Filtering circuit and filter

Abstract

The utility model relates to electronic field especially, and it is a kind of filter circuit and filter.The filter circuit includes input port, output port, filter network;Filter network includes first inductance unit, second inductance unit, first capacitor unit, second capacitor unit, third capacitor unit, fourth capacitor unit, first inductive element;The filter network between input port and output port is built by first inductance unit, second inductance unit, first capacitor unit, second capacitor unit, third capacitor unit, fourth capacitor unit, first inductive element, the simple and small design of filter structure is realized, and performance is stable, especially applicable to various small, portable electronic equipment and wideband communication system.

Description

Technical Field

[0001] This utility model relates to the field of electronics, and in particular to a filter circuit and filter. Background Technology

[0002] In electronic devices and communication systems, signal filtering technology is widely used in signal transmission and reception to remove interference noise, suppress spurious signals, improve signal purity, and protect the stability of equipment operation. Especially in applications involving wide-bandwidth signals, such as medical equipment, industrial control, radio communication, broadcast television signal processing, and signal detection and analysis, efficient signal filtering is essential.

[0003] Currently used filters, such as low-pass filters, high-pass filters, or band-pass filters, are typically only applicable to specific frequency ranges. Furthermore, limitations imposed by traditional design methods mean that the amplitude-frequency characteristics within the passband are prone to fluctuations or instability when covering a wide frequency range, potentially even causing signal distortion. In addition, wideband filters generally suffer from drawbacks such as large size, complex structure, and high production costs, making it difficult to meet the stringent requirements for filter size and integration in portable or miniaturized devices. Utility Model Content

[0004] To solve the above-mentioned technical problems, this utility model provides a filtering circuit and filter, which can be applied to signal processing in electronic equipment and communication systems, and is especially suitable for signal filtering in the frequency range of 0.150MHz-1MHz.

[0005] The present invention provides a filtering circuit suitable for signal filtering in the frequency range of 0.150MHz-1MHz, comprising: an input port, an output port, and a filtering network;

[0006] The filter network is electrically connected between the input port and the output port;

[0007] The filter network includes a first inductor unit, a second inductor unit, a first capacitor unit, a second capacitor unit, a third capacitor unit, a fourth capacitor unit, and a first inductor element;

[0008] The protective grounding terminal of the input port, the first inductor element, and the protective grounding terminal of the output port are connected in series via a protective grounding wire.

[0009] The AC neutral line terminal and AC phase line terminal of the input port are electrically connected to the first input terminal and the second input terminal of the first inductor unit, respectively.

[0010] The first output terminal of the first inductor unit is electrically connected to the first terminal of the first capacitor unit, the first terminal of the third capacitor unit, and the first input terminal of the second inductor unit, and its second output terminal is electrically connected to the first terminal of the second capacitor unit, the second terminal of the third capacitor unit, and the second input terminal of the second inductor unit.

[0011] The second end of the first capacitor unit and the second end of the second capacitor unit are respectively electrically connected to the protective grounding wire;

[0012] The first output terminal of the second inductor unit is electrically connected to the first terminal of the fourth capacitor unit and the AC neutral line terminal of the output port, respectively, and its second output terminal is electrically connected to the second terminal of the fourth capacitor unit and the AC phase line terminal of the output port, respectively.

[0013] Wherein, the first input terminal and the first output terminal of the first inductor unit are connected, and its second input terminal and the second output terminal are connected;

[0014] The first input terminal of the second inductor unit is connected to the first output terminal, and its second input terminal is connected to the second output terminal.

[0015] In one possible implementation, the first inductor unit includes a second inductor element and a third inductor element;

[0016] The first and second input terminals of the second inductor element serve as the first and second input terminals of the first inductor unit, respectively, and its first and second output terminals are electrically connected to the first and second input terminals of the third inductor element, respectively.

[0017] The first and second output terminals of the third inductor element serve as the first and second output terminals of the first inductor unit, respectively.

