JP2006109236A - Filter device and duplexer device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a filter device having desired filter characteristics while miniaturizing the device. <P>SOLUTION: The filter device (1) consists of a plurality of resonators (L1-L3) in which a plurality of juxtaposed through-holes (111-113, 121-123) are formed on a dielectric member (10), conductive layers (132-136, 171-173) are formed on the external peripheral surface of the dielectric member other than a first end surface out of the first and second end surfaces (11, 14) having opened through-holes and on the internal surface of each of the through-holes, and the conductive layers in the through-holes are capacitively coupled with each other. In this device (1), the conductive layer is removed to form a pair of opposing terminal electrodes (141, 142) on both the end surfaces in the arranging direction of the resonators (L1-L3), and frequency adjusters (165, 166) formed by removing one part of the conductive layer is provided on the external peripheral surface between these terminal electrodes (141, 142) and the openings of the through-holes (111-113) of the second surface (14). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a filter device and a duplexer device in which a resonator is formed in a dielectric material, for example.

  With the miniaturization of communication devices and the increase in the frequency of use, technological development relating to the miniaturization of filter devices has been promoted. As such a filter device, a dielectric filter formed by forming a resonator in a dielectric material is known. In the comb line type dielectric filter, a filter circuit is configured by coupling a plurality of resonators having a large diameter portion. There are two known types of coupling between adjacent resonators, capacitive coupling and magnetic coupling. As this related technique, a technique (for example, Patent Document 1) in which a through hole for obtaining magnetic coupling is provided with a large-diameter part (bore face) and a small-diameter part, and a bending-type eccentric part is provided in the resonance hole to provide interstage coupling. The technique (for example, patent document 2) etc. which obtains are proposed. In the filter device in which the resonators are coupled by magnetic coupling, the large diameter portions are decentered in a direction away from each other to generate magnetic coupling between the large diameter portions, and a pole is generated on the high band side of the pass band. ing.

  By the way, in the filter device having such a structure, the input / output terminal and the resonator are capacitively coupled, and an exposed portion of the dielectric member is required to separate the input / output terminal from other ground conductor portions. However, it is known that this exposed portion has an effect of increasing the resonance frequency of the resonator facing the input / output terminal. On the other hand, in order to compensate the resonance frequency of the resonator, which has become higher due to the exposed portion, in the direction of lower frequency, a method of increasing the axial length of the resonator, that is, the resonance length of the entire resonator is known. However, as a result, the size of the filter device is increased. Similarly, in order to compensate the resonance frequency of the resonator in a lower direction, a method of increasing the diameter of the large diameter portion of the resonator is also known, but this method also increases the size of the filter device. Therefore, it has been difficult to make the resonance frequency of the resonator the target frequency and to reduce the overall size of the filter device.

In particular, by reducing the size of the filter device, the distance between the adjacent resonators is also reduced, so that the coupling between the adjacent resonators is strengthened, and in addition, the input / output terminal is separated from the other ground conductor portion. As a result, the capacitive coupling between adjacent resonators increases due to the influence of the exposed ceramic exposed portion (electrode removal portion), so that the desired magnetic coupling is weakened and a sufficient band cannot be obtained. In other words, in a filter device in which a resonator is formed on a dielectric member, the filter characteristics also change as the filter device is downsized. Therefore, it is difficult to obtain a filter device having desired filter characteristics while downsizing. there were.
Japanese Patent Laid-Open No. 5-226909 JP-A-10-256807

  As described above, the conventional filter device and duplexer device have a problem that it is difficult to obtain a filter device having desired filter characteristics while achieving downsizing.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide a filter device and a duplexer device capable of obtaining desired filter characteristics while reducing the size of the filter device.

  In order to achieve the above-described object, a filter device according to a first aspect of the present invention includes a plurality of parallel through holes formed in a dielectric member, and first and second end faces at which the through holes are opened. In the filter device comprising a plurality of resonators in which a conductor layer is formed on the outer peripheral surface of the dielectric member excluding the first end surface and the inner surface of each through hole, and the conductor layers in the through hole are magnetically coupled to each other. The conductor layers are removed from both end faces in the arrangement direction of the resonators to form a pair of opposing terminal electrodes, and a conductor is formed on the outer peripheral surface between the terminal electrodes and the opening of the through hole in the second end face. It is characterized in that a frequency adjustment unit from which a part of the layer is removed is provided.

