CN218850737U

CN218850737U - Low-pass filter

Info

Publication number: CN218850737U
Application number: CN202122659187.4U
Authority: CN
Inventors: 胡海涛; 闫煜峰; 迟晓峰; 吴欣然; 吴晓言; 李梅
Original assignee: Beijing Bbef Science and Technology Co Ltd
Current assignee: Beijing Bbef Science and Technology Co Ltd
Priority date: 2021-11-02
Filing date: 2021-11-02
Publication date: 2023-04-11
Anticipated expiration: 2031-11-02

Abstract

The utility model provides a low-pass filter, which relates to the technical field of filters and comprises a plurality of filter units; each filter unit covers one sub-band frequency, and the combination of a plurality of sub-band frequencies covers the full-band working frequency; a rotating shaft, the plurality of filter units being coaxially arranged with the transmission shaft as a center; and a switching device which selects the filter unit, the low pass filter having a simple structure and capable of realizing full band filtering. The suppression of the short wave broadcast transmitting equipment outside the full frequency band can be realized, the impedance is stable, the size is small, the working frequency covers the frequency range of 3.2MHz-26.1MHz, the improvement of the out-of-band working index is facilitated, and the installation size is small, so that the cost is saved.

Description

Low-pass filter

Technical Field

The utility model relates to a wave filter technical field especially relates to a low pass filter.

Background

In a common wireless communication system, a filter is an indispensable component and is mainly used for frequency band selection and filtering, the filter is a filter circuit consisting of a capacitor, an inductor and a resistor, and the filter can effectively filter a frequency point of a specific frequency in a power line or frequencies except the frequency point to obtain a power signal of the specific frequency or eliminate the power signal of the specific frequency;

based on the design principle of a low-pass filter, the short-wave full-band filter needs to be segmented, the filter designed in the traditional mode is large in size, a change-over switch needs to be added for achieving the full-band, and the cost is high.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a low pass filter, this low pass filter simple structure to can realize full frequency channel filtering.

An embodiment of the present invention provides a low pass filter, which includes,

a plurality of filter units; each filter unit covers one sub-band frequency, and the combination of a plurality of sub-band frequencies covers the full-band working frequency;

a rotating shaft, the plurality of filter units being coaxially arranged with the transmission shaft as a center;

a switching device that selects the filter unit to implement full band filtering.

As a possible implementation manner, the switching device includes a switch and a transmission motor, and the transmission motor drives the driving switch to selectively conduct the plurality of filter units.

In one possible embodiment, the number of the switching devices is two, one of the switching devices is close to the signal input end, and the other switching device is close to the signal output end.

As a possible implementation, the plurality of filter units are uniformly arranged on the periphery of the transmission shaft.

As a possible implementation manner, the low-pass filter further includes a housing, and the switch, the transmission motor and the plurality of sets of filter units are disposed in the housing.

As a possible implementation manner, the signal input end of the low-pass filter is configured at the bottom of the housing, the signal output end is configured at the top of the housing, and the signal is input at the signal input end and output to the signal output end through the filter unit.

As a possible implementation manner, the low-pass filter includes six filter units, namely a first filter unit, a second filter unit, a third filter unit, a fourth filter unit, a fifth filter unit and a sixth filter unit, each filter unit covers a sub-band frequency, and the transmission motor drives the driving switch to selectively conduct a plurality of filter units to filter harmonic signals.

As a possible implementation manner, the first filter unit includes a first capacitor circuit, a first inductor, a second capacitor circuit, a second inductor, a third capacitor circuit, a third inductor, and a fourth capacitor circuit that are sequentially connected in series, and a signal is input through the signal input end and output through the fourth capacitor circuit.

As a possible implementation, the circuit structures of the second filter unit and the third filter unit are the same as the circuit structure of the first filter unit, and the capacitance is different.

As a possible implementation mode, the working frequency of the low-pass filter covers the low-frequency 3.2MHz-26.1MHz frequency range.

