JP2009077303A - Multilayer dielectric bandpass filter - Google Patents

Abstract

In a multilayer dielectric bandpass filter, the position of an attenuation pole can be freely set while maintaining good passband characteristics.
A plurality of stripline resonators (38, 40) disposed between a signal input end (side input electrode (32) and bottom input electrode (54)) and an output end (side output electrode (34) and bottom output electrode (56)). 42, and a capacitor (capacitor electrode 46) disposed between the input end and the stripline resonator on the input end side, and between the input end and the ground (side ground electrode 36). A matching circuit unit including an inductor (inductor electrode 50), and the band-pass filter unit and the matching circuit unit are embedded in the same multilayer dielectric chip, and the inductor of the matching circuit unit is a band It is electromagnetically coupled to the stripline resonator of the pass filter section.
[Selection] Figure 3

Description

  The present invention relates to a multilayer dielectric band-pass filter. More specifically, the present invention relates to a multilayer dielectric chip in which a band-pass filter unit composed of a plurality of stripline resonators and a matching circuit unit composed of a capacitor and an inductor are included in the same multilayer dielectric chip. The present invention relates to a multilayer dielectric bandpass filter that is embedded and has a structure in which an inductor of a matching circuit unit is electromagnetically coupled to a stripline resonator of a bandpass filter unit. This multilayer dielectric band-pass filter is useful for mobile phones and various wireless communication devices, for example.

  In a cellular phone or other various wireless communication devices, a multilayer dielectric bandpass filter is used as a high-frequency component. A conventionally known laminated dielectric bandpass filter has a plurality of stripline resonators arranged in a chip formed by laminating a plurality of dielectric layers and electromagnetically coupled to the band. There is a configuration for expressing pass filter characteristics (see, for example, Patent Document 1).

  With the progress of wireless communication technology in recent years, from the viewpoint of effective utilization of limited frequency resources, this type of multilayer dielectric bandpass filter is required to have high attenuation and steep attenuation characteristics outside the communication band. . Also, in order to attenuate unnecessary signals outside the communication band that are output from the IC used in the wireless communication device, and to attenuate unnecessary external noise outside the communication band that adversely affects the IC, It is required to provide an attenuation pole. Such unwanted signals from ICs and external unwanted noises that adversely affect ICs vary depending on the specifications of each IC manufacturer (IC chip set specifications), and are therefore the attenuation pole required for multilayer dielectric bandpass filters. The frequency position of the signal varies depending on the IC chip set.

Therefore, in the prior art, the electromagnetic coupling degree is adjusted by changing the length, width, spacing, etc. of the stripline resonator, so that the attenuation characteristic and the frequency position of the attenuation pole are designed to satisfy the requirements. Yes. However, since the specifications differ depending on the chip set of each IC manufacturer, it takes time and effort to redesign all the designs each time, and depending on the specifications, the structure itself may have to be changed greatly.
Japanese Patent No. 2806710

  The problem to be solved by the present invention is that in a multilayer dielectric bandpass filter, the frequency position of the attenuation pole can be freely set without affecting the passband while maintaining good characteristics as a bandpass filter. Is to do so. Another problem to be solved by the present invention is that, in a multilayer dielectric bandpass filter, similarly, the characteristics of the bandpass filter are kept good, and the frequency position of the attenuation pole is determined without affecting the passband. It is to have a balun function that performs unbalance-balance conversion while allowing it to be set freely.

  The present invention comprises a band-pass filter unit composed of a plurality of stripline resonators arranged between a signal input end and an output end, and a capacitor and an inductor arranged on the input end side and / or the output end side. A high-pass type matching circuit unit, wherein the band-pass filter unit and the matching circuit unit are embedded in the same multilayer dielectric chip, and the inductor of the matching circuit unit is a stripline resonator of the band-pass filter unit And a laminated dielectric band-pass filter characterized by being electromagnetically coupled to each other. Here, each stripline resonator of the band-pass filter unit is a 1/4 wavelength resonance type with one end open and the other end short-circuited.

  The matching circuit unit can be arranged on the input end side or output end side of the signal, or on both the input end side and the output end side, but is typically arranged on the input end side. Preferably, according to the present invention, a band-pass filter unit including a plurality of stripline resonators disposed between a signal input end and an output end, and a stripline resonator between the input end and the input end side. And a matching circuit unit including an inductor disposed between the input terminal and the ground, and the band-pass filter unit and the matching circuit unit are embedded in the same multilayer dielectric chip. The multilayer dielectric bandpass filter is characterized in that the inductor of the matching circuit unit is electromagnetically coupled to the stripline resonator of the bandpass filter unit.

