JP2012186773A - High-frequency filter circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-frequency filter circuit capable of attenuating disturbing signals and making broadcast signals having two different frequency bands pass through.SOLUTION: A high-frequency filter circuit (1) making broadcast signals having two bands of an upper side band and a lower side band pass through to supply the broadcast signals to a subsequent broadcast signal reception circuit, has: an input terminal (11) to which the broadcast signals of the upper side band and the lower side band are inputted; a first filter part connected to the input terminal (11), having a transmission characteristic by which the broadcast signal of the upper side band is passed through, and in which an input impedance of the lower side band is set to a high impedance; and a second filter part connected to the input terminal (11), having the transmission characteristic by which the broadcast signal of the lower side band is passed through, and in which an input impedance of the upper side band is set to the high impedance.

Description

  The present invention relates to a high-frequency filter circuit that extracts broadcast signals in two different frequency bands.

  In recent years, tuner-equipped mobile phones that can receive digital terrestrial television broadcasting using a frequency band of 470 MHz to 770 MHz (710 MHz) have appeared. In addition, the start of multimedia broadcasting for mobile terminals using an empty frequency band (207.5 MHz to 222 MHz) due to analog stoppage is scheduled, and in the future, there is a demand for mobile phones capable of receiving multimedia broadcasting for mobile terminals. is expected.

  From the viewpoint of miniaturization, mobile terminals such as mobile phones are required to be equipped with a receiver module that integrates a tuner capable of receiving digital terrestrial television broadcasts and a tuner capable of receiving multimedia broadcasts for portable terminals. Yes. Also, it is required to mount a shared antenna that can receive both frequency bands as an antenna for receiving these broadcast signals. A receiving module using a shared antenna as described above includes a receiving circuit corresponding to broadcasting in each frequency band, and a broadcasting signal in a corresponding frequency band obtained by branching the received broadcasting signal is input to each receiving circuit. In such a reception module, it is necessary to provide a dedicated notch filter for attenuating an interference signal such as a mobile phone frequency in the front stage of the reception module in order to realize a favorable reception environment for broadcast signals.

JP 2008-301223 A

  The present invention has been made in view of the above points, and an object of the present invention is to provide a high-frequency filter circuit that can attenuate an interference signal without providing a dedicated notch filter in the front stage of the receiving module, and can easily reduce the number of parts and reduce the size. And

  The high frequency filter circuit of the present invention is a high frequency filter circuit that passes a broadcast signal having two bands, an upper band and a lower band, and supplies the broadcast signal to a subsequent broadcast signal receiving circuit, the upper band and the lower band A first input terminal connected to the input terminal and having a transmission characteristic that allows the upper band broadcast signal to pass therethrough, and wherein the lower band input impedance is set to a high impedance. A filter unit; and a second filter unit connected to the input terminal and having a transmission characteristic that allows the lower-band broadcast signal to pass therethrough, and wherein the upper-band input impedance is set to a high impedance. It is characterized by that.

  According to this configuration, the lower band broadcast signal is attenuated by the first filter unit having transmission characteristics that allow the upper band broadcast signal to pass through and the lower band input impedance set to high impedance. However, the broadcast signal in the upper band can be passed, and for example, the passage of the disturbing signal appearing on the higher frequency side than the upper band is blocked, so that the disturbing signal can be attenuated. In addition, the second filter unit having a transmission characteristic that allows the lower-band broadcast signal to pass and the upper-band input impedance is set to high impedance, does not attenuate the upper-band broadcast signal. Broadcast signals can be passed.

  In the high frequency filter circuit of the present invention, the first filter section may have a notch filter function for attenuating a specific frequency adjacent to the high frequency side of the upper band.

  According to this configuration, since the signal in the predetermined frequency band can be sharply attenuated by the notch filter function included in the first filter unit, there is a disturbance signal in the frequency band close to the first frequency band. But it can attenuate the jamming signal.

  In the high frequency filter circuit of the present invention, the second filter unit is connected to the input terminal and has a low-pass filter whose stop band is higher than the lower band, and is connected to a subsequent stage of the low-pass filter. It may consist of a high-pass filter that uses a lower band than the band as a stop band.

  In the high frequency filter circuit of the present invention, the second filter unit may be a low-pass filter connected to the input terminal and having a higher band than the lower band as a stop band.

