JPS6074809A - Low-pass filter for transmission of waveform - Google Patents
Low-pass filter for transmission of waveformInfo
- Publication number
- JPS6074809A JPS6074809A JP18257183A JP18257183A JPS6074809A JP S6074809 A JPS6074809 A JP S6074809A JP 18257183 A JP18257183 A JP 18257183A JP 18257183 A JP18257183 A JP 18257183A JP S6074809 A JPS6074809 A JP S6074809A
- Authority
- JP
- Japan
- Prior art keywords
- parallel
- ringing
- waveform
- low
- pass filter
- 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
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H7/00—Multiple-port networks comprising only passive electrical elements as network components
- H03H7/01—Frequency selective two-port networks
- H03H7/17—Structural details of sub-circuits of frequency selective networks
- H03H7/1741—Comprising typical LC combinations, irrespective of presence and location of additional resistors
- H03H7/1766—Parallel LC in series path
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H7/00—Multiple-port networks comprising only passive electrical elements as network components
- H03H7/01—Frequency selective two-port networks
- H03H7/06—Frequency selective two-port networks including resistors
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H7/00—Multiple-port networks comprising only passive electrical elements as network components
- H03H7/01—Frequency selective two-port networks
- H03H7/075—Ladder networks, e.g. electric wave filters
Abstract
Description
【発明の詳細な説明】
（１）発明の技術分野
本発明は複数のＬＯ並列共振回路を直列に接続し、かつ
該各共振回路間に並列にキャパシタを設けた波形伝送用
低域通過フィルタにおいて、通過波形に発生するリンギ
ングを減少させる改善に関するものである。Detailed Description of the Invention (1) Technical Field of the Invention The present invention relates to a low-pass filter for waveform transmission in which a plurality of LO parallel resonant circuits are connected in series and a capacitor is provided in parallel between each of the resonant circuits. , which relates to improvements that reduce ringing that occurs in passing waveforms.
（２）従来技術と問題点
従来、１７画像等の波形伝送用の低域通過フィルタ（Ｌ
ＰＦ）として第１図に１例を示すように、インダクタン
スと容量の組合せＬｌｃｌ、 Ｌ２０２． Ｌ３０３よ
シ成るＬＯ並列共振回路１，２．３を直列に接続し、か
つこれらの共振回路１．２．３の両側と各間にそれぞれ
π形となるように容量（キャパシタ） ０４〜Ｃ７を並
列に接続したフィルタ回路が用いられる。(2) Conventional technology and problems Conventionally, 17 low-pass filters (L
PF), as shown in FIG. 1, a combination of inductance and capacitance Llcl, L202. The LO parallel resonant circuits 1, 2.3 consisting of L303 are connected in series, and capacitors 04 to C7 are connected on both sides of these resonant circuits 1.2.3 and between each to form a π-shape. Filter circuits connected in parallel are used.
通常このフィルタ回路の後段には遅延等化器が用いられ
、遮断周波数特性の改善が図られている。Usually, a delay equalizer is used at the subsequent stage of this filter circuit to improve cut-off frequency characteristics.
しかし、７７画像周波数帯域で使用する場合、同図＜ｂ
＞に示すように、同図（α）のＬＰＦ回路に対しパルス
波形を通過させた場合、波形の立上シ、立下ル部分に振
幅の数チに及ぶ「ヒゲ」が生じ画像を埋けさせる現象が
起る。これを−リンギングと称している。このリンギン
グには遮断周波数近傍の特性が大きな関係をもつことが
知られているので、前述の後段に用いる遅延等化器の特
性改善に専ら力が注がれた。しかし、これにも限度があ
如４〜５チ程度のリンギングの発生はやむを得なかった
。However, when used in the 77 image frequency band,
> As shown in the figure (α), when a pulse waveform is passed through the LPF circuit shown in the same figure (α), “whiskers” with several amplitudes occur in the rising and falling portions of the waveform, burying the image. A phenomenon occurs that causes This is called -ringing. Since it is known that the characteristics near the cut-off frequency have a large relationship to this ringing, much effort has been devoted to improving the characteristics of the delay equalizer used in the latter stage mentioned above. However, there is a limit to this, and the occurrence of ringing of about 4 to 5 inches is unavoidable.
（３）発明の目的
本発明の目的は通過波形に発生するリンギングを減少さ
せた波形伝送用低域通過フィルタを提供することである
。(3) Purpose of the Invention An object of the present invention is to provide a low-pass filter for waveform transmission that reduces ringing that occurs in a passed waveform.
