JPH0216802A - Band elimination filter - Google Patents
Band elimination filterInfo
- Publication number
- JPH0216802A JPH0216802A JP63166580A JP16658088A JPH0216802A JP H0216802 A JPH0216802 A JP H0216802A JP 63166580 A JP63166580 A JP 63166580A JP 16658088 A JP16658088 A JP 16658088A JP H0216802 A JPH0216802 A JP H0216802A
- Authority
- JP
- Japan
- Prior art keywords
- frequency
- filter
- capacitor
- inductor
- band elimination
- 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.)
- Pending
Links
- 230000008030 elimination Effects 0.000 title claims description 16
- 238000003379 elimination reaction Methods 0.000 title claims description 16
- 230000005540 biological transmission Effects 0.000 claims abstract description 11
- 239000003990 capacitor Substances 0.000 abstract description 28
- 230000001939 inductive effect Effects 0.000 abstract description 2
- 238000010586 diagram Methods 0.000 description 3
- 239000004020 conductor Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 239000000758 substrate Substances 0.000 description 2
- 101100182136 Neurospora crassa (strain ATCC 24698 / 74-OR23-1A / CBS 708.71 / DSM 1257 / FGSC 987) loc-1 gene Proteins 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 229920003002 synthetic resin Polymers 0.000 description 1
- 239000000057 synthetic resin Substances 0.000 description 1
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
Landscapes
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Control Of Motors That Do Not Use Commutators (AREA)
- Filters And Equalizers (AREA)
Abstract
Description
【発明の詳細な説明】
［産業上の利用分野］
本発明は、誘電体共振器なとの共振器を用いたバンドエ
リミネーションフィルタに関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a band elimination filter using a resonator such as a dielectric resonator.
［従来の技術］
従来のバンドエリミネーションフィルタとしては、たと
えば特開昭６１−１９３５０１号に、第１０図のような
構成が示されている。[Prior Art] As a conventional band elimination filter, a configuration as shown in FIG. 10 is shown in, for example, Japanese Patent Laid-Open No. 193501/1983.
第１０図において、誘電体共振器１は、キャパシタ２に
直列接続されている。また、伝送ライン３はインダクタ
４を有している。インダクタ４の各端において、伝送ラ
イン３とアースとの間には、前記キャパシタ２と共振器
］とが接続されるとともに、それらと並列に別のキャパ
シタ５が接続されている。In FIG. 10, a dielectric resonator 1 is connected in series to a capacitor 2. In FIG. Furthermore, the transmission line 3 has an inductor 4 . At each end of the inductor 4, the capacitor 2 and the resonator] are connected between the transmission line 3 and the ground, and another capacitor 5 is connected in parallel with them.
第１０図のバンドエリミネーションフィルタでは、トラ
ップ周波数をｆ２とした場合には、第１１図に示すよう
な周波数−減衰量特性を一般に示す。The band elimination filter shown in FIG. 10 generally exhibits a frequency-attenuation characteristic as shown in FIG. 11 when the trap frequency is f2.
［発明が解決しようとする課題］
前記従来のバンドエリミネーションフィルタでは、フィ
ルタ特性を得るためのキャパシタ２の他に、アースに直
接接続されるキャパシタ５が必要である。このため、フ
ィルタ構造か複雑とならざるを得ない。[Problems to be Solved by the Invention] The conventional band elimination filter requires a capacitor 5 directly connected to ground in addition to the capacitor 2 for obtaining filter characteristics. Therefore, the filter structure must become complicated.
また、前記従来のバンドエリミネーションフィルタでは
、第１１図に示すように、トラップ周波数ｆ２から周波
数Ｏに至るまで、減衰量が徐々に低下する特性を有して
いることから、優れたフィルタ特性を有しているとは言
い難い。Furthermore, as shown in FIG. 11, the conventional band elimination filter has a characteristic in which the amount of attenuation gradually decreases from the trap frequency f2 to the frequency O, so it has excellent filter characteristics. It is difficult to say that we have it.
本発明の目的は、フィルタ構造を簡略化することにより
製造コストを低減し量産性を向上させるとともに、フィ
ルタ特性を向上させることのできるバンドエリミネーシ
ョンフィルタを提供することにある。An object of the present invention is to provide a band elimination filter that can reduce manufacturing costs and improve mass productivity by simplifying the filter structure, and can also improve filter characteristics.