  In the high frequency filter circuit of the present invention, the second filter section includes an inductor having one end connected to the input terminal, and a high pass connected to the other end of the inductor and having a lower band than the lower band. It may consist of a filter and a low-pass filter connected to a subsequent stage of the high-pass filter and having a higher band than the lower band as a stop band.

  In the high-frequency filter circuit of the present invention, the first filter unit is configured by a bandpass notch SAW filter that attenuates a specific frequency adjacent to the high band side of the upper band and passes the broadcast signal of the upper band. May be.

  In the high-frequency filter circuit of the present invention, the first filter unit may include a low-pass filter that is connected to a subsequent stage of the band-pass notch SAW filter and has a high band side of the upper band as a stop band. .

  In the high frequency filter circuit of the present invention, the high pass filter of the second filter unit may include an inductor provided between the input terminal and the ground and grounding the input terminal.

  According to this configuration, since the input terminal is grounded by the inductor of the high pass filter, static electricity can be discharged through the inductor. For this reason, it is possible to prevent electrostatic breakdown of a receiving circuit or the like connected to the high frequency filter circuit.

  In the high frequency filter circuit of the present invention, the first filter section has a notch filter function for attenuating a specific frequency adjacent to the high band side of the upper band, and the specific frequency to be attenuated by the notch filter function is portable. It may be a frequency band for telephones.

  According to the present invention, it is possible to provide a high-frequency filter circuit that can attenuate an interference signal without providing a dedicated notch filter in the front stage of the receiving module, and can easily reduce the number of components and reduce the size.

FIG. 3 is a circuit block diagram illustrating a configuration example of a high frequency filter circuit according to the first embodiment. FIG. 6 is a circuit diagram illustrating a specific circuit configuration example of a high frequency filter circuit according to a second embodiment. It is a graph which shows the example of the characteristic of the band pass filter used for the signal path | route of a 1st frequency band. It is a graph which shows the example of the characteristic of the low pass filter used for the signal path | route of a 1st frequency band. It is a graph which shows the example of the characteristic of the low pass filter used for the signal path | route of a 2nd frequency band. It is a graph which shows the example of the characteristic of the high pass filter used for the signal path | route of a 2nd frequency band. 6 is a characteristic diagram showing transmission characteristics on the first frequency band side of the high-frequency filter circuit according to Embodiment 1. FIG. 6 is a characteristic diagram showing transmission characteristics on the second frequency band side of the high-frequency filter circuit according to Embodiment 1. FIG. FIG. 10 is a circuit block diagram illustrating another configuration example of the high frequency filter circuit according to the second embodiment. FIG. 6 is a circuit diagram showing another specific circuit configuration example of the high frequency filter circuit according to the second embodiment. FIG. 10 is a characteristic diagram showing transmission characteristics on the first frequency band side of the high frequency filter circuit according to the second embodiment. FIG. 10 is a characteristic diagram showing transmission characteristics on the second frequency band side of the high frequency filter circuit according to the second embodiment. It is a circuit block diagram which shows the structural example of the high frequency filter circuit which concerns on a comparative example.

  Hereinafter, a configuration of a high-frequency filter circuit according to an embodiment of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is a circuit block diagram showing a configuration example of a high frequency filter circuit according to an embodiment of the present invention. In the high frequency filter circuit 1 shown in FIG. 1, a received broadcast signal (RF signal) is introduced from an input terminal 11, a broadcast signal in the first frequency band is output from a first output terminal 12, and a second output terminal The broadcast signal of the second frequency band is output from 13. The first frequency band is a frequency band (upper band) of 470 MHz to 770 MHz (710 MHz) allocated to terrestrial digital television broadcast (hereinafter referred to as first broadcast), and the second frequency band is for mobile terminals. This is a frequency band (lower band) of 207.5 MHz to 222 MHz allocated to multimedia broadcasting (hereinafter referred to as second broadcasting).

  Between the input terminal 11 and the first output terminal 12 of the high-frequency filter circuit 1, the low-frequency side and the high-frequency side of the first frequency band are set as stop bands, and a signal in the second frequency band is received. A first filter unit including a band-pass filter 14 exhibiting high impedance and a low-pass filter 15 having a higher band side than the first frequency band as a stop band is provided. Between the input terminal 11 and the second output terminal 13, a low-pass filter 16 having a high band side from the second frequency band as a stop band and showing a high impedance with respect to a signal in the first frequency band; And a second filter unit including a high-pass filter 17 having a lower band side than the second frequency band as a stop band.

