capacitor is relatively large, so that the occupied area of other components in the filter circuit is reduced under the condition of limited space, and then the high-performance components arranged in the filter circuit are influenced, for example, the inductance with high quality factor arranged in the filter circuit is influenced, and the performance of the filter circuit is difficult to improve.
Disclosure of Invention
The invention provides a filter circuit, a filter and a multiplexer, which aim to reduce the size of the filter circuit on the basis of ensuring the performance of the filter circuit.
In a first aspect, an embodiment of the present invention provides a filter circuit, which includes at least two capacitors connected in series, where the at least two capacitors connected in series include a first capacitor and a second capacitor;
the first capacitor comprises a first capacitor plate, and the second capacitor comprises a second capacitor plate; in a first direction, a vertical projection of the first capacitive plate at least partially overlaps a vertical projection of the second capacitive plate; the first direction is a thickness direction of the first capacitor plate.
Optionally, the first capacitor plate and the second capacitor plate are arranged in parallel.
Optionally, the first capacitor plate includes a first capacitor upper plate and a first capacitor lower plate that are oppositely disposed, the second capacitor plate includes a second capacitor upper plate and a second capacitor lower plate that are oppositely disposed, and the first capacitor lower plate is disposed adjacent to the second capacitor upper plate;
the vertical projection of the first capacitor upper plate in the first direction at least partially overlaps the vertical projection of at least one of the second capacitor upper plate and the second capacitor lower plate in the first direction, or the vertical projection of the first capacitor lower plate in the first direction at least partially overlaps the vertical projection of the second capacitor lower plate in the first direction.
Optionally, a vertical projection of the first capacitor upper plate in the first direction at least partially overlaps a vertical projection of the second capacitor lower plate in the first direction.
Optionally, a vertical projection of the first capacitor upper plate in the first direction completely overlaps with a vertical projection of the second capacitor lower plate in the first direction.
Optionally, the filter circuit further includes a third capacitor, and the third capacitor is connected in series to one end of the first capacitor far from the second capacitor; the third capacitor comprises a third capacitor plate; in a second direction, a vertical projection of the third capacitive plate at least partially overlaps a vertical projection of the second capacitive plate; wherein the second direction is a thickness direction of the second capacitor plate.
Optionally, the third capacitor plate and the second capacitor plate are arranged in parallel.
Optionally, the filter circuit further includes at least two inductors, one end of each of the at least two inductors is connected to a connection point of the capacitor, and the magnetic field directions of the at least two inductors are the same; wherein the connection point of the capacitors is the connection point between the series capacitors.
In a second aspect, an embodiment of the present invention further provides a filter, including the filter circuit provided in the first aspect.
In a third aspect, an embodiment of the present invention further provides a multiplexer, which is characterized by including the filter circuit provided in the first aspect.
According to the technical scheme of the embodiment of the invention, the vertical projections of the first capacitor plate of the first capacitor and the second capacitor plate of the second capacitor in the first direction are at least partially overlapped by arranging at least two capacitors connected in series, so that the first capacitor plate and the second capacitor plate can form a new capacitor, the number of capacitors in the filter circuit is increased on the basis of not additionally arranging the capacitors, and meanwhile, the capacitance value in the filter circuit is increased, so that the performance of the filter circuit can be improved on the basis of not increasing the occupied space of the filter circuit, or the occupied space of the filter circuit can be reduced on the basis of ensuring the performance of the filter circuit, and the integration level of the filter circuit is improved.
Drawings
Fig. 1 is a circuit schematic diagram of a filter circuit according to an embodiment of the present invention;
fig. 2 is a schematic cross-sectional structure diagram of a filter circuit according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of an equivalent circuit of a filter circuit corresponding to FIG. 2;
fig. 4 is a circuit diagram of a filter circuit provided in the prior art;
FIG. 5 is a circuit diagram of another filter circuit according to an embodiment of the present invention;
fig. 6 is a schematic cross-sectional structure diagram of another filter circuit according to an embodiment of the present invention;
FIG. 7 is a circuit diagram of another filtering circuit provided in the prior art;
FIG. 8 is a circuit diagram of another filter circuit according to an embodiment of the present invention;
FIG. 9 is a circuit diagram of another filter circuit according to an embodiment of the present invention;
fig. 10 is a schematic diagram of a performance of the filter circuit provided in fig. 9 when the magnetic field directions of at least two inductors are the same;
fig. 11 is a performance diagram corresponding to the filter circuit provided in fig. 9 when the magnetic field directions of at least two inductors are different;
FIG. 12 is a circuit schematic of another filtering circuit provided in the prior art;
FIG. 13 is a performance diagram of the filter circuit provided in FIG. 12;
FIG. 14 is a performance diagram of the filter circuit provided in FIG. 8;
fig. 15 is a schematic structural diagram of a multiplexer according to an embodiment of the present invention.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.
