JP6909114B2 - Filter and front end circuit - Google Patents

Description

The present invention relates to filters and front-end circuits, eg, filters and front-end circuits having a passband between two suppression bands.

A ladder type filter is used as a band pass filter (BPF) used in a mobile communication terminal such as a mobile phone terminal. A band elimination filter (BEF: Band Elimination Filter) or a band rejection filter (BRF: Band Rejection Filter) using a resonator is known (for example, Patent Documents 1 to 3). High-frequency modules that can support both diversity and carrier aggregation communication methods are known (for example, Patent Document 4).

U.S. Pat. No. 7,915,978 International Publication No. 2016/1255515 U.S. Pat. No. 6710677 JP 2015-2395

Patent Document 1 describes that a pass band is formed by combining a high band notch resonator and a low band notch resonator. However, a configuration with good filter characteristics has not been studied.

The present invention has been made in view of the above problems, and an object of the present invention is to improve the filter characteristics.

In the present invention, a first series resonator having a first anti-resonance frequency, which is connected in series between an input terminal and an output terminal, and the input terminal and the output terminal are connected in parallel, and the first A first parallel resonator having a first resonance frequency higher than one anti-resonance frequency and forming a first suppression band with the first anti-resonance frequency is connected in series between the input terminal and the output terminal. A second series resonator having a second anti-resonance frequency that is higher than the first resonance frequency and forms a first pass band with the first resonance frequency, and between the input terminal and the output terminal. The first series includes a second parallel resonator which is connected in parallel and has a second resonance frequency which is higher than the second anti-resonance frequency and forms a second suppression band with the second anti-resonance frequency. The resonator is a filter connected in parallel with the second series resonator between the input terminal and the output terminal.

In the above configuration, a configuration including a third parallel resonator connected in parallel between the input terminal and the output terminal and having a third resonance frequency higher than the first antiresonance frequency and lower than the first resonance frequency. can do.

In the above configuration, a configuration including a fourth parallel resonator connected in parallel between the input terminal and the output terminal and having a fourth resonance frequency higher than the second antiresonance frequency and lower than the second resonance frequency. can do.

In the above configuration, it is connected in series between the input terminal and the output terminal, includes the first pass band, and is on the low frequency side of the first suppression band and / or on the high frequency side of the second suppression band. The configuration may include a bandpass filter having a third pass band that forms the second pass band.

In the above configuration, the first series resonator, the first parallel resonator, the second series resonator, and the second parallel resonator can be configured to be elastic wave resonators.

In the above configuration, the first pass band may include a first reception band of the first communication standard and a second reception band of the second communication standard higher than the first reception band.

In the above configuration, the first suppression band may include the first transmission band of the first communication standard, and the second suppression band may include the second transmission band of the second communication standard.

The present invention is a front-end circuit including the above filter.

According to the present invention, the filter characteristics can be improved.

FIG. 1 is a block diagram of a front-end circuit according to Comparative Example 1. FIG. 2 is a block diagram of a front-end circuit according to Comparative Example 2. FIG. 3 is a block diagram of the front-end circuit according to the first embodiment. FIG. 4 is a circuit diagram of the filter according to the second embodiment. FIG. 5 is a diagram showing the resonance frequency and the anti-resonance frequency of each resonator in the second embodiment. FIG. 6A is a circuit diagram obtained by extracting S1, S2, P2 and P6 in Example 2, and FIG. 6B shows resonance frequencies and antiresonance frequencies of S1, S2, P2 and P6 in Example 2. It is a figure which shows. FIG. 7 (a) is a circuit diagram in which S1, S2, P2 and P6 in Comparative Example 3 are extracted, and FIG. 7 (b) shows resonance frequencies and antiresonance frequencies of S1, S2, P2 and P6 in Comparative Example 3. It is a figure which shows. FIG. 8 is a diagram showing simulation results of passage characteristics in Example 2 and Comparative Example 3. 9 (a) is a plan view showing an elastic table resonator used in the filter of the second embodiment, and FIG. 9 (b) is a cross-sectional view showing another example of the elastic wave resonator. 10 (a) and 10 (b) are diagrams showing passage characteristics using elastic wave resonators as a series resonator and a parallel resonator, respectively. 11 (a) and 11 (b) are circuit diagrams of samples A and B. FIG. 12 is a diagram showing the passage characteristics of the samples A and B.

