JPS6342745Y2 - - Google Patents
Info
- Publication number
- JPS6342745Y2 JPS6342745Y2 JP108080U JP108080U JPS6342745Y2 JP S6342745 Y2 JPS6342745 Y2 JP S6342745Y2 JP 108080 U JP108080 U JP 108080U JP 108080 U JP108080 U JP 108080U JP S6342745 Y2 JPS6342745 Y2 JP S6342745Y2
- Authority
- JP
- Japan
- Prior art keywords
- fdnr
- filter
- type filter
- circuit
- resistance value
- 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.)
- Expired
Links
- 239000003990 capacitor Substances 0.000 claims description 9
- 230000006866 deterioration Effects 0.000 claims description 4
- 230000005540 biological transmission Effects 0.000 claims 1
- 238000010586 diagram Methods 0.000 description 4
- 230000001419 dependent effect Effects 0.000 description 1
Landscapes
- Networks Using Active Elements (AREA)
Description
【考案の詳細な説明】
この考案はフイルタの中の周波数依存性負性抵
抗（Frequency Dependent Negative
Resistance）形フイルタ（以下FDNR形フイル
タと称す）に係り、特にその低域特性の改良に関
する。[Detailed explanation of the invention] This invention is based on the Frequency Dependent Negative resistance in the filter.
This invention relates to FDNR-type filters (hereinafter referred to as FDNR-type filters), and particularly to improvements in their low-frequency characteristics.
FDNR形フイルタはその一回路例を第１図に
示すが、全体として３次の低域通過フイルタ
（LPF）を形成している。そして、このFDNR形
フイルタの基本は第２図に示すLCフイルタであ
り、このLCフイルタの各素子を演算子ｓ（ｓ＝
jω，ω＝2πf）で割つたものが第１図の回路であ
る。第１図と第２図とを比較して分るように、抵
抗がコンデンサに、コイルが抵抗に、そしてコン
デンサがFDNR回路D1にそれぞれ変換されてい
る。FDNR回路D1は、コンデンサC1を演算子ｓ
で割つたものと等価でなければならず、具体的に
は第３図に示すような回路が知られている。な
お、第３図でＡはアンプである。なお、この第１
図に示されたFDNR形フイルタに使用される抵
抗値はR2，R4が500Ω〜5KΩ、R3が100Ω〜5KΩ
位の値である。 An example of the circuit of the FDNR filter is shown in FIG. 1, and the filter as a whole forms a third-order low-pass filter (LPF). The basis of this FDNR type filter is the LC filter shown in Figure 2, and each element of this LC filter is defined by the operator s (s=
The circuit shown in Fig. 1 is obtained by dividing by jω, ω = 2πf). As can be seen by comparing FIG. 1 and FIG. 2, the resistor has been converted into a capacitor, the coil into a resistor, and the capacitor into an FDNR circuit D1 . FDNR circuit D 1 connects capacitor C 1 to operator s
Specifically, a circuit as shown in FIG. 3 is known. In addition, in FIG. 3, A is an amplifier. Note that this first
The resistance values used in the FDNR type filter shown in the figure are R 2 and R 4 of 500Ω to 5KΩ, and R 3 of 100Ω to 5KΩ.
It is the value of place.
このようなFDNR形フイルタは第１図から分
るように入出力端子がコンデンサＣによつて終端
されているために、第４図に示すような特性が得
られる。すなわち、破線で示すフイルタの設計特
性２１に対して、実線で示す得られた実特性２２
の低周波数領域での特性が劣化している。 As can be seen from FIG. 1, the input and output terminals of such an FDNR type filter are terminated by a capacitor C, so that characteristics as shown in FIG. 4 are obtained. That is, the design characteristic 21 of the filter is shown by a broken line, whereas the obtained actual characteristic 22 is shown by a solid line.
The characteristics in the low frequency range are deteriorated.
以上で説明したように、FDNR形フイルタに
は、低周波数領域（設計特性によつて異なるが数
百Hz以下）での周波数特性が劣化するという欠点
があつた。 As explained above, the FDNR type filter had the drawback that the frequency characteristics deteriorated in the low frequency region (several hundred Hz or less, depending on the design characteristics).