  A filter device according to a second invention is the filter device according to the first invention, wherein the frequency adjusting unit is formed by removing a part of the conductor layer on both side surfaces between the terminal electrode and the second end surface. It is characterized by.

  A filter device according to a third aspect of the present invention is the filter device according to the first aspect of the present invention, characterized in that the frequency adjustment unit is formed on the second end face.

  A filter device according to a fourth invention is the filter device according to the third invention, characterized in that the frequency adjusting portions are formed at both ends of the second end face in the resonator arrangement direction.

  The filter device according to a fifth aspect of the present invention is the filter device according to the fourth aspect of the present invention, characterized in that the frequency adjustment section is formed at both edges of the second end face in the resonator arrangement direction.

  A duplexer device according to a sixth aspect of the invention includes at least one filter device according to the first to fifth aspects of the invention.

  According to the present invention, desired filter characteristics can be obtained while reducing the size of the filter device.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing a basic circuit configuration of a filter device according to one embodiment of the present invention. As shown in FIG. 1, the filter device 1 is a comb line type filter having three resonators, and includes resonators L1 to L3, coupling inductors L11 to L13, coupling capacitors C11 to C13, and input / output capacitance C1. And C2.

  The resonator L1 is a resonator having one end connected to the input / output terminal T1 via the input / output capacitor C1 and the other end grounded. The resonator L1 is configured by forming a through hole in a dielectric material, forming a conductor layer on the inner wall surface of the through hole, and forming a tubular conductor. The resonator L1 is formed in a size corresponding to the pass frequency of the filter device 1, and has a resonance length that is approximately one quarter of the wavelength of the target frequency.

  The resonator L2 is a resonator in which one end is connected to a connection point of the resonator L1 and the input / output capacitor C1 via a coupling inductor L11 and a coupling capacitor C11 connected in parallel to each other, and the other end is grounded. The resonator L2 is configured by forming a through-hole in a dielectric material and forming a tubular conductor by forming a conductor layer on the inner wall surface in the same manner as the resonator L1, but a three-dimensional shape different from that of the resonator L1. have. The resonator L2 is formed in a size corresponding to the pass frequency of the filter device 1, and has a resonance length that is approximately one quarter of the wavelength of the target frequency.

  The resonator L3 is a resonator in which one end is connected to a connection point of the resonator L2, the coupling inductor L11, and the coupling capacitor C11 via a coupling inductor L12 and a coupling capacitor C12 connected in parallel to each other, and the other end is grounded. is there. The resonator L3 is paired with the resonator L1 and has substantially the same size and shape. One end of the resonator L3 is also connected to the input / output terminal T2 via the input / output capacitor C2. Furthermore, one end of the resonator L3 is also connected to one end of the resonator L1 through a coupling inductor L13 and a coupling capacitor C13 connected in parallel to each other.

  As described above, the filter device 1 according to this embodiment is configured by connecting the resonators L1 to L3 in parallel via the coupling inductors L11 to L13 and the coupling capacitors C11 to C13 connected in parallel. That is, the filter device 1 is composed of a three-stage resonator, and its circuit configuration is a symmetric structure.

  Next, the configuration of the filter device according to this embodiment will be described in detail with reference to FIGS. 2 to 4. 2 is a perspective view showing the appearance of the filter device 1 according to this embodiment, FIG. 3 is a perspective view seen from the opposite viewpoint to FIG. 2, and FIG. 4 is a bottom view from the arrow AB in FIG. It is sectional drawing which shows the cross section of 13 directions.

  As shown in FIG. 2, the filter device 1 includes a dielectric member 10 in which a dielectric material such as ceramic is formed in a rectangular parallelepiped shape, and includes a front surface 11, a flat surface 12, a bottom surface 13, a back surface 14, and side surfaces 15 and 16. Have. On the front surface 11, through holes 111 to 113, counterbore holes 121 to 123, and a ground conductor 131 are formed. On the plane 12, electrodes 141 and 142 and a ground conductor 132 are formed. A ground conductor 133 is formed on the bottom surface 13. Through holes 111 to 113 and a ground conductor 134 are formed on the back surface 14. On the side surfaces 15 and 16, ground conductors 135 and 136, auxiliary electrodes 155 and 156, and notches 165 and 166 are formed, respectively.