  The present invention also provides a band-pass filter unit including a plurality of stripline resonators disposed between an unbalanced input terminal for inputting an unbalanced signal and a balanced output terminal for outputting a balanced signal, and the unbalanced input terminal. And a matching circuit unit comprising a capacitor disposed between the stripline resonator on the unbalanced input end side and an inductor disposed between the unbalanced input end and the ground, and the bandpass The filter unit and the matching circuit unit are embedded in the same multilayer dielectric chip, and the inductor of the matching circuit unit is electromagnetically coupled to the stripline resonator of the bandpass filter unit. This is a multilayer dielectric bandpass filter. Here, each stripline resonator of the bandpass filter unit is a half-wavelength resonance type with both ends open.

  In the present invention, “the inductor of the matching circuit unit is electromagnetically coupled to the stripline resonator of the bandpass filter unit” is thereby different from the attenuation pole formed by the bandpass filter unit. This means that the attenuation poles are electromagnetically coupled with a strength that is generated outside the passband.

  In the multilayer dielectric bandpass filter according to the present invention, the bandpass filter unit and the matching circuit unit are embedded in the same multilayer dielectric chip, and the inductor of the matching circuit unit is electromagnetically coupled to the bandpass filter unit. As a result, it is possible to provide an attenuation pole in the attenuation band while maintaining good pass characteristics in the pass band as a bandpass filter. In addition, the frequency position of the attenuation pole can be set freely by changing the degree of coupling between the inductor of the matching circuit section and the bandpass filter section, and the influence of the frequency position of the attenuation pole on the passband is reduced. Can do. Further, according to the present invention, it is possible to provide a balun function for performing unbalance-balance conversion while having such effects.

  FIG. 1 is an equivalent circuit diagram showing an embodiment of a multilayer dielectric bandpass filter according to the present invention. This multilayer dielectric band-pass filter has a configuration in which a matching circuit unit 10 and a band-pass filter unit 12 are arranged between an input end IN and an output end OUT. Here, the bandpass filter unit 12 includes three quarter-wavelength resonance type stripline resonators T1, T2, and T3 that are open at one end and short-circuited at the other end. The electromagnetic field coupling between the stripline resonators T1 and T2 is denoted by M1, and the electromagnetic field coupling between the stripline resonators T2 and T3 is denoted by M2. The matching circuit unit 10 includes a capacitor C and an inductor L. In this embodiment, since the matching circuit unit 10 is arranged on the input end side, a capacitor C is arranged between the input end IN and the stripline resonator T1 connected to the input end, and the input end IN An inductor L is disposed between the ground and the ground. The electromagnetic coupling between the inductor L of the matching circuit unit 10 and the stripline resonator T1 of the bandpass filter unit 12 is represented by Mi.

  First, the band-pass filter unit 12 including the stripline resonators T1, T2, and T3 and the electromagnetic couplings M1 and M2 between the stripline resonators T1, T2, and T3 has four times the electrical length of the stripline resonators T1, T2, and T3 as one. It exhibits a bandpass filter characteristic that resonates at a resonance frequency that is a wavelength and attenuates other frequency bands with a frequency band in the vicinity thereof as a pass band. Here, the passband width and the position of the attenuation pole are changed by the electromagnetic field couplings M1 and M2. When the electromagnetic field coupling M1, M2 is mainly electric field coupling, the attenuation pole is generated in the lower band side than the pass band. Conversely, when the magnetic field coupling is main, the attenuation pole is higher than the pass band. Although it occurs on the band side, in a dielectric band-pass filter having a laminated structure, magnetic coupling is usually the main component, so that the attenuation pole is generated on the higher band side than the pass band.

  Next, the matching circuit unit 10 functions to improve the reflection characteristics in the band and improve the pass characteristics. The combination of the capacitor C and the inductor L becomes a high-pass type matching circuit unit, and improves the attenuation characteristic in the DC to low frequency region. The electromagnetic coupling Mi between the inductor L of the matching circuit unit 10 and the stripline resonator T1 of the bandpass filter unit 12 has another attenuation pole in addition to the attenuation pole generated in the bandpass filter unit 12. It is generated on the lower frequency side than the passband. The extinction pole changes in frequency position depending on the value of the electromagnetic coupling Mi, and further, the change in the electromagnetic coupling Mi has little influence on the passband. Therefore, it is necessary to redesign the bandpass filter unit 12. No. In addition, a steep attenuation characteristic can be obtained by generating the attenuation pole at a frequency position near the passband, and a necessary bandpass filter characteristic can be expressed by changing the frequency position of the attenuation pole. .

