EP0442418A2 - Dielektrischer Filter mit Mustern zur Einstellung der Kopplung - Google Patents

Dielektrischer Filter mit Mustern zur Einstellung der Kopplung Download PDF

Info

Publication number
EP0442418A2
EP0442418A2 EP91101871A EP91101871A EP0442418A2 EP 0442418 A2 EP0442418 A2 EP 0442418A2 EP 91101871 A EP91101871 A EP 91101871A EP 91101871 A EP91101871 A EP 91101871A EP 0442418 A2 EP0442418 A2 EP 0442418A2
Authority
EP
European Patent Office
Prior art keywords
dielectric
coupling
resonators
filter
patterns
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP91101871A
Other languages
English (en)
French (fr)
Other versions
EP0442418A3 (en
Inventor
Tomokazu C/O Oki Electric Ind. Co. Ltd. Komazaki
Katsuhiko C/O Oki Electric Ind. Co. Ltd. Gunji
Norio C/O Oki Electric Ind. Co. Ltd. Onishi
Osamu C/O Oki Electric Ind. Co. Ltd. Yamato
Akira C/O Oki Business Co. Ltd. Mashimo
Kouichi C/O Oki Business Co. Ltd. Ichikawa
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Oki Electric Industry Co Ltd
Original Assignee
Oki Electric Industry Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Oki Electric Industry Co Ltd filed Critical Oki Electric Industry Co Ltd
Publication of EP0442418A2 publication Critical patent/EP0442418A2/de
Publication of EP0442418A3 publication Critical patent/EP0442418A3/en
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01P—WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE
    • H01P1/00—Auxiliary devices
    • H01P1/20—Frequency-selective devices, e.g. filters
    • H01P1/201—Filters for transverse electromagnetic waves
    • H01P1/205—Comb or interdigital filters; Cascaded coaxial cavities
    • H01P1/2056—Comb filters or interdigital filters with metallised resonator holes in a dielectric block
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01P—WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE
    • H01P1/00—Auxiliary devices
    • H01P1/20—Frequency-selective devices, e.g. filters
    • H01P1/201—Filters for transverse electromagnetic waves
    • H01P1/205—Comb or interdigital filters; Cascaded coaxial cavities