  The through holes 111 to 113 are through holes penetrating from the front surface 11 toward the back surface 14 and have a substantially circular cross section. The through holes 111 to 113 are formed in a line in the longitudinal direction of the front surface 11 at a substantially central position in the short direction of the front surface 11.

  The counterbore holes 121 to 123 are concave regions (blind holes) formed from the front surface 11 to the back surface 14 and have substantially the same cross section. The counterbore holes 121 to 123 have an oval cross section in which the long axis is parallel to the short side of the front surface 11. The central axis of the cross section of the front face 11 of the counterbore hole 122 is formed at substantially the same position as the central axis of the cross section of the through hole 112, but the central axis of the cross section of the front face 11 of the counterbore holes 121 and 123 is respectively Similarly, the through holes 111 and 113 are formed eccentrically in the direction away from the central axis of the cross section and the longitudinal direction of the front surface 11. The cross-sections of the counterbore holes 121 to 123 are formed so as to overlap with the cross-sections of the through holes 111 to 113 in the parallel direction of the front surface 11 respectively. Accordingly, the counterbore holes 121 to 123 penetrate toward the back surface 14 at portions where the cross-sections of the through holes 111 and 113 overlap.

  Further, as shown in FIG. 4, the counterbore holes 121 to 123 are integrally formed with the through holes 111 to 113 through stepped portions, respectively. The inner wall surfaces of the counterbore holes 121 to 123 and the through holes 111 to 113 form tubular conductors 171 to 173 by a conductor layer formed integrally with the ground conductor 134.

  The counterbore holes 121 to 123 and the through holes 111 to 113 are integrally formed through the step portions as described above, and constitute tubular conductors 171 to 173 each having a large diameter portion and a small diameter portion. The tubular conductors 171 to 173 are formed integrally with the ground conductor 134 on the small cross-section side, and constitute the resonators L1 to L3 shown in FIG. The resonators L1 to L3 including the tubular conductors 171 to 173 are coupled to each other via virtual coupling inductors L11 to L13 and coupling capacitors C11 to C13 by the dielectric member 10, respectively. The tubular conductors 171 to 173 are formed by, for example, applying a conductive material such as silver to the wall surface of the dielectric member 10 and baking it, and plating a conductive material such as copper. As described above, the central axis of the cross section of the counterbore holes 121 and 123 in the front surface 11 is formed eccentrically in the direction away from the central axis of the cross section of the through holes 111 and 113 and the longitudinal direction of the front surface 11, respectively. The coupling inductor is more dominant than the coupling capacitance, and the resonators L1 to L3 are magnetically coupled to each other.

The ground conductors 131 to 136 are ground electrodes that are grounded when the filter device 1 is mounted, and are formed integrally with each other. The ground conductors 131 to 136 are formed, for example, by applying a conductive material such as silver to the wall surface of the dielectric member 10 and baking it, and plating a conductive material such as copper.
The ground conductor 131 is a small conductor layer formed on the front surface 11 in which counterbore holes 121 to 123 are formed. The grounding conductor 131 is located between the counterbore holes 121 and 122 and the counterbore holes 122 and 123 in the long-side direction (through-hole arrangement direction) on the two long sides of the front surface 11 parallel to the row of the through-holes 111 to 113. ) At a substantially intermediate position so as to straddle the ground conductor 132 formed on the plane 12. The ground conductor 131 is not limited to the surface of the front surface 11, and a notch portion may be formed at a predetermined position on the long side of the front surface 11, and a conductor layer may be formed on the inner wall surface of the notch portion. The ground conductor 131 forms a ground potential region between the opening ends of the counterbore holes 121 and 122 and the counterbore holes 122 and 123, and each of the resonators L1 to L3 formed by the tubular conductors 171 to 173. The coupling between them becomes a magnetic coupling (the magnetic coupling is more dominant than the capacitive coupling).
The ground conductor 132 is a conductor layer formed on the plane 12 parallel to the plane formed by the rows of through holes 111 to 113, and is, for example, a silver thick film or a copper thick film. The ground conductor 132 is formed with electrodes 141 and 142 separated from the ground conductor 132 by exposed portions of the dielectric member 10 along both sides of the through holes 111 to 113 facing in the column direction.
The ground conductor 133 is a conductor layer formed on almost the entire bottom surface 13 facing the ground conductor 132. The ground conductor 134 is a conductor layer formed on the entire surface of the back surface 14 facing the front surface 11 where the counterbore holes 121 to 123 are formed. The ground conductors 135 and 136 are conductor layers formed on the side surfaces 15 and 16 opposed to the through holes 111 and 113 in the column direction. On the side surfaces 15 and 16, auxiliary electrodes 155 and 156 formed integrally with the electrodes 141 and 142 are formed at positions corresponding to the electrodes 141 and 142, and the short-circuit ends of the through holes 111 to 113 are ground conductors. Cutout portions 165 and 166 are formed in a region in contact with the back surface 14 in contact with 134.