Fig. 1 is a circuit diagram of a filter circuit according to an embodiment of the present invention, and fig. 2 is a schematic cross-sectional structure diagram of the filter circuit according to the embodiment of the present invention. As shown in fig. 1 and 2, the filter circuit includes at least two capacitors connected in series, the at least two capacitors connected in series including a first capacitor C1 and a second capacitor C2; the first capacitor C1 includes a first capacitor plate C11, and the second capacitor C2 includes a second capacitor plate C22; in the first direction X, a perpendicular projection of the first capacitive plate C11 at least partially overlaps a perpendicular projection of the second capacitive plate C22; the first direction X is a thickness direction of the first capacitor plate C11.
Specifically, a first end of the first capacitor C1 is used as a first end of the filter circuit, a second end of the first capacitor C1 is connected to a first end of the second capacitor C2, and a second end of the second capacitor C2 is used as a second end of the filter circuit, so that the first capacitor C1 and the second capacitor C2 are connected in series. The first capacitor C1 and the second capacitor C2 have two conductive electrodes, and the common capacitor conductive electrodes may be plates. The first capacitor C1 includes a first capacitor plate C11 that may be divided into two plates with a medium therebetween and at least partially overlapping in vertical projection in the thickness direction such that the first capacitor plate C11 and the medium form a first capacitor C1. Similarly, the second capacitor C2 includes a second capacitor plate C22, which is also divided into two plates, and the two plates have a medium therebetween, and vertical projections in the thickness direction at least partially overlap, so that the second capacitor plate C22 and the medium form a second capacitor C2. In the first direction X, when a vertical projection of the first capacitor plate C11 and a vertical projection of the second capacitor plate C22 at least partially overlap, the first capacitor plate C11 and the second capacitor plate C22 can serve as two plates of a new capacitor, and meanwhile, the first capacitor plate C11 and the second capacitor plate C22 have a certain space in the first direction X, so that a medium is provided between the first capacitor plate C11 and the second capacitor plate C22, and the first capacitor plate C11, the second capacitor plate C22 and the medium therebetween form a new capacitor. Illustratively, when the filter circuit is formed into a package using an injection molding process, the dielectric between the first capacitor plate C11 and the second capacitor plate C22 may be a packaging layer. When the different plate portions of the first capacitor plate C11 and the second capacitor plate C22 form a new capacitor, the new capacitor may have a parallel connection relationship with one of the first capacitor C1 and the second capacitor C2, or may form a pi-type connection with both the first capacitor C1 and the second capacitor C2. And then on the basis that not additionally set up the electric capacity, increased the electric capacity quantity in the filter circuit, increased the capacitance value in the filter circuit simultaneously to can improve filter circuit's performance on the basis that does not increase filter circuit occupation space, perhaps can reduce filter circuit's occupation space on the basis of guaranteeing filter circuit performance, be favorable to improving filter circuit's integrated level.
It should be noted that when the vertical projection of the first capacitor plate C11 at least partially overlaps the vertical projection of the second capacitor plate C22, at least one of the two plates of the first capacitor plate C11 at least partially overlaps the vertical projection of at least one of the two plates of the second capacitor plate C22 in the first direction X, wherein at least one of the two plates of the first capacitor plate C11 is unconnected to at least one of the two plates of the second capacitor plate C22.
The technical scheme of this embodiment, through setting up in the electric capacity of two at least series connections, the first electric capacity polar plate of first electric capacity and the second electric capacity polar plate of second electric capacity are at least partly overlapped in the vertical projection on the first direction, can make first electric capacity polar plate and second electric capacity polar plate form new electric capacity, on the basis that does not additionally set up the electric capacity, electric capacity quantity in the filter circuit has been increased, capacitance value in the filter circuit has been increased simultaneously, thereby can improve the performance of filter circuit on the basis that does not increase filter circuit occupation space, or can reduce filter circuit's occupation space on the basis of guaranteeing the filter circuit performance, be favorable to improving filter circuit's integrated level.