  In the embodiment shown in FIG. 1, the matching circuit unit is arranged on the input end side, but it may be arranged on the output end side. The same effect can be obtained by the lifting. Furthermore, the matching circuit unit may be arranged on both the input end side and the output end side. The coupling and extinction poles are further generated, and the characteristics having the attenuation poles at different frequency positions can be obtained by changing the respective coupling degrees on the input end side and the output end side.

  The equivalent circuit shown in FIG. 1 can be realized by a multilayer dielectric bandpass filter having a structure described with reference to FIGS. FIG. 2 is a perspective view of the external appearance, and FIG. 3 is an explanatory view showing the internal structure of each layer. This multilayer dielectric bandpass filter is formed by printing capacitor electrodes, stripline resonators, input electrodes, output electrodes, ground electrodes, inductors, etc. on a dielectric green sheet with a conductive paste such as Ag or Cu. The dielectric green sheets are laminated in the order shown in FIG. 3 and integrated by pressure bonding, followed by firing.

  As shown in FIG. 2, the multilayer dielectric bandpass filter is a rectangular parallelepiped chip. An input electrode 20 (input end IN) is formed in a band shape so as to reach the lower end edge from the center of the upper end edge of one end surface of the chip and further spread to a part of the bottom surface so as to face the input electrode 20. The output electrode 22 (output end OUT) is formed in a band shape so as to reach the lower end edge from the center of the upper end edge of the other end face and further spread to a part of the bottom face. Further, the ground electrode 24 is formed over most of the upper surface, both side surfaces, and the bottom surface of the chip except for both end surfaces where the input electrode 20 and the output electrode 22 are formed and the vicinity thereof.

  Next, the internal structure of the chip will be described in order from the uppermost layer # 1 to the lowermost layer # 4 with reference to FIG.

  An upper surface ground electrode 30 is formed on the uppermost layer (first layer) # 1 over almost the entire upper surface. The upper surface ground electrode 30 is spaced apart from both sides of the side input electrode 32 and the side output electrode 34 facing each other without reaching the outer peripheral edge, and the opposite side orthogonal to them reaches the outer peripheral edge and reaches the side ground electrode 36. It is continuous.

  Three stripline resonators 38, 40, and 42 (corresponding to T1, T2, and T3 in FIG. 1) are formed on the upper surface of the second layer # 2. Each of the stripline resonators 38, 40, and 42 has an elongated rectangular shape, and one end thereof reaches the outer peripheral edge and continues to the side ground electrode 36 to become a short-circuited end, and the other end does not reach the outer peripheral edge and is in a separated state. Open end. From the side edge near the open end of the stripline resonator 42 on the output end side, the output side connection line 44 is formed so as to reach the end edge on the output side, and is connected to the side surface output electrode 34.

  In the third layer # 3, a capacitor electrode 46 is formed at a position corresponding to the stripline resonator 38 on the input end side in the vertical direction, and the side edge of the capacitor electrode 46 extends from the input side edge to the input side. A connection line 48 is formed and connected to the side input electrode 32. A capacitor C in FIG. 1 is formed between the capacitor electrode 46 and the stripline resonator 38 in the thickness direction.

  In the lowermost layer (fourth layer) # 4, an inductor electrode 50 is formed on the upper surface thereof. One of the inductor electrodes 50 is connected to the side input electrode 32, and the other is connected to the side ground electrode 36. Here, the inductor electrode 50 is formed in a meander shape. However, the inductor electrode 50 may be formed in a coil shape using a through hole, or may have a bowl shape if the inductance value is small. The inductor electrode 50 is provided so as to overlap with or be located in the vicinity of the stripline resonator 38 on the input end side in the vertical direction. A bottom surface ground electrode 52 is formed on almost the entire surface except for the vicinity of both end edges at the portion corresponding to the back surface of the lowermost layer # 4, and both side edges are continuous with the side surface ground electrode. Further, a bottom surface input electrode 54 is formed so as to be continuous with the side surface input electrode 32, and a bottom surface output electrode 56 is formed so as to be continuous with the side surface output electrode 34. Accordingly, the side input electrode 32 and the bottom input electrode 54 become the input electrode 20 (see FIG. 2), and the side output electrode 34 and the bottom output electrode 56 become the output electrode 22 (see FIG. 2). Further, the top surface ground electrode 30, the side surface ground electrode 36, and the bottom surface ground electrode 52 serve as the ground electrode 24.