［課題を解決するための手段］
本発明に係るバンドエリミネーションフィルタは、フィ
ルタ回路と、インダクタンス手段を有する入出力用の伝
送ラインとを含んでいる。前記フィルタ回路は、共振器
と、共振器に直列接続されたキャパシタンス手段とを有
している。そして、前記インダクタンス手段の各端とア
ース間に、前記フィルタ回路のみが接続されている。[Means for Solving the Problems] A band elimination filter according to the present invention includes a filter circuit and an input/output transmission line having an inductance means. The filter circuit includes a resonator and capacitance means connected in series with the resonator. Only the filter circuit is connected between each end of the inductance means and the ground.
［作用および発明の効果］
本発明に係るバンドエリミネーションフィルタでは、伝
送ラインとアースとの間に従来直接接続されていたキャ
パシタが不要になる。この結果、フィルタ構造が簡略化
し、製造コストの低減および量産性の向上を図ることが
できるようになる。[Operations and Effects of the Invention] The band elimination filter according to the present invention does not require a capacitor that has conventionally been directly connected between the transmission line and the ground. As a result, the filter structure is simplified, making it possible to reduce manufacturing costs and improve mass productivity.
また、本発明に係るバンドエリミネーションフィルタに
よれば、トラップ周波数付近における減衰量変化の傾き
が急峻になり、その結果優れたフィルタ特性を実現する
ことかできるようになる。Further, according to the band elimination filter according to the present invention, the slope of the change in attenuation amount near the trap frequency becomes steeper, and as a result, it becomes possible to realize excellent filter characteristics.
［実施例］
第１図は、本発明に係るバンドエリミネーションフィル
タの一実施例を示している。[Embodiment] FIG. 1 shows an embodiment of a band elimination filter according to the present invention.
第１図において、フィルタ回路１０は周波数ｆ２で誘導
性を示す誘電体共振器］１とキャパシタ１２とか直列接
続されることにより構成されている。一方、入出力用の
伝送ライン１３は、インダクタ１４を有している。そし
て、前記インダクタ１４の各端（点Ａ、Ｂには、フィル
タ回路］０のキャパシタ１２側か接続されている。フィ
ルタ回路１０の共振器１〕側は、アース１５に接続され
ている。In FIG. 1, a filter circuit 10 is constructed by connecting in series a dielectric resonator 1 exhibiting inductive properties at a frequency f2 and a capacitor 12. On the other hand, the input/output transmission line 13 has an inductor 14 . Each end of the inductor 14 (points A and B is connected to the capacitor 12 side of the filter circuit 0. The resonator 1 side of the filter circuit 10 is connected to the ground 15.
すなわち、第１図に示すバンドエリミネーションフィル
タでは、点Ａ、 Ｂにおいて、従来のキャパシタ（第
１０図のキャパシタ５）が存在しない。That is, in the band elimination filter shown in FIG. 1, the conventional capacitor (capacitor 5 in FIG. 10) does not exist at points A and B.
したがって、成る周波数ｆ１を考えた場合に、その周波
数において点Ａ、Ｂでは反共振が生じ、開放状態となっ
ているものとみなすことができる。Therefore, when considering the frequency f1, anti-resonance occurs at points A and B at that frequency, and it can be considered that the points A and B are in an open state.
すなわち、点Ａ、Ｂを基準に考えた場合には、第２図に
示すようにＬＣの並列回路１６が構成されており、その
並列回路１６が共振している状態にあるとみなすことが
できる。そして、第２図において、ＬＣ並列回路１６の
キャパシタ１６とインダクタ１４に注目すれば、これら
はπ型の分布定数線路であるとみなすことができる。In other words, when considering points A and B as a reference, an LC parallel circuit 16 is configured as shown in FIG. 2, and it can be considered that the parallel circuit 16 is in a resonant state. . If we pay attention to the capacitor 16 and inductor 14 of the LC parallel circuit 16 in FIG. 2, they can be considered to be a π-type distributed constant line.