Definitions

  • the present invention relates to a dielectric filter which is preferably used in antenna duplexers for mobile telecommunications.
  • FIG. 1 is a perspective view showing a first example of the conventional dielectric filter that adopts the technique of U.S. Patent Re. 32,768.
  • the filter is arranged in such a manner that one stage of a notch filter is inserted which has an attenuation pole at the lower or upper frequency band of the passband.
  • the dielectric filter has five independent blocks of dielectric material 51-1 - 51-5, the height of which is represented by the letter H.
  • the dielectric blocks 51-1 - 51-5 have dielectric resonators 52-1 - 52-5 vertically embedded thereinto in a parallel fashion, each of which dielectric resonators is composed of a cylindrical central conductor.
  • the bottom ends of the central conductors are connected to electrically conductive, metallized patterns formed on the bottom surfaces 53-1 - 53-5 of the dielectric blocks 51-1 - 51-5, respectively.
  • the metallized patterns on the bottom surfaces are further connected to metallized patterns on the sides (hatched portions in FIG. 1) of the dielectric blocks 51-1 -51-5.
  • the central conductors of the dielectric resonators 52-1 - 52-5 are soldered to conductive wires 55-1 - 55-5 extending to a board 56, respectively.
  • the sides of dielectric blocks 51-1 - 51-5 are joined together by soldering so that they are integrally arranged as shown in FIG. 1.
  • the board 56 is provided so that it faces the top surfaces (open surfaces) 54-1 - 54-5 of the dielectric blocks 51-1 - 51-5. Although the bottom surface and sides of the board 56 are not metallized, the top surface (open surface) 57 is provided with conductive patterns 58-1 - 58-5 for adjusting coupling amounts. The coupling amount adjusting patterns 58-1 - 58-5 are soldered to the conductive wires 55-1 - 55-5, respectively. Furthermore, the top surface (open surface) 57 of the board 56 is provided with an input pattern 59-1 for receiving an input signal, and an output pattern 59-2 which is located between the coupling amount adjusting patterns 58-4 and 58-5. An input pin 60-1 and an output pin 60-2. which are made of electrically conductive wires, are soldered to the input pattern 59-1 and output pattern 59-2, respectively.
  • FIG. 2 shows an equivalent circuit of the first example of the conventional dielectric filters shown in FIG. 1.
  • parallel resonance circuits (l52 ⁇ 1, C52 ⁇ 1), (l52 ⁇ 2, C52 ⁇ 2), (l52 ⁇ 3, C52 ⁇ 3), (l52 ⁇ 4, C52 ⁇ 4), (l52 ⁇ 5, C52 ⁇ 5) correspond to inductances and capacitances of dielectric resonators 52-1 - 52-5, respectively.
  • Reference indication C59 ⁇ 1 denotes a capacitance between the input pattern 59-1 and the coupling amount adjusting pattern 58-1; representation C59 ⁇ 2 denotes a capacitance between the output pattern 59-2 and the coupling amount adjusting pattern 58-5; indication C58 ⁇ 1 similarly denotes a capacitance between the coupling amount adjusting pattern 58-1 and the coupling amount adjusting pattern 58-2; reference indication C58 ⁇ 2 denotes a capacitance between the coupling amount adjusting pattern 58-2 and the coupling amount adjusting pattern 58-3; indication C58 ⁇ 3 denotes a capacitance between the coupling amount adjusting pattern 58-3 and the coupling amount adjusting pattern 58-4; and indication C58 ⁇ 4 denotes a capacitance between the coupling amount adjusting pattern 58-4 and the output pattern 59-2.
  • the attenuation amount of the filter in the passband tends to decline as the frequency increases because the dielectric resonators are capacitively coupled and that the notch filter circuit is composed of a serial resonance circuit of C59 ⁇ 2 and L52 ⁇ 5.
  • the notch frequency of the notch filter circuit is the serial resonance frequency of C59 ⁇ 2 and L52 ⁇ 5.
  • FIG. 3 illustrates the attenuation characteristic of the dielectric filter of the first conventional example with its notch frequency at the lower frequency band of the passband.
  • the notch frequency at the lower frequency band of the passband enables the attenuation amount to take a large value, which in turn can reduce the number of stages of the notch filter circuits, resulting in reduction in the size of the filter.
  • the notch frequency is located at the upper frequency band of the passband, one stage of a notch filter circuit is not sufficient to achieve a desired attenuation amount because of the capacitive coupling. Therefore, the number of stages of the notch filter circuits must be increased, thereby increasing the size of the filter.
  • FIG. 4 is a perspective view showing a second example of conventional dielectric filters.
  • reference numeral 71 designates a unitarily constructed dieletric block whose width is represented by W, length is L, and height is H.
  • back surface (back side) 81, left side 82, right side 83 and bottom surface 84 of the dielectric block 71 are formed conductive, metalized surfaces by plating, for example.
  • central conductors 74-1 - 74-4 which function as dielectric resonators (and hence are called dielectric resonators hereinafter) are embedded through the frequency adjusting patterns 72-1 - 72-4, respectively.
  • dielectric resonators 74-1 - 74- 4 embedded are external circuits 75-1 - 75-4 (which are separately depicted above the dielectric block 71 in FIG. 4 for convenience of explanation).