[0018] In one possible implementation, the second inductor unit includes a fourth inductor element and a fifth inductor element;

[0019] The first and second input terminals of the fourth inductor element serve as the first and second input terminals of the second inductor unit, respectively, and its first and second output terminals are electrically connected to the first and second input terminals of the fifth inductor element, respectively.

[0020] The first and second output terminals of the fifth inductor element serve as the first and second output terminals of the second inductor unit, respectively.

[0021] In one possible implementation, the first inductor is 5mH, the second inductor is 15mH, the third inductor is 6mH, the fourth inductor is 30mH, and the fifth inductor is 5mH.

[0022] In one possible implementation, the first capacitor unit includes a first capacitor and a second capacitor connected in series;

[0023] The second capacitor unit includes a third capacitor and a fourth capacitor connected in series.

[0024] In one possible implementation, the third capacitor unit includes a fifth capacitor;

[0025] The fourth capacitor unit includes the sixth capacitor.

[0026] In one possible implementation, the first capacitor, the second capacitor, the third capacitor, and the fourth capacitor are all 1000pF, and the fifth capacitor and the sixth capacitor are both 4700pF.

[0027] In one possible implementation, the fifth capacitor and the sixth capacitor are X-type safety capacitors.

[0028] This utility model also provides a filter, including a PCB printed circuit board and the filter circuit described above;

[0029] The filter circuit is mounted on the PCB printed circuit board.

[0030] In one possible implementation, the PCB printed circuit board has a length of 115mm and a width of 50mm.

[0031] The technical solution provided by this utility model has at least the following beneficial effects:

[0032] By constructing a filter network between the input and output ports using a first inductor unit, a second inductor unit, a first capacitor unit, a second capacitor unit, a third capacitor unit, a fourth capacitor unit, and a first inductor element, a simplified and miniaturized filter structure is achieved. The filter exhibits stable performance and is particularly suitable for various miniaturized and portable electronic devices and broadband communication systems. Attached Figure Description

[0033] Figure 1 A circuit schematic diagram of a filter circuit provided for an embodiment of this utility model;

[0034] Figure 2 The noise waveform diagram before using the filter circuit is provided for the embodiments of this utility model;

[0035] Figure 3The noise waveform diagram after using the filtering circuit is provided for the embodiment of this utility model;

[0036] In the attached diagram, 11 is the first inductor unit; 12 is the second inductor unit; 13 is the first capacitor unit; 14 is the second capacitor unit; 15 is the third capacitor unit; and 16 is the fourth capacitor unit. Detailed Implementation

[0037] To enhance understanding of this utility model, it will be described in further detail below with reference to the accompanying drawings and embodiments. These embodiments are only used to explain this utility model and do not limit the scope of protection of this utility model.

[0038] Please refer to Figures 1 to 3 The present invention provides a filtering circuit suitable for signal filtering in the frequency range of 0.150MHz-1MHz, comprising: an input port P1, an output port P2, and a filtering network;

[0039] The filter network is electrically connected between the input port P1 and the output port P2;

[0040] The filter network includes a first inductor unit 11, a second inductor unit 12, a first capacitor unit 13, a second capacitor unit 14, a third capacitor unit 15, a fourth capacitor unit 16, and a first inductor element L1.

[0041] The protective grounding terminal PE_I of the input port P1, the first inductor L1, and the protective grounding terminal PE_O of the output port P2 are connected in series via a protective grounding wire.

[0042] The AC neutral line terminal N_I and AC phase line terminal L_I of the input port P1 are electrically connected to the first input terminal and the second input terminal of the first inductor unit 11, respectively.

[0043] The first output terminal of the first inductor unit 11 is electrically connected to the first terminal of the first capacitor unit 13, the first terminal of the third capacitor unit 15, and the first input terminal of the second inductor unit 12, and its second output terminal is electrically connected to the first terminal of the second capacitor unit 14, the second terminal of the third capacitor unit 15, and the second input terminal of the second inductor unit 12.

