JP2009302898A - Laminated bandpass filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that the filter size is increased because of a distributed constant type utilizing a resonator of a 1/4 wavelength, and it is impossible to manufacture a small filter. <P>SOLUTION: In a laminated bandpass filter, a first coil L1, a second coil L2, a third coil L#, and a fourth coil L4 of which one ends are grounded, respectively, and which are magnetically coupled to each other are provided inside a laminated body, the first coil is connected to an input terminal via a first capacitor, the fourth coil is connected to an output terminal via a second capacitor, the first coil is connected to the second coil via a third capacitor, the third coil is connected to the fourth coil via a fourth capacitor, and the second coil is connected to the third coil via a fifth capacitor, to form the bandpass filter. A magnetic coupling between the first coil and the second coil and the magnetic coupling between the third coil and the fourth coil are positive, while a magnetic coupling between the first coil and the third coil, the magnetic coupling between the second coil and the fourth coil, and the magnetic coupling between the first coil and the fourth coil are negative. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a laminated band-pass filter in which an insulator layer and a conductor pattern are laminated and a band-pass filter is formed in the laminated body.

  By coupling a plurality of quarter-wave resonators with a conventional bandpass filter with capacitance (so-called comb line coupling), a plurality of capacitors are connected between the input terminal 51 and the output terminal 52 as shown in FIG. C11 to C15 are connected in series, a quarter wavelength resonator Q1 is connected between the connection point of the capacitor C11 and the capacitor C12 and the ground, and a quarter wavelength resonator is connected between the connection point of the capacitor C12 and the capacitor C13 and the ground. Q2 is a resonator in which a quarter wavelength resonator Q3 is connected between the connection point between the capacitor C13 and the capacitor C14 and the ground, and a quarter wavelength resonator Q4 is connected between the connection point between the capacitor C14 and the capacitor C15 and the ground. (For example, refer to Patent Document 1).

Japanese Patent Laid-Open No. 4-30602

  In recent years, mobile communication devices such as mobile phones have been reduced in size and height, and this type of bandpass filter used in mobile communication devices is also desired to be downsized. Since the conventional bandpass filter is a distributed constant type using a 1/4 wavelength resonator, the length of the conductor constituting the resonator is determined depending on the operating frequency, although there are some differences in the dielectric constant of the dielectric. End up. For example, when the frequency used is 3.5 GHz, even if a dielectric material having a dielectric constant of 21 is used as the dielectric, in order to form a quarter-wave resonator, the conductor constituting the resonator Needs to be 3.89 mm. Therefore, the conventional bandpass filter cannot be manufactured as small as 2.0 mm × 1.25 mm × 0.8 mm, which is desired in mobile communication devices and the like.

  An object of the present invention is to provide a multilayer bandpass filter whose size can be reduced without degrading characteristics.

  The multilayer bandpass filter according to the present invention includes a first coil, a second coil, and a third coil, in which an insulator layer and a conductor pattern are stacked and one end of each layer is grounded and magnetically coupled to each other. And the fourth coil, the first coil is connected to the input terminal via the first capacitor, the fourth coil is connected to the output terminal via the second capacitor, The second coil is connected via a third capacitor, the third coil and the fourth coil are connected via a fourth capacitor, and the second coil and the third coil connect the fifth capacitor. A band-pass filter connected through the first coil and the first coil, the magnetic coupling between the first coil and the second coil, and the magnetic coupling between the third coil and the fourth coil are positive. Magnetic coupling between third coils, second carp When the magnetic coupling and between the fourth coil, the magnetic coupling between the first coil and the fourth coil negative.

