CN215187067U - Filter circuit and television antenna amplifier - Google Patents

Abstract

The application provides a filter circuit and a television antenna amplifier, wherein the filter circuit comprises a switching module, and the switching module comprises a control unit and at least two filter units. This application makes one of at least two filter unit switch on through the control unit switchablely, filters the signal of different frequencies in the input signal through at least two filter unit to can switch different filter unit according to the filtering requirement of different regional frequency signal, application scope is extensive.

Description

Filter circuit and television antenna amplifier

Technical Field

The application belongs to the technical field of signal processing, and particularly relates to a filter circuit and a television antenna amplifier.

Background

An antenna is a component used in a radio device for transmitting or receiving electromagnetic waves, which converts a guided wave propagating on a transmission line into an electromagnetic wave propagating in an unbounded medium (usually free space) or vice versa. In radio communication, broadcasting, television, radar, navigation, electronic countermeasure, remote sensing, radio astronomy and other engineering systems, all of which transmit information by using electromagnetic waves, the systems operate by using antennas, and the antennas are generally provided with antenna amplifiers.

The antenna amplifier is an ultrahigh frequency, broadband and low noise amplifier used between an antenna and a feeder line, and is generally used for filtering interference signals and enhancing received weak signals, so that the information receiving quality is improved. However, the filter circuit inside the antenna amplifier can only filter one frequency signal of multiple interference signals, and the filter signal is single and has a narrow application range.

SUMMERY OF THE UTILITY MODEL

An object of the application is to provide a filter circuit, aim at solving the single problem of traditional filter circuit filtering interference signal frequency.

In order to achieve the above object, in a first aspect, an embodiment of the present application provides a filter circuit, including a switching module, where the switching module includes a control unit and at least two filter units;

the at least two filtering units are respectively used for filtering signals with different frequencies in the input signals;

the control unit is used for switchably enabling one filtering unit of the at least two filtering units to be conducted, and the rest filtering units to be not conducted.

In a possible implementation manner of the first aspect, the at least two filtering units are connected in parallel, the control unit includes a switch and a PIN diode, the switch is used for switching and connecting a power supply to one of the at least two filtering units, and an input end and an output end of each filtering unit are respectively connected with an anode of one PIN diode.

In another possible implementation manner of the first aspect, the filtering unit includes a first capacitor, and a first inductor, at least one resonant unit, and a second inductor connected in series, where one end of the first capacitor is connected to one end of the resonant unit, and the other end of the first capacitor is grounded.

In another possible implementation manner of the first aspect, the resonant unit includes a third inductor, a second capacitor, and a third capacitor, where the third inductor is connected in parallel with the second capacitor, one end of the third capacitor is connected to one end of the second capacitor, and the other end of the third capacitor is grounded.

In another possible implementation of the first aspect, the at least two filtering units comprise a 4G filtering unit and a 5G filtering unit; the 4G filtering unit is used for filtering 4G mobile communication signals in the input signals; the 5G filtering unit is used for filtering 5G mobile communication signals in the input signals; the control unit is used for switchably enabling the 4G filtering unit or the 5G filtering unit to be conducted;

the input signal is a ground wave television signal, the filter circuit further comprises a high-pass filter module, the output end of the high-pass filter module is connected with the input end of the switching module, and the high-pass filter module is used for enabling an ultrahigh frequency signal or a very high frequency signal and an ultrahigh frequency signal in the ground wave television signal to pass through.

In another possible implementation manner of the first aspect, the high-pass filtering module includes multiple sets of filtering units and a fourth capacitor connected in series, the filtering unit includes a fourth inductor, a fifth capacitor and a sixth capacitor, one end of the fifth capacitor is an input end of the filtering unit, the other end of the fifth capacitor is connected to one end of the fourth inductor, the other end of the fifth capacitor is an output end of the filtering unit, and the other end of the fourth inductor is grounded after being connected in series to the sixth capacitor.

In another possible implementation manner of the first aspect, the filter circuit further includes an amplifying module, an input end of the amplifying module is connected to an output end of the switching module, and the amplifying module is configured to amplify the signal filtered by the switching module.

In another possible implementation manner of the first aspect, the filter circuit further includes a signal strength adjusting module, an output end of the signal strength adjusting module is connected to an input end of the switching module, and the signal strength adjusting module is configured to adjust the strength of the input signal.

In another possible implementation manner of the first aspect, the signal strength adjusting module includes an adjustable resistor and a resistor, a fixed end of the adjustable resistor is connected in series with the resistor and then grounded, and a sliding end of the adjustable resistor is connected to the input end of the switching module.