したがって、この実施例に係るバンドエリミネーション
フィルタは、第３図に示すように、点Ａと点８間に分布
定数線路１８が配置され、点Ａ。Therefore, in the band elimination filter according to this embodiment, as shown in FIG.
Ｂとアースとの間にインダクタ１９が配置された回路を
備えているとみなすことができる。この第３図の回路の
共振器１１をＬＣ並列回路であると考えると、その等価
回路は第４図のように示される。第４図では、キャパシ
タ１２とアース１５との間には、並列接続されたキャパ
シタ２０とインダクタ２１とが配置されている。ここで
、点Ａとアース１５との間のアドミタンスＹは、次式に
よって得られる。It can be considered that the circuit includes an inductor 19 placed between B and ground. If the resonator 11 of the circuit shown in FIG. 3 is considered to be an LC parallel circuit, its equivalent circuit is shown as shown in FIG. In FIG. 4, a capacitor 20 and an inductor 21 are arranged in parallel between the capacitor 12 and the ground 15. Here, the admittance Y between point A and ground 15 is obtained by the following equation.
Ｙ”［ｕ／’Ｌ＋ＬＯＣＩＣｏ ＬＡ／’（Ｌｏｅ
ｏ＋’＋Ｃ＋＋ＬｏＣ１，）十ｌ Ｊ ／Ｊｕ）Ｌｌ
（ｌ−ｗ”ＬｖＣｏ Ｌ４）”ＬｏＣ＋ ）なお、上
式において、Ｌｏはインダクタ２１のインダクタンス、
Ｌｌはインダクタ１つのインダクタンス、ｃｏはキャパ
シタ２０のキャパシタンス、Ｃ４はキャパシタ１２のキ
ャパシタンスである。Y"[u/'L+LOCICo LA/'(Loe
o+'+C++LoC1,) 10l J /Ju)Ll
(l-w”LvCo L4)”LoC+) In the above equation, Lo is the inductance of the inductor 21,
Ll is the inductance of one inductor, co is the capacitance of the capacitor 20, and C4 is the capacitance of the capacitor 12.
ここで、反共振周波数をｆｌとし、トラップ周波数をｆ
２とすると、反共振周波数ｆ、では、アドミタンスＹが
０となり、トラップ周波数ｆ２ではアドミタンスＹが無
限大となる。この場合の周波数とアドミタンスとの関係
を図示すれば、第５図のようになる。これを伝送ライン
１３の通過特性として見ると、周波数と減衰量との関係
は第６図のようになる。第６図に示すように、反共振周
波数ｆ、においては、減衰量がＯとなる。したかって、
従来のバンドエリミネーションフィルタの特性を示す第
１１図と比較すれば明らかなように、トラップ周波数ｆ
２周辺での減衰量の変化はこの実施例によればより急峻
となる。すなわち、トラツブ周波数ｆ２よりも低い周波
数領域での通過特性か改善されることになる。一方、周
波数ｆ１を通過帯域として用いれば、挿入損失が小さく
なる。Here, the anti-resonance frequency is fl and the trap frequency is f
2, the admittance Y becomes 0 at the antiresonance frequency f, and the admittance Y becomes infinite at the trap frequency f2. The relationship between frequency and admittance in this case is illustrated in FIG. 5. If this is seen as a passing characteristic of the transmission line 13, the relationship between frequency and attenuation amount is as shown in FIG. As shown in FIG. 6, at the anti-resonant frequency f, the attenuation amount is O. I wanted to,
As is clear from a comparison with FIG. 11 showing the characteristics of a conventional band elimination filter, the trap frequency f
According to this embodiment, the change in attenuation amount around 2 becomes more steep. In other words, the pass characteristics in a frequency range lower than the trouble frequency f2 are improved. On the other hand, if the frequency f1 is used as the passband, the insertion loss will be reduced.
次に、この実施例に係るバンドエリミネーションフィル
タの具体的構成を説明する。Next, a specific configuration of the band elimination filter according to this embodiment will be explained.
たとえば、第７図に示す構成を採用することができる。For example, the configuration shown in FIG. 7 can be adopted.