On the basis of the technical scheme, the first capacitor plate and the second capacitor plate are arranged in parallel.
Specifically, when the first and second capacitor plates are used to form a new capacitor, the capacitance value of the new capacitor is inversely proportional to the distance between the first and second capacitor plates. The first capacitor plate and the second capacitor plate are arranged in parallel, so that the distance between the two plates of the new capacitor is a fixed value, the capacitance value of the new capacitor is easy to calculate, and the overlapping area of the first capacitor plate and the second capacitor plate in the first direction is set according to the requirement of the filter circuit.
On the basis of the technical schemes, the first capacitor plate comprises a first capacitor upper plate and a first capacitor lower plate which are oppositely arranged, the second capacitor plate comprises a second capacitor upper plate and a second capacitor lower plate which are oppositely arranged, and the first capacitor lower plate and the second capacitor upper plate are adjacently arranged; the vertical projection of the first capacitor upper plate in the first direction at least partially overlaps the vertical projection of at least one of the second capacitor upper plate and the second capacitor lower plate in the first direction, or the vertical projection of the first capacitor lower plate and the second capacitor lower plate in the first direction at least partially overlaps.
Specifically, when the first capacitor is connected in series with the second capacitor, the lower plate of the first capacitor can be electrically connected with the upper plate of the second capacitor. At the moment, the potential of the lower plate of the first capacitor is the same as that of the upper plate of the second capacitor. When a new capacitor is formed, the upper electrode plate of the first capacitor and the upper electrode plate of the second capacitor can be arranged to form the new capacitor, and the new capacitor is connected with the first capacitor in parallel. Or the upper pole plate of the first capacitor and the lower pole plate of the second capacitor can be arranged to form a new capacitor, and the new capacitor is in pi-type connection with the first capacitor and the second capacitor at the moment. Or the first capacitor lower plate and the second capacitor lower plate can be arranged to form a new capacitor, and the new capacitor is connected with the second capacitor in parallel.
Preferably, with continued reference to fig. 2, a vertical projection of the first capacitor upper plate C111 in the first direction X at least partially overlaps a vertical projection of the second capacitor lower plate C222 in the first direction X.
Specifically, fig. 3 is an equivalent circuit schematic diagram of a filter circuit corresponding to fig. 2. As shown in fig. 2 and 3, when the vertical projection of the first capacitor upper plate C111 in the first direction X and the vertical projection of the second capacitor lower plate C222 in the first direction X at least partially overlap, the first capacitor upper plate C111 and the second capacitor lower plate C222 form a new capacitor as the first parasitic capacitor Cs 1. At this time, the first end of the first parasitic capacitor Cs1 is connected with the first end of the first capacitor C1, and the second end of the first parasitic capacitor Cs1 is connected with the second end of the second capacitor C2, so that the first parasitic capacitor Cs1, the first capacitor C1 and the second capacitor C2 form pi-type connection.
Fig. 4 is a circuit schematic diagram of a filter circuit provided in the prior art. As shown in fig. 4, the conventional filter circuit may include three capacitors connected in a T-shape, namely, a first T-shaped capacitor C01, a second T-shaped capacitor C02, and a third T-shaped capacitor C03. The first T-shaped capacitor C01 and the second T-shaped capacitor C02 are connected in series, and one end of the third T-shaped capacitor C03 is connected to the connection point of the first T-shaped capacitor C01 and the second T-shaped capacitor C02. In this case, three capacitors are required for the filter circuit. On the basis, referring to fig. 2 and fig. 3, by arranging the filter circuit to include the first capacitor C1 and the second capacitor C2, the vertical projection of the first capacitor upper plate C111 in the first direction X and the vertical projection of the second capacitor lower plate C222 in the first direction X at least partially overlap, so that the first parasitic capacitor Cs1, the first capacitor C1 and the second capacitor C2 form a pi-type connection, the number of capacitors can be reduced on the basis of maintaining the performance of the filter circuit, and the occupied space of the filter circuit is reduced. Meanwhile, the T-shaped connection of the capacitor can be converted into the pi-shaped connection, and on the basis of keeping the equivalent capacitance value of the filter circuit unchanged, the capacitance value requirements of the first capacitor and the second capacitor can be reduced, so that the occupied space of the filter circuit can be further reduced.
