JPH036035Y2 - - Google Patents
Info
- Publication number
- JPH036035Y2 JPH036035Y2 JP13838286U JP13838286U JPH036035Y2 JP H036035 Y2 JPH036035 Y2 JP H036035Y2 JP 13838286 U JP13838286 U JP 13838286U JP 13838286 U JP13838286 U JP 13838286U JP H036035 Y2 JPH036035 Y2 JP H036035Y2
- Authority
- JP
- Japan
- Prior art keywords
- voltage
- operational amplifier
- switch
- sweep
- output
- 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 11
- 238000010586 diagram Methods 0.000 description 5
- 238000001228 spectrum Methods 0.000 description 2
- 239000013078 crystal Substances 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000010408 sweeping Methods 0.000 description 1
Landscapes
- Amplifiers (AREA)
Description
【考案の詳細な説明】
「産業上の利用分野」
この考案は例えばスペクトラムアナライザの電
圧制御発振器に掃引電圧を供給する掃引電圧発生
回路に関し、特に測定目的に応じてステツプ型の
掃引電圧、又は直線型の掃引電圧の両方を発生で
きるようにしたものである。[Detailed description of the invention] "Industrial application field" This invention relates to a sweep voltage generation circuit that supplies a sweep voltage to a voltage controlled oscillator of a spectrum analyzer, for example. It is designed to be able to generate both types of sweep voltages.
「従来技術の説明」
第３図Ａ及び第４図Ａに従来の掃引電圧発生回
路の回路図を示す。"Description of Prior Art" FIGS. 3A and 4A are circuit diagrams of conventional sweep voltage generation circuits.
第３図Ａは、非反転入力端子が接地され、出力
端子と反転入力端子との間に帰還用抵抗器４が接
続された演算増幅器２の反転入力端子に、可変電
圧源１から入力抵抗器３を通じて電圧を供給する
ようにしたものである。この電圧を順次変化させ
ていくことにより、出力端子５から第３図Ｂに示
すステツプ状の電圧波形を得、これを例えばスペ
クトラムアナライザの電圧制御発振器に供給し
て、その発振周波数をステツプ状に変化させるよ
うにしたものである。このステツプ状の電圧波形
は、被測定信号の周波数特性を精度良く測定しよ
うとする時は、有効である。しかしこの変化は比
較的低速であるため、被測定信号の広帯域にわた
るおおよその周波数特性を測定しようとするため
に高速掃引させるのには使用できないという欠点
がある。またこのステツプ状の掃引電圧は、例え
ば水晶発振器の振幅特性など、振幅がある周波数
で急激に変化するものの測定には用いることがで
きない。 In FIG. 3A, an input resistor is connected from a variable voltage source 1 to an inverting input terminal of an operational amplifier 2 whose non-inverting input terminal is grounded and a feedback resistor 4 is connected between the output terminal and the inverting input terminal. Voltage is supplied through 3. By sequentially changing this voltage, a step voltage waveform as shown in FIG. It was designed to change. This step-like voltage waveform is effective when attempting to accurately measure the frequency characteristics of a signal under test. However, since this change is relatively slow, it has the disadvantage that it cannot be used for high-speed sweeping in order to measure the approximate frequency characteristics of the signal under test over a wide band. Furthermore, this step-like sweep voltage cannot be used to measure things whose amplitude changes rapidly at a certain frequency, such as the amplitude characteristics of a crystal oscillator.
