JP5152192B2 - Chip type filter parts - Google Patents

Description

  The present invention relates to a chip-type filter component such as a band-pass filter that transmits, for example, a millimeter-wave band electric signal. More specifically, a ground electrode is disposed so as to surround a resonator electrode, and the resonator The present invention relates to a chip-type filter component having an input / output electrode coupled to an electrode.

  Conventionally, various filter parts used as band pass filters in millimeter wave band communication devices have been proposed. For example, Patent Document 1 below discloses a dual mode bandpass filter 1001 shown in FIG. In the dual mode bandpass filter 1001, a resonator electrode 1003 made of a metal film is formed at a certain height position of the dielectric substrate 1002. The resonator electrode 1003 is formed with a through hole 1003a. By forming the through hole 1003a, the resonator electrode 1003 is decoupled from the resonance caused by the electromagnetic field generated in the length direction of the resonator electrode 1003 and the resonance caused by the electromagnetic field generated in the width direction, so that a bandpass filter is obtained. The following characteristics can be obtained.

  When the dual-mode bandpass filter 1001 is an actual filter component, the input electrode 1005 and the output electrode 1006 are coupled to the resonator electrode 1003. In FIG. 17, the resonator electrode 1003 is normally embedded at a certain height in the dielectric substrate 1002 although it is illustrated as if it was formed on the upper surface of the dielectric substrate 1002. In addition, ground electrodes are formed on the top, bottom, and side surfaces of the dielectric substrate 1002 so as to surround the resonator electrode 1003.

  When the ground electrode as described above is formed, the cylindrical ground electrode and the dielectric substrate 1002 act like a waveguide. Therefore, resonance in the waveguide mode determined by the shape of the dielectric substrate 1002 occurs inside the dielectric substrate 1002. The pass band of the dual-mode bandpass filter described in Patent Document 1 is a 20 to 30 GHz band, but resonance caused by the waveguide mode occurs in a frequency band near the pass band. Therefore, the input electrode 1005 and the output electrode 1006 are coupled with the resonance of the waveguide mode, and the resonance of the waveguide mode is spurious in the pass band or the attenuation band located on the low band side and the high band side of the pass band. Tended to occur as. Therefore, there has been a problem that the frequency characteristics of the dual mode bandpass filter deteriorate.

On the other hand, Patent Document 2 below proposes a method for attenuating spurious vibrations based on waveguide mode resonance in this type of filter component. Here, ground electrodes are formed on the upper surface, the lower surface, and the pair of side surfaces of the dielectric substrate. On both opposing end faces of the dielectric substrate, the input electrode and the output electrode are formed so as to extend in the vertical direction. A via hole electrode extending in the vertical direction is formed in the dielectric substrate so as to sandwich the input electrode and the output electrode, and spurious can be reduced by connecting the via hole electrode to the ground electrode. .
JP 2001-237610 A JP 2004-304761 A

  In the structure that reduces spurious as described in Patent Document 2, it becomes more difficult to attenuate the resonance as the resonance that becomes spurious becomes a higher order mode. Therefore, there is a limit to what spurious can be reduced. Therefore, there is a strong demand for further reduction of the effect of spurious due to the waveguide mode.

  Moreover, in the dual mode bandpass filter described in Patent Document 1, two resonances generated in the resonator electrodes arranged in one plane are coupled. In this structure, since the filter has a two-stage configuration, there is one attenuation pole. Therefore, in order to increase the attenuation, it is necessary to increase the number of stages. Therefore, in order to increase the number of stages, it is necessary to arrange two dual-mode bandpass filters so as to be coupled in the plane direction, and the shape of the filter component has to be increased.

  The object of the present invention is to reduce the spurious due to the waveguide mode composed of the ground electrode and the dielectric, in which the ground electrode is formed so as to surround the resonator electrode in view of the above-described state of the prior art. Another object of the present invention is to provide a chip-type filter component capable of improving the attenuation characteristics.

According to the present invention, a chip body having an upper surface, a lower surface, a pair of side surfaces, and first and second end surfaces facing each other, and a plurality of dielectric layers laminated, A resonator electrode formed on the chip body, a first electrode portion extending in the stacking direction of the chip body, and a first dielectric portion of the plurality of dielectric layers in the chip body. An input electrode and an output electrode having a second electrode portion formed on the layer and having a first end portion that is a coupling portion where the second electrode portion is coupled to the resonator electrode; And a ground electrode provided on the chip body so as to form a cylindrical body surrounding the resonator electrode, and the first end from the point connected to the first electrode portion of the second electrode portion The electrode length of the second electrode part, which is the length to the part, corresponds to the resonance frequency of the resonator electrode. Of the length of 1/2 are different, and the coupling portion of the input electrode, and the coupling portion of the output electrode is arranged to face the input electrode and the output electrode, wherein the first end A second end that is different from the first electrode and between the second end of the input electrode and the ground electrode and between the second end of the output electrode and the ground electrode. A chip-type filter component in which two capacitors are formed is provided.
The stacking direction of the chip body is a stacking direction of a plurality of dielectric layers, that is, a direction connecting the upper surface and the lower surface of the chip body.