Optionally, with continued reference to fig. 2, the vertical projection of the first capacitor upper plate C111 in the first direction X completely overlaps with the vertical projection of the second capacitor lower plate C222 in the first direction X.
Specifically, the area where the perpendicular projections of the two plates of the capacitor in the thickness direction overlap is proportional to the capacitance value. The two plates of the first parasitic capacitor Cs1 are a first capacitor upper plate C111 and a second capacitor lower plate C222. By completely overlapping the vertical projection of the first capacitor upper plate C111 in the first direction X with the vertical projection of the second capacitor lower plate C222 in the first direction X, the overlapping area of the vertical projections of the two plates of the first parasitic capacitor Cs1 in the thickness direction can be maximized, so that the first parasitic capacitor Cs1 has a large capacitance value, and the performance of the filter circuit is improved.
Fig. 5 is a circuit diagram of another filter circuit according to an embodiment of the present invention, and fig. 6 is a schematic cross-sectional structure diagram of another filter circuit according to an embodiment of the present invention. As shown in fig. 5 and fig. 6, the filter circuit further includes a third capacitor C3, the third capacitor C3 is connected in series to the end of the first capacitor C1 away from the second capacitor C2; the third capacitor C3 includes a third capacitor plate C33; in the second direction Y, a perpendicular projection of the third capacitor plate C33 at least partially overlaps with a perpendicular projection of the second capacitor plate C22; wherein the second direction Y is a thickness direction of the second capacitor plate C22.
Specifically, the third capacitor C3 is connected in series to one side of the first capacitor C1 and the second capacitor C2, so that the series connection of the third capacitor C3, the first capacitor C1 and the second capacitor C2 is realized. For example, as shown in fig. 5, the third capacitor C3 may be connected in series with the first capacitor C1 at a side thereof away from the second capacitor C2. The second direction Y is a thickness direction of the second capacitor plate C22, the first direction X is a thickness direction of the first capacitor plate C11, and the second direction Y is the same direction as the first direction X when the first capacitor plate C11 and the second capacitor plate C22 are parallel. The third capacitor plate C33 may be divided into two plates with a medium between them, and the perpendicular projections in the thickness direction at least partially overlap, such that the third capacitor plate C33 and the medium form a third capacitor C3. When the vertical projection of the third capacitor plate C33 and the vertical projection of the second capacitor plate C22 at least partially overlap in the second direction Y, the third capacitor plate C33 and the second capacitor plate C22 can be used as two plates of another new capacitor, and meanwhile, the third capacitor plate C33 and the second capacitor plate C22 have a certain space in the second direction Y, so that a medium can be provided between the third capacitor plate C33 and the second capacitor plate C22. Illustratively, when the filter circuit is formed into a package using an injection molding process, the dielectric between the third capacitor plate C33 and the second capacitor plate C22 may be a package layer. So that the third capacitor plate C33 and the second capacitor plate C22 and the medium between them form another new capacitance. And then on the basis that not additionally set up the electric capacity, increased the electric capacity quantity in the filter circuit, increased the capacitance value in the filter circuit simultaneously to can improve filter circuit's performance on the basis that does not increase filter circuit occupation space, perhaps can reduce filter circuit's occupation space on the basis of guaranteeing filter circuit performance, be favorable to improving filter circuit's integrated level.
For example, the third capacitor plate C33 may include a third capacitor upper plate C331 and a third capacitor lower plate C332 disposed opposite to each other, the first capacitor plate C11 may include a first capacitor upper plate C111 and a first capacitor lower plate C112 disposed opposite to each other, and the second capacitor plate C22 may include a second capacitor upper plate C221 and a second capacitor lower plate C222 disposed opposite to each other. The third capacitor lower plate C332 may be connected to the first capacitor upper plate C111, and the first capacitor lower plate C112 is connected to the second capacitor upper plate C221, so as to implement the series connection of the first capacitor C1, the second capacitor C2, and the third capacitor C3. At this time, the vertical projections of the third capacitor upper plate C331 and the second capacitor lower plate C222 in the second direction Y may be at least partially overlapped, and another new capacitor may be formed as the second parasitic capacitor Cs 2. At this time, the first end of the second parasitic capacitor Cs2 is connected to the third capacitor upper plate C331, and the second end of the second parasitic capacitor Cs2 is connected to the second capacitor lower plate C222, so that the equivalent pi-type connection among the second parasitic capacitor Cs2, the third capacitor C3 and the second capacitor C2 is realized.