  In the example shown in FIG. 2 and FIG. 3, each layer is connected by side electrodes (side input electrode 32, side output electrode 34, side ground electrode 36), but some or all of them are through holes. It is also possible to adopt a configuration to be performed. The side electrode is formed by printing a conductive paste after the lamination integration. In addition, the output end side of the bandpass filter unit is directly coupled, but may be capacitively coupled. Each layer is composed of one or more dielectric green sheets.

  The filter characteristics of the multilayer dielectric bandpass filter having such a structure will be described with reference to FIG. The characteristic curve a shows the characteristic in the case of only the bandpass filter part (conventional example). The characteristic curve b shows the characteristic when the coupling between the inductor of the matching circuit section and the stripline resonator of the bandpass filter section is almost absent or very weak (comparative example). On the other hand, the characteristic curve c shows characteristics when the coupling between the inductor of the matching circuit section and the stripline resonator of the bandpass filter section is slightly strong (the present invention), and the attenuation pole p1 is around 1.5 GHz. Appears. The characteristic curve d shows the characteristic when the coupling between the inductor of the matching circuit section and the stripline resonator of the bandpass filter section is further strengthened (the present invention). In this case, the attenuation pole p2 appears in the vicinity of 2 GHz, and it can be seen that the attenuation characteristic is even steeper. That is, as the coupling is weakened, the frequency position of the attenuation pole moves to the low frequency side. In any case, since the present invention is a high-pass type matching circuit section, the attenuation characteristic is improved at a frequency lower than 2 GHz. Further, as is clear from the comparison of the characteristic curves a to d, even if the matching circuit unit is provided as in the present invention, the pass band and the high band side attenuation characteristic are hardly affected (the band pass filter unit). It can be seen that the frequency position of the original attenuation pole p3 formed by (3) hardly changes).

  The degree of coupling between the inductor of the matching circuit unit and the stripline resonator of the bandpass filter unit is determined by the thickness of the second layer # 2 and the third layer # 3 or the horizontal direction of the inductor electrode 50 with respect to the stripline resonator 38. It can be adjusted by misalignment. If the layer thickness is increased, the bond is weak, and if the layer thickness is thin, the bond is strong. If the displacement amount is large, the bond is weak, and if the displacement amount is small, the bond is strong. Actually, the positional deviation amount has a larger influence on the change in the coupling degree than the layer thickness (an effect of increasing or decreasing the attenuation), and it is difficult to change the layer thickness greatly. It is more effective to adjust the shift amount (overlapping degree). Incidentally, in the example of FIG. 3, when the inductor electrode 50 is shifted to the left to reduce the overlap with the stripline resonator 38, the coupling becomes weak and the frequency position of the attenuation pole moves to the low frequency side (leftward).

  FIG. 5 is an equivalent circuit diagram showing another embodiment of the multilayer dielectric bandpass filter according to the present invention. The multilayer dielectric bandpass filter includes a matching circuit unit 10 and a bandpass filter unit 12 arranged between an unbalanced input terminal IN that inputs an unbalanced signal and balanced output terminals OUT1 and OUT2 that output a balanced signal. It is the structure which combined. Here, the band-pass filter unit 12 includes three half-wavelength resonance type stripline resonators T1, T2, and T3 that are open at both ends. The electromagnetic field coupling between the stripline resonators T1 and T2 is denoted by M1, and the electromagnetic field coupling between the stripline resonators T2 and T3 is denoted by M2. The matching circuit unit 10 includes a capacitor C and an inductor L. The matching circuit unit 10 is disposed on the unbalanced input end side, and a capacitor C is disposed between the unbalanced input end IN and the stripline resonator T1 on the unbalanced input end side, and the unbalanced input end IN, the ground, The inductor L is disposed between the two. The electromagnetic coupling between the inductor L of the matching circuit unit 10 and the bandpass filter unit 12 is represented by Mi.