第７図において、基板３０の」二面には、互いに間隙を
隔てたコンデンサ電極３１．３２か形成されている。各
コンデンサ電極３１間には、これと一体に形成されたイ
ンダクタ電極３３か配置されている。共振器３４の開放
端側中心導体３５はコンデンサ電極３２に接続されてい
る。なお、コンデンサ電極３１．３２により静電容量が
実現されている。In FIG. 7, capacitor electrodes 31 and 32 are formed on two surfaces of the substrate 30 with a gap between them. An inductor electrode 33 formed integrally with each capacitor electrode 31 is arranged between each capacitor electrode 31 . A center conductor 35 on the open end side of the resonator 34 is connected to the capacitor electrode 32. Note that capacitance is realized by the capacitor electrodes 31 and 32.
また、前記インダクタ電極３３に代えて、第８図に示す
ように、インダクタ３６を隣接するコンデンサ電極３１
間に接続してもよい。Moreover, instead of the inductor electrode 33, as shown in FIG.
It may be connected in between.
また、基板３０等を設けず、第９図のように、共振器３
４の開放端に円板状のコンデンサ３７を接続し、コンデ
ンサ３７の他方の電極にインダクタ３８を有する伝送ラ
イン３９を接続するようにしてもよい。In addition, as shown in FIG. 9, without providing the substrate 30, etc., the resonator 3
A disk-shaped capacitor 37 may be connected to the open end of the capacitor 4, and a transmission line 39 having an inductor 38 may be connected to the other electrode of the capacitor 37.
さらに、コンデンサ３７に代えて、合成樹脂のブッシン
グに金属ピンの一部を残して挿入した端子を用い、金属
ピンと共振器の内導体との間で静電容量を実現してもよ
い。Further, instead of the capacitor 37, a terminal inserted into a synthetic resin bushing with a portion of the metal pin left may be used to realize capacitance between the metal pin and the inner conductor of the resonator.
また、誘電体共振器に代えて、ＬＣ共振器やストリップ
ライン共振器を採用してもよい。Further, instead of the dielectric resonator, an LC resonator or a stripline resonator may be used.
第１図は、本発明に係る一実施例の回路図である。第２
図、第３図、第４図は、第１図の回路のそれぞれ見方を
変えた等価回路図である。第５図は周波数−アドミタン
ス特性を示すグラフである。
第６図は、周波数−減衰量特性を示すグラフである。第
７図および第８図はそれぞれ別の実施例の平面部分図で
ある。第９図は、さらに他の実施例の斜視部分図である
。第１０図は、従来例の第１図に相当する図である。第
１１図は従来例の第６図に相当するグラフである。
１０はフィルタ回路、］１は共振器、１２はキャパシタ
、］３は伝送ライン、１４はインダクタ、］５はアース
、３１．３２はコンデンサ電極、３３．３６．３８はイ
ンダクタ、３４は共振器、３つは伝送ラインである。
第１０図FIG. 1 is a circuit diagram of an embodiment according to the present invention. Second
1, 3, and 4 are equivalent circuit diagrams of the circuit shown in FIG. 1 from different perspectives. FIG. 5 is a graph showing frequency-admittance characteristics. FIG. 6 is a graph showing frequency-attenuation characteristics. FIGS. 7 and 8 are partial plan views of different embodiments, respectively. FIG. 9 is a perspective partial view of still another embodiment. FIG. 10 is a diagram corresponding to FIG. 1 of the conventional example. FIG. 11 is a graph corresponding to FIG. 6 of the conventional example. 10 is a filter circuit,] 1 is a resonator, 12 is a capacitor, ] 3 is a transmission line, 14 is an inductor, ] 5 is ground, 31.32 is a capacitor electrode, 33, 36, 38 is an inductor, 34 is a resonator, Three are transmission lines. Figure 10
Claims (1)
とからなるフィルタ回路と、 インダクタンス手段を有する入出力用の伝送ラインとを
含み、 前記インダクタンス手段の各端とアース間に前記フィル
タ回路のみを接続した バンドエリミネーションフィルタ。[Claims] The filter circuit includes a resonator, a capacitance means connected in series with the resonator, and an input/output transmission line having an inductance means, between each end of the inductance means and the ground. A band elimination filter in which only the filter circuit described above is connected.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63166580A JPH0216802A (en) | 1988-07-04 | 1988-07-04 | Band elimination filter |