（４）発明の構成
前記目的を達成するため、波形伝送用低域通過フィルタ
は複数のＬＯ並列共振回路を直列に接続し、かつ該各共
振回路間にキャパシタを設けた波形伝送用低域通過フィ
ルタにおいて、選択された前記ＬＯ並列共振回路内のり
、Ｏと並列に所定値の抵抗を接続したことを特徴とする
ものである。(4) Structure of the Invention In order to achieve the above-mentioned object, a low-pass filter for waveform transmission has a plurality of LO parallel resonant circuits connected in series, and a capacitor provided between each of the resonant circuits. The filter is characterized in that a resistor of a predetermined value is connected in parallel with the selected LO parallel resonant circuit.
（５）発明の実施例
本発明では遮断周波数近傍の損失が大きいとリンギング
が小さくなることに着目したものである。(5) Embodiments of the Invention The present invention focuses on the fact that when the loss near the cutoff frequency is large, the ringing becomes small.
しかしこの損失を大きくすると遮断特性が低下するから
、これを許容範囲に留め、できるだけリンギングを減少
するようにしたものである。However, if this loss is increased, the cutoff characteristics deteriorate, so this is kept within an allowable range and ringing is reduced as much as possible.
第２図は本発明の実施例の構成説明図である。FIG. 2 is an explanatory diagram of the configuration of an embodiment of the present invention.
同図において、第１図の従来例と異なる点は、ＬＣ並列
共振回路のうち選択された共振回路１１．１２に示すよ
うに、第１図の共振回路１，２に対しり、０と並列にそ
れぞれ抵抗Ｒ１＋ Ｒ２を接続したものである、これに
よシフィルタ特性を低下させることなくりンギングをか
なシ減少させることができる。In the figure, the difference from the conventional example in Figure 1 is that, as shown in the resonant circuits 11 and 12 selected from the LC parallel resonant circuits, the resonant circuits 1 and 2 in Figure 1 are parallel to 0. By this, ringing can be significantly reduced without deteriorating the filter characteristics.
第３図はＴＶ画像波形に用いるＬＰＦの損失特性の１例
を示すものである。■は従来例に、■は本発明に対応す
るもので、第１段と第２段の共振回路の共振点が抵抗接
続によシ降下している特性を示している。さらに本発明
の場合、遮断周波数近傍では■は■よシ緩傾斜となシ損
失が大きくなっているが、これがリンギングを減少させ
る効果を有する。FIG. 3 shows an example of loss characteristics of an LPF used for TV image waveforms. (2) corresponds to the conventional example, and (2) corresponds to the present invention, showing a characteristic in which the resonance points of the first and second stage resonant circuits are lowered due to the resistance connection. Furthermore, in the case of the present invention, near the cut-off frequency, (2) has a gentler slope than (2), and the loss is larger, but this has the effect of reducing ringing.
第４図と第５図は第６図の遮断周波数近傍のそれぞれの
損失と遅延特性の詳細説明図である。4 and 5 are detailed explanatory diagrams of respective loss and delay characteristics in the vicinity of the cutoff frequency in FIG. 6.
両図において、■は従来例の抵抗のない場合、［有］は
第１段の共振回路にＲ１”’： Ｉ ＫΩを入れた場合
、■は第１段、第２段の共振回路にルー２にΩ＋ Ｒ２
” ２ ＫΩを入れた場合の特性を示したものである。In both figures, ■ indicates the case without a conventional resistor, [with] indicates that R1'': I KΩ is inserted in the first stage resonant circuit, and ■ indicates that the loop is connected to the first and second stage resonant circuits. 2 to Ω + R2
” This shows the characteristics when 2 KΩ is inserted.
これによシ■の場合リンギングを■に比して２０’％以
上減少することができ、実際の画面上ではかな多画像の
ほけ現象を改善することができる。しかも遮断特性と−
してはこの程度に低下させても実用上支障がない。As a result, ringing can be reduced by more than 20'% in case of (2) compared to (2), and the blurring phenomenon of kana multi-images on an actual screen can be improved. Moreover, the blocking characteristics and −
Even if it is reduced to this extent, there is no practical problem.
