Filtering circuit and filter device

Abstract

The application discloses a filter circuit and a filter device. The filter circuit comprises an input port, an output port, a first resonator, a second resonator, a third resonator and a fourth resonator. The input port is connected with the first resonator, and the output port is connected with the second resonator. Electromagnetic coupling is arranged between the first resonator and the second resonator, electromagnetic coupling is arranged between the first resonator and the third resonator, electromagnetic coupling is arranged between the second resonator and the fourth resonator, and the third resonator is connected with the fourth resonator, so as to improve the bandwidth of the filter circuit. The filter circuit is constructed by using resonators with small volume. The electromagnetic coupling strength between the resonators is adjusted by controlling the spacing of the resonators in the filter circuit, so that the filter circuit can stably work in a millimeter wave frequency band under the condition of meeting the miniaturization requirement of the filter circuit, and the bandwidth, suppression and other performances of the filter circuit are improved.

Description

Technical Field

[0001] This application relates to the field of electronic circuit technology, and in particular to a filter circuit and filter device. Background Technology

[0002] With societal development, electronic products have become an indispensable part of people's lives and work. Electronic products contain integrated chips, the basic components of which are mostly integrated circuits. Filter circuits, as a crucial part of integrated circuits, are used in communication products such as wireless and wired communications.

[0003] Existing communication products are increasingly demanding filters with low insertion loss, high rejection, and small size. However, as signal frequencies increase and wavelengths shorten, the size of the line resonators resonating with these signals needs to be reduced. To make filters suitable for signals with very short wavelengths, such as millimeter waves, the line resonators need to be formed from very small conductors. Based on existing filter circuit manufacturing processes, traditional filter circuit structures cannot meet the requirements of high bandwidth and high frequency. Summary of the Invention

[0004] This application provides a filter circuit and filter device that, while meeting the requirements for miniaturization of the filter circuit, makes the filter circuit suitable for the millimeter-wave frequency band and effectively improves the bandwidth of the filter circuit.

[0005] To achieve the above objectives, this application provides the following technical solution:

[0006] A filter circuit includes: an input port, an output port, a first resonator, a second resonator, a third resonator, and a fourth resonator;

[0007] The input port is connected to the first resonator, and the output port is connected to the second resonator;

[0008] The first resonator and the second resonator are electromagnetically coupled, the first resonator and the third resonator are electromagnetically coupled, the second resonator and the fourth resonator are electromagnetically coupled, and the third resonator is connected to the fourth resonator to improve the bandwidth of the filter circuit.

[0009] The external signal is input to the filtering circuit via the input port, and is filtered by the first resonator, the second resonator, the third resonator, and the fourth resonator to obtain a filtered signal, which is then transmitted to the outside via the output port.

[0010] Optionally, the input port is connected to the first resonator via a first capacitor, and the output port is connected to the second resonator via a second capacitor.

[0011] Optionally, one end of the third resonator is connected to one end of the fourth resonator through a third capacitor, and the other end of the third resonator is grounded through the fourth capacitor.

[0012] Optionally, the other end of the fourth resonator is grounded via a fifth capacitor.

[0013] Optionally, the first resonator, the second resonator, the third resonator, and the fourth resonator are all U-shaped resonators.

[0014] Optionally, a fifth resonator may also be included;

[0015] The first resonator and the fifth resonator are electromagnetically coupled together, and the fifth resonator and the second resonator are electromagnetically coupled together, which replaces the electromagnetic coupling between the first resonator and the second resonator to increase the transmission zero point of the filter circuit.

[0016] Optionally, one end of the fifth resonator is grounded through a sixth capacitor, and the other end of the fifth resonator is grounded through a seventh capacitor.

[0017] Optionally, the fifth resonator is a linear resonator.

[0018] A filtering device includes an electromagnetic shielding cavity, a dielectric filler, and the filtering circuit.

[0019] The filter circuit is placed in the electromagnetic shielding cavity, and the interior of the electromagnetic shielding cavity is filled with the dielectric filler.

[0020] Optionally, the dielectric filler includes a first dielectric filler and a second dielectric filler;

[0021] The electromagnetic shielding cavity is filled with the first dielectric filler, the first dielectric filler is wrapped with the second dielectric filler, and the filter circuit is placed inside or on one side of the surface of the second dielectric filler.