[0044] The second end of the first capacitor unit 13 and the second end of the second capacitor unit 14 are respectively electrically connected to the protective grounding wire;

[0045] The first output terminal of the second inductor unit 12 is electrically connected to the first terminal of the fourth capacitor unit 16 and the AC neutral line terminal N_O of the output port P2, respectively, and its second output terminal is electrically connected to the second terminal of the fourth capacitor unit 16 and the AC phase line terminal L_O of the output port P2, respectively.

[0046] Wherein, the first input terminal of the first inductor unit 11 is connected to the first output terminal, and its second input terminal is connected to the second output terminal;

[0047] The first input terminal of the second inductor unit 12 is connected to the first output terminal, and its second input terminal is connected to the second output terminal.

[0048] In this embodiment, the input port P1 and output port P2 can adopt a conventional three-pin connection structure interface. The first inductor unit 11 and the second inductor unit 12 can be constructed by connecting conventional inductor coils in series and parallel. The first capacitor unit 13, the second capacitor unit 14, the third capacitor unit 15, and the fourth capacitor unit 16 can be constructed by connecting conventional capacitors in series and parallel. The first inductor unit 11 and the first capacitor unit 13 and the second capacitor unit 14 combine to form a first-stage resonant circuit. The second inductor unit 12 and the third capacitor unit 15 and the fourth capacitor unit 16 combine to form a second-stage resonant circuit. The first-stage resonant circuit and the second-stage resonant circuit together construct a stepped filter network, realizing the functions of frequency selection, filtering, and tuning the center frequency and bandwidth of the filter, improving the stability and consistency of the filter circuit throughout the entire operating frequency range. The first inductor element L1 can be a conventional inductor coil (e.g., 5mH), which can further filter and smooth the signal.

[0049] In one possible implementation, the first inductor unit 11 includes a second inductor element L2 and a third inductor element L3;

[0050] The first and second input terminals of the second inductor element L2 serve as the first and second input terminals of the first inductor unit 11, respectively, and its first and second output terminals are electrically connected to the first and second input terminals of the third inductor element L3, respectively.

[0051] The first and second output terminals of the third inductor element L3 serve as the first and second output terminals of the first inductor unit 11, respectively.

[0052] In this embodiment, the second inductor L2 and the third inductor L3 can be conventional common-mode inductors. The second inductor L2 can be 15mH, and the third inductor L3 can be 6mH. A first inductor coil is wound between the first input and first output terminals of the second inductor L2, and a second inductor coil is wound between its second input and second output terminals; the two inductor coils are symmetrical. Similarly, a first inductor coil is wound between the first input and first output terminals of the third inductor L3, and a second inductor coil is wound between its second input and second output terminals; the two inductor coils are symmetrical.

[0053] In one possible implementation, the second inductor unit 12 includes a fourth inductor element L4 and a fifth inductor element L5;

[0054] The first and second input terminals of the fourth inductor L4 serve as the first and second input terminals of the second inductor unit 12, respectively, and its first and second output terminals are electrically connected to the first and second input terminals of the fifth inductor L5, respectively.

[0055] The first and second output terminals of the fifth inductor element L5 serve as the first and second output terminals of the second inductor unit 12, respectively.

[0056] In this embodiment, the fourth inductor L4 and the fifth inductor L5 can be conventional common-mode inductors. The fourth inductor L4 can be 30mH, and the fifth inductor L5 can be 5mH. A first inductor coil is wound between the first input and first output terminals of the fourth inductor L4, and a second inductor coil is wound between its second input and second output terminals; the two inductor coils are symmetrical. Similarly, a first inductor coil is wound between the first input and first output terminals of the fifth inductor L5, and a second inductor coil is wound between its second input and second output terminals; the two inductor coils are symmetrical.