In a second aspect, an embodiment of the present application provides a television antenna amplifier, including the filter circuit.

Compared with the prior art, the embodiment of the application has the advantages that: according to the filter circuit, one of the at least two filter units is switched on through the control unit in a switchable manner, and signals with different frequencies in the input signals are filtered through the at least two filter units, so that different filter units can be switched according to the filtering requirements of frequency signals in different regions, and the application range is wide.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a switching module of a filter circuit according to an embodiment of the present disclosure;

fig. 2(a) -fig. 2(b) are two circuit schematic diagrams of a filtering unit of a filtering circuit provided in an embodiment of the present application;

fig. 3 is a circuit schematic diagram of a switching module of a filter circuit according to an embodiment of the present disclosure;

fig. 4 is a circuit schematic diagram of a high-pass filtering module of a filtering circuit provided in an embodiment of the present application;

fig. 5 is a schematic circuit diagram of an amplifying module of a filter circuit according to an embodiment of the present disclosure;

fig. 6 is a circuit schematic diagram of a signal strength adjusting module of a filter circuit according to an embodiment of the present disclosure;

fig. 7 is a waveform diagram of a signal with a 4G frequency filtered by the filter circuit according to an embodiment of the present disclosure;

fig. 8 is a waveform diagram of a signal filtered by the filter circuit according to the embodiment of the present application for filtering a 5G frequency;

fig. 9 is a european certification standard diagram of gain values of frequency signals of a filter circuit according to an embodiment of the present application.

Wherein, in the figures, the respective reference numerals:

the device comprises a 1-switching module, a 11-control unit, a 12-filtering unit, a 2-high-pass filtering module, a 3-amplifying module and a 4-signal intensity adjusting module.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects to be solved by the present application clearer, the present application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or be indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or be indirectly connected to the other element.

It will be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like, refer to an orientation or positional relationship illustrated in the drawings for convenience in describing the present application and to simplify description, and do not indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the present application.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present application, "at least two" means two or more unless specifically limited otherwise.

The signal receiving end of the television antenna can often receive ground wave television signals and mobile communication signals of a mobile phone at the same time, but the television antenna generally only needs the ground wave television signals, the mobile communication signals of the mobile phone are interference signals, the television antenna amplifier of the traditional antenna generally can only filter one mobile communication signals of the mobile phone, the filtered signals are single, the application range is small, and the effect of filtering the signals can be lost when the local frequency signals are changed or the geographical position of the television antenna amplifier is changed.

Therefore, the filtering circuit integrates at least two filtering units for filtering signals with different frequencies, and different filtering units are switched to be conducted through the control unit, so that filtering of signals with different frequencies in input signals of the television antenna is achieved. Therefore, different filtering units can be selected to filter frequency signals with the maximum interference according to local actual requirements, so that the mutual interference between ground wave television signals received by the television and mobile communication signals of the mobile phone is avoided, the actual receiving effect of the television is improved, the filtering requirements of the frequency signals in different regions can be met, and the application range is wide.

Fig. 1 is a schematic structural diagram of a filter circuit provided in a first embodiment of the present application, and as shown in fig. 1, for convenience of description, only a part related to the present embodiment is shown, and the present application shows a filter circuit, which includes a switch module 1, where the switch module 1 includes a control unit 11 and at least two filter units 12; the at least two filtering units 12 are respectively used for filtering signals with different frequencies in the input signal; the control unit is configured to switchably render one filter unit 12 of the at least two filter units 12 conductive and the remaining filter units 12 non-conductive.

In the embodiment of the present application, only one filtering unit 12 of at least two filtering units 12 is turned on by the control unit 11 at a time to filter a signal of one frequency in the input signal, so that different filtering units 12 can be freely switched on by the control unit 11 according to local actual needs, and signals of different frequencies in the input signal are respectively filtered, and are individually debugged without interfering with each other.

Illustratively, when the Mobile Communication signals in the filter circuit application area are mainly the Mobile Communication signals of the 4 th-Generation Mobile Communication Technology (4G) and the Mobile Communication signals of the fifth-Generation Mobile Communication Technology (5G), the at least two filter units 12 may include a 4G filter unit and a 5G filter unit; the 4G filtering unit is used for filtering 4G mobile communication signals in the input signals; the 5G filtering unit is used for filtering 5G mobile communication signals in the input signals; the control unit is used for switchably enabling the 4G filtering unit or the 5G filtering unit to be conducted.