| FI893231A FI893231A (en) | 1988-07-04 | 1989-07-03 | BANDELIMINERINGSFILTER. |
| NO89892754A NO892754L (en) | 1988-07-04 | 1989-07-03 | BAANDSPERREFILTER. |
| EP19890306771 EP0350256A3 (en) | 1988-07-04 | 1989-07-04 | Band elimination filter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63166580A JPH0216802A (en) | 1988-07-04 | 1988-07-04 | Band elimination filter |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0216802A true JPH0216802A (en) | 1990-01-19 |
Family
ID=15833909
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63166580A Pending JPH0216802A (en) | 1988-07-04 | 1988-07-04 | Band elimination filter |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0350256A3 (en) |
| JP (1) | JPH0216802A (en) |
| FI (1) | FI893231A (en) |
| NO (1) | NO892754L (en) |
Cited By (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03181205A (en) * | 1989-12-11 | 1991-08-07 | Fuji Elelctrochem Co Ltd | Dielectric filter |
| JPH03247001A (en) * | 1990-02-23 | 1991-11-05 | Fuji Elelctrochem Co Ltd | Dielectric filter |
| JPH03254203A (en) * | 1990-03-02 | 1991-11-13 | Fujitsu Ltd | Dielectric filter and its resonator |
| JPH03254202A (en) * | 1990-03-02 | 1991-11-13 | Fujitsu Ltd | Dielectric resonator and filter using same |
| JPH0490602A (en) * | 1990-08-03 | 1992-03-24 | Fuji Elelctrochem Co Ltd | Dielectric resonator and dielectric filter |
| JPH04103201A (en) * | 1990-08-22 | 1992-04-06 | Fuji Elelctrochem Co Ltd | Dielectric band stop filter |
| JPH04196829A (en) * | 1990-11-28 | 1992-07-16 | Hitachi Ltd | Branching filter device and mobile radio equipment using same |
| WO1992012546A1 (en) * | 1990-12-26 | 1992-07-23 | Ube Industries, Ltd. | Dielectric filter |
| JPH04311103A (en) * | 1991-04-10 | 1992-11-02 | Murata Mfg Co Ltd | Dielectric coaxial resonator and dielectric filter |
| JPH054603U (en) * | 1991-06-27 | 1993-01-22 | 京セラ株式会社 | Band elimination filter |
| JPH05167309A (en) * | 1991-12-11 | 1993-07-02 | Fuji Elelctrochem Co Ltd | Dielectric filter |
| JPH05167308A (en) * | 1991-12-11 | 1993-07-02 | Fuji Elelctrochem Co Ltd | Dielectric filter |
| JPH07321509A (en) * | 1994-05-20 | 1995-12-08 | Kokusai Electric Co Ltd | Frequency band variable filter |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA2037262A1 (en) * | 1990-03-02 | 1991-09-03 | Hiroyuki Sogo | Dielectric resonator and a filter using same |
| GB2247125B (en) * | 1990-08-16 | 1995-01-11 | Technophone Ltd | Tunable bandpass filter |
| US5293141A (en) * | 1991-03-25 | 1994-03-08 | Sanyo Electric Co., Ltd. | Dielectric filter having external connection terminals on dielectric substrate and antenna duplexer using the same |
| US5202654A (en) * | 1991-07-22 | 1993-04-13 | Motorola, Inc. | Multi-stage monolithic ceramic bandstop filter with isolated filter stages |
| KR20010052211A (en) * | 1998-03-18 | 2001-06-25 | 윌리암 제이. 템블린 | Narrow-band band-reject filter apparatus and method |
| US6529750B1 (en) | 1998-04-03 | 2003-03-04 | Conductus, Inc. | Microstrip filter cross-coupling control apparatus and method |
| WO2002013382A2 (en) | 2000-08-07 | 2002-02-14 | Conductus, Inc. | Varactor tuning for a narrow band filter |
| US7437187B1 (en) | 2000-10-30 | 2008-10-14 | Conductus, Inc. | Superconductive filter with capacitive patches providing reduced cross-coupling |