[0022] The filtering circuit provided in this application includes an input port, an output port, a first resonator, a second resonator, a third resonator, and a fourth resonator. The input port is connected to the first resonator, and the output port is connected to the second resonator. Electromagnetic coupling is provided between the first and second resonators, between the first and third resonators, and between the second and fourth resonators. The third resonator is connected to the fourth resonator to improve the bandwidth of the filtering circuit. This application utilizes small resonators to construct the filtering circuit. By controlling the spacing between the resonators in the filtering circuit, the electromagnetic coupling strength between them is adjusted. This achieves the miniaturization requirement of the filtering circuit while enabling stable operation in the millimeter-wave frequency band, improving the bandwidth and suppression performance of the filtering circuit. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 A schematic diagram of the architecture of a filter circuit provided in an embodiment of this application;

[0025] Figure 2 A schematic diagram of a U-shaped resonator provided in an embodiment of this application;

[0026] Figure 3 A schematic diagram of a frequency variation curve provided in an embodiment of this application;

[0027] Figure 4 A schematic diagram of another filtering circuit architecture provided in an embodiment of this application;

[0028] Figure 5 A schematic diagram of a linear resonator provided in an embodiment of this application;

[0029] Figure 6 A schematic diagram of another frequency variation curve provided in an embodiment of this application;

[0030] Figure 7 A schematic diagram of the architecture of a filtering device provided in an embodiment of this application;

[0031] Figure 8 This is a schematic diagram of another filtering device architecture provided in an embodiment of this application. Detailed Implementation

[0032] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0033] like Figure 1 The diagram shown is a schematic diagram of the architecture of a filter circuit provided in an embodiment of this application.

[0034] The filter circuit includes a first resonator 101, a second resonator 102, a third resonator 103, a fourth resonator 104, an input port 105, and an output port 106.

[0035] The input port 105 is connected to the first resonator 101 through the first capacitor C1, and the output port 106 is connected to the second resonator 102 through the second capacitor C2.

[0036] Electromagnetic coupling is provided between the first resonator 101 and the second resonator 102, and electromagnetic coupling is provided between the first resonator 101 and the third resonator 103. One end of the third resonator 103 is connected to one end of the fourth resonator 104 through the third capacitor C3, and the other end of the third resonator 103 is grounded through the fourth capacitor C4. Electromagnetic coupling is provided between the second resonator 102 and the fourth resonator 104, and the other end of the fourth resonator 104 is grounded through the fifth capacitor C5, so as to improve the bandwidth of the filter circuit.

[0037] In the actual filtering process, the external signal is input to the filter circuit 100 through the input port 105. The external signal is filtered by the first resonator 101, the second resonator 102, the third resonator 103, and the fourth resonator 104 to obtain the filtered signal, which is then transmitted to the outside through the output port 106.

[0038] The resonator types used by the first resonator 101, the second resonator 102, the third resonator 103, and the fourth resonator 104 include, but are not limited to, small-sized resonators such as linear resonators, L-type resonators, U-type resonators, open-loop resonators, and stepped-impedance resonators. Furthermore, the first resonator 101, the second resonator 102, the third resonator 103, and the fourth resonator 104 may use the same type of resonator or different types of resonators.

[0039] Specifically, the first resonator 101, the second resonator 102, the third resonator 103, and the fourth resonator 104 shown in the embodiments of this application all adopt U-shaped resonators. For the specific shape of the U-shaped resonator, please refer to... Figure 2 As shown.

[0040] A U-shaped resonator consists of three conductors. For example... Figure 1 As can be seen, the first resonator 101 includes a first conductor line TL1, a second conductor line TL2 and a third conductor line TL3; the second resonator 102 includes a fourth conductor line TL4, a fifth conductor line TL5 and a sixth conductor line TL6; the third resonator 103 includes a seventh conductor line TL7, an eighth conductor line TL8 and a ninth conductor line TL9; and the fourth resonator 104 includes a tenth conductor line TL10, an eleventh conductor line TL11 and a twelfth conductor line TL12.

[0041] Based on the characteristics of resonators, it is known that the natural frequency of a resonator can be controlled by adjusting its length (specifically, the length of the conductor wires in the resonator) and the capacitance of the capacitor connected to the resonator. Therefore, the lengths of the first resonator 101, the second resonator 102, the third resonator 103, and the fourth resonator 104 shown in the embodiments of this application, as well as the capacitances of the first capacitor C1, the second capacitor C2, the third capacitor C3, the fourth capacitor C4, and the fifth capacitor C5, can be set by a technician according to actual conditions.