Fig. 7 is a circuit diagram of another filtering circuit provided in the prior art. As shown in fig. 7, the conventional filter circuit may include five capacitors connected in a double T-shape, i.e., a fourth T-shaped capacitor C04 and a fifth T-shaped capacitor C05 are added on the basis of fig. 4. The fourth T-type capacitor C04 is connected in series with the first T-type capacitor C01 and the second T-type capacitor C02, and one end of the fifth T-type capacitor C05 is connected to the connection point of the fourth T-type capacitor C04 and the first T-type capacitor C01. In this case, five capacitors are required to be provided in the filter circuit. On the basis, referring to fig. 5 and fig. 6, by arranging the filter circuit to include the first capacitor C1, the second capacitor C2 and the third capacitor C3, in the first direction X, the vertical projection of the first capacitor upper plate C111 at least partially overlaps the vertical projection of the second capacitor lower plate C222, and in the second direction Y, the vertical projection of the third capacitor plate C33 at least partially overlaps the vertical projection of the second capacitor plate C22, so that the first parasitic capacitor Cs1 and the second parasitic capacitor Cs2 can be formed, the number of capacitors can be reduced on the basis of maintaining the performance of the filter circuit, and the occupied space of the filter circuit is reduced. Meanwhile, the T-shaped connection of the capacitor can be converted into the pi-shaped connection, and on the basis of keeping the equivalent capacitance value of the filter circuit unchanged, the capacitance value requirements of the first capacitor and the second capacitor can be reduced, so that the occupied space of the filter circuit can be further reduced.
Preferably, referring to fig. 6, a vertical projection of the third capacitor plate C33 in the second direction Y completely overlaps a vertical projection of the second capacitor plate C22 in the second direction Y, so that an overlapping area of the vertical projections of the two plates of the second parasitic capacitor Cs2 in the thickness direction can be maximized, which is beneficial to realizing that the first parasitic capacitor Cs1 has a large capacitance value, and is beneficial to improving the performance of the filter circuit.
On the basis of the technical scheme, the third capacitor plate and the second capacitor plate are arranged in parallel.
Specifically, when the third capacitor plate and the second capacitor plate are used to form a new capacitor, the capacitance value of the new capacitor is inversely proportional to the distance between the third capacitor plate and the second capacitor plate. Through setting up third capacitor plate and second capacitor plate parallel arrangement, can make the distance between two polar plates of new electric capacity be the definite value to make the capacitance value of new electric capacity calculate easily, so that set up the overlap area of third capacitor plate and second capacitor plate in the second direction according to filter circuit's needs.
Fig. 8 is a circuit diagram of another filter circuit according to an embodiment of the present invention. As shown in fig. 8, the filter circuit further includes at least two inductors L, one end of each of the at least two inductors L is connected to a connection point of the capacitor, and the magnetic field directions of the at least two inductors L are the same; wherein, the connecting point of the capacitor is the connecting point between the series capacitors.
Specifically, the capacitor comprises at least two capacitors connected in series, and the connection point of the capacitors is the connection point between the capacitors connected in series. Illustratively, as shown in fig. 8, the capacitor includes a first capacitor C1, a second capacitor C2, and a third capacitor C3 connected in series. The connection points of the capacitors include a connection point N1 between the first capacitor C1 and the second capacitor C2, and a connection point N2 between the third capacitor C3 and the first capacitor C1. The filter circuit comprises two inductors L, and one end of each inductor L is connected with the connection point of one capacitor. Illustratively, as shown in fig. 8, one end of one inductor L is connected to a connection point N1 of the first capacitor C1 and the second capacitor C2, and one end of the other inductor L is connected to a connection point N2 of the third capacitor C3 and the first capacitor C1. The at least two inductors L are in the same magnetic field direction, so that positive coupling can be formed between the at least two inductors L, a transmission zero point can be formed, and the filtering performance of the filter circuit can be improved.
For example, fig. 9 is a circuit schematic diagram of another filter circuit according to an embodiment of the present invention, fig. 10 is a performance schematic diagram corresponding to the filter circuit provided in fig. 9 when the magnetic field directions of at least two inductors are the same, and fig. 11 is a performance schematic diagram corresponding to the filter circuit provided in fig. 9 when the magnetic field directions of at least two inductors are different. Wherein the abscissa is frequency and the ordinate is insertion loss. As can be seen from fig. 10 and 11, by setting the magnetic field directions of the at least two inductors L to be the same and providing the positive coupling between the at least two inductors L, a transmission zero point can be formed outside the passband frequency range of the filter circuit, so that the suppression effect of the filter circuit can be improved, and the filtering effect of the filter circuit can be effectively improved.