  In a specific aspect of the chip-type filter component according to the present invention, the electrode length of the second electrode portion is set to a length that is ½ of a wavelength corresponding to a frequency lower than the resonance frequency of the resonator electrode. Yes. In this case, the resonance corresponding to the electrode length of the resonator formed by the second electrode portion of the input electrode and the output electrode on the lower band side than the pass band of the filter formed by the resonator electrode and the chip body. f0 is generated, and a harmonic 2nd harmonic resonance 2f0 is generated on the higher frequency side than the pass band. Between the resonance f0 and the resonance 2f0 of the second harmonic wave is an attenuation region of a band-pass filter formed by the second electrode portion of the input electrode and the output electrode, respectively, so that the main filter portion including the resonator electrode Is the attenuation band of each bandpass filter composed of the input electrode and the output electrode. Therefore, unnecessary spurious due to the waveguide mode that occurs in the vicinity of the passband of the main filter can be more reliably reduced.

  In another specific aspect of the chip-type filter component according to the present invention, a first capacitor is formed between the first end of the input electrode and the first end of the output electrode, A band-pass filter is configured by the second electrode portion of the input electrode, the second electrode portion of the output electrode, and the first capacitor.

  In another specific aspect of the chip-type filter component according to the present invention, each first electrode portion of the input electrode and the output electrode extends in the stacking direction in the chip body. However, in the present invention, the first electrode portions of the input electrode and the output electrode may be formed so as to extend in the stacking direction on the first and second end faces of the chip body, respectively.

  In the chip-type filter component according to the present invention, preferably, the resonator electrode is formed on a dielectric layer different from the dielectric layer on which the second electrode portion of the input electrode and the output electrode is formed. Has been. In this case, the coupling distance between the resonator electrode and the second electrode portion of the input electrode and the output electrode can be adjusted in consideration of the portion extending in the stacking direction of the chip body. Further, the resonator electrode, the input electrode and the output electrode can be arranged so as to partially overlap each other in the stacking direction of the chip body, thereby reducing the size.

  In still another specific aspect of the chip-type filter component according to the present invention, the chip body has a rectangular plate shape, and at least one end of each first electrode portion of the input electrode and the output electrode. Are formed so as to be exposed on at least one of the upper surface and the lower surface of the rectangular plate-shaped chip body, and the ground electrode has a surface parallel to the upper surface, the lower surface, and the pair of side surfaces. Is configured. In other words, the above-described resonance of the waveguide mode is generated by the cylindrical ground electrode and the chip body, but spurious due to the waveguide mode can be effectively reduced according to the present invention.

  Regarding the shape of the cylindrical body formed by the ground electrode, at least one cylindrical body surface parallel to the upper surface, the lower surface, and the pair of side surfaces of the chip body may be embedded in the chip body. Alternatively, the ground electrode may be formed on an upper surface, a lower surface, and a pair of side surfaces of the chip body.

  In still another specific aspect of the chip-type filter component according to the present invention, the resonator electrode is formed so as to generate a plurality of non-degenerate resonance modes, and the plurality of resonance modes are coupled. Thus, a through-hole is formed in the resonator electrode, thereby forming a dual-mode bandpass filter unit by coupling a plurality of resonance modes. That is, the resonator electrode may be formed so as to constitute the dual mode bandpass filter described in Patent Document 1. In this case, preferably, a through conductor is further provided, which penetrates the through hole so as not to contact the resonator electrode and is electrically connected to the ground electrode. Thereby, spurious can be further reduced.

However, the resonator electrode in the chip-type filter component according to the present invention is not limited to the one constituting the dual mode bandpass filter portion as described in Patent Document 1.
(Effect of the invention)

  In the chip-type filter component according to the present invention, the electrode lengths of the second electrode portions of the input electrode and the output electrode are different from a length corresponding to ½ of the wavelength corresponding to the resonance frequency of the resonator electrode, and Since the first ends of the input electrode and the output electrode are arranged to face each other and a coupling capacitance is formed between the input electrodes, the waveguide in the vicinity of the pass band of the main filter portion formed by the resonator electrode It is possible to reduce the influence of spurious due to the mode and improve the attenuation characteristic. This is because a λ / 2 resonator is formed by the input electrode and the output electrode, a two-stage bandpass filter is formed by the λ / 2 resonator and the coupling capacitor, and the passband of the bandpass filter is This is because the spurious due to the waveguide mode is located in the attenuation region of the band-pass filter because it is different from the pass band of the main filter section, thereby reducing the spurious due to the waveguide mode.

  Therefore, according to the present invention, it is possible to effectively reduce spurious due to the waveguide mode by improving the structure of the input electrode.

  Further, in the dual mode bandpass filter as described in Patent Document 1, it is necessary to increase the number of stages in order to increase the attenuation. On the other hand, in the chip type filter component provided by the present invention, the attenuation pole by the two-stage band pass filter is added, so that the attenuation can be increased without increasing the size.