[Front-end circuit of Comparative Example 1]
As a front-end circuit, a receiving circuit for a diversity antenna in a fourth-generation mobile phone terminal will be described as an example. FIG. 1 is a block diagram of a front-end circuit according to Comparative Example 1. As shown in FIG. 1, the front-end circuit 110 includes an antenna terminal 11, an HB (high band) filter 12a, an MB (middle band) filter 12b, an LB (low band) filter 12c, switches 13, 15, 17, and a filter 14. 18, LNA (low noise amplifier) 16 and RFIC (Radio Frequency Integrated Circuit) 20 are provided. HB, MB and LB include, for example, a band of 2300 MHz to 2690 MHz, a band of 1710 MHz to 2170 MHz and a band of 699 MHz to 960 MHz, respectively.

The antenna 10 is connected to the antenna terminal 11. The antenna 10 is, for example, a diversity antenna. The HB filter 12a is a high-pass filter that allows the HB signal among the signals input to the antenna terminal 11 to pass through and suppresses the MB and LB signals. The MB filter 12b is a bandpass filter that allows the MB signal among the signals input to the antenna terminal 11 to pass through and suppresses the HB and LB signals. The LB filter 12c is a low-pass filter that allows the LB signal among the signals input to the antenna terminal 11 to pass through and suppresses the HB and MB signals.

The filters 14 and 18 are bandpass filters, and are provided for each frequency band (band) corresponding to, for example, the LTE standard (E-UTRA Operating Band). The filters 14 and 18 pass signals in the reception band of each band and suppress other signals. Filters 14 and 18 corresponding to three bands, respectively, are connected as HB, MB and LB. The LNA 16 amplifies the high frequency signal. Switches 13, 15 and 17 connect filters 14 and 18 corresponding to the received band. The RFIC 20 processes the received high frequency signal.

In the 4th generation mobile phone terminal, in order to support carrier aggregation, the diversity receiving circuit also supports carrier aggregation. When performing carrier aggregation using two bands, switches 13, 15 and 17 select the corresponding filters 14 and 18. As a result, the reception signals of the two bands can be received at the same time.

In carrier aggregation, transmission signals of two bands are transmitted at the same time. The transmitted signal interferes with the front-end circuit 110. Therefore, the filter 14 suppresses the signal in the transmission band. In Comparative Example 1, the switches 13 and 15 connect only the filter 14 in the band receiving at the same time to the antenna 10. Therefore, the suppression of the transmission band can be improved in the filters 14 and 18. However, the provision of switches 13, 15 and 17 increases insertion loss and distortion.

[Front-end circuit of Comparative Example 2]
FIG. 2 is a block diagram of a front-end circuit according to Comparative Example 2. As shown in FIG. 2, the front-end circuit 112 is not provided with switches 13, 15 and 18. Within each of the HB, MB and LB, the filters 14 are connected in parallel without a switch. Within each of the HB, MB and LB, the filters 18 are connected in parallel without a switch. Other configurations are the same as in Comparative Example 1, and the description thereof will be omitted.

In Comparative Example 2, since the switches 13, 15 and 17 are not provided, the insertion loss and the distortion can be reduced. However, since the filters 14 are connected in parallel in each HB, MB, and LB, the degree of suppression in the transmission band becomes small.

FIG. 3 is a block diagram of the front-end circuit according to the first embodiment. As shown in FIG. 3, in the front-end circuit 100, a BRF is used as the filter 14. A bandpass filter is used as the HB filter 12a and the LB filter 12c. Other configurations are the same as in Comparative Example 2, and the description thereof will be omitted.

In the first embodiment, the degree of suppression in the transmission band can be improved by using the filter 14 as a BRF.

Example 2 is an example of the BRF used in Example 1 and is an example of a filter for LTE standard bands B12, B13 and band B5 in LB. The transmission band and reception band of band B12 are 699 MHz to 716 MHz and 729 MHz to 746 MHz, respectively. The transmission band and reception band of band B13 are 777 MHz to 787 MHz and 746 MHz to 756 MHz, respectively. The transmission band and reception band of band B5 are 824 MHz to 849 MHz and 869 MHz to 894 MHz, respectively.

FIG. 4 is a circuit diagram of the filter according to the second embodiment. As shown in FIG. 4, the filters 14a and 14b are connected in parallel between the input terminal Tin and the output terminal Tout. The input terminal Tin and the output terminal Tout are connected to, for example, the LB filter 12c and the LNA 16 of the first embodiment, respectively.