[0057] In one possible implementation, the first inductor L1 is 5mH, the second inductor L2 is 15mH, the third inductor L3 is 6mH, the fourth inductor L4 is 30mH, and the fifth inductor L5 is 5mH.

[0058] In one possible implementation, the first capacitor unit 13 includes a first capacitor C1 and a second capacitor C2 connected in series.

[0059] The second capacitor unit 14 includes a third capacitor C3 and a fourth capacitor C4 connected in series.

[0060] In this embodiment, the first capacitor C1, the second capacitor C2, the third capacitor C3, and the fourth capacitor C4 are conventional capacitors.

[0061] In one possible implementation, the third capacitor unit 15 includes a fifth capacitor C5;

[0062] The fourth capacitor unit 16 includes a sixth capacitor C6.

[0063] In one possible implementation, the first capacitor C1, the second capacitor C2, the third capacitor C3, and the fourth capacitor C4 are all 1000pF, and the fifth capacitor C5 and the sixth capacitor C6 are both 4700pF.

[0064] In one possible implementation, the fifth capacitor C5 and the sixth capacitor C6 are X-type safety capacitors.

[0065] In this embodiment, the frequency band of the filter circuit can be precisely controlled by accurately adjusting the inductance values ​​of the inductors (first inductor L1, second inductor L2, third inductor L3, fourth inductor, fifth inductor L5, etc.) and the capacitance values ​​of the capacitors (first capacitor C1, second capacitor C2, third capacitor C3, fourth capacitor, fifth capacitor C5, sixth capacitor C6, etc.). In practical implementation, matching resistors can also be set at the input port P1 and the output port P2 respectively to improve the impedance matching performance of the filter network and ensure the stability of the filtering effect.

[0066] In the specific implementation process, the component parameters of the filter network of this utility model were precisely calculated and tested. With the first inductor L1 at 5mH, the second inductor L2 at 15mH, the third inductor L3 at 6mH, the fourth inductor L4 at 30mH, and the fifth inductor L5 at 5mH, and the first capacitor C1, second capacitor C2, third capacitor C3, and fourth capacitor C4 all at 1000pF, and the fifth capacitor C5 and sixth capacitor C6 both at 4700pF, its passband exhibits good frequency characteristics throughout the entire 0.150MHz-1MHz range, achieving ideal amplitude-frequency and phase-frequency performance indicators, meeting the needs of broadband signal processing in practical engineering. Actual test results are as follows: Figure 2 and Figure 3 Combining, as in 2 and Figure 3 It can be observed that after using the filter circuit in this utility model, the noise at the highest point decreased by 50 dB, and the average noise level decreased by 20 dB-30 dB.

[0067] It should be emphasized that the beneficial effects of the filter circuit in this utility model include, but are not limited to: achieving a wide operating frequency band (0.150MHz-1MHz), meeting the diverse application needs of broadband communication and signal processing; stable signal transmission performance within the passband, flat amplitude-frequency response, and low signal distortion; simple structure, low cost, easy mass production, and conducive to widespread application and promotion; and small size design, facilitating high integration in space-constrained electronic devices or portable systems.

[0068] This utility model also provides a filter, including a PCB printed circuit board and the filter circuit described above;

[0069] The filter circuit is mounted on the PCB printed circuit board.

[0070] In this embodiment, the filter circuit is modularly packaged using a PCB printed circuit board, facilitating industrial production and subsequent maintenance. The filter is suitable for signal filtering within the frequency range of 0.150MHz-1MHz, classifying it as a wideband filter. This filter features a simple structure, reasonable design, small size, and stable performance, making it particularly suitable for various miniaturized, portable electronic devices and medical equipment.

[0071] In one possible implementation, the PCB printed circuit board has a length of 115mm and a width of 50mm.