第４図Ａは非反転入力端子が接地され、出力端
子と反転入力端子との間にコンデンサ６、及びリ
セツト用抵抗器８とスイツチ７の直列回路が並列
に接続された演算増幅器２の反転入力端子に、可
変電圧源１から入力抵抗器３を通じて電圧を供給
するようにしたものである。通常、スイツチ７は
開かれており、出力端子５から出力される電圧は
可変電圧源１の設定電圧に対応した勾配で増加し
ていく。そして出力電圧が所定の値に達した時、
スイツチ７を閉じてコンデンサ６に蓄積された電
荷をリセツト用抵抗器８を通じて出力電圧を初期
値に戻す。その後再びスイツチ７を開いて可変電
圧源１の出力電圧を積分することにより、第４図
Ｂに示す直線型の掃引電圧を発生させるようにし
たものである。この直線型の掃引電圧は被測定信
号を広帯域にわたり連続的に周波数特性を測定す
るのに有効であるが、特定の周波数における周波
数特性を高精度に測定できないという欠点があ
る。 Figure 4A shows the inverting input of an operational amplifier 2 whose non-inverting input terminal is grounded and a capacitor 6 and a series circuit of a reset resistor 8 and a switch 7 are connected in parallel between the output terminal and the inverting input terminal. A voltage is supplied to the terminal from a variable voltage source 1 through an input resistor 3. Normally, the switch 7 is open, and the voltage output from the output terminal 5 increases with a slope corresponding to the set voltage of the variable voltage source 1. And when the output voltage reaches a predetermined value,
The switch 7 is closed and the charge accumulated in the capacitor 6 is passed through the reset resistor 8 to return the output voltage to its initial value. Thereafter, the switch 7 is opened again and the output voltage of the variable voltage source 1 is integrated, thereby generating the linear sweep voltage shown in FIG. 4B. Although this linear sweep voltage is effective for continuously measuring the frequency characteristics of the signal under test over a wide band, it has the disadvantage that the frequency characteristics at a specific frequency cannot be measured with high precision.
また第４図Ａの回路でコンデンサ６の放電時間
を短くするために、帰還用抵抗器４として抵抗値
のかなり小さなものを用いなければならない。従
つてこの回路で第３図のようにステツプ型の電圧
波形を発生しようとすると、抵抗器３の抵抗値も
小さくしなければならないが、それに伴つてコン
デンサ６の容量を大きくするか、又は可変電圧源
１の出力電圧小さくしなければいけない。通常コ
ンデンサ６としてフイルムコンデンサを使用して
いるが、容量を大きくしなければいけない場合、
他のコンデンサを使用しなければならず、外形が
大きくなると共に、高価になるという欠点があ
る。また可変電圧源１の出力電圧を小さくした場
合、リーク電流やオフセツト電圧の影響を受け、
精度良く測定できなくなるという欠点を生ずる。 Further, in order to shorten the discharge time of the capacitor 6 in the circuit shown in FIG. 4A, it is necessary to use a feedback resistor 4 having a considerably small resistance value. Therefore, if this circuit is to generate a step-type voltage waveform as shown in Figure 3, the resistance value of resistor 3 must also be reduced, but the capacitance of capacitor 6 must be increased accordingly, or a variable The output voltage of voltage source 1 must be reduced. A film capacitor is normally used as capacitor 6, but if the capacitance needs to be increased,
The disadvantage is that another capacitor must be used, the size is large, and the cost is high. Also, when the output voltage of variable voltage source 1 is reduced, it is affected by leakage current and offset voltage,
This has the disadvantage that accurate measurements cannot be made.
「問題点を解決するための手段」
この考案による掃引電圧発生回路は、可変電圧
源を入力抵抗器を通じて演算増幅器の反転入力端
子に接続し、この演算増幅器の反転入力端子と出
力端子との間にコンデンサ、及び帰還抵抗器とス
イツチの直列回路を並列に接続すると共に、演算
増幅器の出力電圧を初期電圧に戻すリセツト手段
を設ける。そして直線型の掃引電圧を発生する時
は上記スイツチを開いて可変電圧源の出力電圧を
積分する。ステツプ型の掃引電圧を発生する時は
上記スイツチを閉じて、可変電圧源の出力電圧を
変化させていく。また演算増幅器の出力電圧が所
定値に達して初期電圧に戻す時は、上記リセツト
手段を動作させるようにしたものである。"Means for solving the problem" The sweep voltage generation circuit according to this invention connects a variable voltage source to the inverting input terminal of an operational amplifier through an input resistor, and connects the inverting input terminal and output terminal of the operational amplifier. A capacitor and a series circuit of a feedback resistor and a switch are connected in parallel to each other, and a reset means is provided for returning the output voltage of the operational amplifier to the initial voltage. When generating a linear sweep voltage, the switch is opened to integrate the output voltage of the variable voltage source. When generating a step type sweep voltage, the above switch is closed and the output voltage of the variable voltage source is varied. Further, when the output voltage of the operational amplifier reaches a predetermined value and is returned to the initial voltage, the reset means is operated.