  • the external circuits 75-1 and 75-2 connect the dielectric resonators 74-1 and 74-2, and the external circuits 75-3 and 75-4 connect the dielectric resonators 75-3 and 75-4 so that those external circuits form portions of the attenuation poles.
  • the external circuits 75-1 - 75-4 are composed of the following elements: cylindrical portions 78-1 - 78-4 which are made of a dielectric material such as a glass epoxy resin with a diameter of D, and are inserted into the dielectric resonators 74-1 - 74-4, respectively: an input pin 76-1 formed on the top surface of the cylindrical portion 78-1; coupling pins 77-1 and 77-2 formed on the top surfaces of the cylindrical portions 78-2 and 78-3, respectively: an output pin 76-2 formed on the top surface of the cylindrical portion 78-4; a conductive wire 79-1 connecting between the input pin 76-1 and the coupling pin 77-1; and an electrically conductive wire 79-2 connecting between the coupling pin 77-2 and the output pin 76-2.
  • the diameter of the pins is represented by d ( ⁇ D).
  • the insides of the hole 73-1 - 73-3 are not plated by any conductive, metallized layer, only simple holes with certain diameters and depths. Those diameters and depths are varied to adjust the coupling amounts between the dielectric resonators.
  • the holes for the dielectric resonators and the holes for adjusting the coupling amounts formed in nearly parallel.
  • FIG. 5 is an equivalent circuit of the dielectric filter of FIG. 4.
  • the inductance of the conductive wire 79-1 connecting the input pin 76-1 and the coupling pin 77-1, and that of the conductive wire 79-2 connecting between the output pin 76-2 and the coupling pin 77-2 are neglected because they are small enough.
  • notations designate inductances and capacitances of the dielectric resonators 74-1 - 74-4, respectively.
  • Indication C71 represents the capacitance between the input pin 76-1 and the dielectric resonator 74-1
  • C75 represents the capacitance between the output pin 76-2 and the dielectric resonator 74-4.
  • Represetation l72 denotes the inductance between the dielectric resonators 74-1 and 74-2, which is controlled by adjusting the hole 73-1
  • l73 denotes the inductance between the dielectric resonators 74-2 and 74-3, which is controlled by adjusting the hole 73-2
  • l74 denotes the inductance between the dielectric resonators 74-3 and 74-4, which is controlled by adjusting the hole 73-3.
  • Reference indication C77 represents the capacitance between the coupling pin 77-1 and the dielectric resonator 74-2.
  • C78 represents the capacitance between the coupling pin 77-2 and the dielectric resonator 74-3.
  • the equivalent circuit shows that the attenuation poles ft ⁇ exist in the upper frequency band of the passband.
  • the attenuation poles ft ⁇ can be expressed as
  • FIG. 6 illustrates the attenuation characteristic of the second example of the conventional dielectric filters This figure shows that the attenuation pole frequency ft ⁇ exists at the upper frequency band of the passband.
  • This type of dielectric filter has the following two problems arising from using the holes for adjusting the coupling between the dielectric resonators: one is that its size cannot be made small; and the other is that the coupling adjustment is difficult.
  • the conventional dielectric filters present the following problems:
  • the first type of dielectric fi lter which uses the notch filter to form the attenuation pole frequency at the lower frequency band of the passband has the problem that its size cannot be made small because one stage of a notch filter provides only insufficient attenuation, and hence the increasing number of stages of the notch filters must be provided.
  • the second type of dielectric filter which uses the holes to form the attenuation pole frequency at the upper frequency band of the passband has the problem that the adjustment of the coupling amounts is difficult and takes long time, in addition to the fact that its size cannot be made small. This is because the holes of more than a certain diameter are required, and the coupling amounts must be adjusted by changing positions, diameters, and depths of the holes.
  • a dielectric filter having a dielectric block including a uniform, single dielectric material, and a plurality of dielectric resonators each of which includes a central conductor formed in the dielectric block in an approximately parallel fashion, the dielectric filter comprising: at least one coupling amount adjusting patterns each of which is formed on the top surface of the dielectric block between the two adjacent dielectric resonators and is grounded so that the dielectric resonators are coupled through inductive impedance.
  • a dielectric filter has the coupling amount adjusting patterns each of which is formed between the two adjacent dielectric resonators and is grounded. This enables the dielectric resonators to be coupled through inductive impedances, which makes the attenuation amount in the upper frequency band of the passband greater than that in the lower frequency band of the passband.
  • a dielectric filter of a desired frequency characteristic can be achieved with a small number of stages of the dielectric resonators.