FIG. 1A is a plan view of a chip-type filter component according to the first embodiment of the present invention, FIG. 1B is a front view, and FIG. 1C is a bottom view. FIG. 2 is an exploded perspective view of the chip-type filter component according to the first embodiment of the present invention. FIG. 3 is a schematic plan sectional view of the height position where the input electrode and the second electrode portion of the output electrode of the chip-type filter component according to the first embodiment of the present invention are formed. FIG. 4 is a diagram showing an equivalent circuit of the chip-type filter component of the first embodiment. FIG. 5 is a diagram illustrating frequency characteristics of the chip-type filter component of the first embodiment. FIG. 6 is an exploded perspective view of a chip-type filter component prepared for comparison. FIG. 7 is a diagram showing frequency characteristics obtained by simulation for the chip-type filter component shown in FIG. FIG. 8 is a schematic exploded perspective view for explaining a chip type filter component of a second comparative example prepared for comparison. FIG. 9 is a diagram illustrating frequency characteristics obtained by simulation of the chip-type filter component of the second comparative example. FIG. 10 is an exploded perspective view of a chip filter component of a third comparative example prepared for comparison. FIG. 11 is a diagram showing frequency characteristics obtained by simulation for the chip type filter component shown in FIG. FIG. 12 is a diagram showing actually measured frequency characteristics of the chip-type resonant component of the comparative example shown in FIG. FIG. 13 is a diagram showing actual frequency characteristics of the chip-type resonant component of the third comparative example shown in FIG. FIGS. 14A and 14B are a perspective view and a plan view of a chip type filter component according to a modification of the first embodiment. FIG. 15 is a schematic front cross-sectional view of a modified chip type filter component shown in FIG. FIGS. 16A to 16J are plan view mode plane cross-sectional views at different height positions of the chip type filter component of the second embodiment. FIG. 17 is a perspective view for explaining a conventional dual mode bandpass filter.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Chip type filter component 2 ... Chip body 2a ... Upper surface 2b ... Lower surface 2c, 2d ... Side surface 2e, 2f ... 1st, 2nd end surface 3 ... Marker for direction identification 4 ... Input terminal electrode 5 ... Output terminal electrode 6, DESCRIPTION OF SYMBOLS 7 ... Conductive film 8 ... Resonator electrode 8a ... Through-hole 11 ... Input electrode 11a ... 1st electrode part 11b ... 2nd electrode part 11b1 ... Center part 11b2 ... 1st narrow part 11b3 ... 1st edge part 11b4 ... 1st 2 narrow width portion 11b5 ... second end portion 12 ... output electrode 12a ... first electrode portion 12b ... second electrode portion 12b1 ... center portion 12b2 ... first narrow width portion 12b3 ... first end portion 12b4 ... second narrow Width portion 12b5 ... second end portion 13,14 ... ground electrode 13a-13d ... notch 15-18 ... via hole electrode 19 ... through conductor 51 ... chip-type filter component 52,53 ... λ / 2 resonator electrode 54 ... via hole electricity 61 ... Input electrode 61a ... First electrode part 61b ... Second electrode part 61b1 ... Coupling part 61b2 ... First end 62 ... Output electrode 62a ... First electrode part 62b ... Second electrode part 62b1 ... Coupling part 62b2 ... First 1 end A, B ... gap

  Hereinafter, the present invention will be clarified by describing specific embodiments of the present invention with reference to the drawings.

  1A to 1C are a plan view, a front view, and a bottom view of a chip type filter component according to a first embodiment of the present invention. The chip type filter component 1 has a rectangular plate-shaped chip body 2. The chip body 2 may have a shape other than a rectangular plate shape.

  In the present embodiment, the chip body 2 has a structure in which a plurality of dielectric layers are stacked. FIG. 2 is a schematic exploded perspective view for explaining the internal structure of the chip type filter component 1, that is, the electrode formed on the dielectric layer, the via hole electrode formed therein, and the like.

  The dielectric material constituting the chip body 2 is not particularly limited, and synthetic resin or dielectric ceramics can be used. The chip body 2 has an upper surface 2a, a lower surface 2b, side surfaces 2c and 2d, and first and second end surfaces 2e and 2f.

  An input terminal electrode 4 and an output terminal electrode 5 are formed on the lower surface 2b. Further, on the upper surface 2a, the direction identifying marker 3 of the chip body 2 is formed so as to be brought closer to the first end surface 2e side from the center.

  Further, a conductive film 6 covering the side surface 2c of the chip body 2 and reaching the upper surface and the lower surface, and a conductive film 7 covering the side surface 2d and reaching the upper surface and the lower surface are formed. The conductive films 6 and 7 constitute a part of the ground electrode.

  On the other hand, as shown in FIG. 2, a resonator electrode 8 made of a metal film is formed in the vicinity of the intermediate height position in the chip body 2. The resonator electrode 8 has a through hole 8a. The planar shape of the resonator electrode 8 is rectangular, and the through hole 8a is also rectangular. However, the shape of the resonator electrode 8 and the shape of the through hole 8a are not particularly limited as long as two coupled resonances can be generated so as to operate as a dual mode bandpass filter. That is, similar to the resonator electrode of the dual-mode bandpass filter described in Patent Document 1, the resonance propagating in the direction connecting the input / output coupling points and the resonance propagating in the direction orthogonal to the resonance are combined. The shape and dimensions of the resonator electrode 8 may be determined so that the pass band can be configured.

  An input electrode 11 shown in a plan view in FIG. 3 is formed on a dielectric layer at a height different from that of the dielectric layer on which the resonator electrode 8 is formed, in this embodiment on a lower dielectric layer. And each 2nd electrode part 11b, 12b of the output electrode 12 is arrange | positioned.