  The electrodes 141 and 142 are rectangular planar conductor regions formed in the vicinity of the front surface 11 on the plane 12, and correspond to the input / output terminals T 1 and T 2 of the filter device 1. The electrodes 141 and 142 are formed corresponding to the positions and sizes of the counterbore holes 121 and 123 in the parallel direction of the plane 12, and form input / output capacitors C1 and C2 between the counterbore holes 121 and 123. ing. The electrodes 141 and 142 are formed, for example, by providing an exposed portion of the dielectric member 10 that surrounds the rectangular shape together with the ground conductor 132 by screen printing or the like.

  The auxiliary electrodes 155 and 156 are rectangular planar conductor regions formed integrally with the electrodes 141 and 142 on the side surfaces 15 and 16, respectively. The auxiliary electrodes 155 and 156 are formed by exposing the dielectric member and separating it from the ground conductor. Therefore, the ground conductors 133, 135, and 136 are formed with dielectric member exposed portions that form the auxiliary electrodes 155 and 156.

  In the filter device 1 of this embodiment, resonators L1 to L3 including through holes 111 to 113 and counterbore holes 121 to 123 are configured from the front surface 11 to the back surface 14. The electrodes 141 and 142 are formed on the plane 12 parallel to the plane formed by the rows of the resonators L1 to L3, and constitute input / output capacitors C1 and C2. The auxiliary electrodes 155 and 156 are formed integrally with the electrodes 141 and 142 on the side surfaces 15 and 16 facing the resonators L1 and L3 in the column direction of the resonators L1 to L3, respectively. That is, the electrodes 141 and 142 are disposed so as to be integrated with the auxiliary electrodes 155 and 156 so as to surround the resonators L1 and L3. The auxiliary electrodes 155 and 156 act to increase the capacity of the input / output capacitors C1 and C2 and improve the frequency characteristics of the filter device 1.

  The notches 165 and 166 are on the side surfaces 15 and 16 facing in the column direction of the resonators L1 to L3 and are in contact with the ground conductor 134 on the back surface 14 in which the openings of the through holes 111 to 113 are formed. This is an exposed region of the dielectric member 10 formed in a rectangular shape. The notch portions 165 and 166 are exposed to the dielectric member 10 by screen printing or the like together with the ground conductors 135 and 136 so as to contact the back surface 14 facing the front surface 11 where the counterbore holes 121 to 123 are formed. Formed. The notch portions 165 and 166 adjust the characteristic frequency of the resonators L1 and L3 by adjusting the area and shape thereof to increase or decrease the number of ground conductors surrounding the through holes 111 and 113 constituting the resonators L1 and L3. It acts as a frequency adjustment unit.

  As shown in FIG. 4, the tubular conductors 171 to 173 have a cross section in which the opening on the front surface 11 is larger than the opening on the back surface 14. The tubular conductors 171 to 173 have a step portion at a position about 30% of the length of the through holes 111 to 113 from the front surface 11 side. The through holes 111 to 113 and the counterbore holes larger in diameter than these are provided. 121 to 123 are combined. Regarding the tubular conductors 171 and 173, the counterbore holes 121 and 123 having large cross sections are moved closer to the through hole 112 than the through holes 111 and 113. On the other hand, in the tubular conductor 172, the central axis of the large diameter portion and the central axis of the small diameter portion are substantially the same.