The filter 14a has a series resonator S1 connected in series between the input terminal Tin and the output terminal Tout, and parallel resonators P1 and P2 connected in parallel. The series resonator S1 and the parallel resonators P1 and P2 are connected in a π shape. The filter 14b has a series resonator S2 connected in series between the input terminal Tin and the output terminal Tout, and parallel resonators P3 to P6 connected in parallel. The series resonator S2 and the parallel resonators P3 and P6 are connected in a π shape.

FIG. 5 is a diagram showing the resonance frequency and the anti-resonance frequency of each resonator in the second embodiment. FIG. 5 is a conceptual diagram of the passage characteristic S21 between the input terminal Tin and the output terminal Tout. The transmission band Tx and the reception band Rx of the bands B5, B12 and B13 are shown by broken lines. S1 (fa) and S2 (fa) indicate the anti-resonance frequencies of the series resonators S1 and S2, and P1 (fr) to P6 (fr) indicate the resonance frequencies of the parallel resonators P1 to P6.

FIG. 6A is a circuit diagram obtained by extracting S1, S2, P2 and P6 in Example 2, and FIG. 6B shows resonance frequencies and antiresonance frequencies of S1, S2, P2 and P6 in Example 2. It is a figure which shows. As shown in FIG. 6A, the filter 14a has a series resonator S1 and a parallel resonator P2. The filter 14b has a series resonator S2 and a parallel resonator P6.

FIG. 6B is a conceptual diagram of the passage characteristic S21 between the input terminal Tin and the output terminal Tout in the series resonators S1 and S2 and the parallel resonators P2 and P6. The arrows in FIG. 6B indicate the resonance frequency (fr) and the antiresonance frequency (fa) of each resonator. The filters 14a and 14b are BEFs. The resonance frequency P2 (fr) of the parallel resonator P2 is higher than the antiresonance frequency S1 (fa) of the series resonator S1. The suppression band 50 is formed by S1 (fa) and P2 (fr). The resonance frequency S1 (fr) of the series resonator S1 forms a pass band on the low frequency side of the suppression band 50. The resonance frequency P6 (fr) of the parallel resonator P6 is higher than the antiresonance frequency S2 (fa) of the series resonator S2. The suppression band 52 is formed by S2 (fa) and P6 (fr). The anti-resonance frequency P6 (fa) of the parallel resonator S6 forms a pass band on the high frequency side of the suppression band 52. The anti-resonance frequency S2 (fa) of the series resonator S2 is higher than the resonance frequency P2 (fr) and the anti-resonance frequency P2 (fa) of the parallel resonator P2. As a result, a pass band 54 is formed between the suppression bands 50 and 52 by the anti-resonance frequency P2 (fa) and the resonance frequency S2 (fr).

As shown in FIG. 5, the resonance frequency P1 (fr) of the parallel resonator P1 is provided in the suppression band 50. Resonance frequencies P3 (fr) to P5 (fr) of parallel resonators P3 to P5 are provided in the suppression band 52. The attenuation poles formed by the resonance frequencies P1 (fr) and P3 (fr) to P5 (fr) of the parallel resonators P1 and P3 to P5 improve the degree of suppression of the suppression bands 50 and 52. The suppression band 50 includes the transmission band of band B12, and the suppression band 52 includes the transmission band of bands B13 and B5. The pass band 54 includes the reception bands of bands B12 and B13. Since the reception bands of the bands B12 and B13 are continuous, one pass band 54 can be used. The filters 14a and 14b are BRFs (or BEFs) with suppression bands 50 and 52, respectively.

The passing characteristics of Example 2 and Comparative Example 3 were simulated. The circuit configuration of Comparative Example 3 is the same as that of FIG. 4, but the filters 14a and 14b are bandpass filters.

FIG. 7 (a) is a circuit diagram in which S1, S2, P2 and P6 in Comparative Example 3 are extracted, and FIG. 7 (b) shows resonance frequencies and antiresonance frequencies of S1, S2, P2 and P6 in Comparative Example 3. It is a figure which shows. As shown in FIG. 7A, the filter 14a has a series resonator S1 and a parallel resonator P2. The filter 14b has a series resonator S2 and a parallel resonator P6.