Advantageous effects

The utility model provides a low-pass filter, which comprises a plurality of filter units; each filter unit covers one sub-band frequency, and the combination of a plurality of sub-band frequencies covers the full-band working frequency; a rotating shaft, the plurality of filter units being coaxially arranged with the transmission shaft as a center; and a switching device for selecting the filter unit, wherein the low-pass filter has a simple structure and can realize full-band filtering.

Drawings

In order to more clearly illustrate one or more embodiments or prior art solutions of the present specification, the drawings used in the description of the embodiments or prior art will be briefly described below, it is obvious that the drawings in the description below are only some embodiments described in the present specification, and that other drawings may be obtained by those skilled in the art without inventive labor.

Fig. 1 is a schematic plan view of a low-pass filter according to an embodiment of the present invention;

fig. 2 is a schematic perspective plan view of a low pass filter according to an embodiment of the present invention;

fig. 3 is a circuit diagram of a low pass filter according to an embodiment of the present invention;

fig. 4 is a circuit diagram of a first filter unit according to an embodiment of the present invention;

fig. 5 is a circuit diagram of a second filter unit according to an embodiment of the present invention;

fig. 6 is a circuit diagram of a third filter unit according to an embodiment of the present invention;

fig. 7 is a circuit diagram of a fourth filter unit according to an embodiment of the present invention;

fig. 8 is a circuit diagram of a fifth filter unit according to an embodiment of the present invention;

fig. 9 is a circuit diagram of a sixth filter unit according to an embodiment of the present invention.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the following embodiments, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

The invention will be further described with reference to the following description and specific examples, taken in conjunction with the accompanying drawings:

fig. 1 shows a schematic plan structure diagram of a low-pass filter according to an embodiment of the present invention; fig. 2 is a schematic perspective view of an embodiment of the present invention; fig. 3 is a circuit diagram of a low pass filter according to an embodiment of the present invention; as shown in fig. 1-3, the low pass filter includes,

a plurality of filter units 60; each filter unit covers one sub-band frequency, and the combination of a plurality of sub-band frequencies covers the full-band working frequency;

a rotating shaft 50, the plurality of filter units 60 being coaxially arranged with the transmission shaft 50 as a center;

a switching device 30, wherein the switching device 30 selects the filter unit 60 to realize full-band filtering.

The present embodiment proposes a low-pass filter including a plurality of filter units 60; wherein each filter unit 60 covers one sub-band frequency, and a combination of multiple sub-band frequencies covers the full-band operating frequency; a rotating shaft 50, the plurality of filter units 60 being coaxially arranged around the shaft 50; and a switching device 30, wherein the switching device 30 selects the filter unit 60, and a signal is input at the signal input end 10 and output to the signal output end 20 through the filter unit. The suppression of the short wave broadcast transmitting equipment outside the full frequency band can be realized, the impedance is stable, the size is small, the working frequency covers the frequency range of 3.2MHz-26.1MHz, the improvement of the out-of-band working index is facilitated, and the installation size is small, so that the cost is saved.

Specifically, the switching device 30 includes a switch 301 and a transmission motor, and the transmission motor drives the driving switch 301 to selectively turn on the plurality of filter units 60. The switching means 30 may be two, one being close to the signal input 10 and the other being close to the signal output 20.

In some embodiments, the plurality of filter units 60 are uniformly arranged on the outer circumference of the transmission shaft. The 6 filter units can cover the working frequency in sequence, can be combined to cover the frequency range of 3.2MHz-26.1MHz at the low frequency, and can also be combined to cover the frequency range of 3.2MHz-26.1MHz at the low frequency in a disorderly sequence.