  In the filter device 1, the high-frequency signal input to the input / output terminal 141 is input to the counterbore 121 of the tubular conductor 171 through the input / output capacitance C <b> 1 that is an equivalent capacitor. The tubular conductors 171 to 173 corresponding to the resonators L1 to L3 are coupled at high frequency via coupling inductors L11 to L13 and coupling capacitors C11 to C13 which are equivalently connected in parallel to each other. Therefore, the high-frequency signal input to the counterbore hole 121 resonates in the resonators L1 to L3. The high-frequency signal excited by resonating with the resonator L3 is output from the counterbore 123 to the input / output terminal 142 via the input / output capacitor C2, which is an equivalent capacitor. When a high frequency signal is input to the input / output terminal 142, the high frequency signal is output to the input / output terminal 141 in the reverse procedure.

Next, with reference to FIGS. 1 to 4, the relationship between the structure and operation of the filter device 1 according to this embodiment will be described in detail.
In the filter device 1 according to this embodiment, the counterbore holes 121 and 123 constituting the resonators L1 and L3 are formed so as to be separated from the counterbore hole 122 located at the center of the resonator array. The coupling inductor between L1 and L3 is more dominant than the coupling capacitance. That is, the resonators L1 to L3 are coupled at a high frequency by magnetic coupling (a state in which magnetic coupling is dominant over capacitive coupling). It is generally known that a filter device having magnetic coupling produces a pole of attenuation characteristics on the high frequency side of the pass frequency band.

  By the way, it is empirically known that if the ground conductor 132 is provided with the exposed portions to form the input / output terminals T1 and T2 and the electrodes 141 and 142 are formed, the center frequency of the resonator shifts to a frequency higher than the design frequency. It has been. In particular, when the dielectric member exposed regions are provided in the ground conductors 133, 135, and 136 in order to provide the auxiliary electrodes 155 and 156 as in the filter device according to this embodiment, the tendency is increased. This is considered to be because the frequency characteristics of the resonators L1 to L3 that should be surrounded by the ground conductor change due to an increase in the exposed portion of the dielectric member 10. On the other hand, in order to lower the pass frequency band as a whole in order to cancel the change in the frequency characteristics thus generated, a method of increasing the resonance length of the resonators L1 to L3, or a counterbore constituting the resonators L1 to L3. A method of enlarging the diameters 121 to 123 is conceivable.

  However, when the resonance lengths of the resonators L1 to L3 are increased and the diameters of the counterbore holes 121 to 123 are increased, the size of the entire filter device 1 must be increased. Therefore, it has been an obstacle to downsizing the filter device in which the through hole provided in the dielectric member is configured as a resonator.

  In the filter device according to this embodiment, the notches 165 and 166 are provided in the vicinity of the opening in the ground conductor 134 of the tubular conductors 171 to 173, thereby lowering the resonance frequency of the resonators L1 and L3. The center frequency can be lowered. That is, since the dielectric member 10 is exposed by cutting the ground conductor in the vicinity of the ground-side ends of the tubular conductors 171 and 173 corresponding to the resonators L1 and L3, the resonance is achieved without increasing the overall size of the filter device 1. The center frequency of the instrument can be shifted downward. More specifically, the ground conductor at the ground side end of the tubular conductors 171 to 173 on the surfaces (side surfaces 15 and 16) facing in the row direction formed by the tubular conductors 171 to 173 is cut to expose the dielectric member 10. Since the portion is provided, the center frequency of the resonator can be shifted in a lower direction without increasing the size of the entire filter device 1.