  The bandpass filter 14 has a high impedance for signals in frequency bands other than the first frequency band, particularly for signals in the second frequency band. The band-pass filter 14 has a function as a notch filter that sharply attenuates a signal in a frequency band (800 MHz band) for mobile phones. Since the bandpass filter 14 has a high impedance with respect to the broadcast signal in the second frequency band, the broadcast signal in the second frequency band is blocked by the bandpass filter 14 and propagates to the lowpass filter 16 with low loss. Further, since the bandpass filter 14 functions as a notch filter, it is possible to transmit the broadcast signal in the first frequency band with low loss and sufficiently attenuate the signal in the frequency band for mobile phones that is an interference signal. . Thereby, the broadcast signal in the second frequency band is guided to the low-pass filter 16, the broadcast signal in the first frequency band is allowed to pass through, and the interference signal in the frequency band adjacent to the first frequency band can be sufficiently attenuated. it can. As such a bandpass filter 14, for example, a bandpass notch SAW filter can be used.

  The low-pass filter 16 has a high impedance with respect to a signal in the first frequency band that is a frequency band higher than the second frequency band. Since the low-pass filter 16 has a high impedance with respect to the broadcast signal in the first frequency band, the low-pass filter 16 suppresses the broadcast signal in the first frequency band from flowing toward the low-pass filter 16 and flows to the band-pass filter 14 without loss. Act as you can. Thereby, the broadcast signal in the first frequency band can be supplied to the bandpass filter 14 without loss, and the broadcast signal in the second frequency band is allowed to pass through, so that the signal on the higher frequency side than the second frequency band Can be sufficiently attenuated.

  The low-pass filter 15 has a transmission characteristic in which a frequency band higher than the first frequency band is a stop band, and outputs a signal in the first frequency band to the first output terminal 12 side. The high pass filter 17 has a transmission characteristic in which a frequency band lower than the second frequency band is a stop band, and outputs a signal in the second frequency band to the second output terminal 13 side. The low-pass filter 15 or the high-pass filter 17 may be omitted depending on the application and specifications.

  FIG. 2 is a circuit diagram showing a specific circuit configuration example of the high frequency filter circuit 1 shown in FIG.

  As shown in FIG. 2, the low-pass filter 15 has inductors 151 and 152 connected in series between the band-pass filter 14 and the first output terminal 12, and one end connected to a connection node of the inductors 151 and 152. And an inductor 153 and a capacitor 154 connected between the other end of the inductor 153 and the ground. The specific configuration of the low-pass filter 16 is the same as the specific configuration of the low-pass filter 15. That is, the low pass filter 16 includes inductors 161 and 162 connected in series between the input terminal 11 and the high pass filter 17, an inductor 163 having one end connected to a connection node of the inductors 161 and 162, and other than the inductor 163. And a capacitor 164 connected between the end and the ground.

  The high pass filter 17 includes a capacitor 171 and an inductor 172 connected in parallel between the low pass filter 16 and the second output terminal 13, and an inductor 173 connected between one end of the inductor 172 on the antenna side and the ground. And an inductor 174 connected between the other end of the inductor 172 and the ground.

  Each filter is not limited to the specific configuration described above. For example, the high-pass filter 17 may not have a configuration (π type) connected to the ground voltage via the inductors 173 and 174 as shown in FIG. However, static electricity generated on the input terminal 11 side of the high frequency filter circuit can be discharged by configuring the high pass filter 17 to be connected to the ground via the inductors 173 and 174. Thereby, it is possible to prevent electrostatic breakdown of a receiving circuit connected to the first output terminal 12 or the second output terminal 13. For this reason, it is preferable that the high-pass filter 17 is connected to the ground via the inductors 173 and 174.

  FIG. 3 is a characteristic diagram illustrating an example of transmission characteristics (frequency (GHz) -attenuation (dB) characteristics) of the bandpass filter 14 illustrated in FIGS. 1 and 2. In FIG. 3, the vertical axis represents the attenuation amount, and the horizontal axis represents the frequency. FIG. 3 shows that the first frequency band (470 MHz to 770 MHz (710 MHz)) is hardly attenuated, but is greatly attenuated in other frequency bands. In particular, steep attenuation is observed in the 800 MHz band of 830 MHz to 845 MHz. This is because the band-pass filter 14 has a notch filter function using an 800 MHz band signal as an attenuation pole. By providing such a notch filter function, an interference signal (800 MHz band signal) in a frequency band close to a desired signal (here, a signal of 470 MHz to 770 MHz (710 MHz)) can be appropriately attenuated.