In the embodiment of the application, the 4G filtering unit or the 5G filtering unit is switched on through the control unit according to the requirement of filtering the 4G mobile communication signal or the 5G mobile communication signal according to the regional requirement, so that the 4G frequency or the 5G frequency in the input ground wave television signal is filtered, the mutual interference between the ground wave television signal received by the television and the mobile communication signal of the mobile phone is avoided, and the actual receiving effect of the television is improved. The terrestrial wave television signals may include terrestrial digital television signals and terrestrial analog television signals, among others.

Illustratively, at least two filtering units 12 are connected in parallel, the control unit 11 includes a switch and a PIN diode, the switch is used for switching and connecting the power supply to one filtering unit 12 of the at least two filtering units 12, and the input end and the output end of each filtering unit 12 are respectively connected with the anode of one PIN diode.

In the embodiment of the application, the input end and the output end of each filtering unit 12 are respectively connected with the anode of a PIN diode, namely, each filtering unit 12 is connected with two PIN diodes, through the characteristics of good performance and thorough performance when the PIN diodes are switched on and switched off, one filtering unit 12 corresponding to two PIN diodes is switched on completely, other filtering units 12 are switched off completely, the signal insertion loss is small, and the isolation effect is good.

In this embodiment of the application, the at least two filtering units 12 may include two or more than two, and when the at least two filtering units 12 include more than two, only the corresponding PIN diodes and the filtering units 12 need to be added, and the switches are adjusted to the corresponding number of section switches, such as three-section switches, four-section switches, and only one of the filtering units 12 is turned on each time.

Wherein, the PIN diode specifically is: a thin layer of low-doped intrinsic semiconductor layer is added between P and N semiconductor materials of a common diode to form a P-I-N structure diode, and the PIN diode has wide application from low Frequency to high Frequency, is mainly used in the field of Radio Frequency (RF) and is used as an RF switch and an RF protection circuit.

Fig. 2(a) -2 (b) are schematic diagrams of filtering units of a filtering circuit provided in an embodiment of the present application, and different filtering units may be selected for different input signals.

Illustratively, as shown in fig. 2(a), the filtering unit 12 may include: one end of an inductor L13 is connected with one end of an inductor L14, one end of a capacitor C35 and one end of a capacitor C38, the other end of the inductor L14, the other end of the capacitor C35 and one end of a capacitor C33 are connected with one end of an inductor L19, the other end of the capacitor C38 and the other end of the capacitor C33 are all grounded, wherein the capacitor C38 is a first capacitor, the inductor L13 is a first inductor, the inductor L19 is a first inductor, and the inductor L14, the capacitor C35 and the capacitor C33 are resonant units.

Illustratively, as shown in fig. 2(b), the filtering unit 12 may include: an inductor L13, an inductor L14, an inductor L15, an inductor L16, an inductor L17 and an inductor L19 are sequentially connected, a capacitor C35 is connected in parallel to two ends of the inductor L13, a capacitor C31 is connected in parallel to two ends of the inductor L15, a capacitor C28 is connected in parallel to two ends of the inductor L16, a capacitor C26 is connected in parallel to two ends of the inductor L17, one end of a capacitor C38 is connected to a common connection position of the inductor L13 and the inductor L14, one end of a capacitor C33 is connected to a common connection position of the capacitor C35 and the capacitor C31, one end of a capacitor C29 is connected to a common connection position of the capacitor C31 and the capacitor C28, one end of a capacitor C27 is connected to a common connection position of the capacitor C28 and the capacitor C26, one end of a capacitor C25 is connected to a common connection position of the capacitor C26 and the inductor L19, and the other end of the capacitor C38, the other end of the capacitor C33 and the other end of the capacitor C29 are all grounded. The capacitor C38 is a first capacitor, the inductor L13 is a first inductor, and the inductor L19 is a first inductor, (the inductor L14, the capacitor C35, the capacitor C33), (the inductor L15, the capacitor C31, the capacitor C29), (the inductor L16, the capacitor C28, the capacitor C27), (the inductor L17, the capacitor C26, and the capacitor C25) are all resonant units.

Illustratively, the filtering unit 12 may include at least two capacitors connected in series.

Illustratively, two filter units 12 are taken as an example. In the circuit provided by the application, the filtering unit 12 may include a thirteenth inductor L13, a fourteenth inductor L14, a fifteenth inductor L15, a sixteenth inductor L16, a seventeenth inductor L17, and a nineteenth inductor L19, a nineteenth resistor R19 in the control unit 11 is sequentially connected to anodes of the fourteenth inductor L14, the thirteenth inductor L13, and the third PIN diode D3, and a nineteenth resistor R19 is sequentially connected to anodes of the fifteenth inductor L15, the sixteenth inductor L16, the seventeenth inductor L17, the nineteenth inductor L19, and the fifth PIN diode D5.