On this basis, fig. 12 is a circuit schematic diagram of another filtering circuit provided in the prior art, and fig. 13 is a performance schematic diagram of the filtering circuit provided in fig. 12. Wherein the abscissa is frequency and the ordinate is insertion loss. As shown in fig. 12, the filter circuit further includes two filter inductors L 'on the basis of five capacitors having a double T-type connection, the two filter inductors L' are respectively connected in series between one end of the fifth T-type capacitor C05 and a connection point of the fourth T-type capacitor C04 and the first T-type capacitor C01, and between one end of the third T-type capacitor C03 and a connection point of the first T-type capacitor C01 and the second T-type capacitor C02. As shown in fig. 13, the filter circuit has two transmission zeroes outside the passband frequency range.
Fig. 14 is a schematic diagram of a performance of the filter circuit provided in fig. 8. Wherein the abscissa is frequency and the ordinate is insertion loss. With continued reference to fig. 8 and 14, when the first capacitor C1 and the second capacitor C2 have a first parasitic capacitor Cs1 therebetween, the third capacitor C3 and the second capacitor C2 have a first parasitic capacitor Cs2 therebetween, and the magnetic fields of the at least two inductors L are in the same direction, the filter circuit also has two transmission zeros outside the passband frequency range. Therefore, the first parasitic capacitor Cs1 is arranged between the first capacitor C1 and the second capacitor C2, the first parasitic capacitor Cs2 is arranged between the third capacitor C3 and the second capacitor C2, and the magnetic field directions of at least two inductors L are the same, so that the filter circuit can reduce the number of capacitors without reducing transmission zeros, and reduce the occupied space of the filter circuit. Meanwhile, the capacitance value required by the capacitor can be reduced on the basis of keeping the equivalent capacitance value of the filter circuit unchanged, so that the occupied space of the filter circuit can be further reduced.
The embodiment of the invention also provides a filter. The filter comprises the filter circuit provided by any embodiment of the invention.
Specifically, the filter at least includes the filter circuit provided in any embodiment of the present invention, and therefore has the beneficial effects of the filter circuit, which are not described herein again. In addition, the filter can also comprise other filter circuits for improving the filtering function of the filter. For example, the other filter circuit may be a low-pass filter circuit, a high-pass filter circuit, or a band-pass filter circuit, and the embodiment of the present invention is not limited thereto.
The embodiment of the invention also provides a multiplexer. Fig. 15 is a schematic structural diagram of a multiplexer according to an embodiment of the present invention. As shown in fig. 15, the multiplexer includes a filter circuit 210 according to any embodiment of the present invention.
With continued reference to fig. 15, the multiplexer includes a first terminal IN and at least two second terminals; each of the filter circuits 210 is connected IN series between the first terminal IN and any one of the second terminals of the multiplexer.
Specifically, fig. 15 exemplarily shows that the multiplexer includes a first terminal IN and n second terminals OUT1 and OUT2 … … OUTn, respectively. Each of the filter circuits 210 is connected IN series between the first terminal IN and a second terminal. For example, the first filter circuit 210 is connected IN series between the first terminal IN and the first second terminal OUT1, the second filter circuit 210 is connected IN series between the first terminal IN and the first second terminal OUT2 … …, and so on. Since the multiplexer has the filter circuit 210 provided in any embodiment of the present invention, the multiplexer has the beneficial effects of the filter circuit, and details are not described herein.
It should be noted that the multiplexer may further include another filter circuit, where the another filter circuit is connected IN series between the first terminal IN and any one of the second terminals, and the another filter circuit may be a low-pass filter circuit, a high-pass filter circuit, or a band-pass filter circuit, which is not limited IN the embodiment of the present invention.
It is to be noted that the foregoing is only illustrative of the preferred embodiments of the present invention and the technical principles employed. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.
Claims (10)
1. A filter circuit is characterized by comprising at least two capacitors connected in series, wherein the at least two capacitors connected in series comprise a first capacitor and a second capacitor;
the first capacitor comprises a first capacitor plate, and the second capacitor comprises a second capacitor plate; in a first direction, a vertical projection of the first capacitive plate at least partially overlaps a vertical projection of the second capacitive plate; the first direction is a thickness direction of the first capacitor plate.