「実施例」
第１図にこの考案の一実施例である掃引電圧発
生回路の回路図を示す。可変電圧源１は入力抵抗
器３を通じて、また可変電圧源１と逆極性の電圧
源１０は第二スイツチ７及びリセツト用抵抗器８
を通じて演算増幅器２の反転入力端子に接続され
ている。また演算増幅器２の出力端子と反転入力
端子との間にはコンデンサ６、及び帰還抵抗器４
と第一スイツチ９の直列回路が並列に接続されて
いる。Embodiment FIG. 1 shows a circuit diagram of a sweep voltage generation circuit which is an embodiment of this invention. The variable voltage source 1 is connected through an input resistor 3, and the voltage source 10 with the opposite polarity to the variable voltage source 1 is connected to a second switch 7 and a reset resistor 8.
It is connected to the inverting input terminal of the operational amplifier 2 through the inverting input terminal of the operational amplifier 2. Further, a capacitor 6 and a feedback resistor 4 are connected between the output terminal and the inverting input terminal of the operational amplifier 2.
and the first switch 9 are connected in parallel.
この回路において直線型の掃引電圧を発生する
時は、第一スイツチ９及び第二スイツチ７を開い
て積分回路を構成し、可変電圧源１の出力電圧を
積分する。そして演算増幅器２の出力電圧が出力
モード変更点Vaに達して直線型の掃引電圧から
ステツプ型の掃引電圧に切り換える時は、第一ス
イツチ９を閉じる。同時に可変電圧源１の出力電
圧をVa×R1／R2に設定する。ここでR1、R2はそ
れぞれ入力抵抗器３、帰還抵抗器４の抵抗値であ
る。以後、所定のステツプで可変電圧源１の出力
電圧を増加させていく。演算増幅器２の出力電圧
が出力モード変更点Vbに達してステツプ型の掃
引電圧から直線型の掃引電圧に切り換える時は第
一スイツチ９を開く。同時に可変電圧源１の出力
電圧を、上記掃引電圧の変化率に対応した電圧に
設定して積分を行う。演算増幅器２の出力電圧が
最終値に達した時、第一スイツチ９を開くと共
に、第二スイツチ７を閉じる。そして電圧源１０
から可変電圧源１の出力電圧と逆極性の電圧を供
給して、演算増幅器２の出力電圧を減少させてい
く。演算増幅器２の出力電圧が初期電圧に戻つた
時、第二スイツチ７を開き、再び上記のように直
線型又はステツプ型の掃引電圧を発生させる。 When a linear sweep voltage is generated in this circuit, the first switch 9 and the second switch 7 are opened to form an integrating circuit, and the output voltage of the variable voltage source 1 is integrated. When the output voltage of the operational amplifier 2 reaches the output mode change point Va and the linear sweep voltage is switched to the step sweep voltage, the first switch 9 is closed. At the same time, the output voltage of variable voltage source 1 is set to Va×R 1 /R 2 . Here, R 1 and R 2 are the resistance values of the input resistor 3 and feedback resistor 4, respectively. Thereafter, the output voltage of the variable voltage source 1 is increased in predetermined steps. When the output voltage of the operational amplifier 2 reaches the output mode change point Vb and the step type sweep voltage is switched to the linear type sweep voltage, the first switch 9 is opened. At the same time, the output voltage of the variable voltage source 1 is set to a voltage corresponding to the rate of change of the sweep voltage, and integration is performed. When the output voltage of the operational amplifier 2 reaches the final value, the first switch 9 is opened and the second switch 7 is closed. and voltage source 10
A voltage having a polarity opposite to the output voltage of the variable voltage source 1 is supplied from the variable voltage source 1 to reduce the output voltage of the operational amplifier 2. When the output voltage of the operational amplifier 2 returns to the initial voltage, the second switch 7 is opened and a linear or step type sweep voltage is generated again as described above.