  • the inductive impedance couplings accomplished by the coupling amount adjusting patterns enable not only the distances between the dielectric resonators to be shortened thereby reducing the required space, but also the coupling adjustment to be carried out more easily, thereby shortening the time required for adjusting the filter in its manufacturing process.
  • FIG. 7 is a perspective view showing an illustrative embodiment of a polarized type of dielectric filter according to the present invention.
  • reference numeral 11 designates a unitarily constructed dielectric block made of a dielectric material such as a ceramic with the width of W. length of L. and height of H. Typical values of W. L and H are, for example, 4.3 mm, 16.0 mm and 9.0 mm, respectively.
  • On the front surface (front side 21, back surface (back side) 22, left side 23, right side 24, and bottom surface 25 of the dielectric block 11 are formed electrically conductive, metallized layers by plating, for example, as shown by hatches in this figure.
  • dielectric block 11 On the top surface (open surface) 25 of the dielectric block 11, are formed also electrically conductive, frequency adjusting patterns 12-1 - 12-4, and coupling amount adjusting patterns 13-1 - 13-3 with gaps 14-1 - 14-6.
  • central conductors 15-1 - 15-4 which function as dielectric resonators (and hence are called dielectric resonators hereinafter) are embedded through the frequency adjusting patterns 12-1 - 12-4, respectively.
  • dielectric resonators 15-1 - 15-4 are inserted and embedded external circuits 16-1 - 16-4 (which are separately depicted above the dielectric block 11 in FIG. 7 for convenience of explanation).
  • the external circuits 16-1 and 16-2 connect the dielectric resonators 15-1 and 15-2, and the external circuits 16-3 and 16-4 connects the dielectric resonators 15-3 and 15-4 so that the external circuits form the attenuation poles.
  • the external circuits 16- 1 - 16-4 are composed of the following elements: cylindrical portions 19-1 - 19-4 which are made of a dielectric material such as a glass epoxy resin with a diameter of D, and are inserted into the dielectric resonators 15-1 - 15-4 respectively; an electrically conductive input coupling pin 17-1 formed on the top surface of the cylindrical portion 19-1; coupling pins 18-1 and 18-2 formed on the top surfaces of the cylindrical portions 19-2 and 19-3, respectively; an output coupling pin 17-2 formed on the top surface of the cylindrical portion 19-4; an electrically conductive wire 20-1 connecting between the input coupling pin 17-1 and the coupling pin 18-1; and an also electrically conductive wire 20-2 connecting between the coupling pin 18-2 and the output coupling pin 17-2.
  • Respective one ends of the coupling amount adjusting patterns 13-1 - 13-3 are connected to the front surface (front side) 21 of the dielectric block 11, and the other ends thereof are connected to the metallized pattern on the back surface (back side) 22 of the dielectric block 11.
  • the coupling adjusting patterns 13-1 - 13-3 function as electrodes for adjusting the coupling amount: the coupling adjusting pattern 13-1 is provided for adjusting the inductive impedance coupling between the frequency adjusting patterns 12-1 and 12-2; the coupling adjusting pattern 13-2 is for adjusting the inductive impedance coupling between the frequency adjusting patterns 12-2 and 12-3; and the coupling adjusting pattern 13-1 is provided for adjusting the inductive impedance coupling between the frequency adjusting patterns 12-3 and 12-4.
  • the electromagnetic field around the dielectric resonator 15-3 is propagated through the gap 14-5, coupling amount adjusting pattern 13-3, gap 14-6, and the frequency adjusting pattern 12-4, to the dielectric resonator 15-4, and then to the external circuit 16-4.
  • the electric signal in the form of the electromagnetic field from the dielectric resonator 15-3 is also propagated to the dielectric resonator 15-4 and the external circuit 16-4 by way of external circuit 16-3 and the conductive wire 20-2.
  • the output coupling pin 17-2 of the external circuit 16-4 is connected to a load not shown in this figure, and hence the electric signal applied to the input coupling pin 17-1 is finally propagated to the load via the output coupling pin 17-2.
  • FIG. 8 is an equivalent circuit of the polarized type of dielectric filter of the illustrative embodiment of the present invention.
  • reference indication l1 denotes the inductance of the dielectric resonator 15-1 and indication C1 denotes the capacitance of the dielectric resonator 15-1.
  • Reference indication C11 indicates the capacitance between the input coupling pin 17-1 and the dielectric resonator 15-1
  • indication C15 indicates the capacitance between the output coupling pin 17-2 and the dielectric resonator 15-4.
  • a box jX12 represents the inductive impedance between the dielectric resonator 15-1 and the dielectric resonator 15-2.
  • box jX13 is the inductive impedance between the dielectric resonator 15-2 and the dielectric resonator 15-3; and box jX14 is the inductive impedance between the dielectric resonators 15-3 and 15-4.
  • Representation C21 indicates the capacitance between the coupling pin 18-1 and the dielectric resonator 15-2
  • indication C22 indicates the capacitance between the coupling pin 18-2 and the dielectric resonator 15-3.