2. The filter circuit of claim 1, wherein the first capacitor plate and the second capacitor plate are arranged in parallel.
3. The filter circuit according to claim 1 or 2, wherein the first capacitor plate comprises a first upper capacitor plate and a first lower capacitor plate which are oppositely arranged, the second capacitor plate comprises a second upper capacitor plate and a second lower capacitor plate which are oppositely arranged, and the first lower capacitor plate is arranged adjacent to the second upper capacitor plate;
the vertical projection of the first capacitor upper plate in the first direction at least partially overlaps the vertical projection of at least one of the second capacitor upper plate and the second capacitor lower plate in the first direction, or the vertical projection of the first capacitor lower plate in the first direction at least partially overlaps the vertical projection of the second capacitor lower plate in the first direction.
4. The filter circuit of claim 3, wherein a perpendicular projection of the first capacitive upper plate in the first direction at least partially overlaps a perpendicular projection of the second capacitive lower plate in the first direction.
5. The filter circuit of claim 4, wherein a vertical projection of the first capacitor upper plate in the first direction completely overlaps a vertical projection of the second capacitor lower plate in the first direction.
6. The filter circuit according to claim 1, further comprising a third capacitor connected in series with an end of the first capacitor remote from the second capacitor; the third capacitor comprises a third capacitor plate; in a second direction, a vertical projection of the third capacitive plate at least partially overlaps a vertical projection of the second capacitive plate; wherein the second direction is a thickness direction of the second capacitor plate.
7. The filter circuit of claim 6, wherein the third capacitive plate and the second capacitive plate are arranged in parallel.
8. The filter circuit according to claim 6, further comprising at least two inductors, wherein one end of at least two of the inductors is connected to a connection point of a capacitor, and magnetic fields of at least two of the inductors have the same direction; wherein the connection point of the capacitors is the connection point between the series capacitors.
9. A filter comprising a filter circuit as claimed in any one of claims 1 to 8.
10. A multiplexer comprising the filter circuit of any one of claims 1-8.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210220194.0A CN114584093A (en) | 2022-03-08 | 2022-03-08 | Filter circuit, filter and multiplexer |
| PCT/CN2022/137885 WO2023169025A1 (en) | 2022-03-08 | 2022-12-09 | Filter circuit, filter and multiplexer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210220194.0A CN114584093A (en) | 2022-03-08 | 2022-03-08 | Filter circuit, filter and multiplexer |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114584093A true CN114584093A (en) | 2022-06-03 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210220194.0A Pending CN114584093A (en) | 2022-03-08 | 2022-03-08 | Filter circuit, filter and multiplexer |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN114584093A (en) |
| WO (1) | WO2023169025A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2023169025A1 (en) * | 2022-03-08 | 2023-09-14 | 安徽安努奇科技有限公司 | Filter circuit, filter and multiplexer |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP6319758B2 (en) * | 2013-02-28 | 2018-05-09 | デクセリアルズ株式会社 | Capacitance device, resonance circuit, and electronic equipment |
| KR20170109782A (en) * | 2016-03-22 | 2017-10-10 | 삼성전기주식회사 | Complex electronic component |
| CN105719613B (en) * | 2016-04-22 | 2018-06-01 | 上海天马微电子有限公司 | array substrate, display panel and display device |
| CN108011605A (en) * | 2017-12-06 | 2018-05-08 | 深圳振华富电子有限公司 | One kind miniaturization is high to suppress LTCC bandpass filters |
| CN108512520B (en) * | 2018-02-27 | 2022-04-29 | 苏州汉天下电子有限公司 | Monolithic integrated structure of bulk acoustic wave resonator and capacitor, manufacturing method thereof, filter, duplexer, and radio frequency communication module |
| CN114584093A (en) * | 2022-03-08 | 2022-06-03 | 安徽安努奇科技有限公司 | Filter circuit, filter and multiplexer |
-
2022
- 2022-03-08 CN CN202210220194.0A patent/CN114584093A/en active Pending
- 2022-12-09 WO PCT/CN2022/137885 patent/WO2023169025A1/en unknown
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2023169025A1 (en) * | 2022-03-08 | 2023-09-14 | 安徽安努奇科技有限公司 | Filter circuit, filter and multiplexer |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2023169025A1 (en) | 2023-09-14 |
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