  FIG. 4 is a graph showing an example of frequency characteristics of the low-pass filter 15 shown in FIGS. 1 and 2. In FIG. 4, the vertical axis indicates the attenuation (dB) and the horizontal axis indicates the frequency (GHz). From FIG. 4, it is attenuated greatly in a frequency band higher than the first frequency band (470 MHz to 770 MHz (710 MHz)).

  FIG. 5 is a characteristic diagram showing frequency characteristics of the low-pass filter 16 shown in FIGS. 1 and 2. In FIG. 5, the vertical axis represents attenuation (dB) and the horizontal axis represents frequency (GHz). From FIG. 5, it is attenuated greatly in a frequency band higher than the second frequency band (207.5 MHz to 222 MHz).

  FIG. 6 is a characteristic diagram showing frequency characteristics of the high-pass filter 17 shown in FIGS. 1 and 2. In FIG. 6, the vertical axis indicates the attenuation (dB), and the horizontal axis indicates the frequency (GHz). From FIG. 6, it is attenuated greatly in a frequency band lower than the second frequency band (207.5 MHz to 222 MHz).

  7 and 8 are characteristic diagrams showing the overall transmission characteristics of the high-frequency filter circuit 1 including the filters having the characteristics shown in FIGS. FIG. 7 shows the transmission characteristics of the first filter unit including the band pass filter 14 and the low pass filter 15. FIG. 8 shows the transmission characteristics of the second filter unit composed of the low-pass filter 16 and the high-pass filter 17.

  As described above, according to the present embodiment, the first filter unit having a transmission characteristic that allows the broadcast signal of the first frequency band to pass through, and the input impedance of the second frequency band is set to high impedance; The interference signal can be attenuated by the second filter unit having a transmission characteristic that allows the broadcast signal of the second frequency band to pass through and the input impedance of the first frequency band being set to high impedance. In addition, since the input impedance of the second frequency band is set to high impedance in the first filter unit, and the input impedance of the first frequency band is set to high impedance in the second filter unit, the number of parts is reduced. Even if it is reduced, the received broadcast signal can be branched. Thus, according to the present embodiment, it is possible to provide a high-frequency filter circuit that can attenuate an interference signal and can easily reduce the number of components and reduce the size. In addition, advantageous effects can be obtained from the viewpoint of circuit configuration, manufacturing cost, prevention of electrostatic breakdown, and the like.

  Note that this embodiment can be implemented in combination with any of the other embodiments.

(Embodiment 2)
Next, another embodiment of the present invention will be described. FIG. 9 is a circuit block diagram showing a configuration example of a high frequency filter circuit according to another embodiment. The same parts as those of the high frequency filter circuit 1 shown in FIG. As with the high frequency filter circuit 1 shown in FIG. 1, the high frequency filter circuit 2 shown in FIG. 9 has an input terminal 11 to which a broadcast signal in the first frequency band and a broadcast signal in the second frequency band are input. And a first output terminal 12 from which a broadcast signal in the first frequency band is output, and a second output terminal 13 from which a broadcast signal in the second frequency band is output.

  The first filter unit having the first frequency band as the transmission band uses the low frequency side and the high frequency side as the stop band relative to the first frequency band, and exhibits a high impedance to the signal in the second frequency band. A band-pass filter 14 and a low-pass filter 15 having a higher band side than the first frequency band as a stop band are provided.

  The second filter unit having the second frequency band as a transmission band is arranged so that the connection order of the low-pass filter 16 and the high-pass filter 17 is reversed as compared with the high-frequency filter circuit 1 shown in FIG. ing. Between the input terminal 11 and the high-pass filter 17, an inductor 18 showing a high impedance for a signal in the first frequency band is connected. That is, between the input terminal 11 and the second output terminal 13, an inductor 18 having a high impedance with respect to the first frequency band, and a high-pass filter having a stop band on the lower frequency side than the second frequency band. 17 and a low-pass filter 16 having a higher band side than the second frequency band as a stop band.

  FIG. 10 is a circuit diagram showing a specific circuit configuration example of the high-frequency filter circuit 2 shown in FIG.

  As shown in FIG. 10, the low pass filter 15 is connected to the inductors 151 and 152 connected in series between the band pass filter 14 and the first output terminal 12, and to the connection node of the inductors 151 and 152. An inductor 153, and a capacitor 154 connected between the inductor 153 and the ground. The low pass filter 16 includes inductors 161 and 162 connected in series between the high pass filter 17 and the second output terminal 13, an inductor 163 connected to a connection node of the inductors 161 and 162, an inductor 163, And a capacitor 164 connected to the ground.