  The multilayer bandpass filter according to the present invention includes a first coil, a second coil, and a third coil, in which an insulator layer and a conductor pattern are stacked and one end of each layer is grounded and magnetically coupled to each other. And the fourth coil, the first coil is connected to the input terminal via the first capacitor, the fourth coil is connected to the output terminal via the second capacitor, The second coil is connected via a third capacitor, the third coil and the fourth coil are connected via a fourth capacitor, and the second coil and the third coil connect the fifth capacitor. A band-pass filter connected through the first coil and the first coil, the magnetic coupling between the first coil and the second coil, and the magnetic coupling between the third coil and the fourth coil are positive. Magnetic coupling between third coils, second carp When the magnetic coupling and between the fourth coil, since the magnetic coupling between the first coil and the fourth coil negatively, can be miniaturized its shape without degrading the characteristics.

The multilayer bandpass filter according to the present invention includes a first capacitor portion in which an insulator layer and a conductor pattern for a capacitor are laminated, a laminate of an insulator layer and a coil conductor pattern, and a coil conductor pattern between the insulator layers is spiral. The first coil portion connected to the second capacitor portion, the second capacitor portion in which the insulator layer and the conductor pattern for capacitor are laminated, the insulator layer and the conductor pattern for coil are laminated, and the coil conductor pattern between the insulator layers is spiral. A second coil portion connected to the first capacitor portion and a third capacitor portion in which an insulator layer and a capacitor conductor pattern are laminated are laminated to form a laminated body. Each of these laminates has a first coil, a second coil, a third coil, and a fourth coil that are grounded at one end and are magnetically coupled to each other. The first coil is a first capacitor. Is connected to the input terminal via the second capacitor, the fourth coil is connected to the output terminal via the second capacitor, the first coil and the second coil are connected via the third capacitor, A band-pass filter is formed in which the coil and the fourth coil are connected via the fourth capacitor, and the second coil and the third coil are connected via the fifth capacitor. Magnetic coupling between the first coil and the second coil, magnetic coupling between the third coil and the fourth coil is positive, magnetic coupling between the first coil and the third coil, and the second coil Magnetic coupling between the fourth coil and the first coil; Magnetic coupling between the fourth coil is set to a negative. The conductor pattern formed in the multilayer body is rotationally symmetrical with respect to the capacitor conductor pattern formed at the center of the second capacitor portion in the stacking direction.
Therefore, the multilayer bandpass filter of the present invention can handle the bandpass filter as a lumped constant.

Hereinafter, embodiments of the multilayer bandpass filter of the present invention will be described with reference to FIGS.
FIG. 1 is a circuit diagram of an embodiment of the multilayer bandpass filter of the present invention, FIG. 2 is an exploded perspective view showing an embodiment of the multilayer bandpass filter of the present invention, and FIG. 3 is an illustration of the multilayer bandpass filter of the present invention. It is a perspective view which shows an Example.
The coil L1 has one end grounded and the other end connected to the input terminal 11 via the capacitor C1. One end of the coil L2 is grounded, and the other end is connected to the other end of the coil L1 via the capacitor C3. The coil L4 has one end grounded and the other end connected to the output terminal via the capacitor C2. One end of the coil L3 is grounded, and the other end is connected to the other end of the coil L4 via the capacitor C4. A capacitor C5 is connected between the other end of the coil L2 and the other end of the coil L3. Further, a capacitor C6 is connected between the input terminal 11 and the output terminal 12. Capacitors C7 to C10 are stray capacitances generated between the windings constituting each coil.
These coils L1 to L4 are formed so that the magnetic coupling between the coil L1 and the coil L2 and the magnetic coupling between the coil L3 and the coil L4 are respectively positive, and between the coil L1 and the coil L3. The magnetic coupling, the magnetic coupling between the coil L2 and the coil L4, and the magnetic coupling between the coil L1 and the coil L4 are formed so as to be negative.