  The input electrode 11 includes a first electrode portion 11a composed of a via-hole electrode extending in the thickness direction of the chip body 2, that is, the stacking direction, and a second electrode formed to extend in the horizontal direction on the dielectric layer at a certain height position. Part 11b. Similarly, the output electrode 12 also has a first electrode portion 12a made of a via hole electrode extending in the stacking direction, and a second electrode portion 12b formed on the dielectric layer. The upper ends of the first electrode portions 11a and 12a are connected to and connected to the second electrode portions 11b and 12b. On the other hand, the lower ends of the first electrode portions 11 a and 12 a are drawn out to the lower surface 2 b of the chip body 2. The lower ends of the first electrode portions 11 a and 12 a are electrically connected to the input terminal electrode 4 and the output terminal electrode 5 formed on the lower surface of the chip body 2, respectively.

  On the other hand, in the center of the second electrode portion 11b, there is a central portion 11b1 that is relatively thicker than other portions. The upper end of the first electrode portion 11a is joined to the lower surface of the central portion 11b1.

  On the other hand, the second electrode part 11b has a first narrow part 11b2 having a relatively narrow width that extends from the central part 11b1 to the side face 2c. The tip of the first narrow portion 11b2 is the first end portion 11b3 in the present invention, and is also a coupling portion coupled to the resonator electrode 8. Further, on the opposite side of the first narrow portion 11b2, the second narrow portion 11b4 is connected to the central portion 11b1. The tip of the second narrow portion 11b4 is opposed to an electrode connected to a ground potential described later.

  On the other hand, the second electrode portion 12b of the output electrode 12 similarly has a central portion 12b1 and first and second narrow width portions 12b2 and 12b4. The tip of the first narrow portion 12b2 is the first end 12b3 in the present invention. The first end portion 11b3 of the input electrode 11 and the first end portion 12b3 of the output electrode 12 are opposed to each other with a gap therebetween, thereby forming a coupling capacitor Cp.

  Further, the electrode lengths of the second electrode portions 11b and 12b, that is, the points connected to the first electrode portions 11a and 12a of the second electrode portions 11b and 12b, that is, the first electrode portions 11a and 11b of the central portions 11b1 and 12b1, The length from the point linked to 12a to the first end portions 11b3 and 12b3 is different from the length of ½ of the wavelength corresponding to the resonance frequency in the resonator electrode 8, more specifically. Is ½ the wavelength corresponding to a frequency lower than the resonance frequency of the resonator electrode 8.

  The input electrode 11 and the output electrode 12 are coupled to the resonator electrode 8 via a dielectric layer at the first end.

  On the other hand, a ground electrode 13 is formed on the dielectric layer at a height position above the resonator electrode 8, and a ground electrode 14 is posted on the dielectric layer below the resonator electrode 8. ing. The ground electrode 14 is formed on the dielectric layer below the second electrode portions 11 b and 12 b of the input electrode 11 and the output electrode 12. Each of the ground electrodes 13 and 14 is formed to have a larger area than the resonator electrode 8 so that the resonator electrode 8 is included when seen in a plan view.

  The ground electrodes 13 and 14 are formed so as to reach the side surface 2c and the side surface 2d of the chip body 2, respectively. However, the ground electrodes 13 and 14 are set back with respect to the first end surface 2e and the second end surface 2f with gaps A and B therebetween.

  The ground electrode 13 is formed with a plurality of notches 13a to 13d that open toward the side surface 2c or the side surface 2d. That is, a plurality of cutouts 13a and 13b opened on the side surface 2c are formed, and a plurality of cutouts 13c and 13d opened toward the side surface 2d are formed.

  These notches 13a to 13d are provided to increase the adhesion between the ceramic sheet layers. A similar notch is also formed in the ground electrode 14.

  The ground electrodes 13 and 14 are connected to the conductive films 6 and 7 described above on the side surface 2c or the side surface 2d.

  On the other hand, the ground electrodes 13 and 14 are electrically connected to each other by via-hole electrodes 15 to 18 penetrating the chip body 2.

  The via-hole electrodes 15 to 18 penetrate the periphery of the portion where the resonator electrode 8 is provided in the stacking direction so as not to be electrically connected to the resonator electrode 8.

  The upper ends of the via-hole electrodes 15 to 18 are connected to the ground electrode 13, and the lower ends are connected to the ground electrode 14.

  Therefore, the resonator electrode 8 constituting the dual mode bandpass filter is surrounded by a ground electrode which is a cylindrical body formed by the ground electrodes 13 and 14 and the conductive films 6 and 7.

  In the present embodiment, the through conductor 19 is formed so as to penetrate the through hole 8 a of the resonator electrode 8. The through conductor 19 has an upper end connected to the ground electrode 13 and a lower end connected to the ground electrode 14. Accordingly, the through conductor 19 is connected to the ground potential in the same manner as the via hole electrodes 15 to 18. In the present embodiment, since the through hole 8a is provided, it is possible to adjust the degree of coupling of two resonances generated in the resonator electrode 8 by the through hole 8a. That is, by adjusting the shape and size of the through-hole 8a, it is possible to adjust the degree of coupling of the two resonances that are combined to form the dual mode bandpass filter. The through conductor 19 is inside the through hole 8 a and may be disposed anywhere as long as it is not electrically connected to the resonator electrode 8. Since the conductive films 6 and 7 on the side surfaces 2c and 2d of the chip body 2 and the ground electrodes 13 and 14 are formed, resonance due to a waveguide mode that occurs when the chip body 2 functions as a waveguide. The through conductor 19 has a function of shifting the peak to the high frequency side. Thereby, the spurious characteristic of the filter can be improved.