Specifically, the low pass filter further includes a housing 40, and the switch 301, the transmission motor, and the plurality of filter units 60 are disposed in the housing 40. The signal input terminal 10 of the low pass filter is disposed at the bottom of the housing 40, the signal output terminal 20 is disposed at the top of the housing 40, and the signal is input at the signal input terminal 10 and then output to the signal output terminal 20 through the filter unit 60. The low-pass filter includes six filter units, namely a first filter unit 601, a second filter unit 602, a third filter unit 603, a fourth filter unit 604, a fifth filter unit 605 and a sixth filter unit 606, each filter unit covers a sub-band frequency, and the driving motor drives the driving switch 301 to selectively switch on the plurality of filter units 60 to filter harmonic signals, and only the carrier signals can pass through.

fig. 4 is a circuit diagram of a first filter unit according to an embodiment of the present invention; fig. 5 is a circuit diagram of a second filter unit according to an embodiment of the present invention; fig. 6 is a circuit diagram of a third filter unit according to an embodiment of the present invention;

as shown in fig. 4-6, the first filter unit 601 includes a first capacitor circuit 6011, a first inductor L1, a second capacitor circuit 6012, a second inductor L2, a third capacitor circuit 6013, a third inductor L3, and a fourth capacitor circuit 6014 connected in series in sequence, where a signal is input through the signal input terminal and output through the fourth capacitor circuit 6014. One end of the first capacitor circuit 6011 is connected to the input end of the first inductor L1, the other end is grounded, one end of the second capacitor circuit 6012 is connected to the input end of the second inductor L2, the other end is grounded, one end of the third capacitor circuit 6013 is connected to the input end of the third inductor L3, the other end is grounded, one end of the fourth capacitor circuit 6014 is connected to the output end of the third inductor L3, the other end is grounded, the circuit structures of the second filter unit 602 and the third filter unit 603 are the same as the circuit structure of the first filter unit 601, and the capacitances are different.

Fig. 7 is a circuit diagram of a third filter unit according to an embodiment of the present invention; fig. 7 is a circuit diagram of a fourth filter unit according to an embodiment of the present invention; fig. 8 is a circuit diagram of a fifth filter unit according to an embodiment of the present invention; fig. 9 is a circuit diagram of a sixth filter unit according to an embodiment of the present invention. The working principle of the circuit is the same as that of the circuit diagram of the first filter unit, and the description thereof is omitted.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention.

Claims

1. A low-pass filter, characterized in that the low-pass filter comprises:

a plurality of filter units, wherein each filter unit covers one sub-band frequency, and the combination of the plurality of sub-band frequencies covers the full-band operating frequency;

a transmission shaft, the plurality of filter units being coaxially arranged with the transmission shaft as a center;

2. A low-pass filter as claimed in claim 1, characterized in that the switching means comprise a switch and a drive motor, which drives the switch to selectively switch on the plurality of filter units.

3. A low-pass filter as claimed in claim 2, characterized in that said switching means are two, one near the signal input and the other near the signal output.

4. A low-pass filter as claimed in claim 1, wherein said plurality of filter units are arranged uniformly around the periphery of said drive shaft.

5. A low-pass filter as claimed in claim 2, further comprising a housing, said switch and said drive motor and sets of filter units being disposed within said housing.

6. A low-pass filter as claimed in claim 3, characterized in that the signal input of the low-pass filter is arranged at the bottom of the housing and the signal output is arranged at the top of the housing, the signal being input at the signal input and output via the filter unit to the signal output.

7. A low-pass filter as claimed in claim 3, characterized in that the low-pass filter comprises six filter units, namely a first filter unit, a second filter unit, a third filter unit, a fourth filter unit, a fifth filter unit and a sixth filter unit, each filter unit covers a sub-band frequency, and the driving motor drives the switch to selectively switch on the plurality of filter units to filter out harmonic signals.

8. A low-pass filter as claimed in claim 7, characterized in that said first filter unit comprises a first capacitor circuit, a first inductor, a second capacitor circuit, a second inductor, a third capacitor circuit, a third inductor, and a fourth capacitor circuit connected in series in this order, and a signal is input through said signal input terminal and output through said fourth capacitor circuit.

9. A low-pass filter as claimed in claim 7, characterized in that the circuit configuration of the second filter unit and the third filter unit is identical to the circuit configuration of the first filter unit and has a different capacitance.

10. A low-pass filter as claimed in any one of claims 1 to 9, characterized in that the operating frequency of the low-pass filter covers a low frequency range of 3.2MHz to 26.1 MHz.