A common connection point of a fourteenth inductor L14 and a thirteenth inductor L13 is connected with one end of a thirty-fifth capacitor C35 and one end of a thirty-eighth capacitor C38, a common connection point of a fourteenth inductor L14 and a fifteenth inductor C15 is connected with the other end of a thirty-fifth capacitor C35, one end of a thirty-third capacitor C33 and one end of a thirty-eleventh capacitor C31, a common connection point of a fifteenth inductor L15 and a sixteenth inductor L16 is connected with the other end of a thirty-eleventh capacitor C31, one end of a twenty-ninth capacitor C29 and one end of a twenty-eighth capacitor C28, a common connection point of a sixteenth inductor L16 and a seventeenth inductor L17 is connected with the other end of a twenty-eighth capacitor C28, one end of a twenty-seventh capacitor C27 and one end of a twenty-sixth capacitor C26, a common connection point of a seventeenth inductor L17 and a nineteenth inductor L19 is connected with the other end of a twenty-sixth capacitor C26 and one end of a twenty-eighth capacitor C25, and the thirty-eighth capacitor C38, the other end of the thirty-third capacitor C33, the other end of the twenty-ninth capacitor C29, the other end of the twenty-seventh capacitor C27 and the other end of the twenty-fifth capacitor C25 are all grounded, and the filtering effect is good.

In the circuit provided by the application, the filtering unit 12 may include a twenty-seventh inductor L27, a twenty-sixth inductor L26, a twenty-fifth inductor L25, a twenty-fourth inductor L24, a twenty-eighth inductor L28 and a twenty-ninth inductor L29, a twenty-third resistor R23 in the control unit 11 sequentially connects anodes of the twenty-seventh inductor L27, the twenty-sixth inductor L26, the twenty-fifth inductor L25, the twenty-fourth inductor L24 and the fourth PIN diode D4, and a twenty-third resistor R23 sequentially connects anodes of the twenty-eighth inductor L28, the twenty-ninth inductor L29 and the sixth PIN diode D6.

A common connection point of a twenty-fourth inductor L24 and a twenty-fifth inductor L25 is connected with one end of a fifty-fifth capacitor C55 and one end of a fifty-sixth capacitor C56, a common connection point of a twenty-fifth inductor L25 and a twenty-sixth inductor L26 is connected with the other end of a fifty-sixth capacitor C56, one end of a fifty-seventh capacitor C57 and one end of a fifty-eighth capacitor C58, a common connection point of a twenty-sixth inductor L26 and a twenty-seventh inductor L27 is connected with the other end of a fifty-eighth capacitor C58, one end of a fifty-ninth capacitor C59 and one end of a sixty capacitor C60, a common connection point of a twenty-seventh inductor L27 and a twenty-eighth inductor L28 is connected with the other end of a sixty capacitor C60, one end of a sixty-first capacitor C61 and one end of a sixty-second capacitor C62, a common connection point of a twenty-eighth inductor L28 and a twenty-ninth inductor L29 is connected with the other end of a sixty capacitor C62 and one end of a sixty capacitor C63, the other end of the fifty-fifth capacitor C55, the other end of the fifty-seventh capacitor C57, the other end of the fifty-ninth capacitor C59, the other end of the sixty-first capacitor C61 and the other end of the sixty-third capacitor C63 are all grounded, and the filtering effect is good.

Based on the filter unit 12 shown in fig. 2(b), fig. 3 is a circuit schematic diagram of the switching module of the filter circuit provided in the embodiment of the present application, as shown in fig. 3, exemplarily, the control unit 11 may include a switch K1 and a third PIN diode D3, a fourth PIN diode D4, a fifth PIN diode D5 and a sixth PIN diode D6, a first PIN of the switch K1 is connected to one end of a thirtieth capacitor C30 and the power VCC, a second PIN of the switch K1 is connected to one end of a fifty-third capacitor C53 and one end of a thirty-second inductor L32, another end of the fifty-second inductor L32 is connected to one end of a fifty-first capacitor C51 and one end of a nineteenth resistor R19, another end of a nineteenth resistor R19 is connected to the filter unit 12, and another ends of the thirty-first capacitor C30, the third capacitor C53 and the fifty-first capacitor C51 are all grounded; a third pin of the switch K1 is connected to one end of a fifty-fourth capacitor C54 and one end of a thirty-seventh inductor L37, the other end of the thirty-seventh inductor L37 is connected to one end of a forty-ninth capacitor C49 and one end of a twenty-third resistor R23, the other end of the twenty-third resistor R23 is connected to the filtering unit 12, and the other end of the fifty-fourth capacitor C54 and the other end of the forty-ninth capacitor C49 are both grounded.