Subsequently, an example of the filter device 1 according to this embodiment will be described with reference to FIGS. 2, 3, and 5. FIG. 5 is a diagram showing the transmission characteristics (attenuation characteristics) and reflection characteristics of one example of the filter device according to this embodiment.
First, as the dielectric member 10 shown in FIG. 2, a ceramic having a relative dielectric constant of 45 was cut into a rectangular parallelepiped having a width of 2.80 mm, a height of 1.44 mm, and a depth (length) of 4.64 mm. Then, through-holes 111 to 113 having a diameter of 0.4 mm were formed in a row at approximately the center position in the short direction of the front surface 11 (surface of 2.80 mm × 1.44 mm) of the cut dielectric member. The distance between the through holes was set to 0.7 mm. Oval counterbore holes 121 to 123 were formed in the cross section of the three through holes in the front. Among these, the counterbore holes 121 and 123 at both ends are moved away from the central counterbore hole 122 so that the central axes thereof are decentered from the through holes of the through holes 111 and 113. A rectangular piece-like groove for forming the ground conductor 131 was formed at a substantially intermediate position between the counterbore holes 121 and 122 and the counterbore holes 122 and 123 on the long side of the front face.

  An example of characteristics of the obtained filter device 1 is shown in FIG. In FIG. 5, the solid line indicates the pass characteristic (attenuation characteristic) of the filter device 1, and the broken line indicates the reflection characteristic. As shown in FIG. 5, the attenuation characteristic (attenuation curve) on the high frequency side of the passing frequency band was steep, and an attenuation pole was obtained in the vicinity of 2.08 GHz. Further, the reflection characteristic was approximately 15 dB or more in the entire pass frequency band, and a good filter device was obtained.

Subsequently, a first modification of the filter device according to this embodiment will be described. 6 and 7 are perspective views showing a first modification of the filter device 1 of this embodiment. Note that the same components as those in FIGS. 2 and 3 are denoted by the same reference numerals, and redundant description is omitted.
6 and 7 are similar to the first embodiment shown in FIGS. 2 and 3, and the through holes 111 to 113, the counterbore holes 121 to 123, the ground conductors 131 to 136, the electrodes 141 and 142, And auxiliary electrodes 155 and 156. This modification differs from the first embodiment in that notches 265 and 266 are formed on the back surface 14 instead of the notches 165 and 166 formed on the side surfaces 15 and 16.

  As shown in FIG. 7, in the filter device 2 according to this modification, between the long side of the back surface 14 in contact with the plane 12 on which the electrodes 141 and 142 are formed and the short-circuit ends of the through holes 111 and 113, respectively. Rectangular cutouts 265 and 266 whose long sides are parallel to the long side of the back surface 14 are formed. The notches 265 and 266 are provided with a dielectric member exposed portion on the grounding side of the tubular conductors 171 and 173 corresponding to the resonators L1 and L3, similarly to the notches 165 and 166 in the first embodiment. By reducing the number of ground conductors corresponding to the resonators L1 and L3, the entire pass frequency band of the entire filter device 2 is shifted to the low frequency side.

Next, a second modification of the filter device according to this embodiment will be described. FIG. 8 is a perspective view showing a second modification of the filter device of this embodiment. Note that the same components as those in FIGS. 6 and 7 are denoted by the same reference numerals, and redundant description is omitted.
Also in the second modification, as in the first modification shown in FIGS. 6 and 7, the through holes 111 to 113, the counterbore holes 121 to 123, the ground conductors 131 to 136, the electrodes 141 and 142, and the auxiliary electrode 155 and 156. This modified example is different from the first modified example in that notched portions 365 and 366 are formed instead of the notched portions 265 and 266 formed on the back surface 14.

  As shown in FIG. 8, in the filter device 3 according to this modification, rectangular cutout portions 365 and 366 along the short side of the back surface 14 are formed. Cutout portions 365 and 366 are provided with a dielectric member exposed portion on the grounding side of tubular conductors 171 and 173 corresponding to resonators L1 and L3, similarly to cutout portions 265 and 266 in the first modification. By reducing the number of ground conductors corresponding to the resonators L1 and L3, the entire pass frequency band of the entire filter device 3 is shifted to the low frequency side.

Furthermore, a third modification of the filter device according to this embodiment will be described. FIG. 9 is a perspective view showing a third modification of the filter device of this embodiment. Note that the same components as those in FIGS. 6 and 7 are denoted by the same reference numerals, and redundant description is omitted.
Also in the third modified example, as in the first modified example shown in FIGS. 6 and 7, the through holes 111 to 113, the counterbore holes 121 to 123, the ground conductors 131 to 136, the electrodes 141 and 142, and the auxiliary electrode 155 and 156. In this modification, notches 255 and 256 of the first modification and notches 365 and 366 of the second modification are added to the first embodiment.