| US7610072B2 (en) | 2003-09-18 | 2009-10-27 | Superconductor Technologies, Inc. | Superconductive stripline filter utilizing one or more inter-resonator coupling members |
| GB2512032B (en) * | 2013-01-31 | 2020-07-29 | Clive Baty David | Filter |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01103001A (en) * | 1987-10-15 | 1989-04-20 | Murata Mfg Co Ltd | Dielectric filter |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1568141A (en) * | 1920-08-13 | 1926-01-05 | American Telephone & Telegraph | Frequency selective circuits |
| JPS605602A (en) * | 1983-06-23 | 1985-01-12 | Murata Mfg Co Ltd | Asymmetric trap |
| JPS61105901A (en) * | 1984-10-30 | 1986-05-24 | Sumitomo Electric Ind Ltd | Notch filter |
| JPS61191101A (en) * | 1985-02-19 | 1986-08-25 | Murata Mfg Co Ltd | Filter |
| JPS61193501A (en) * | 1985-02-21 | 1986-08-28 | Murata Mfg Co Ltd | Filter |
| JPS61208902A (en) * | 1985-03-13 | 1986-09-17 | Murata Mfg Co Ltd | Mic type dielectric filter |
-
1988
- 1988-07-04 JP JP63166580A patent/JPH0216802A/en active Pending
-
1989
- 1989-07-03 NO NO89892754A patent/NO892754L/en unknown
- 1989-07-03 FI FI893231A patent/FI893231A/en not_active Application Discontinuation
- 1989-07-04 EP EP19890306771 patent/EP0350256A3/en not_active Withdrawn
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01103001A (en) * | 1987-10-15 | 1989-04-20 | Murata Mfg Co Ltd | Dielectric filter |
Cited By (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03181205A (en) * | 1989-12-11 | 1991-08-07 | Fuji Elelctrochem Co Ltd | Dielectric filter |
| JPH03247001A (en) * | 1990-02-23 | 1991-11-05 | Fuji Elelctrochem Co Ltd | Dielectric filter |
| JPH03254203A (en) * | 1990-03-02 | 1991-11-13 | Fujitsu Ltd | Dielectric filter and its resonator |
| JPH03254202A (en) * | 1990-03-02 | 1991-11-13 | Fujitsu Ltd | Dielectric resonator and filter using same |
| JPH0490602A (en) * | 1990-08-03 | 1992-03-24 | Fuji Elelctrochem Co Ltd | Dielectric resonator and dielectric filter |
| JPH04103201A (en) * | 1990-08-22 | 1992-04-06 | Fuji Elelctrochem Co Ltd | Dielectric band stop filter |
| JPH04196829A (en) * | 1990-11-28 | 1992-07-16 | Hitachi Ltd | Branching filter device and mobile radio equipment using same |
| WO1992012546A1 (en) * | 1990-12-26 | 1992-07-23 | Ube Industries, Ltd. | Dielectric filter |
| US5493261A (en) * | 1990-12-26 | 1996-02-20 | Ube Industries, Ltd. | Dielectric filter using quarter wavelength coaxial dielectric resonators connected in series |
| JPH04311103A (en) * | 1991-04-10 | 1992-11-02 | Murata Mfg Co Ltd | Dielectric coaxial resonator and dielectric filter |
| JPH054603U (en) * | 1991-06-27 | 1993-01-22 | 京セラ株式会社 | Band elimination filter |
| JPH05167309A (en) * | 1991-12-11 | 1993-07-02 | Fuji Elelctrochem Co Ltd | Dielectric filter |
| JPH05167308A (en) * | 1991-12-11 | 1993-07-02 | Fuji Elelctrochem Co Ltd | Dielectric filter |
| JPH07321509A (en) * | 1994-05-20 | 1995-12-08 | Kokusai Electric Co Ltd | Frequency band variable filter |
Also Published As
| Publication number | Publication date |
|---|---|
| NO892754D0 (en) | 1989-07-03 |
| NO892754L (en) | 1990-01-05 |
| FI893231A0 (en) | 1989-07-03 |
| EP0350256A3 (en) | 1990-11-28 |
| FI893231A (en) | 1990-01-05 |
| EP0350256A2 (en) | 1990-01-10 |
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