  • Notation l21 denotes the inductance of the conductive wire 20-1 connecting the input pin 17-1 and the coupling pin 18-1
  • l22 denotes the inductance of the conductive wire 20-2 connecting the coupling pin 18-2 and the output pin 17-2.
  • the values l21 and C21, and l22 and C22 are specified to satisfy the conditions:
  • the values l21 and l22 can be neglected.
  • the equivalent circuit can be depicted as shown in FIG. 9.
  • the attenuation pole frequency f ⁇ satisfies the relation f ⁇ > f0, where f0 denotes the central frequency of the passband. This means that the pole frequency f ⁇ is located in the upper frequency band of the passband.
  • the attenuation amount becomes infinite at the attenuation pole frequencies expressed by
  • FIG. 10 plots the attenuation characteristic of the polarized type of dielectric filter of the illustrative embodiment of the present invention.
  • the x-axis represents the frequency (MHz) and the y-axis represents the attenuation amount (dB).
  • the polarized type of dielectric filter of FIG. 7 has an attenuation pole at a higher frequency than the passband, that is, in the upper frequency band of the passband.
  • FIG. 11 illustrates an equivalent circuit between the dielectric resonators 15-1 and 15-2 of FIG. 7.
  • box jX12 of FIG. 9 corresponds to the part designated by C01, C02 and l12.
  • expression C01 is directed to the capacitance between the frequency adjusting pattern 12-1 of the dielectric resonator 15-1 and the coupling amount adjusting pattern 13-1;
  • indication C02 denotes the capacitance between the coupling amount adjusting pattern 13-1 and the frequency adjusting pattern 12-2 of the dielectric resonator 15-2;
  • reference indicatino l12 designates the equivalent inductance of the inductive impedance of the coupling amount adjusting pattern 13-1.
  • FIG. 12 plots the coupling amounts obtained as the results of the experiment. As seen from this figure, as the width t of the coupling adjusting pattern becomes narrower, the coupling amounts become smaller.
  • the contents in the parentheses following characters K12 and K23 in FIG. 12 designate the differences between the resonance frequencies of the two dielectric resonators.
  • the coupling amount can also be varied by changing values C01 and C02 in FIG. 11. This corresponds to changing the gap 14-1 between the frequency adjusting pattern 12-1 and the coupling amount adjusting pattern 13-1, and the gap 14-2 between the frequency adjusting pattern 12-2 and the coupling amount adjusting pattern 13-1.
  • the present invention is provided with the coupling amount adjusting patterns 13-1 - 13-3 formed on the top surface (open surface) 26 of the dielectric block 11 to achieve the inductive impedances.
  • This enables the filer to be made smaller than the conventional filters with adjusting holes.
  • the coupling amount adjusting patterns are formed on the top surface (open surface) of the dielectric block, the widths of the coupling amount adjusting patterns can be easily controlled by laser trimming or the similar trimming method, which will facilitate the adjustment of the filter characteristics.
  • FIG. 13 is a plan view of an alternative embodiment of the present invention which is resultant from changing the top pattern of the embodiment shown in FIG. 7.
  • the top pattern of FIG. 7 corresponds to that of FIG. 13 when a gap T is made zero in FIG. 13.
  • FIG. 15 plots the coupling amounts obtained as the results of the experiment. As seen from this figure, the coupling amount can be increased by about 20% by making T nonzero.
  • FIG. 14 illustrates an equivalent circuit between the dielectric resonators 91-1 and 91-2 of FIG. 13.
  • FIG. 14 indicates the existence of a capacitance C12 ⁇ 1 between the coupling amount adjusting pattern 93-1 and the metallized pattern formed on the back surface (back side) 22 of the dielectric block 11.
  • This capacitance C12 ⁇ 1 makes the composite impedance l12 ⁇ 1 and C12 ⁇ 1 smaller than when capacitance C12 ⁇ 1 does not exist, thereby increasing the coupling amount.
  • the width of the coupling amount adjusting pattern may advantageously be made wider. This will impose a limit on reducing the size of the filter.
  • the method in accordance with the second embodiment directed to FIG. 15, however, enables the coupling amount to increase by 20% by making T nonzero. This achieves a small filter of a larger coupling amount.
  • polarized type of dielectric filters In the above, described are embodiments of polarized type of dielectric filters.
  • a non-polarized type of dielectric filters although not shown in drawings, is also possible by removing, for example, the external circuits 16-2 and 16-3 of the structure shown in FIG. 7.
  • the dielectric resonators are coupled by the inductive impedances, the attenuation amount in the upper frequency band of the passband can be made larger than that of the conventional filters using capacitive coupling.
  • a still another alternative embodiment of the present invention is directed to dielectric filters in which metallized layers on the sides of the dielectric block 11 of FIG. 7 are extended to the top surface of the block 11 except for areas surrounding the top surfaces of the central conductors of the dielectric resonators.