FIG. 7B is a conceptual diagram of the passage characteristic S21 between the input terminal Tin and the output terminal Tout in the series resonators S1 and S2 and the parallel resonators P2 and P6. As shown in FIG. 7B, the pass band 58 is formed by the anti-resonance frequency P2 (fa) of the parallel resonator P2 of the filter 14a and the resonance frequency S1 (fr) of the series resonator S1. The resonance frequency P2 (fr) of the parallel resonator P2 and the antiresonance frequency S1 (fa) of the series resonator S1 form an attenuation pole outside the pass band 58. A pass band 59 is formed by the anti-resonance frequency P6 (fa) of the parallel resonator P6 of the filter 14b and the resonance frequency S2 (fr) of the series resonator S2. The resonance frequency P6 (fr) of the parallel resonator P6 and the antiresonance frequency S2 (fa) of the series resonator S2 form an attenuation pole outside the pass band 59.

In Example 2, a ladder type filter using an LC element (capacitor and inductor) and a surface acoustic wave resonator was used as the LB filter 12c. The LB filter 12c is a BPF and has a pass band of 729 MHz to 794 MHz. In Comparative Example 3, a filter using an LC element was used as the LB filter 12c. The LB filter 12c is an LPF and has a pass band of 0 MHz to 900 MHz. The resonators of the filters 14a and 14b of Example 2 and Comparative Example 3 were surface acoustic wave resonators.

FIG. 8 is a diagram showing simulation results of passage characteristics in Example 2 and Comparative Example 3. As shown in FIG. 8, in the transmission band of the bands B12 and B13, Example 2 has a higher degree of suppression than Comparative Example 3.

9 (a) is a plan view showing an elastic table resonator used in the filter of the second embodiment, and FIG. 9 (b) is a cross-sectional view showing another example of the elastic wave resonator. 9 (a) and 9 (b) are examples of surface acoustic wave resonators and piezoelectric thin film resonators, respectively.

As shown in FIG. 9A, an IDT (Interdigital Transducer) 41 and a reflector 42 are formed on the substrate 40. The IDT 41 has a pair of comb-shaped electrodes 41a facing each other. The comb-shaped electrode 41a has a plurality of electrode fingers 41b and a bus bar 41c for connecting the plurality of electrode fingers 41b. Reflectors 42 are provided on both sides of the IDT 41. IDT 41 excites surface acoustic waves on the substrate 40. The substrate 40 is a piezoelectric substrate such as a lithium tantalate substrate or a lithium niobate substrate. The IDT 41 and the reflector 42 are formed of, for example, an aluminum film or a copper film. The substrate 40 may be bonded to a support substrate such as a sapphire substrate, an alumina substrate, a spinel substrate, a crystal substrate, or a silicon substrate. A protective film or a temperature compensation film may be provided to cover the IDT 41 and the reflector 42.

As shown in FIG. 9B, the piezoelectric film 46 is provided on the substrate 40. The lower electrode 44 and the upper electrode 48 are provided so as to sandwich the piezoelectric film 46. A gap 45 is formed between the lower electrode 44 and the substrate 40. The lower electrode 44 and the upper electrode 48 excite elastic waves in the thickness longitudinal vibration mode in the piezoelectric film 46. The lower electrode 44 and the upper electrode 48 are metal films such as a ruthenium film. The piezoelectric film 46 is, for example, an aluminum nitride film. The substrate 40 is, for example, a silicon substrate, a semiconductor substrate such as gallium arsenide, or an insulating substrate such as a sapphire substrate, an alumina substrate, a spinel substrate, or a glass substrate.

10 (a) and 10 (b) are diagrams showing passage characteristics using elastic wave resonators as a series resonator and a parallel resonator, respectively. As shown in FIG. 10A, in the series resonator, the antiresonance frequency S (fa) becomes the attenuation pole. Looking at the low frequency side of the anti-resonance frequency S (fa), the amount of attenuation sharply decreases between the anti-resonance frequency S (fa) and the resonance frequency S (fr). On the resonance frequency S (fr) and its low frequency side, the amount of attenuation is small and the pass band is formed. Looking at the high frequency side of the antiresonance frequency S (fa), the decrease in the amount of attenuation is gradual as compared with the low frequency side of the antiresonance frequency S (fa). Therefore, the high frequency side of the antiresonance frequency S (fa) becomes the suppression band.