（６）発明の詳細
な説明したように、本発明によれば、選択されたＬＯ並
列共振回路内、のり、Ｏと並列に所定の抵抗を接続する
ことによシ、遮断特性の許容範囲でリンギングを減少す
ることを図ったものである。(6) As described in detail, according to the present invention, by connecting a predetermined resistor in parallel with the glue and O in the selected LO parallel resonant circuit, the cutoff characteristics can be maintained within the allowable range. This is intended to reduce ringing.
従来遅延等化器の改善では限界とされていたリンギング
の大きさをかなシ減少し得て画質改善に役立つものであ
る。It is possible to significantly reduce the magnitude of ringing, which has been considered a limit in conventional delay equalizer improvements, and is useful for improving image quality.
第１図（α） 、 （６）は従来例の構成と問題点の説
明図、第２図は本発明の実施例の構成説明図、第３図は
従来例と比較して示す本発明の実施例の特性図、第４図
と第５図は本発明の要部の特性の詳細説明図であシ、図
中１．２，５，１１．１２はＬＯ並列共振回路、Ｌｌ”
”ＩＩ３はインダクタンス、０１〜０７はキャパシタ、
Ｒ１＋ Ｒ２は抵抗を示す。
特許出願人富士通株式会社
復代理人 弁理士 １）坂 善 重
第１図
（ａ）
第２図Figures 1 (α) and (6) are explanatory diagrams of the configuration and problems of the conventional example, Figure 2 is an explanatory diagram of the configuration of the embodiment of the present invention, and Figure 3 is a diagram showing the configuration of the present invention in comparison with the conventional example. The characteristic diagrams of the embodiment, FIG. 4 and FIG. 5 are detailed explanatory diagrams of the characteristics of the main parts of the present invention. In the diagram, 1.2, 5, 11.12 are LO parallel resonant circuits,
"II3 is an inductance, 01 to 07 are capacitors,
R1+R2 represents resistance. Patent applicant Fujitsu Ltd. Sub-agent Patent attorney 1) Yoshishige Saka Figure 1 (a) Figure 2
Claims (1)
回路間に並列にキャパシタを設けた波形伝送用低域通過
フィルタにおいて、選択された前記ＬＯ並列共振回路内
のり、０と並列に所定値の抵抗を接続したことを特徴と
する波形伝送用低域通過フィルタ。In a low-pass filter for waveform transmission in which a plurality of LO parallel resonant circuits are connected in series and a capacitor is provided in parallel between each of the resonant circuits, a predetermined value is set in parallel with zero in the selected LO parallel resonant circuit. A low-pass filter for waveform transmission characterized by connecting a resistor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18257183A JPS6074809A (en) | 1983-09-30 | 1983-09-30 | Low-pass filter for transmission of waveform |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18257183A JPS6074809A (en) | 1983-09-30 | 1983-09-30 | Low-pass filter for transmission of waveform |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS6074809A true JPS6074809A (en) | 1985-04-27 |
Family
ID=16120601
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP18257183A Pending JPS6074809A (en) | 1983-09-30 | 1983-09-30 | Low-pass filter for transmission of waveform |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6074809A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4918591A (en) * | 1987-09-18 | 1990-04-17 | Euchner & Co. | High frequency interference suppression filter for circuits to be connected to a conductor |
| US5015975A (en) * | 1988-08-19 | 1991-05-14 | Murata Manufacturing Co., Ltd. | Noise filter |
| WO2009106628A1 (en) * | 2008-02-29 | 2009-09-03 | Nujira Limited | Improved filter for switched mode power supply |
-
1983
- 1983-09-30 JP JP18257183A patent/JPS6074809A/en active Pending
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4918591A (en) * | 1987-09-18 | 1990-04-17 | Euchner & Co. | High frequency interference suppression filter for circuits to be connected to a conductor |
| US5015975A (en) * | 1988-08-19 | 1991-05-14 | Murata Manufacturing Co., Ltd. | Noise filter |
| WO2009106628A1 (en) * | 2008-02-29 | 2009-09-03 | Nujira Limited | Improved filter for switched mode power supply |
| CN102067444A (en) * | 2008-02-29 | 2011-05-18 | 努吉拉有限公司 | Improved filter for switched mode power supply |
| US8879284B2 (en) | 2008-02-29 | 2014-11-04 | Nujira Limited | Filter for switched mode power supply |
| US9608445B2 (en) | 2008-02-29 | 2017-03-28 | Snaptrack, Inc. | Filter for switched mode power supply |
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