  First, the band-pass filter unit 12 including the stripline resonators T1, T2, and T3 and the electromagnetic couplings M1 and M2 between the stripline resonators T1, T2, and T3 reduces the electrical length of the stripline resonators T1, T2, and T3 by two. It exhibits a bandpass filter characteristic that resonates at a resonance frequency that is a wavelength and attenuates other frequency bands with a frequency band in the vicinity thereof as a pass band. Here, the passband width and the position of the attenuation pole are changed by the electromagnetic field couplings M1 and M2. When the electromagnetic field coupling M1, M2 is mainly electric field coupling, the attenuation pole is generated on the lower band side than the pass band. Conversely, when the magnetic field coupling is main, the attenuation pole is higher than the pass band. However, in a dielectric band-pass filter having a laminated structure, magnetic coupling is mainly used, so that the attenuation pole is generated at a higher frequency side than the pass band.

  Next, the matching circuit unit 10 functions to improve the reflection characteristics in the band and improve the pass characteristics. The combination of the capacitor C and the inductor L becomes a high-pass type matching circuit unit, and the attenuation characteristics in the DC to low frequency region are also improved. The electromagnetic coupling Mi between the inductor L of the matching circuit unit 10 and the stripline resonator T1 of the bandpass filter unit 12 has another attenuation pole in addition to the attenuation pole generated in the bandpass filter unit 12. It is generated on the lower frequency side than the passband. The extinction pole changes in frequency position depending on the value of the electromagnetic coupling Mi, and the change in the electromagnetic coupling Mi hardly affects the passband. Therefore, the bandpass filter unit 12 needs to be redesigned. No. In addition, a steep attenuation characteristic can be obtained by generating the attenuation pole at a frequency position near the pass band, and a necessary bandpass filter characteristic can be expressed by changing the frequency position of the attenuation pole. it can.

  The equivalent circuit shown in FIG. 5 can be realized by a laminated dielectric bandpass filter having a structure described with reference to FIGS. FIG. 6 is a perspective view of the appearance, and FIG. 7 is an explanatory diagram showing the internal structure of each layer.

  As shown in FIG. 6, the multilayer dielectric bandpass filter of this embodiment is in the form of a rectangular parallelepiped dielectric chip. An unbalanced input electrode 60 (input end IN) is formed in a strip shape so as to reach the lower edge from the center of the upper edge of one end surface of the chip and further spread to a part of the bottom surface, and is opposed to the unbalanced input electrode 60. Two balanced output electrodes 62 (output ends OUT1, OUT2) are formed in a strip shape so as to extend from the upper end edge of the other end surface to the lower end edge and further spread to a part of the bottom surface. Further, the ground electrode 64 is formed over most of the upper surface, both side surfaces, and the bottom surface of the chip except for both end surfaces and the vicinity thereof where the unbalanced input electrode 60 and the balanced output electrode 62 are formed.

  Next, the internal structure of the chip will be described in order from the uppermost layer # 1 to the lowermost layer # 4 with reference to FIG.

  An upper surface ground electrode 70 is formed on almost the entire upper surface of the uppermost layer (first layer) # 1. In the upper surface ground electrode 70, both sides near the side input electrode 72 and the side output electrode 74 facing each other do not reach the outer peripheral edge but are separated from each other, and the opposite side orthogonal to them reaches the outer peripheral edge and reaches the side ground electrode 76. It is continuous.

  On the upper surface of the second layer # 2, three stripline resonators 78, 80, and 82 (corresponding to T1, T2, and T3 in FIG. 5) are formed. Each of the stripline resonators 78, 80, and 82 has an elongated rectangular shape, and both ends of the stripline resonators 78 do not reach the outer peripheral edge and are separated from each other and become open ends. Output side connection lines 84 are formed from the side edges near both open ends of the strip line resonator 82 on the output end side so as to reach the end edge on the output side, and are connected to the side output electrode 74. Therefore, the phase of the output signal is shifted by 180 degrees between the two side surface output electrodes 74, and a balun function is added.

  In the third layer # 3, a capacitor electrode 86 is formed at a position corresponding to the stripline resonator 78 on the input end side in the vertical direction, and the side edge of the capacitor electrode 86 extends from the input side edge to the input side. A connection line 88 is formed and connected to the side input electrode 72. A capacitor C in FIG. 5 is formed between the capacitor electrode 86 and the stripline resonator 78.