As shown in FIG. 10B, in the parallel resonator, the resonance frequency P (fr) becomes the attenuation pole. Looking at the high frequency side of the resonance frequency P (fr), the amount of attenuation sharply decreases between the resonance frequency P (fr) and the antiresonance frequency P (fa). On the anti-resonance frequency P (fa) and its high frequency side, the amount of attenuation is small and the pass band is formed. On the low frequency side of the resonance frequency P (fr), the amount of attenuation decreases more slowly than on the high frequency side of the resonance frequency P (fr). Therefore, the low frequency side of the resonance frequency P (fr) becomes the suppression band.

Therefore, as shown in FIG. 6B, the resonance frequency P2 (fr) (first resonance frequency) of the parallel resonator P2 (first parallel resonator) is set from the anti-resonance frequency S1 (fa) of the series resonator S1. It is provided so as to form a suppression band 50 (first suppression band) with a high anti-resonance frequency S1 (fa). The anti-resonance frequency S2 (fa) (second anti-resonance frequency) of the series resonator S2 is higher than the resonance frequency P2 (fr), and a pass band 54 (first pass band) is formed between the series resonator S2 and the resonance frequency P2 (fr). Provide to do so. The resonance frequency P6 (fr) (second resonance frequency) of the parallel resonator P6 (second parallel resonator) is higher than the anti-resonance frequency S2 (fa) and is located between the anti-resonance frequency S2 (fa) and the suppression band 52 ( It is provided so as to form a second suppression band).

In this way, the shoulders on the low frequency side of the suppression bands 50 and 52 are formed mainly at the anti-resonance frequencies of the series resonators S1 and S2, respectively, and the shoulders on the high frequency side of the suppression bands 50 and 52 are mainly resonated in parallel, respectively. It is formed at the resonance frequency of the instruments P1 and P2. As a result, the suppression characteristics of the suppression bands 50 and 52 can be improved, and the passage characteristics of the pass band 54 between the suppression bands 50 and 52 can be improved. In this way, the filter characteristics can be improved.

The series resonators S1 and S2 are connected in parallel between the input terminal Tin and the output terminal Tout. This improves the pass characteristics of the pass band. The series resonators S1 and S2 may be connected in series.

As shown in FIG. 5, the resonance frequency P1 (fr) of the parallel resonator P1 is higher than the antiresonance frequency S1 (fa) of the series resonator S1 and lower than the resonance frequency P2 (fr) of the parallel resonator P2. Thereby, the suppression characteristic of the suppression band 50 can be improved. The resonance frequencies P3 (fr) to P5 (fr) of the parallel resonators P3 to P5 are higher than the antiresonance frequency S2 (fa) of the series resonator S2 and lower than the resonance frequency P6 (fr) of the parallel resonator P6. Thereby, the suppression characteristic of the suppression band 52 can be improved.

This will be described with reference to Samples A and B. 11 (a) and 11 (b) are circuit diagrams of samples A and B. As shown in FIG. 11A, sample A is a π-type filter. A series resonator S1 is connected in series between terminals T1 and T2, and parallel resonators P1 and P2 are connected in parallel.

As shown in FIG. 11B, sample B is a T-type filter. The series resonators S1 and S2 are connected in series between the terminals T1 and T2, and the parallel resonator P2 is connected in parallel.

FIG. 12 is a diagram showing the passage characteristics of the samples A and B. As shown in FIG. 12, the samples A and B have a suppression band 55 in the transmission band Tx of the band B5. In both samples A and B, the suppression band 55 is formed by the anti-resonance frequency S1 (fa) of the series resonator S1 and the resonance frequency P2 (fr) of the parallel resonator P2. In sample A, the resonance frequency P1 (fr) of the parallel resonator P1 is located near the center of the suppression band 55. In sample B, the anti-resonance frequency S2 (fa) of the series resonator S2 is located near the center of the suppression band 55.

In sample A, the amount of attenuation in the suppression band 55 is larger than that in sample B. This is because the parallel impedance is lowered by providing the resonance frequency P1 (fr) of the parallel resonator P1 near the center of the suppression band 55. Therefore, the degree of suppression of the suppression band 55 can be made larger than that of the sample B in which the anti-resonance frequency S2 (fa) of the series resonator S2 is provided near the center of the suppression band 55.