Exemplarily, the anode of the third PIN diode D3 is connected to the input terminal of the filtering unit 12, the cathode of the third PIN diode D3 is connected to one end of an eighteenth capacitor C18 and a fifteenth resistor R15, the other end of the eighteenth capacitor C18 is connected to the input signal, and the other end of the fifteenth resistor R15 is grounded; the anode of the fifth PIN diode D5 is connected to the output end of the filter unit 12, the cathode of the fifth PIN diode D5 is connected to one end of a forty-sixth capacitor C46 and one end of an eighteenth resistor R18, the other end of the eighteenth resistor R18 is grounded, and the other end of the forty-sixth capacitor C46 outputs a signal.

The anode of the fourth PIN diode D4 is connected with the input end of the filtering unit 12, the cathode of the fourth PIN diode D4 is connected with the common connection part of the eighteenth capacitor C18 and the fifteenth resistor R15, the anode of the sixth PIN diode D6 is connected with the output end of the filtering unit 12, and the cathode of the sixth PIN diode D6 is connected with the common connection part of the forty-sixth capacitor C46 and the eighteenth resistor R18.

In the embodiment of the application, when the switch K1 is turned on, a current flows from the nineteenth resistor R19 through the thirteenth inductor L13, the fourteenth inductor L14, the fifteenth inductor L15, the sixteenth inductor L16, the seventeenth inductor L17, and the nineteenth inductor L19 through the third PIN diode D3 and the fifth PIN diode D5, respectively, so that the third PIN diode D3 and the fifth PIN diode D5 are turned on, at this time, the fourth PIN diode D4 and the sixth PIN diode D6 are turned off, and after passing through the above circuit, a signal with a frequency above 790MHz is filtered.

When the switch K1 switches on the third PIN, current flows from the twenty-third resistor R23 through the twenty-seventh inductor L27, the twenty-sixth inductor L26, the twenty-fifth inductor L25, the twenty-fourth inductor L24, the twenty-eighth inductor L28, and the twenty-ninth inductor L29 through the fourth PIN diode D4 and the sixth PIN diode D6, respectively, so that the fourth PIN diode D4 and the sixth PIN diode D6 are turned on, at this time, the third PIN diode D3 and the fifth PIN diode D5 are turned off, the signal with a frequency of 694MHz or higher is filtered out after passing through the above circuits, and the filtered signal is output to the low-noise amplification module 6 through the forty-sixth capacitor C46.

In this embodiment of the application, the control unit 11 may also be implemented by using a multi-switch component or an intelligent controller, and specifically, the intelligent controller determines according to a detection result of a mobile communication signal in an actual input signal to implement automatic switching.

Fig. 4 is a schematic circuit diagram of a high-pass filtering module of the filtering circuit provided in the embodiment of the present application, as shown in fig. 4, an input signal is a ground wave television signal, the filtering circuit further includes the high-pass filtering module, an output end of the high-pass filtering module is connected to an input end of the switching module, and the high-pass filtering module is configured to pass an ultra-high frequency signal or a very-high frequency signal and an ultra-high frequency signal in the ground wave television signal.

In the embodiment of the present application, when the input signal is a terrestrial television signal, the Ultra High Frequency (UHF) signal or the Very High Frequency (VHF) signal and the ultrahigh Frequency signal in the terrestrial television signal are passed through the High-pass filtering module, because the input signal is usually 470MHz or more for terrestrial television and belongs to the ultrahigh Frequency signal.

The high-pass filtering module 2 may include multiple sets of filtering units and a fourth capacitor connected in series, the filtering unit includes a fourth inductor, a fifth capacitor and a sixth capacitor, one end of the fifth capacitor is an input end of the filtering unit, the other end of the fifth capacitor is connected with one end of the fourth inductor, the other end of the fifth capacitor is an output end of the filtering unit, and the other end of the fourth inductor is grounded after being connected in series with the sixth capacitor.