  In the lowermost layer (fourth layer) # 4, an inductor electrode 90 is formed on the upper surface. One of the inductor electrodes 90 is connected to the side input electrode 72, and the other is connected to the side ground electrode 76. Here, the inductor electrode 90 is formed in a meander shape. However, the inductor electrode 90 may be formed in a coil shape using a through hole, or may have a bowl shape if the inductance value is small. The inductor electrode 90 is provided so as to overlap with or be positioned near the stripline resonator 78 on the input end side in the vertical direction. A bottom surface ground electrode 92 is formed on almost the entire surface except for the vicinity of both end edges at the portion corresponding to the back surface of the lowermost layer # 4, and both side edges are continuous with the side surface ground electrode 76. Further, a bottom surface input electrode 94 is formed so as to be continuous with the side surface input electrode 72, and a bottom surface output electrode 96 is formed so as to be continuous with the side surface output electrode 74. Therefore, the side surface input electrode 72 and the bottom surface input electrode 74 become the unbalanced input electrode 60 (see FIG. 6), and the side surface output electrode 74 and the bottom surface output electrode 96 become the balanced output electrode 62 (see FIG. 6). Further, the upper surface ground electrode 70, the side surface ground electrode 76 and the bottom surface ground electrode 92 become the ground electrode 64.

  As in the previous embodiment, the multilayer dielectric bandpass filter of this embodiment uses a bandpass filter section and a matching circuit section to maintain a good pass characteristic in the passband, and an inductor in the matching circuit section. By coupling electromagnetically with the portion, an attenuation pole can be provided in the attenuation band without affecting the pass band, and by changing the degree of coupling, the frequency position of the attenuation pole can be changed. In addition, this embodiment has a balun function for performing unbalance-balance conversion.

The equivalent circuit schematic which shows one Example of the laminated type dielectric band pass filter which concerns on this invention. FIG. 3 is an external view of the multilayer dielectric bandpass filter. Explanatory drawing which shows the internal structure of the laminated type dielectric band pass filter. The graph which shows the filter characteristic. The equivalent circuit schematic which shows the other Example of the laminated type dielectric band pass filter which concerns on this invention. FIG. 3 is an external view of the multilayer dielectric bandpass filter. Explanatory drawing which shows the internal structure of the laminated type dielectric band pass filter.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Matching circuit part 12 Band pass filter part 20 Input electrode 22 Output electrode 24 Ground electrode 38, 40, 42 Stripline resonator 46 Capacitor electrode 50 Inductor electrode

Claims (5)

  Band-pass filter unit consisting of a plurality of stripline resonators arranged between the signal input and output ends, and high-pass matching consisting of capacitors and inductors arranged on the input and / or output sides The bandpass filter unit and the matching circuit unit are embedded in the same multilayer dielectric chip, and the inductor of the matching circuit unit is electromagnetically coupled to the stripline resonator of the bandpass filter unit. A laminated dielectric band-pass filter characterized by being coupled to   A band-pass filter unit comprising a plurality of stripline resonators disposed between the input end and the output end of the signal; and a capacitor disposed between the input end and the stripline resonator on the input end side. A matching circuit unit including an inductor disposed between the input terminal and the ground, and the bandpass filter unit and the matching circuit unit are embedded in the same laminated dielectric chip, and the matching circuit A laminated dielectric band-pass filter, characterized in that the inductor of the part is electromagnetically coupled to the stripline resonator of the band-pass filter part.   The multilayer dielectric bandpass filter according to claim 1 or 2, wherein each stripline resonator of the bandpass filter section is a 1/4 wavelength resonance type with one end open and the other end short-circuited.   A band-pass filter unit comprising a plurality of stripline resonators disposed between an unbalanced input terminal for inputting an unbalanced signal and a balanced output terminal for outputting a balanced signal, the unbalanced input terminal and the unbalanced input A matching circuit unit including a capacitor disposed between the stripline resonator on the end side and an inductor disposed between the unbalanced input terminal and the ground, and the bandpass filter unit and the matching circuit The dielectric layer is embedded in the same multilayer dielectric chip, and the inductor of the matching circuit unit is electromagnetically coupled to the stripline resonator of the bandpass filter unit. Path filter.   The multilayer dielectric bandpass filter according to claim 4, wherein each stripline resonator of the bandpass filter section is a half-wavelength resonance type with both ends open.

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