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Control Of Motors That Do Not Use Commutators (AREA)
EP19910101871 1990-02-14 1991-02-11 Dielectric filter having coupling amount adjusting patterns Withdrawn EP0442418A3 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP31575/90 1990-02-14
JP2031575A JPH03236603A (ja) 1990-02-14 1990-02-14 誘電体フィルタ

Publications (2)

Publication Number Publication Date
EP0442418A2 true EP0442418A2 (de) 1991-08-21
EP0442418A3 EP0442418A3 (en) 1992-09-16

Family

ID=12334977

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19910101871 Withdrawn EP0442418A3 (en) 1990-02-14 1991-02-11 Dielectric filter having coupling amount adjusting patterns

Country Status (4)

Country Link
EP (1) EP0442418A3 (de)
JP (1) JPH03236603A (de)
KR (1) KR920000173A (de)
CA (1) CA2036305A1 (de)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0552761A1 (de) * 1992-01-23 1993-07-28 Murata Manufacturing Co., Ltd. Dielektrischer Resonator und Herstellungsverfahren dafür
EP0809315A1 (de) * 1996-05-23 1997-11-26 Ngk Spark Plug Co., Ltd. Dielektrischer Filter
EP0878862A1 (de) * 1997-05-13 1998-11-18 Hughes Electronics Corporation Bandpassfilter mit gleichzeitiger Kopplung und Methode
GB2339340A (en) * 1998-07-08 2000-01-19 Samsung Electro Mech Dielectric filter
DE19857358A1 (de) * 1998-11-03 2000-05-18 Samsung Electro Mech Dielektrisches Filter
EP1009059A1 (de) * 1998-12-10 2000-06-14 Ngk Spark Plug Co., Ltd Dielektrisches Filter mit regelbarer Frequenzbandbreite

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20220078202A (ko) * 2020-12-03 2022-06-10 삼성전기주식회사 커플링 부재를 포함하는 마이크로스트립 안테나 및 마이크로스트립 안테나 모듈
CN112952327A (zh) * 2021-03-11 2021-06-11 华中科技大学温州先进制造技术研究院 高带外抑制特性的六腔四零点陶瓷波导滤波器

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0713284Y2 (ja) * 1987-09-21 1995-03-29 株式会社村田製作所 一体成形型誘電体フィルタの共振周波数調整構造
US4823098A (en) * 1988-06-14 1989-04-18 Motorola, Inc. Monolithic ceramic filter with bandstop function
US5015974A (en) * 1988-06-20 1991-05-14 Oki Electric Industry Co., Ltd. Isolating circuit and dielectric filter for use therein