  The inductor 18 is an inductor having a high impedance with respect to a signal in the first frequency band. The inductor 18 can prevent the signal in the first frequency band from propagating to the high-pass filter 17 disposed in the subsequent stage, and can input the signal in the first frequency band to the band-pass filter 14 without loss.

  The high pass filter 17 includes a capacitor 171 and an inductor 172 connected in parallel between the inductor 18 and the low pass filter 16, an inductor 173 connected between one end of the capacitor 171 and the inductor 172, and a ground voltage, and a capacitor 171. And an inductor 174 connected between the other end of the inductor 172 and the ground.

  Each filter is not limited to the specific configuration described above. From the viewpoint of preventing electrostatic breakdown of a receiving circuit or the like connected to the first output terminal 12 or the second output terminal 13, the high-pass filter 17 is connected to the ground voltage via the inductors 173 and 174. It is preferable that Further, the inductor 18 may be replaced with a resistance element or the like that can prevent the signal in the first frequency band from propagating to the high-pass filter 17 disposed in the subsequent stage.

  11 and 12 are graphs showing the frequency (GHz) -attenuation (dB) characteristics of the high-frequency filter circuit 2 shown in FIGS. 9 and 10. FIG. 11 shows the attenuation characteristic on the first output terminal 12 side. FIG. 12 shows the attenuation characteristic on the second output terminal 13 side. In FIGS. 11 and 12, the vertical axis indicates the amount of attenuation, and the horizontal axis indicates the frequency. 11 and 12, it can be seen that the high-frequency filter circuit 2 shown in FIGS. 9 and 10 also passes signals in a desired frequency band and attenuates signals in other frequency bands.

  The high frequency filter 2 according to the present embodiment can achieve the same effect as the high frequency filter circuit 1. This embodiment can be implemented in combination with any of the other embodiments.

(Comparative example)
FIG. 13 is a circuit block diagram showing a comparative example of the high frequency filter circuit. A low pass filter 34 is connected to the input terminal 31 of the high frequency filter circuit 3. The low-pass filter 34 has a high-pass filter 35 and a low-pass filter 36 on the first output terminal 32 side, and a low-pass filter 37 and a high-pass filter 38 on the second output terminal 33 side.

  The high-frequency filter circuit 3 shown in FIG. 13 demultiplexes a signal in the first frequency band and a signal in the second frequency band by a high-pass filter 35 and a low-pass filter 37 following the low-pass filter 34. For this reason, the circuit configurations of the high-pass filter 35 and the low-pass filter 37 are limited, and the connection relationship between the low-pass filter 37 and the high-pass filter 38 connected downstream of the low-pass filter 37 is also fixed. Further, the matching circuit for the subsequent stage and the circuit for improving the circuit stability need to be individually designed.

  Since the high frequency filter circuits 1 and 2 according to the present embodiment use the band pass filter 14 and the low pass filter 16 to demultiplex the signal in the first frequency band and the signal in the second frequency band. Compared with the high frequency filter circuit 3 described above, the degree of freedom of circuit configuration is increased. For example, the high frequency filter circuit 1 according to FIG. 1 (and FIG. 2) and the high frequency filter circuit 2 according to FIG. 9 (and FIG. 10) can be selected as the high frequency filter circuit. This increases the number of options for the matching circuit and facilitates circuit matching with the subsequent stage. As described above, the high-frequency filter circuit according to the embodiment is preferable because there are many options from the viewpoint of improving the circuit stability.

  Further, since the high frequency filter circuit according to the embodiment does not use the low pass filter 34 unlike the high frequency filter circuit 3, the number of components can be reduced. Thereby, it is possible to reduce the size as compared with the high frequency filter circuit 3. Further, it can be manufactured at a lower cost than the high frequency filter circuit 3.

  Further, when the π-type high-pass filter 17 is used in the high-frequency filter circuit, the high-pass filter 17 is connected to the ground via the inductors 173 and 174, so that static electricity generated on the input terminal 11 side of the high-frequency filter circuit is reduced to the ground voltage side. (See FIG. 2 or FIG. 10). For this reason, it is possible to prevent electrostatic breakdown of a receiving circuit or the like connected to the subsequent stage without separately providing an electrostatic discharge element.