Specifically, in the embodiment of the present application, the high-pass filtering module 2 may include a capacitor C2, a capacitor C3, a capacitor C4, a capacitor C5, a capacitor C6, a capacitor C7, a capacitor C9, an inductor L2, an inductor L3, and an inductor L4, where an input signal is sequentially connected to the capacitor C2, the capacitor C3, the capacitor C4, and the capacitor C9, a common connection between the capacitor C2 and the capacitor C3 is sequentially connected to one ends of the inductor L2 and the capacitor C5, a common connection between the capacitor C3 and the capacitor C4 is sequentially connected to one ends of the inductor L3 and the capacitor C6, a common connection between the capacitor C4 and the capacitor C9 is sequentially connected to one end of the inductor L4 and the capacitor C7, and the other end of the capacitor C5, the other end of the capacitor C6, and the other end of the capacitor C7 are all grounded. Wherein C9 is a fourth capacitor, (capacitor C2, inductor L2, capacitor C5), (capacitor C3, inductor L3, capacitor C6), (capacitor C4, inductor L4, and capacitor C7) are all the filter units 12.

In the embodiment of the present application, the high-pass filtering module 2 may be a band-pass filter or a band-stop filter, and only the ultra-high frequency signal or the very-high frequency signal and the ultra-high frequency signal pass through, for example, the high-pass filtering module 2 may only pass through a terrestrial television signal above 470MHz, that is, filter a frequency signal below 470MHz, and retain the ultra-high frequency signal. In the field of communication circuits, low-frequency signals are 30-300 kHz signals, medium-frequency signals are 300-3000 kHz signals, high-frequency signals are 3-30 MHz signals, the frequency range is 30-300 MHz signals which are very high-frequency signals, and the frequency range is 300-3000 MHz signals which are ultrahigh-frequency signals.

Fig. 5 is a schematic circuit diagram of an amplifying module of a filter circuit provided in an embodiment of the present application, and as shown in fig. 5, the filter circuit further includes an amplifying module 3, an input end of the amplifying module 3 is connected to an output end of the switching module 1, and the amplifying module 3 is configured to amplify a signal filtered by the switching module 1. Namely, the signal filtered by the filtering unit 12 is amplified by the amplifying module 3, so that the product gain is improved and the receiving effect is enhanced.

For example, in the embodiment of the present application, the amplifying module 3 may include a chip IC1 and a transistor Q1, a fourth pin of the chip IC1 is connected to an input signal, a fifth pin and a second pin of the chip IC1 are both grounded, a sixth pin of the chip IC1 is connected in series with a thirty-first inductor L31 and then connected to one end of a forty-second capacitor C40 and one end of a twelfth resistor R12, the other end of the twelfth resistor R12 is connected to one end of a twentieth capacitor C20, one end of a twenty-first resistor R21 and one end of a thirty-third inductor L30, the other end of the thirty-third inductor L30 is connected to one end of a twentieth inductor L20 and one end of a seventeenth resistor R17, and the other end of the twentieth inductor L20 and the other end of the seventeenth resistor R17 are both connected to the first pin of the chip IC 1; the other end of the twenty-first resistor R21 is connected with one end of a fifty-second capacitor C52 and one end of a twenty-second resistor R22, the other end of the twenty-second resistor R22 is connected with one end of a fifty-second capacitor C50, one end of a fifth resistor R5, one end of a sixth resistor R6, one end of a seventh resistor R7, one end of a thirty-second capacitor C32 and one end of a twenty-third inductor L23, and the other end of a fortieth capacitor C40, the other end of a twentieth capacitor C20, the other end of a fifty-second capacitor C52, the other end of a fifty-second capacitor C50 and the other end of a thirty-second capacitor C32 are all grounded.

A third pin of the chip IC1 is connected in series with one end of a forty-second capacitor C42, a forty-seventh capacitor C47 and a forty-first capacitor C41 in sequence, the other end of the forty-first capacitor C41 is connected with one end of a fourteenth resistor R14, a base of the transistor Q1, one end of a forty-third capacitor C43 and one end of a thirty-ninth capacitor C39, the other end of the forty-third capacitor C43 is connected with a first emitter of the transistor Q1, one end of a thirty-seventh capacitor C37 and one end of an eighth resistor R8, the other end of the thirty-ninth capacitor C39 is connected with a second emitter of the transistor Q1, one end of an eleventh resistor R11 and one end of a forty-fifth capacitor C9, a collector of the transistor Q1 is connected with one end of a thirteenth resistor R13, one end of a forty-eighth capacitor C48, one end of an eighteenth inductor L18, one end of a forty-fourth capacitor C44, the other end of a thirteenth resistor R13 and one end of an eighth capacitor C87458 are connected with a twenty-second inductor L22, the other end of the twenty-second inductor L22 is connected with the other end of the fourteenth resistor R14, the other end of the eighteenth inductor L18 is connected with the other end of the fifth resistor R5, the other end of the sixth resistor R6, the other end of the seventh resistor R7 and one end of the thirty-fourth capacitor C34, the other end of the forty-fourth capacitor C44 is connected with the output signal and the other end of the twenty-third inductor L23, and the other end of the thirty-seventh capacitor C37, the other end of the eighth resistor R8, the other end of the eleventh resistor R11, the other end of the forty-fifth capacitor C45 and the other end of the thirty-fourth capacitor C34 are all grounded.