  The input terminal electrode 4, the output terminal electrode 5, the conductive films 6 and 7, and the direction identification marker 3 formed on the outer surface of the chip body 2 described above can be formed of an appropriate conductive material. Examples of such a conductive material include metals or alloys such as Ag, Cu, Al, and Pt. These conductive films and electrodes formed on the outer surface can be applied by applying and baking these conductive materials, or by a thin film forming method such as sputtering or plating.

  Further, the resonator electrode 8, the input electrode 11 and the output electrode 12, the via hole electrodes 15 to 18, the through conductor 19 and the like formed in the chip body 2 are also formed of the appropriate conductive material described above. Can do. For the electrodes formed inside these, when the chip body formed by laminating dielectric layers is obtained by the ceramic integrated firing technique, the conductive paste is printed or filled so as to form these electrodes. In addition, it can be formed by baking together with ceramics when firing the ceramics.

  Note that portions of the conductive films 6 and 7 extending to the upper surface and the lower surface of the chip body 2 need not be provided.

  FIG. 4 shows an equivalent circuit of the chip type filter component of the present embodiment.

  In the present embodiment, a dual-mode bandpass filter based on two resonances coupled at the resonator electrode 8 is formed as the main filter portion 21. The filter unit 21 is coupled to the λ / 2 resonators 22 and 23 by a coupling capacitor Ce. Further, the λ / 2 resonators 22 and 23 are constituted by filters coupled by a coupling capacitor Cp. Here, the λ / 2 resonator is formed by the second electrode portions 11b and 12b, and the coupling capacitance Cp is taken out between the first end portions 11b3 and 12b3 of the input electrode 11 and the output electrode 12 described above. Capacitance.

  Further, the capacitance Ca and the capacitance Cb in FIG. 4 are electrostatic capacitances generated between the input electrode 11 and the output electrode 12 and the ground potential. Specifically, the capacitance between the second electrode portion 11b and the second narrow width portion 11b4 and the via-hole electrode 15 and between the second electrode portion 11b and the electrode pad 15a on the same plane is electrostatic capacitance. Capacitance that is connected to the end of the second narrow portion 12b4 of the second electrode portion 12b and the via-hole electrode 17 and is taken out between the second electrode portion 12b and the electrode pad 17a on the same plane. Is the capacitance Cb.

  The feature of this embodiment is that a bandpass filter composed of the λ / 2 resonator and the coupling capacitor Cp is connected in parallel to a main filter section composed of a dual mode bandpass filter, thereby reducing unwanted spurious. That is what is being illustrated. This will be described more specifically.

  As described above, when the ground electrode is formed so as to have a cylindrical shape surrounding the resonator electrode 8, resonance due to the waveguide mode appears as spurious. In the present embodiment, this spurious is suppressed by adding a band-pass filter composed of the λ / 2 resonators 22 and 23 and the coupling capacitor Cp shown in FIG.

  In other words, in the present embodiment, the electrode length l of the second electrode portions 11 b and 12 b is ½ of the wavelength corresponding to a frequency lower than the resonance frequency of the resonator electrode 8. Therefore, a resonance f0 corresponding to the electrode length l of the λ / 2 resonator is generated on the low frequency side of the pass band of the main filter unit, and the second harmonic f0 is generated on the high frequency side of the pass band of the main filter unit. Resonance occurs. A frequency band between the resonance f0 and the second harmonic resonance 2f0 is an attenuation region of a bandpass filter including the λ / 2 resonator and the coupling capacitor Cp.

  Therefore, the resonator length of the bandpass filter, that is, the wavelength λ of the resonator of λ / 2 is selected as described above so that the pass band of the main filter portion becomes the attenuation region. Unnecessary spurious due to the waveguide mode in the passband of the part or in the vicinity thereof can be effectively reduced.

  In the present embodiment, as described above, the electrode lengths of the second electrode portions 11b and 12b are ½ of the wavelength corresponding to a frequency lower than the resonance frequency of the resonator electrode 8. However, the electrode length may be ½ of the wavelength corresponding to a frequency higher than the resonance frequency of the resonator electrode 8. Even in such a case, the pass band of the main filter becomes the attenuation region of the bandpass filter added as described above, and therefore, unnecessary spurious due to the waveguide mode can be reduced.

  However, preferably, as in the present embodiment, the lengths of the input electrode 11 and the output electrode 12 are ½ of the wavelength corresponding to a frequency lower than the resonance frequency of the resonator electrode 8. desirable. Thereby, as described above, an attenuation region of the bandpass filter can be formed between the resonance f0 and the resonance 2f0 of the second harmonic, and spurious due to the waveguide mode can be effectively reduced. it can.

  In the present embodiment, since the capacitors Ca and Cb are formed between the second end portions of the input electrode 11 and the output electrode 12 and the ground potential, the second electrode which is a λ / 2 resonator. The electrode lengths of the parts 11b and 12b can be shortened, thereby increasing the degree of freedom in designing the second electrode parts 11b and 12b. Further, the chip type filter component 1 can be reduced in size.

  It will be described based on a specific experimental example that the spurious due to the waveguide mode can be reduced in the chip type filter component 1 of the present embodiment.