In the filter of the second embodiment, as shown in FIG. 5, suppression bands 50 and 52 are provided on both sides of the reception band Rx of the bands B12 and B13, and a pass band 54 corresponding to the reception band Rx of the bands B12 and B13 is formed. ing. A suppression band 52 is provided on the low frequency side of the reception band Rx of band B5, but there is no suppression band on the high frequency side. Therefore, as shown in FIG. 8, the pass band of the LB filter 12c of the first embodiment includes the pass band 54, and the pass band 56 (second pass band) for the reception band of the band B5 is on the high frequency side of the suppression band 52. Is provided so as to form. As a result, a suppression band can be formed on the high frequency side of the pass band 56 including the reception band Rx of the band B5 of FIG.

As described above, the pass band of the bandpass filter is provided so as to include the pass band 54 and to form the pass band 56 on the low frequency side of the suppression band 50 and / or the high frequency side of the suppression band 52. As a result, a part of the resonator for forming the second pass band can be used for the suppression bands 50 and 52. Therefore, the degree of suppression of the suppression bands 50 and 52 can be improved.

In the second embodiment, the series resonators S1 and S2 and the parallel resonators P1 to P6 are preferably elastic wave resonators as illustrated in FIGS. 9 (a) and 9 (b). As a result, it is possible to form a BRF or BEF having a high degree of suppression in the suppression band using the characteristics shown in FIGS. 10 (a) and 10 (b).

As shown in FIGS. 5 and 8, the pass band 54 includes the reception band (first reception band) of band B12 (first communication standard) and the reception band (second reception band) of band B13 (second communication standard). including. As a result, the number of filters can be reduced.

The suppression band 50 includes the transmission band of band B12 (first transmission band), and the suppression band 52 includes the transmission band of band B13 (second transmission band). Thereby, the degree of suppression in the transmission band of the bands B12 and 13 can be improved.

As in the first embodiment, the filter of the second embodiment can be used for the front-end circuit. Although the first embodiment is an example of a receiving circuit for a diversity antenna, the filter according to the second embodiment may be used for a front-end circuit having a transmitting circuit or a transmitting / receiving circuit.

Although the examples of the present invention have been described in detail above, the present invention is not limited to such specific examples, and various modifications and modifications are made within the scope of the gist of the present invention described in the claims. It can be changed.

50, 52 suppression band 54, 56 pass band

Claims (8)

A first series resonator connected in series between the input terminal and the output terminal and having a first antiresonance frequency,
A first parallel that is connected in parallel between the input terminal and the output terminal and has a first resonance frequency that is higher than the first antiresonance frequency and forms a first suppression band between the first antiresonance frequency. Resonator and
A second series resonance that is connected in series between the input terminal and the output terminal and has a second antiresonance frequency that is higher than the first resonance frequency and forms a first passband between the first resonance frequency. With a vessel
A second parallel connected in parallel between the input terminal and the output terminal and having a second resonance frequency higher than the second antiresonance frequency and forming a second suppression band between the second antiresonance frequency and the second antiresonance frequency. Resonator and
Equipped with a,
The first series resonator is a filter connected in parallel with the second series resonator between the input terminal and the output terminal. It is connected in parallel between said output terminal and said input terminal, filter according to claim 1, further comprising a third parallel resonator having a third resonant frequency lower than the higher first resonant frequency than the first reaction resonant frequency .. The first or second aspect of claim 1 or 2, further comprising a fourth parallel resonator connected in parallel between the input terminal and the output terminal and having a fourth resonance frequency higher than the second antiresonance frequency and lower than the second resonance frequency. Filter. A second pass band that is connected in series between the input terminal and the output terminal, includes the first pass band, and is on the low frequency side of the first suppression band and / or on the high frequency side of the second suppression band. The filter according to any one of claims 1 to 3 , further comprising a bandpass filter having a third pass band forming the above. The filter according to any one of claims 1 to 4 , wherein the first series resonator, the first parallel resonator, the second series resonator, and the second parallel resonator are elastic wave resonators. The filter according to any one of claims 1 to 5 , wherein the first pass band includes a first reception band of the first communication standard and a second reception band of the second communication standard higher than the first reception band. The first suppression band comprises a first transmission band of the first communication standard, the second suppression band filter according to claim 6, further comprising a second transmission band of the second communication standard. A front-end circuit comprising the filter according to any one of claims 1 to 7.

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