[0072] In this embodiment, the input port P1, the filter network, and the output port P2 in the filter circuit can be arranged sequentially along the length of the PCB printed circuit board. The input port P1 and the output port P2 are located at the edge of the PCB printed circuit board.

[0073] The above embodiments should not limit the present invention in any way. All technical solutions obtained by equivalent substitution or equivalent conversion fall within the protection scope of the present invention.

Claims

1. A filter circuit suitable for filtering signals in the frequency range 0.150 MHz - 1 MHz, characterized in that include: Input port, output port, filter network; The filter network is electrically connected between the input port and the output port; The filter network includes a first inductor unit, a second inductor unit, a first capacitor unit, a second capacitor unit, a third capacitor unit, a fourth capacitor unit, and a first inductor element; The protective grounding terminal of the input port, the first inductor element, and the protective grounding terminal of the output port are connected in series via a protective grounding wire. The AC neutral line terminal and AC phase line terminal of the input port are electrically connected to the first input terminal and the second input terminal of the first inductor unit, respectively. The first output terminal of the first inductor unit is electrically connected to the first terminal of the first capacitor unit, the first terminal of the third capacitor unit, and the first input terminal of the second inductor unit, and its second output terminal is electrically connected to the first terminal of the second capacitor unit, the second terminal of the third capacitor unit, and the second input terminal of the second inductor unit. The second end of the first capacitor unit and the second end of the second capacitor unit are respectively electrically connected to the protective grounding wire; The first output terminal of the second inductor unit is electrically connected to the first terminal of the fourth capacitor unit and the AC neutral line terminal of the output port, respectively, and its second output terminal is electrically connected to the second terminal of the fourth capacitor unit and the AC phase line terminal of the output port, respectively. Wherein, the first input terminal and the first output terminal of the first inductor unit are connected, and its second input terminal and the second output terminal are connected; The first input terminal of the second inductor unit is connected to the first output terminal, and its second input terminal is connected to the second output terminal.

2. The filter circuit of claim 1, wherein, The first inductor unit includes a second inductor element and a third inductor element; The first and second input terminals of the second inductor element serve as the first and second input terminals of the first inductor unit, respectively, and its first and second output terminals are electrically connected to the first and second input terminals of the third inductor element, respectively. The first and second output terminals of the third inductor element serve as the first and second output terminals of the first inductor unit, respectively.

3. The filter circuit of claim 2, wherein, The second inductor unit includes a fourth inductor element and a fifth inductor element; The first and second input terminals of the fourth inductor element serve as the first and second input terminals of the second inductor unit, respectively, and its first and second output terminals are electrically connected to the first and second input terminals of the fifth inductor element, respectively. The first and second output terminals of the fifth inductor element serve as the first and second output terminals of the second inductor unit, respectively.

4. The filter circuit of claim 3, wherein, The first inductor has a capacitance of 5mH, the second inductor has a capacitance of 15mH, the third inductor has a capacitance of 6mH, the fourth inductor has a capacitance of 30mH, and the fifth inductor has a capacitance of 5mH.

5. The filter circuit of claim 1, wherein, The first capacitor unit includes a first capacitor and a second capacitor connected in series; The second capacitor unit includes a third capacitor and a fourth capacitor connected in series.

6. The filter circuit of claim 5, wherein, The third capacitor unit includes a fifth capacitor; The fourth capacitor unit includes the sixth capacitor.

7. The filter circuit of claim 6, wherein, The first capacitor, the second capacitor, the third capacitor, and the fourth capacitor are all 1000pF, and the fifth capacitor and the sixth capacitor are both 4700pF.

8. The filter circuit of claim 6, wherein, The fifth and sixth capacitors are X-type safety capacitors.

9. A filter, characterized by Includes a PCB printed circuit board and a filter circuit as described in any one of claims 1 to 8; The filter circuit is mounted on the PCB printed circuit board.

10. The filter of claim 9, wherein, The PCB printed circuit board is 115mm long and 50mm wide.

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