この考案は上記のような従来のものの欠点を除
去するためになされたもので、入出力端子の終端
コンデンサに抵抗を並列に付加することで、周波
数特性の劣化を補正したFDNR形フイルタを提
供することを目的としている。 This idea was made to eliminate the drawbacks of the conventional filters as described above, and provides an FDNR type filter that corrects the deterioration of frequency characteristics by adding a resistor in parallel to the terminal capacitor of the input and output terminals. The purpose is to
以下、この考案の実施例について、第５図を参
照して説明する。同図において、R31とR35とは
第１図に示す基本回路に本考案の目的のために付
加された抵抗である。これらの抵抗に対する条件
は、基本回路には無い素子であるので基本回路に
使用される抵抗の抵抗値に比べて特性に影響を与
えない程度に大きい抵抗値であること、及び抵抗
値のバラツキを考慮しながらR35の値をR31に対
して数％程度故意に大きくすることの２点であ
る。R31＝R35の場合の周波数特性は改善されな
い。上記の２つの条件を満足する抵抗を選択すれ
ば、FDNR形フイルタの低域特性の劣化を第４
図破線２１のように補正でき理想的な特性を有す
るFDNR形フイルタを得ることができる。 An embodiment of this invention will be described below with reference to FIG. In the figure, R 31 and R 35 are resistors added to the basic circuit shown in FIG. 1 for the purpose of the present invention. The conditions for these resistors are that since they are elements that are not present in the basic circuit, they must have a resistance value that is large enough not to affect the characteristics compared to the resistance value of the resistor used in the basic circuit, and that variations in resistance values must be minimized. The two points are to intentionally increase the value of R 35 by several percent compared to R 31 while taking this into consideration. The frequency characteristics in the case of R 31 =R 35 are not improved. If you select a resistor that satisfies the above two conditions, the deterioration of the low frequency characteristics of the FDNR type filter can be reduced by
It is possible to obtain an FDNR type filter that can be corrected as shown by the broken line 21 in the figure and has ideal characteristics.
具体的な設計例を示せば、コンデンサＣの容量
が10000PFのときR31＝56KΩ，R32＝62KΩであ
つた。また別のフイルタにおいては、Ｃ＝2500P
のときR31＝300KΩ，R32＝315KΩであつた。 To give a specific design example, when the capacitance of capacitor C is 10000PF, R 31 =56KΩ and R32 =62KΩ. In another filter, C=2500P
At that time, R 31 = 300KΩ and R 32 = 315KΩ.
以上のように、この考案によればFDNR形フ
イルタの欠点であつた低域特性での劣化を簡単な
構成により防止することが可能であり、実用効果
の大きいものである。 As described above, according to this invention, it is possible to prevent deterioration in low-frequency characteristics, which was a drawback of the FDNR type filter, with a simple configuration, and it is highly effective in practical use.
第１図はFDNR形フイルタの一回路例を示す
図、第２図はFDNR形フイルタの基本となるLC
フイルタの一例を示す図、第３図はFDNR回路
の一回路例を示す図、第４図はFDNR形フイル
タの周波数特性図、第５図はこの考案の一実施例
を示す回路図である。
なお、図中の符号Ｃはコンデンサ、D1はFD−
NR回路、R1，R2，R3，R31，R35は抵抗である。
Figure 1 shows an example of the circuit of an FDNR type filter, and Figure 2 shows the basic LC of the FDNR type filter.
FIG. 3 is a diagram showing an example of a filter, FIG. 3 is a diagram showing an example of a FDNR circuit, FIG. 4 is a frequency characteristic diagram of an FDNR type filter, and FIG. 5 is a circuit diagram showing an embodiment of this invention. In addition, the symbol C in the figure is a capacitor, and D1 is FD-
In the NR circuit, R 1 , R 2 , R 3 , R 31 , and R 35 are resistors.
Claims (1)
の終端コンデンサの値を同じにするとともに、こ
れらのコンデンサに対して並列にそれぞれ抵抗を
付加し、その抵抗が特性に影響を与えない程大き
な抵抗値であり、かつ出力側の抵抗値を入力側の
抵抗値に対して大きくするという２条件を満足す
るようになし、低域伝達特性の劣化を補正したこ
とを特徴とするFDNR形フイルタ。 In the FDNR type filter, the value of the termination capacitor on the input side and the output side is the same, and a resistor is added in parallel to each of these capacitors, and the resistance value is large enough not to affect the characteristics. An FDNR type filter, characterized in that it satisfies two conditions: , and the resistance value on the output side is made larger than the resistance value on the input side, thereby correcting deterioration of low-frequency transmission characteristics.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP108080U JPS6342745Y2 (en) | 1980-01-09 | 1980-01-09 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP108080U JPS6342745Y2 (en) | 1980-01-09 | 1980-01-09 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS56104232U JPS56104232U (en) | 1981-08-14 |
| JPS6342745Y2 true JPS6342745Y2 (en) | 1988-11-09 |
Family
ID=29597948
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP108080U Expired JPS6342745Y2 (en) | 1980-01-09 | 1980-01-09 |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6342745Y2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6187409A (en) * | 1984-10-03 | 1986-05-02 | Murata Mfg Co Ltd | Frequency variable type low-pass filter |
| FR2909239A1 (en) * | 2006-11-27 | 2008-05-30 | Thomson Licensing Sas | ACTIVE PASS FILTER |
-
1980
- 1980-01-09 JP JP108080U patent/JPS6342745Y2/ja not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| JPS56104232U (en) | 1981-08-14 |
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