The amplifying module 3 amplifies and strengthens the filtered weak signal and then sends the amplified weak signal to a television or other receiving and processing circuits. Meanwhile, the amplification block 3 of 0 to multiple stages may be selected according to the strength of the local reception signal. The chip IC1 is NJG1152KA1, and is a radio frequency amplification chip.

Fig. 6 is a circuit schematic diagram of a signal strength adjusting module of a filter circuit provided in an embodiment of the present application, and as shown in fig. 6, the filter circuit further includes a signal strength adjusting module 4, an output end of the signal strength adjusting module 4 is connected to an input end of the switching module 1, and the signal strength adjusting module is configured to adjust strength of an input signal. The signal strength adjusting module 4 may include an adjustable resistor VR2 and a second resistor R2, a fixed end of the adjustable resistor VR2 is connected in series with the second resistor R2 and then grounded, and a sliding end of the adjustable resistor VR2 is connected to the input end of the switching module 1.

For example, in the embodiment of the present application, the signal strength adjusting module 4 may include an adjustable resistor VR2 and a second resistor R2, a first fixed end of the adjustable resistor VR2 is connected in series with the second resistor R2 and then grounded, a second fixed end of the adjustable resistor VR2 is connected to the input signal, a sliding end of the adjustable resistor VR2 is connected to one end of a freewheeling diode D2 and one end of a fifteenth capacitor C15, another end of the fifteenth capacitor C15 is connected to one end of an eighteenth capacitor C18 and one end of an eighth inductor L8, another end of the eighth inductor L8 is grounded, and another end of the eighteenth capacitor C18 is connected to the input end of the switching module 1.

The resistance is adjusted through the adjustable resistor VR2, so that the intensity of the input signal is adjusted, and the intensity of the input signal is kept within a reasonable range. If the input signal is lower than the reasonable range, the signal-to-noise ratio is too poor, and the amplified signal cannot be played; if the input signal exceeds the reasonable range, the post-amplification circuit will be saturated, and the playing effect will be affected.

Illustratively, when the high-pass filtering module 2 and the signal intensity adjusting module 4 are arranged at the same time, the high-pass filtering module 2 and the signal intensity adjusting module 4 are connected in sequence, and the positions can be changed. Exemplarily, in the embodiment of the present application, an input end of the high-pass filtering module 2 is connected to an input signal, an output end of the high-pass filtering module 2 is connected to an input end of the signal strength adjusting module 4, an output end of the signal strength adjusting module 4 is connected to an input end of the switching module 1, an output end of the switching module 1 is connected to an input end of the amplifying module 3, and an output end of the amplifying module outputs a finally processed signal.

Fig. 7 is a waveform diagram of a signal of the filter circuit provided by the embodiment of the present application for filtering a 4G frequency, as shown in fig. 7, a product operating frequency is 470-782MHz, and a gain is ± 2dB, where a curve is a test waveform, a horizontal line is a maximum value and a minimum value of a set gain, a middle value of the waveform diagram gain setting is 25dB, and parameters of the amplifier can be adjusted according to different gain values, such as 10dB, 12dB, 15dB, 20dB, 30dB, and the like.

Fig. 8 is a waveform diagram of a signal of a filter circuit provided by an embodiment of the present application for filtering a 5G frequency, as shown in fig. 8, a product operating frequency is 470-694MHz, and a gain ± 2dB, where a curve is a test waveform, a horizontal line is a maximum value and a minimum value of a set gain, a middle value of the gain setting of the waveform diagram is 25dB, and parameters of an amplifier can be adjusted according to different gain values, such as 10dB, 12dB, 15dB, 20dB, 30dB, and so on.

Fig. 9 is a european certification standard graph of gain values of frequency signals of the filter circuit according to the embodiment of the present application, and as shown in fig. 9, the maximum value and the minimum value of the operating frequency gain in the embodiment of the present application are set according to the certification standard of european export.

The application also discloses a television antenna amplifier which comprises a filter circuit.

In the embodiment of the application, the filter circuit is applied to a television antenna amplifier of a television, so that the mutual interference between a ground wave television signal received by the television and a mobile communication signal of a mobile phone is avoided, the actual receiving effect of the television is improved, the filtering requirements of frequency signals in different regions can be considered, the television can be sold in multiple regions, a user can automatically implement the upgrade switching from 4G to 5G, and the application range is wide.