  FIG. 5 is a diagram showing reflection characteristics and transmission characteristics of the chip type filter component 1 of the present embodiment. A solid line indicates reflection characteristics, and a broken line indicates pass characteristics. As is clear from the pass characteristics, an attenuation pole indicated by an arrow C is formed on the lower frequency side than the center frequency of 26 GHz. This attenuation pole is added by a band pass filter formed by the λ / 2 resonator and Cp. In the pass characteristic, spurious due to the waveguide mode is reduced to 32 GHz. This will be described in more detail with reference to FIGS.

  FIG. 6 is a schematic exploded perspective view showing a chip-type resonant component prepared for comparison. The chip-type resonant component 1101 has a configuration in which the resonator electrode 8, the via-hole electrodes 15 to 18 and the through conductor 19 are deleted from the chip-type filter component 1. Further, the second narrow width portions 11b4 and 12b4 are removed from the input electrode 11 and the output electrode 12 of the filter component 1. That is, in the input electrode 1111 and the output electrode 1112, the second electrode portions 1111b and 1112b have only the center portions 1111b1 and 1112b1 connected to the first electrode portions 1111a and 1112a and the first narrow width portions 1111b2 and 1112b2. . About another point, it is comprised similarly to the chip-type filter component 1 of the said Example.

  FIG. 7 shows pass characteristics and reflection characteristics of the chip-type resonant component 1101. The solid line indicates the pass characteristic, and the broken line indicates the reflection characteristic.

  Here, since the resonator electrode 8 and the λ / 2 resonator are not formed, spurious characteristics appear due to the shapes of the cylindrical body made of the ground electrode and the input / output electrodes in the chip-type filter component 1.

  As can be seen from FIG. 7, in order to increase the spurious attenuation due to the waveguide mode to 20 dB or more, the usable frequency band is 20 GHz or less.

  Next, for comparison, a chip-type resonant component 1141 shown in an exploded perspective view in FIG. 8 was prepared. In this resonant component 1141, in addition to the chip-type resonant component 1101 shown in FIG. 6, a plurality of via-hole electrodes 15 to 18 that connect upper and lower ground electrodes and a through conductor 19 are provided. The other points are the same as those of the chip-type resonant component 1101 shown in FIG.

  Here, in order to reduce the resonance caused by the chip shape, that is, the resonance caused by the waveguide mode, the via-hole electrodes 15 to 18 and the through conductor 19 are formed in a portion where the electric field strength is strong. FIG. 9 shows pass characteristics and reflection characteristics of the chip-type resonant component 1141 obtained in this way. As can be seen from FIG. 9, the response frequency band of 20 dB or more shifts to 27 GHz. That is, it can be seen that the spurious response can be shifted to around 27 GHz. When the spurious suppression effect described in Patent Document 2 is used, spurious attributed to the shape can be reduced as in the case of FIG. However, there is a limit to such spurious mitigation methods.

  On the other hand, FIG. 10 is an exploded perspective view of a chip-type resonant component as a comparative example having a structure in which a λ / 2 resonator is formed of an input electrode and an output electrode, similarly to the chip-type resonant component of the above embodiment. In this chip type resonance component 1161, in addition to the structure shown in FIG. 8, the second electrode portions 11b and 12b further cause the λ / 2 resonator to be the second electrode portions 11b and 12b of the chip type filter component 1. The configuration is the same. Therefore, in other words, the configuration is the same as that of the chip type filter component 1 except that the resonator electrode 8 is not provided.

  That is, the coupling capacitance Cp is formed between the first end portions of the input electrode 11 and the output electrode 12, and the second electrode portions 11b and 12b constitute the λ / 2 resonator described above, thereby A band pass filter is configured.

  FIG. 11 shows the transmission characteristics and reflection characteristics of the chip-type resonant component 1161. A solid line indicates reflection characteristics, and a broken line indicates pass characteristics.

  As is clear from FIG. 11, the resonance f0 of the bandpass filter formed as described above appears at the position indicated by the arrow D, and the second harmonic resonance 2f0 appears at the position indicated by the arrow E. Therefore, it can be seen that the spurious response can be suppressed in the band indicated by F in FIG. That is, one pass band of a bandpass filter having a λ / 2 resonator appears in the vicinity of 21 GHz, and resonance due to the higher-order mode appears in the vicinity of 33 GHz. Therefore, the range in which the spurious level is 20 dB or more is a frequency range of 19 GHz or less and a frequency range F of 22 to 31 GHz.

  Therefore, in the chip type filter component 1, since the pass band of the main filter portion is located in the range of 22 to 31 GHz, the chip type filter component 1 includes the λ / 2 resonator and the coupling capacitance Cp. It can be seen that the spurious due to the waveguide mode is effectively suppressed by adding the bandpass filter, and a good attenuation characteristic can be obtained. Therefore, it has become possible to provide a chip type filter component having a center frequency of 27 GHz or more, which has been difficult to realize so far.

  The frequency characteristics of the chip-type filter component 1 shown in FIG. 5 are actually measured values, whereas the frequency characteristics of the chip-type resonant components shown in FIGS. 7, 9, and 11 are results of simulation. . 12 and 13 show actual measurement values of the frequency characteristics of the chip-type filter components 1141 and 1161. That is, the characteristics shown in FIGS. 12 and 13 are actually measured values corresponding to the characteristics obtained by the simulations shown in FIGS.