Such a band pass filter is formed in a laminated body by laminating an insulator layer and a conductor pattern as shown in FIG.
The insulator layers 21A to 21I are formed using an insulating material such as a magnetic material, a non-magnetic material, or a dielectric material.
A capacitor conductive pattern G is formed on the surface of the insulating layer 21A. Capacitor conductor pattern G is drawn out to the side surface where insulator layer 21A faces.
Capacitor conductor pattern 22A and capacitor conductor pattern 22B are formed on the surface of insulator layer 21B. The capacitor conductor pattern 22A and the capacitor conductor pattern 22B are formed at positions facing the capacitor conductor pattern G so that one end portions thereof face each other. The lead-out end of the capacitor conductor pattern 22A and the lead-out end of the capacitor conductor pattern 22B are drawn to the opposing end surfaces of the insulator layer 21B.
A capacitor conductive pattern 23A is formed on the surface of the insulating layer 21C. Capacitor conductor pattern 23A has a lead-out end that is drawn out to one end face of insulator layer 21C.
A capacitor conductor pattern 23B is formed on the surface of the insulator layer 21D. The capacitor conductor pattern 23B is formed at a position facing the capacitor conductor pattern 23A.
A coil conductor pattern 24A and a coil conductor pattern 25A are formed on the surface of the insulator layer 21E. Each of the coil conductor pattern 24A and the coil conductor pattern 25A is formed with less than one turn, and one end of the insulator layer 21E is drawn to one side surface.
A coil conductor pattern 24B and a coil conductor pattern 25B are formed on the surface of the insulating layer 21F. The coil conductor pattern 24B is formed for less than one turn, and one end is connected to the other end of the coil conductor pattern 24A. The coil conductor pattern 25B is formed with less than one turn, and one end is connected to the other end of the coil conductor pattern 25A and the other end is connected to the capacitor conductor pattern 23B.
A capacitor conductor pattern 26A and a coil conductor pattern 24C are formed on the surface of the insulator layer 21G. The coil conductor pattern 24C is formed with less than one turn, and one end is connected to the capacitor conductor pattern 26A. In this way, the coil conductor pattern 24A, the coil conductor pattern 24B, and the coil conductor pattern 22C are spirally connected to form the coil L2, and the coil conductor pattern 25A and the coil conductor pattern 25B are spirally connected. As a result, the coil L4 is formed. The coils L2 and L4 are formed so as to be magnetically negatively coupled.
The capacitor conductor pattern 26B and the capacitor conductor pattern 26C are formed on the surface of the insulating layer 21H so as not to contact each other. The capacitor conductor pattern 26B is formed at a position facing the capacitor conductor pattern 26A. The capacitor conductor pattern 26C is connected to the other end of the coil conductor pattern 25B.
A capacitor conductor pattern 26D and a coil conductor pattern 28A are formed on the surface of the insulator layer 21I. The coil conductor pattern 28A has less than one turn, and one end is connected to the capacitor conductor pattern 26D. The capacitor conductor pattern 26D is formed at a position facing the capacitor conductor pattern 26C so as to overlap the end portion of the capacitor conductor pattern 26A.
A coil conductor pattern 27A and a coil conductor pattern 28B are formed on the surface of the insulating layer 21J. The coil conductor pattern 27A has less than one turn, and one end is connected to the capacitor conductor pattern 26B. The coil conductor pattern 28B is formed for less than one turn, and one end is connected to the other end of the coil conductor pattern 28A.
A coil conductor pattern 27B and a coil conductor pattern 28C are formed on the surface of the insulator layer 21K. The coil conductor pattern 27B and the coil conductor pattern 28C are each formed for less than one turn. One end of the coil conductor pattern 27B is connected to the other end of the coil conductor pattern 27A, and the other end is drawn to one side surface of the insulator layer 21K. Also, one end of the coil conductor pattern 28C is connected to the other end of the coil conductor pattern 28B, and the other end is drawn to one side surface of the insulator layer 21K. In this way, the coil conductor pattern 27A and the coil conductor pattern 27B are spirally connected to form the coil L1, and the coil conductor pattern 28A, the coil conductor pattern 28B, and the coil conductor pattern 28C are spirally connected. As a result, the coil L3 is formed. The coil L1 and the coil L3 are magnetically negatively coupled to each other, the coil L1 and the coil L2 are magnetically positively coupled to each other, the coil L3 and the coil L4 are magnetically positively coupled to each other, and the coil L1 The coil L4 is magnetically negatively coupled to each other, and the coil L3 and the coil L2 are magnetically negatively coupled to each other.
A capacitor conductive pattern 29A is formed on the surface of the insulating layer 21L. The capacitor conductor pattern 29A is connected to the other end of the coil conductor pattern 27A.
A capacitor conductor pattern 29B is formed on the surface of the insulating layer 21M. The capacitor conductor pattern 29B is formed at a position facing the capacitor conductor pattern 29A, and the leading end is led out to the other end surface of the insulating layer 21M.
A capacitor conductor pattern 22C and a capacitor conductor pattern 22D are formed on the surface of the insulator layer 21N. Capacitor conductor pattern 22C and capacitor conductor pattern 22D are formed so that their one ends face each other. The lead-out end of the capacitor conductor pattern 22A and the lead-out end of the capacitor conductor pattern 22B are drawn to the opposing end surfaces of the insulator layer 21B.
A capacitor conductor pattern G is formed on the surface of the insulator layer 21O. Capacitor conductor pattern G is drawn out to the side surface where insulator layer 21O is opposed.
An insulator layer 21P is laminated on the insulator layer 21O.
The laminated body thus laminated has the first capacitor portion and the insulating layers 21E to 21G and these insulating layers 21A to 21D and the conductor patterns formed on these insulating layers. The first coil portion is formed by the conductor pattern formed on the insulator layer, and the second capacitor portion is formed by the conductor pattern formed on the insulator layers 21G to 21I and these insulator layers. The second coil portion is formed by the conductor patterns formed on the insulator layers 21I to 21K and these insulator layers, and the third coil portion is formed by the conductor patterns formed on the insulator layers 21L to 21O and these insulator layers. The capacitor part is configured. The conductor patterns formed on the insulator layers 21A to 21G and the conductor patterns formed on the insulator layers 21I to 21O are the capacitor conductor patterns 26B and 26C formed at the center in the stacking direction of the second capacitor portion. The conductive patterns having the same shape and size are opposite to each other with respect to the laminated surface of the capacitor conductor patterns 26B and 26C, that is, in opposite directions, that is, arranged in a vertically symmetrical position with respect to the laminated surface. The insulating layer is formed in a rotationally symmetrical manner rotated 180 degrees in the length direction.
In such a laminated body, as shown in FIG. 3, the input terminal 31 and the output terminal 32 are formed on the end face of the laminated body, and the ground terminals 33 and 34 are formed on the side surfaces. The capacitor conductor patterns 22A, 22C, and 29B are connected to the input terminal 31, the capacitor conductor patterns 22B, 22D, and 23A are connected to the output terminal 32, and the capacitor conductor pattern G is connected to the ground terminals 33 and 34.