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5949310A (en) * 1992-01-23 1999-09-07 Murata Manufacturing Co., Ltd. Dielectric filter having a pattern electrode disposed within a dielectric body and manufacturing method thereof
EP0552761A1 (de) * 1992-01-23 1993-07-28 Murata Manufacturing Co., Ltd. Dielektrischer Resonator und Herstellungsverfahren dafür
US6069542A (en) * 1992-01-23 2000-05-30 Murata Manufacturing Co., Ltd. Dielectric filter having resonator electrodes, shield electrodes, and coupling electrodes disposed within a dielectric body
EP0809315A1 (de) * 1996-05-23 1997-11-26 Ngk Spark Plug Co., Ltd. Dielektrischer Filter
US5864264A (en) * 1996-05-23 1999-01-26 Ngk Spark Plug Co., Ltd. Dielectric filter
EP0878862A1 (de) * 1997-05-13 1998-11-18 Hughes Electronics Corporation Bandpassfilter mit gleichzeitiger Kopplung und Methode
GB2339340B (en) * 1998-07-08 2003-07-16 Samsung Electro Mech Dielectric filter
GB2339340A (en) * 1998-07-08 2000-01-19 Samsung Electro Mech Dielectric filter
US6636132B1 (en) 1998-07-08 2003-10-21 Partron Co., Ltd. Dielectric filter
DE19857358A1 (de) * 1998-11-03 2000-05-18 Samsung Electro Mech Dielektrisches Filter
US6169464B1 (en) 1998-11-03 2001-01-02 Samsung Electro-Mechanics Co., Ltd. Dielectric filter
US6304159B1 (en) 1998-12-10 2001-10-16 Ngk Spark Plug Co., Ltd. Dielectric filter with adjustable frequency bandwidth
EP1009059A1 (de) * 1998-12-10 2000-06-14 Ngk Spark Plug Co., Ltd Dielektrisches Filter mit regelbarer Frequenzbandbreite

Also Published As

Publication number Publication date
KR920000173A (ko) 1992-01-10
JPH03236603A (ja) 1991-10-22
CA2036305A1 (en) 1991-08-15
EP0442418A3 (en) 1992-09-16

Similar Documents

Publication Publication Date Title
EP0510971B1 (de) Dielektrischer Filter
US3451015A (en) Microwave stripline filter
US5239279A (en) Ceramic duplex filter
US5404118A (en) Band pass filter with resonator having spiral electrodes formed of coil electrodes on plurality of dielectric layers
US4996506A (en) Band elimination filter and dielectric resonator therefor
US4800347A (en) Dielectric filter
US5227747A (en) Dielectric filter having coupling amount adjusting patterns
JPH06283904A (ja) 誘電体フィルタおよびこれを用いた分波器
US6597263B2 (en) Dielectric filter having notch pattern
JPS58103202A (ja) 誘電体フイルタ
EP0442418A2 (de) Dielektrischer Filter mit Mustern zur Einstellung der Kopplung
US5563561A (en) Dielectric block apparatus having two opposing coaxial resonators separated by an electrode free region
EP0576273B1 (de) Koaxialer Resonator und dielektrisches Filter mit einem derartigen Resonator
KR100249838B1 (ko) 유자형 공진기를 갖는 고주파 필터
KR19990034141A (ko) 스텝 임피던스 공진기를 갖는 듀플렉서
EP0798803A2 (de) Dielektrisches Filter
US5859575A (en) Dielectric filter
JPH03108801A (ja) 誘電体フィルタ
EP1019976A1 (de) Bandpassfilter in schlitzleitungstechnik
CN221239781U (zh) 通信设备用滤波器
US4994775A (en) High-pass filter for microstrip circuit
JPS6314501A (ja) 高周波フイルタ
JPS6264101A (ja) 帯域通過ろ波器
KR100344228B1 (ko) 공진기 결합형 유전체 필터
EP0508734A1 (de) Keramisches Filter

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): DE FR GB

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): DE FR GB

17P Request for examination filed

Effective date: 19921106

17Q First examination report despatched

Effective date: 19940805

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 19960814