  In FIG. 12, the frequency range in which spurious appears is a band of 26 GHz or less, whereas in FIG. 13, the frequency range in which spurious at a level of 20 dB or more appears is a frequency range of 16 GHz or less and a frequency range of 18 to 36 GHz. It can be seen that it is suitable for constituting a main filter section and a resonator having a pass band in the vicinity of 24 to 30 GHz.

  Further, as described above, the bandpass filter composed of the λ / 2 resonator and the coupling capacitor Cp also functions as a trap filter. Therefore, it is possible to add one attenuation pole outside the pass band of the main filter section. This can also improve the attenuation characteristics.

  In the above experimental example, a response of 20 dB or more is assumed to be spurious, but the suppression amount is not limited to this and may be appropriately selected according to the application. That is, depending on the application, a spurious signal of 10 dB or higher may be suppressed, or a response of 30 dB or higher may be suppressed. Depending on the application, the level of spurious to be suppressed changes, and the usable frequency band also changes. However, as in the above embodiment, a λ / 2 resonator is configured with input / output electrodes and a coupling capacitance is used. By configuring the band pass filter by adding Cp, similarly, spurious in the pass band of the main filter unit can be effectively reduced, and the attenuation characteristic can be improved.

  Further, in the chip type filter component 1 of the present embodiment, the main filter portion is constituted by a dual mode bandpass filter, and in this case, two resonances orthogonal to each other are coupled at the resonator electrode. Therefore, in order to increase the attenuation, the dual mode bandpass filter needs to have a multistage configuration. However, according to the present embodiment, it is added to the input side and the output side without using a multistage configuration. Since the attenuation characteristic can be improved by the bandpass filter, the out-of-band attenuation can be increased without increasing the size.

  In the present embodiment, the λ / 2 resonator is modified and used as the second electrode portions 11b and 12b. However, the purpose is to suppress the spurious due to the shape of the main filter portion in the pass band. Therefore, the input / output electrodes may be formed so as to constitute another LC resonator instead of the λ / 2 resonator. In this case, the band-pass filter formed by the input electrode and the output electrode needs to be formed so as to be connected in parallel to the main resonator and filter.

  Further, in the chip type filter component 1 of the first embodiment, the first electrode portions 11a and 12a of the input electrode 11 and the output electrode 12 are formed by via hole electrodes penetrating the inside of the chip body 2, but FIG. As in the modification shown in FIGS. 4A and 4B, the first electrode portions 11a and 12a extending in the stacking direction of the chip body 2 may be formed on the first end surface 2e and the second end surface 2f. Here, the first electrode portions 11a and 12a are extended in the stacking direction at the center of the end surfaces 2e and 2f, and the second electrode portions 11b and 12b are drawn to the end surfaces 2e and 2f as shown in FIG. The first electrode portions 11a and 12a are electrically connected. Thus, the first electrode portions 11a and 12a of the input electrode 11 and the output electrode 12 in the present invention may be formed on the end surfaces 2e and 2f.

  In the above embodiment, the ground electrodes 13 and 14 embedded in the chip body 2 are used as the ground electrodes forming the cylindrical body. However, as in the modification shown in FIGS. 14 and 15. The ground electrode 41 may be formed so as to cover the upper surface 2a, the lower surface 2b, and the pair of side surfaces 2c, 2d of the chip body 2. That is, the ground electrode portion forming the cylindrical body may be a cylindrical body having a surface parallel to the upper surface, the lower surface, and the pair of side surfaces of the chip body 2, and at least one of the cylindrical body surfaces is the first surface. As in the embodiment, it may be embedded in the chip body. Further, as in the present modification, ground electrodes may be formed on the upper surface 2a, the lower surface 2b, and the pair of side surfaces 2c and 2d of the chip body 2.

  In the above embodiment, the main filter unit is a dual mode bandpass filter using the resonator electrode 8 having the through-hole 8a. However, in the present invention, the main filter unit needs to be a dual mode bandpass filter. Other resonators or filters may be used.

  FIG. 16 is a view for explaining a chip type filter component according to the second embodiment of the present invention. FIGS. 16A to 16J are a plan view of the chip type filter component and a chip type filter component. It is a typical plane sectional view of a different height position in a chip body.

  Here, the conductive films 6 and 7 are formed in the same manner as in the first embodiment so as to extend from the side surfaces 2c and 2d of the chip body 2 to the upper and lower surfaces. The ground electrode 13 is formed at the next height position of the upper surface 2a, and the λ / 2 resonator electrodes 52 and 53 are opposed to each other with a gap at the lower height position of the ground electrode 13. ing. The λ / 2 resonator electrodes 52 and 53 constitute a multistage filter that can obtain characteristics as a band-pass filter having a center frequency in the vicinity of 10 to 30 GHz. The λ / 2 resonator electrodes 52 and 53 include electrode body portions 52a and 53a extending in the short side direction of a rectangular dielectric layer, and the opposite λ / 2 resonator electrode 53 or one end of the electrode body portions 52a and 53a. Projection parts 52b and 53b as part of the capacity unit bent and extended toward the side 52 are provided.

  A via-hole conductor 54 is disposed between the λ / 2 resonator electrodes 52 and 53. The via-hole conductor 54 extends in the stacking direction, the upper end of the via-hole conductor 54 is electrically connected to the ground electrode 13, and the lower end is electrically connected to the ground electrode 14.