[0042] Based on the characteristics of electromagnetic coupling, it is known that the electromagnetic coupling strength between two resonators can be controlled by adjusting the spacing between them (including but not limited to horizontal and vertical spacing). Specifically, increasing the spacing between the two resonators can improve the electromagnetic coupling strength. Furthermore, based on the characteristics of filter circuits, enhancing the electromagnetic coupling strength between each resonator can increase the bandwidth of the filter circuit, thereby improving the passband performance of the filter devices and making the filter circuit suitable for the millimeter-wave frequency band. Therefore, the spacing between the first resonator 101 and the second resonator 102, the spacing between the first resonator 101 and the third resonator 103, and the spacing between the second resonator 102 and the fourth resonator 104 shown in the embodiments of this application can be set by technicians according to actual conditions.

[0043] Specifically, targeting Figure 1 The filter circuit shown is simulated, and the resulting curves of electromagnetic wave oscillation frequency versus signal transmission frequency are as follows: Figure 3 As shown.

[0044] In summary, this embodiment utilizes small resonators to construct a filter circuit. By controlling the spacing between the resonators in the filter circuit, the electromagnetic coupling strength between them is adjusted. This achieves the miniaturization requirement of the filter circuit while enabling it to operate stably in the millimeter-wave frequency band, thus improving the bandwidth, suppression, and other performance characteristics of the filter circuit.

[0045] Optional, such as Figure 4 The diagram shown is a schematic diagram of another filtering circuit architecture provided in an embodiment of this application.

[0046] The filter circuit includes a first resonator 401, a second resonator 402, a third resonator 403, a fourth resonator 404, a fifth resonator 405, an input port 406, and an output port 407.

[0047] The input port 406 is connected to the first resonator 401 through the first capacitor C1, and the output port 407 is connected to the second resonator 402 through the second capacitor C2.

[0048] Electromagnetic coupling is provided between the first resonator 401 and the fifth resonator 405, electromagnetic coupling is provided between the fifth resonator 405 and the second resonator 402, electromagnetic coupling is provided between the second resonator 402 and the fourth resonator 404, electromagnetic coupling is provided between the first resonator 401 and the third resonator 403, one end of the fifth resonator 405 is grounded through the sixth capacitor C6, and the other end of the fifth resonator 405 is grounded through the seventh capacitor C7, one end of the third resonator 403 is connected to one end of the fourth resonator 404 through the third capacitor C3, the other end of the third resonator 403 is grounded through the fourth capacitor C4, and the other end of the fourth resonator 404 is grounded through the fifth capacitor C5.

[0049] In this embodiment, the fifth resonator 405 uses a linear resonator. Specifically, the shape of the linear resonator can be found in [reference needed]. Figure 5 As shown.

[0050] It should be noted that the length of the fifth resonator 405, and the capacitances of the sixth capacitor C6 and the seventh capacitor C7, can be set by technicians according to the actual situation. Furthermore, the spacing between the first resonator 401 and the fifth resonator 405, and the spacing between the fifth resonator 405 and the second resonator 402, can also be set by technicians according to the actual situation.

[0051] For a linear resonator, the linear resonator includes a conductor wire, such as... Figure 4 It can be seen that the fifth resonator 405 includes the thirteenth conductor line TL13.

[0052] Compared to Figure 1 The filter circuit shown in this embodiment additionally adds a fifth resonator 405. Specifically, the electromagnetic coupling between the first resonator 401 and the fifth resonator 405, and the electromagnetic coupling between the fifth resonator 405 and the second resonator 402, are used to replace... Figure 1The electromagnetic coupling between the first resonator 101 and the second resonator 102 shown in the diagram increases the electromagnetic coupling component in the filter circuit, thereby increasing the transmission zero point of the filter circuit and making the filtering effect of the filter circuit more prominent.

[0053] Specifically, targeting Figure 4 The filter circuit shown is simulated, and the resulting Frequency-Transmission curve is as follows: Figure 6 As shown.

[0054] In summary, this embodiment utilizes small resonators to construct a filter circuit. By controlling the spacing between the resonators in the filter circuit, the electromagnetic coupling strength between them is adjusted. This achieves the miniaturization requirement of the filter circuit while enabling it to operate stably in the millimeter-wave frequency band, thus improving the bandwidth, suppression, and other performance characteristics of the filter circuit.

[0055] Based on the specific application scenarios of the filtering circuit, this application also provides a filtering device.

[0056] like Figure 7 The diagram shown is a schematic representation of the architecture of a filtering device provided in an embodiment of this application.

[0057] The filtering device includes an electromagnetic shielding cavity 701, a dielectric filler 702, and a filtering circuit 703.

[0058] The filter circuit 703 is placed in the electromagnetic shielding cavity 701, and the cavity of the electromagnetic shielding cavity 701 is filled with dielectric filler 702.