  As shown in FIG. 8, in the filter device 4 according to this modified example, notches 165 and 166 provided in the vicinity of the tubular conductors 171 to 173 in contact with the ground conductor 134 and a plane on which the electrodes 141 and 142 are formed. 12, notches 265 and 266 formed between the long side of the back surface 14 in contact with 12 and the open ends of the through holes 111 and 113, and rectangular notches 365 and 366 along the short side of the back surface 14 Is formed. With this configuration, the exposed area of the dielectric member exposed portion provided on the ground side of the tubular conductors 171 and 173 corresponding to the resonators L1 and L3 becomes larger, and the ground conductor corresponding to the resonators L1 and L3. By further reducing the area, the entire pass frequency band of the filter device 4 can be shifted to the low frequency side.

  Subsequently, a second embodiment of the present invention will be described in detail with reference to FIGS. 10 and 11. 10 and 11 are perspective views showing the overall configuration of the duplexer apparatus according to the second embodiment. The duplexer device according to this embodiment is a duplexer device configured using the filter device according to the first embodiment of the present invention.

As shown in FIG. 10, the duplexer device 5 includes a dielectric member 50 in which a dielectric material such as ceramic is formed in a rectangular parallelepiped shape, and includes through holes 511 to 517, counterbore holes 521 to 526, and a ground conductor. 531 to 536, electrodes 541 to 543, an auxiliary electrode 556, and a notch 566 are formed. The through hole, counterbore hole, electrode, and auxiliary electrode correspond to the through hole, counterbore hole, electrode, and auxiliary electrode according to the first embodiment, respectively.
The duplexer device 5 according to this embodiment includes a filter device having an attenuation pole on the low-frequency side composed of a resonator constituted by through holes 511 to 513 and counterbore holes 521 to 523, and through holes 514 to 516 and a seat. This is a combination of a filter device having an attenuation pole on the high frequency side composed of a resonator constituted by the bores 524 to 526.

  The through holes 511 to 516 are through holes penetrating from the front surface 51 to the back surface 54 of the dielectric member 50 and have a substantially circular cross section. The through holes 511 to 516 are formed substantially in a row in the longitudinal direction of the front surface 51 at a substantially central position in the short direction of the front surface 51. The counterbore holes 521 to 526 are concave regions (blind holes) formed from the front surface 51 to the back surface 54 of the dielectric member 50. The counterbore holes 521 to 526 have an oval cross section whose major axis is parallel to the front short side. The counterbore holes 521 and 523 are formed such that the central axes of the cross sections are eccentric in the direction approaching the longitudinal axis of the front surface 51 from the central axes of the cross sections of the through holes 511 and 513, respectively. That is, the through holes 511 to 513 and the counterbore holes 521 to 523 are capacitively coupled to each other, and constitute a filter device having a pole on the low frequency side of the pass frequency band. On the other hand, the counterbore holes 524 and 526 are arranged so that the central axes of the cross sections thereof are separated from the central axes of the cross sections of the through holes 514 and 516, respectively, in the longitudinal direction of the front surface 51, as in the first embodiment. It is formed eccentrically. That is, the through holes 514 to 516 and the counterbore holes 524 to 526 are magnetically coupled to each other and constitute a filter device having a pole on the high frequency side of the pass frequency band.

  The electrodes 541 and 542 are rectangular planar conductor regions formed by providing exposed portions of the dielectric member 50 in a rectangular shape in the vicinity of the front surface 51 on the flat surface 52, and counterbore holes 521 and 526. The electrode 543 is connected to the through hole 517 through an equivalent input / output capacitor. Through hole 517 is electromagnetically coupled to counterbore holes 523 and 524. That is, the duplexer device 5 constitutes a duplexer having the electrode 543 as a common input / output terminal and the electrodes 541 and 542 as transmission or reception terminals.