It should be understood that, the sequence numbers of the steps in the foregoing embodiments do not imply an execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

It will be apparent to those skilled in the art that, for convenience and brevity of description, only the above-mentioned division of the functional units and modules is illustrated, and in practical applications, the above-mentioned function distribution may be performed by different functional units and modules according to needs, that is, the internal structure of the apparatus is divided into different functional units or modules, so as to perform all or part of the functions described above. Each functional unit and module in the embodiments may be integrated in one processing unit, or each unit may exist alone physically, or two or more units are integrated in one unit, and the integrated unit may be implemented in a form of hardware, or in a form of software functional unit. In addition, specific names of the functional units and modules are only for convenience of distinguishing from each other, and are not used for limiting the protection scope of the present application. The specific working processes of the units and modules in the primary quasi-resonant control system can refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the above embodiments, the descriptions of the respective embodiments have respective emphasis, and reference may be made to the related descriptions of other embodiments for parts that are not described or illustrated in a certain embodiment.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

In the embodiments provided in the present application, it should be understood that the disclosed filter circuit and method may be implemented in other ways. For example, the above-described filter circuit embodiments are merely illustrative, and for example, a division of a module or a unit is only one logical functional division, and an actual implementation may have another division, for example, at least two units or components may be combined or integrated into another primary quasi-resonant control system, or some features may be omitted or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may also be distributed on at least two network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.

The above embodiments are only used to illustrate the technical solutions of the present application, and not to limit the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present application and are intended to be included within the scope of the present application.

Claims (10)

1. A filter circuit is characterized by comprising a switching module, wherein the switching module comprises a control unit and at least two filter units;

the at least two filtering units are respectively used for filtering signals with different frequencies in the input signals;

the control unit is used for switchably enabling one filtering unit of the at least two filtering units to be conducted, and the rest filtering units to be not conducted.

2. The filter circuit according to claim 1, wherein said at least two filter units are connected in parallel, said control unit comprises a switch and a PIN diode, said switch is configured to switch a power supply to one of said at least two filter units, and an input terminal and an output terminal of each of said filter units are respectively connected to an anode of one of said PIN diodes.

3. The filter circuit according to claim 1, wherein the filter unit comprises a first capacitor and a first inductor, at least one resonant unit and a second inductor connected in series, one end of the first capacitor is connected to one end of the resonant unit, and the other end of the first capacitor is grounded.

4. The filter circuit according to claim 3, wherein the resonant unit comprises a third inductor, a second capacitor and a third capacitor, the third inductor and the second capacitor are connected in parallel, one end of the third capacitor is connected to one end of the second capacitor, and the other end of the third capacitor is grounded.

5. The filter circuit of claim 1, wherein the at least two filter units comprise a 4G filter unit and a 5G filter unit; the 4G filtering unit is used for filtering 4G mobile communication signals in the input signals; the 5G filtering unit is used for filtering 5G mobile communication signals in the input signals; the control unit is used for switchably enabling the 4G filtering unit or the 5G filtering unit to be conducted;

the input signal is a ground wave television signal, the filter circuit further comprises a high-pass filter module, the output end of the high-pass filter module is connected with the input end of the switching module, and the high-pass filter module is used for enabling an ultrahigh frequency signal or a very high frequency signal and an ultrahigh frequency signal in the ground wave television signal to pass through.

6. The filter circuit according to claim 5, wherein the high-pass filter module includes a plurality of sets of filter units and a fourth capacitor connected in series, the filter units include a fourth inductor, a fifth capacitor and a sixth capacitor, one end of the fifth capacitor is an input end of the filter unit, the other end of the fifth capacitor is connected to one end of the fourth inductor, the other end of the fifth capacitor is an output end of the filter unit, and the other end of the fourth inductor is connected to ground after being connected in series with the sixth capacitor.

7. The filter circuit according to claim 1, further comprising an amplification module, an input of the amplification module being connected to an output of the switching module, the amplification module being configured to amplify the signal filtered by the switching module.

8. The filter circuit of claim 1, further comprising a signal strength adjustment module, an output of the signal strength adjustment module being coupled to an input of the switching module, the signal strength adjustment module being configured to adjust the strength of the input signal.

9. The filter circuit according to claim 8, wherein the signal strength adjusting module comprises an adjustable resistor and a resistor, a fixed end of the adjustable resistor is connected in series with the resistor and then grounded, and a sliding end of the adjustable resistor is connected to the input end of the switching module.

10. A television antenna amplifier comprising a filter circuit as claimed in any one of claims 1 to 9.

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