[0059] In this embodiment, the electromagnetic shielding cavity 701 includes an upper metal surface 7011, a lower metal surface 7012, and a plurality of metal pillars 7013. Specifically, the upper metal surface 7011 is connected to the lower metal surface 7012 through each of the metal pillars 7013.

[0060] The electromagnetic shielding cavity 701 is used to prevent high-frequency electromagnetic waves from entering its interior, thereby preventing the filter circuit 703 from being affected by high-frequency electromagnetic waves.

[0061] The dielectric materials used in dielectric filler 702 include, but are not limited to, materials suitable for millimeter-wave communication scenarios such as glass, ceramic materials, and PP materials.

[0062] The filter circuit 703 is the same as the filter circuit mentioned in the above embodiments, and will not be described again here.

[0063] In summary, the filtering device shown in this embodiment encapsulates the filtering circuit in an electromagnetic shielding cavity and fills the interior of the electromagnetic shielding cavity with a dielectric filler, which can prevent the filtering circuit from being affected by high-frequency electromagnetic waves, thereby effectively improving the filtering performance of the filtering circuit.

[0064] Optional, such as Figure 8 The diagram shown is a schematic diagram of another filtering device provided in an embodiment of this application.

[0065] The filtering device includes an electromagnetic shielding cavity 801, a first dielectric filler 802, a second dielectric filler 803, and a filtering circuit 804.

[0066] The structure of the electromagnetic shielding cavity 801 is the same as described above. Figure 7 The electromagnetic shielding cavity shown has the same structure, so it will not be described again here.

[0067] The dielectric materials used in the first dielectric filler 802 and the second dielectric filler 803 may be the same or different.

[0068] In this embodiment, the electromagnetic shielding cavity 100 is filled with a first dielectric filler 802, the first dielectric filler 802 is wrapped with a second dielectric filler 803, and a filter circuit 804 is placed inside or on one side of the surface of the second dielectric filler 803.

[0069] The filter circuit 804 is the same as the filter circuit mentioned in the above embodiments, and will not be described again here.

[0070] In summary, the filtering device shown in this embodiment encapsulates the filtering circuit in an electromagnetic shielding cavity, and fills the interior of the electromagnetic shielding cavity with a first dielectric filler and a second dielectric filler. This can prevent the filtering circuit from being affected by high-frequency electromagnetic waves, thereby effectively improving the filtering performance of the filtering circuit.

[0071] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0072] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A filter circuit, characterized in that, include: Input port, output port, first resonator, second resonator, third resonator, fourth resonator, and fifth resonator; The first resonator, the second resonator, the third resonator, and the fourth resonator are all U-shaped resonators; The fifth resonator is a linear resonator; The input port is connected to the first resonator, and the output port is connected to the second resonator; Electromagnetic coupling is provided between the first resonator and the second resonator, between the first resonator and the third resonator, and between the second resonator and the fourth resonator. The third resonator is connected to the fourth resonator to increase the bandwidth of the filter circuit. Electromagnetic coupling is provided between the first resonator and the fifth resonator, and between the fifth resonator and the second resonator, to replace the electromagnetic coupling between the first resonator and the second resonator, thereby increasing the transmission zero point of the filter circuit. The external signal is input to the filtering circuit via the input port, and is filtered by the first resonator, the second resonator, the third resonator, and the fourth resonator to obtain a filtered signal, which is then transmitted to the outside via the output port.

2. The filter circuit according to claim 1, characterized in that, The input port is connected to the first resonator via a first capacitor, and the output port is connected to the second resonator via a second capacitor.

3. The filter circuit according to claim 1, characterized in that, One end of the third resonator is connected to one end of the fourth resonator through a third capacitor, and the other end of the third resonator is grounded through the fourth capacitor.

4. The filter circuit according to claim 1, characterized in that, The other end of the fourth resonator is grounded through the fifth capacitor.

5. The filter circuit according to claim 1, characterized in that, One end of the fifth resonator is grounded through the sixth capacitor, and the other end of the fifth resonator is grounded through the seventh capacitor.

6. A filtering device, characterized in that, Includes an electromagnetic shielding cavity, a dielectric filler, and a filter circuit as described in any one of claims 1-5; The filter circuit is placed in the electromagnetic shielding cavity, and the interior of the electromagnetic shielding cavity is filled with the dielectric filler.

7. The filtering device according to claim 6, characterized in that, The dielectric filler includes a first dielectric filler and a second dielectric filler; The electromagnetic shielding cavity is filled with the first dielectric filler, the first dielectric filler is wrapped with the second dielectric filler, and the filter circuit is placed inside or on one side of the surface of the second dielectric filler.

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