  A cutout portion 566 is formed on the ground end side of the through hole 516 on the side surface 56 facing the through hole 516 in the through hole row direction, and an exposed region of the dielectric member 50 is formed. Therefore, since the duplexer device 5 has the notch portion 566, the shift of the passing frequency band caused by the dielectric exposed portion forming the electrode 542 and the auxiliary electrode 556 is increased, and the size of the through hole or the counterbore hole is increased. You can adjust without doing.

In addition, this invention is not limited only to the said embodiment.
In the above embodiment, the dielectric member of the filter device is a rectangular parallelepiped, but is not limited to this. That is, the same effect can be obtained as long as the resonator composed of the through hole and the counterbore is provided in the same direction.

  Moreover, in the said embodiment, although the dielectric material member is comprised with the ceramic, it is not limited to this. That is, any dielectric material having a relative dielectric constant suitable for constituting a filter device can be applied in the same manner.

  Further, in the above-described embodiment, the notch for adjusting the characteristic frequency is formed on both sides of the plane where the input / output terminals of the filter device are formed, the rear end where the grounded through-hole opening is formed, and the like. However, the present invention is not limited to this. That is, even if it is formed at a position on the outer peripheral surface between the grounded through-hole opening and the electrode part forming the input / output terminal, more preferably, it is formed at a position close to the grounded through-hole opening. The effect of can be produced.

  The present invention can be applied to the telecommunication equipment manufacturing industry and the like.

It is a figure which shows the fundamental circuit structure of the filter apparatus of the 1st Embodiment of this invention. It is a perspective view which shows the external appearance of the filter apparatus which concerns on this embodiment. It is the perspective view which showed the external appearance of the filter apparatus which concerns on this embodiment from the viewpoint opposite to FIG. It is sectional drawing which shows the cross section of a bottom face direction from arrow AB of FIG. It is a figure which shows the example of a characteristic of 1 Example of the filter apparatus which concerns on this embodiment. It is a perspective view which shows the external appearance of the 1st modification of the filter apparatus of this embodiment. It is the perspective view which showed the external appearance of the 1st modification of the filter apparatus of this embodiment from the viewpoint opposite to FIG. It is a perspective view which shows the external appearance of the 2nd modification of the filter apparatus of this embodiment. It is a perspective view which shows the external appearance of the 3rd modification of the filter apparatus of this embodiment. It is a perspective view which shows the external appearance of the duplexer apparatus which concerns on the 2nd Embodiment of this invention. It is a perspective view which shows the external appearance of the duplexer apparatus which concerns on the 2nd Embodiment of this invention from a viewpoint opposite to FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Filter apparatus, 5 ... Duplexer apparatus, 10 ... Dielectric member, 11 ... Front, 12 ... Plane, 13 ... Bottom, 14 ... Back, 15, 16 ... Side, 111-113 ... Through-hole, 121-123 ... Seat Boring holes, 131 to 136: grounding conductors, 141, 142 ... input / output terminals, 155, 156 ... auxiliary electrodes, 165, 166, 265, 266, 365, 366 ... notches, 171 through 173 ... tubular conductors.

Claims (6)

A plurality of parallel through-holes are formed in the dielectric member, and the outer peripheral surface of the dielectric member excluding the first end surface of the first and second end surfaces where the through-holes open, and the through-holes In the filter device comprising a plurality of resonators in which a conductor layer is formed on the inner surface and the conductor layers in the through hole are magnetically coupled to each other,
While removing the conductor layer on both end faces in the arrangement direction of the resonator to form a pair of opposing terminal electrodes,
A filter device, wherein a frequency adjusting unit from which a part of the conductor layer is removed is provided on an outer peripheral surface between the terminal electrodes and the opening of the through hole on the second end surface.   2. The filter device according to claim 1, wherein the frequency adjustment unit is formed by removing a part of the conductor layer on both side surfaces between the terminal electrode and the second end surface.   The filter device according to claim 1, wherein the frequency adjustment unit is formed on the second end face.   The filter device according to claim 3, wherein the frequency adjustment unit is formed at both ends of the second end face in the resonator arrangement direction.   5. The filter device according to claim 4, wherein the frequency adjustment unit is formed at both edges of the second end face in the resonator arrangement direction. 6.   A duplexer device comprising at least one filter device according to any one of claims 1 to 5.

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