  In the multilayer bandpass filter formed in this way, the coil L1 is formed by the coil conductor pattern 27A and the coil conductor pattern 27B, and the coil L2 is formed by the coil conductor pattern 24A, the coil conductor pattern 24B, and the coil conductor pattern 24C. However, the coil conductor pattern 28A, the coil conductor pattern 28B, and the coil conductor pattern 28C form the coil L3, and the coil conductor pattern 25A and the coil conductor pattern 25B form the coil L4. The capacitor C1 is formed by the capacitance between the capacitor conductor pattern 29A and the capacitor conductor pattern 29B, and the capacitor C2 is formed by the capacitance between the capacitor conductor pattern 23A and the capacitor conductor pattern 23B. Further, the capacitor C3 is formed by the capacitance between the capacitor conductor pattern 26A and the capacitor conductor pattern 26B, the capacitor C4 is formed by the capacitance between the capacitor conductor pattern 26C and the capacitor conductor pattern 26D, and the capacitor conductor pattern 26A and the capacitor conductor pattern. Capacitor C5 is formed by the capacitance between 26D. Furthermore, a capacitor C6 is formed by the capacitance between the capacitor conductor pattern 22A and the capacitor conductor pattern 22B and the capacitance between the capacitor conductor pattern 22C and the capacitor conductor pattern 22D.