  The ground electrodes 13 and 14 reach both ends of the chip body 2 in the width direction, respectively. Therefore, a cylindrical body composed of the conductive films 6 and 7 and the ground electrodes 13 and 14 is disposed so as to surround the multistage filter portion formed by the λ / 2 resonator electrodes 52 and 53 and the via-hole conductor 54. Therefore, also in this embodiment, the ground electrode in the shape of a cylindrical body may act as a waveguide together with the chip body 2, and spurious due to the waveguide mode may appear.

  However, also in this embodiment, the input / output electrodes 61 and 62 coupled to the main filter section having the λ / 2 resonator electrodes 52 and 53 constitute a band pass filter that reduces spurious due to the waveguide mode. ing. That is, the input electrode 61 and the output electrode 62 are via-hole electrodes and have first electrode portions 61 a and 62 a extending in the stacking direction of the chip body 2.

  The lower ends of the first electrode portions 61 a and 62 a are connected to the input terminal electrode 4 and the output terminal electrode 5. The upper ends of the first electrode portions 61a and 62a are connected to 61b1 and 62b1 of the second electrode portions 61b and 62b configured similarly to the second electrode portions 11b and 12b of the above-described embodiment. That is, the second electrode portions 61b and 62b have first end portions 61b2 and 62b2 which are coupling portions coupled to the filter portion including the λ / 2 resonator electrodes 52 and 53.

  The first end portion 61b2 and the first end portion 62b2 are opposed to each other with a gap therebetween, and a coupling capacitance Cp is formed at this portion. Further, in the input electrode 61 and the output electrode 62, a λ / 2 resonator having the wavelength λ as the electrode length of the second electrode portions 61b and 62b is configured. The λ / 2 resonator and the coupling capacitor Cp constitute a bandpass filter, and the bandpass filter reduces spurious due to the waveguide mode in the pass band of the main filter section composed of the λ / 2 resonator electrodes 52 and 53. It is possible to reduce the impact. That is, by making λ different from the wavelength of the resonance frequency of the main filter unit, spurious due to the waveguide mode due to the shape can be effectively reduced as in the first embodiment.

Claims (11)

A chip body having an upper surface, a lower surface, a pair of side surfaces, and first and second end surfaces facing each other, and a stack of a plurality of dielectric layers;
A resonator electrode formed in the chip body;
A first electrode portion extending in the stacking direction of the chip body, and a second electrode connected to the first electrode portion and formed on one dielectric layer of the plurality of dielectric layers in the chip body. An input electrode and an output electrode, and having a first end that is a coupling portion in which the second electrode portion is coupled to the resonator electrode;
A ground electrode provided on the chip body so as to constitute a cylindrical body surrounding the resonator electrode;
The electrode length of the second electrode portion, which is the length from the point connected to the first electrode portion of the second electrode portion to the first end portion, corresponds to the resonance frequency of the resonator electrode. The input electrode coupling portion and the output electrode coupling portion are arranged to face each other, and the input electrode and the output electrode are connected to the first electrode. A second end different from the end, and between the second end of the input electrode and the ground electrode and between the second end of the output electrode and the ground electrode. A chip type filter component in which a second capacitor is formed .   2. The chip-type filter component according to claim 1, wherein an electrode length of the second electrode portion is set to a half of a wavelength corresponding to a frequency lower than a resonance frequency of the resonator electrode.   A first capacitor is formed between the first end of the input electrode and the first end of the output electrode, and the second electrode portion of the input electrode and the second electrode portion of the output electrode The chip-type filter component according to claim 1, wherein a band-pass filter is configured by the first capacitor. The first electrode portion each of the input electrode and the output electrode, in the chip body, and extends in the stacking direction, the chip-type filter component according to any one of claims 1-3. The first electrode portion each of said input electrode and said output electrode, respectively, a first of said chip body, is formed to extend in the stacking direction in the second end surface, any one of claims 1 to 3 Chip type filter parts as described in 1. The said resonator electrode is formed on the dielectric material layer different from the dielectric material layer in which the said 2nd electrode part of the said input electrode and the said output electrode is formed, The any one of Claims 1-5 The chip-type filter component according to the item. The chip body has a rectangular plate shape,
At least one end portion of each first electrode portion of the input electrode and the output electrode is formed to be exposed on at least one of the upper surface or the lower surface of the rectangular plate-shaped chip body, and the ground electrode is , the top surface constitutes a cylindrical member having a surface parallel to the bottom surface and a pair of said side surfaces, a chip-type filter component according to any one of claims 1-6. In cylindrical body the ground electrode constitutes the upper surface of the chip body, the at least one tubular body surface of a plane parallel to the lower surface and a pair of side surfaces, are embedded in the chip body, to claim 7 The chip-type filter component as described. The chip-type filter component according to claim 7 , wherein the ground electrode is formed on an upper surface, a lower surface, and a pair of side surfaces of the chip body. The resonator electrode is formed to produce a plurality of non-degenerate resonance modes, and a through-hole is formed in the resonator electrode to couple the plurality of resonance modes, thereby The chip-type filter component according to any one of claims 1 to 9, wherein a dual-mode bandpass filter unit is configured by coupling a plurality of resonance modes. The chip type filter component according to claim 10 , further comprising a through conductor penetrating through the through hole so as not to contact the resonator electrode and electrically connected to the ground electrode.

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