  As described above, the high-frequency filter circuits 1 and 2 according to the embodiment have transmission characteristics that allow the broadcast signal in the first frequency band to pass, and the input impedance in the second frequency band is set to high impedance. Interference signals are attenuated by the first filter unit and the second filter unit having transmission characteristics that allow the broadcast signal of the second frequency band to pass and the input impedance of the first frequency band being set to high impedance. Can be made. In addition, since the input impedance of the second frequency band is set to high impedance in the first filter unit, and the input impedance of the first frequency band is set to high impedance in the second filter unit, the number of parts is reduced. Even if it is reduced, the received broadcast signal can be branched. Thus, according to the present embodiment, it is possible to provide a high-frequency filter circuit that can attenuate an interference signal and can easily reduce the number of components and reduce the size. In addition, advantageous effects can be obtained from the viewpoint of circuit configuration, manufacturing cost, prevention of electrostatic breakdown, and the like.

  In addition, this invention is not limited to description of the said embodiment, It can change suitably in the aspect in which the effect is exhibited, and can be implemented. For example, the configuration of various filters constituting the high frequency filter circuit can be changed as appropriate within the range in which the effects of the invention are exhibited. Further, the characteristics of elements such as inductors and capacitors constituting various filters can be set according to the target characteristics.

  Further, the pass frequency band of the high frequency filter circuit is not limited to the first frequency band (470 MHz to 710 MHz (770 MHz)) or the second frequency band (207.5 MHz to 222 MHz) described above. When receiving broadcasts in other frequency bands, the characteristics of various filters constituting the high-frequency filter circuit may be changed so that the intended pass frequency characteristics can be obtained.

  In addition, the present invention can be implemented with appropriate modifications without departing from the scope of the present invention.

  The high-frequency filter circuit of the present invention is useful, for example, for receiving terrestrial digital television broadcasts in mobile phones and multimedia broadcasts for portable terminals.

1, 2, 3 High frequency filter circuit 11, 31 Input terminal 12, 32 First output terminal 13, 33 Second output terminal 14 Band pass filter 15, 16, 34, 36, 37 Low pass filter 17, 35, 38 High pass Filter 18 Inductor

Claims (9)

A high-frequency filter circuit that passes a broadcast signal having two bands, an upper band and a lower band, and supplies the broadcast signal to a subsequent broadcast signal receiving circuit,
An input terminal to which broadcast signals of the upper band and the lower band are input;
A first filter unit connected to the input terminal, having a transmission characteristic for allowing the broadcast signal of the upper band to pass through, and having the input impedance of the lower band set to high impedance;
A second filter unit connected to the input terminal and having a transmission characteristic for allowing the lower band broadcast signal to pass; and wherein the upper band input impedance is set to a high impedance;
A high-frequency filter circuit comprising:   2. The high frequency filter circuit according to claim 1, wherein the first filter unit has a notch filter function of attenuating a specific frequency adjacent to a high frequency side of the upper band.   The second filter unit includes a low pass filter connected to the input terminal and having a higher band than the lower band, and a lower band connected to a subsequent stage of the low pass filter and having a lower band than the lower band. 3. The high frequency filter circuit according to claim 1, wherein the high frequency filter circuit is a high pass filter.   3. The high frequency filter circuit according to claim 1, wherein the second filter unit includes a low-pass filter connected to the input terminal and having a higher band than the lower band as a stop band.   The second filter unit includes an inductor having one end connected to the input terminal, a high-pass filter connected to the other end of the inductor and having a lower band than the lower band, and a subsequent stage of the high-pass filter. The high-frequency filter circuit according to claim 1, further comprising: a low-pass filter connected to a low-pass filter and having a higher band than the lower band as a stop band.   The first filter unit includes a bandpass notch SAW filter that attenuates a specific frequency adjacent to a high frequency side of the upper band and passes a broadcast signal of the upper band. The high frequency filter circuit according to claim 1.   7. The high-frequency filter according to claim 6, wherein the first filter unit includes a low-pass filter that is connected to a subsequent stage of the band-pass notch SAW filter and uses a high band side of the upper band as a stop band. circuit.   6. The high frequency filter according to claim 3, wherein the high-pass filter of the second filter unit includes an inductor provided between the input terminal and a ground and grounding the input terminal. Filter circuit. The first filter unit has a notch filter function for attenuating a specific frequency adjacent to a high frequency side of the upper band, and the specific frequency to be attenuated by the notch filter function is a frequency band for a mobile phone. The high frequency filter circuit according to claim 1, wherein:

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