  In such a multilayer bandpass filter, the dielectric constant of the insulator layer is 4.6, the line width of the coil conductor pattern is 100 μm, the input / output impedance is 50Ω, and the overall shape of the element is 2 mm × 1.25 mm × 0. As shown in FIG. 4, the pass band is 3.3 to 3.8 GHz, the insertion loss in the pass band is 2.0 dB, the reflection loss in the pass band is 15.6 dB, and the attenuation is 500 to 2700 MHz. The attenuation amount of 30.6 dB and 4800 to 5950 MHz was 27.7 dB. In FIG. 4, the horizontal axis represents frequency, the vertical axis represents attenuation, 41 represents transmission characteristics, and 42 represents reflection characteristics.

It is a circuit diagram of the Example of the multilayer bandpass filter of this invention. It is a disassembled perspective view which shows the Example of the laminated | stacked band pass filter of this invention. It is a perspective view which shows the Example of the laminated type band pass filter of this invention. It is a characteristic view of the multilayer bandpass filter of the present invention. It is a circuit diagram of the conventional band pass filter.

Explanation of symbols

11 Input terminal 12 Output terminal L1-L4 Coil C1-C10 Capacitor

Claims (3)

  The insulating layer and the conductor pattern are laminated, and each of the laminated bodies includes a first coil, a second coil, a third coil, and a fourth coil that are grounded at one end and are magnetically coupled to each other. The first coil is connected to the input terminal via the first capacitor, the fourth coil is connected to the output terminal via the second capacitor, and the first coil and the second coil are connected to the first terminal. 3 is connected via a capacitor, the third coil and the fourth coil are connected via a fourth capacitor, and the second coil and the third coil are connected via a fifth capacitor. A connected band-pass filter is formed, and the magnetic coupling between the first coil and the second coil and the magnetic coupling between the third coil and the fourth coil are positive, Magnetic coupling between the second coil and the third coil, the second coil and the third coil Magnetic coupling and between 4 coils, laminate type band pass filter, characterized in that the magnetic coupling between the first coil and the fourth coil negative.   A first capacitor portion in which an insulator layer and a conductor pattern for a capacitor are stacked, a first coil portion in which an insulator layer and a conductor pattern for a coil are stacked, and the coil conductor pattern between the insulator layers is spirally connected A second capacitor part in which an insulator layer and a conductor pattern for a capacitor are laminated; a second coil in which an insulator layer and a conductor pattern for a coil are laminated, and the coil conductor pattern between the insulator layers is spirally connected And a first capacitor and a second coil that are grounded at one end and are magnetically coupled to each other. , Having a third coil and a fourth coil, the first coil being connected to the input terminal via the first capacitor, and the fourth coil being connected to the output terminal via the second capacitor The first coil and the second coil are connected via a third capacitor, the third coil and the fourth coil are connected via a fourth capacitor, and the second coil And a third coil are connected to each other via a fifth capacitor, and a magnetic coupling between the first coil and the second coil, and the third coil are formed. Positive magnetic coupling between the fourth coil, magnetic coupling between the first coil and the third coil, magnetic coupling between the second coil and the fourth coil, and the first coil A multilayer bandpass filter characterized in that the magnetic coupling between one coil and the fourth coil is negative.   3. The multilayer bandpass according to claim 2, wherein the conductor pattern formed in the multilayer body is rotationally symmetric with respect to a capacitor conductor pattern formed in the center of the second capacitor portion in the stacking direction. filter.

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