また第２図にこの考案の他の実施例を示す。こ
れは第１図のように電圧源１０を設けてこの電圧
源１０と演算増幅器２の反転入力端子との間に第
二スイツチ７とリセツト用抵抗器８の直列回路を
接続する代わりに、この直列回路を演算増幅器２
の出力端子と反転入力端子との間に接続したもの
である。リセツト用抵抗器８としては抵抗値の小
さいものを用いる。直線型の掃引電圧又はステツ
プ型の掃引電圧を発生する方法は第１図の回路と
同じである。演算増幅器２の出力電圧をリセツト
する時は、第二スイツチ７を閉じる。この時、コ
ンデンサ６に蓄積された電荷は抵抗値の小さいリ
セツト用抵抗器８を通じて急速に放電される。そ
して演算増幅器２の出力電圧が初期電圧に戻つた
時、第二スイツチ７を開いて直線型又はステツプ
型の掃引電圧を発生させる。 FIG. 2 shows another embodiment of this invention. This is done instead of providing a voltage source 10 and connecting a series circuit of a second switch 7 and a reset resistor 8 between this voltage source 10 and the inverting input terminal of the operational amplifier 2 as shown in FIG. Series circuit operational amplifier 2
is connected between the output terminal and the inverting input terminal. As the reset resistor 8, one with a small resistance value is used. The method of generating a linear sweep voltage or a step sweep voltage is the same as in the circuit of FIG. When resetting the output voltage of the operational amplifier 2, the second switch 7 is closed. At this time, the charge accumulated in the capacitor 6 is rapidly discharged through the reset resistor 8 having a small resistance value. When the output voltage of the operational amplifier 2 returns to the initial voltage, the second switch 7 is opened to generate a linear or step type sweep voltage.
「考案の効果」
以上説明したようにこの考案による掃引電圧発
生回路は、スイツチと可変電圧源の簡単な操作に
より直線型の掃引電圧、ステツプ型の掃引電圧を
混合して発生することができる。従つてこの掃引
電圧発生回路を例えばスペクトラムアナライザに
用いることにより、被測定信号を広帯域にわたつ
て表示できると同時に、特定の帯域の周波数特性
を高精度に表示できる。``Effects of the Invention'' As explained above, the sweep voltage generation circuit according to this invention can mix and generate a linear sweep voltage and a step sweep voltage by simple operation of a switch and a variable voltage source. Therefore, by using this sweep voltage generating circuit in, for example, a spectrum analyzer, it is possible to display the signal under test over a wide band, and at the same time, it is possible to display the frequency characteristics of a specific band with high precision.
第１図及び第２図はこの考案による掃引電圧発
生回路の回路図、第３図Ａ及び第４図Ａは従来の
掃引電圧発生回路の回路図、第３図Ｂは第３図Ａ
の掃引電圧発生回路から発生する掃引電圧を示す
グラフ、第４図Ｂは第４図Ａの掃引電圧発生回路
から発生する掃引電圧を示すグラフである。
1 and 2 are circuit diagrams of a sweep voltage generation circuit according to this invention, FIGS. 3A and 4A are circuit diagrams of a conventional sweep voltage generation circuit, and FIG. 3B is a circuit diagram of a conventional sweep voltage generation circuit.
FIG. 4B is a graph showing the sweep voltage generated from the sweep voltage generation circuit of FIG. 4A.
Claims (1)
の反転入力端子と該可変電圧源との間に接続さ
れた入力抵抗器と、上記演算増幅器の反転入力
端子と出力端子との間に接続されたコンデンサ
とから成る積分回路と、 Ｂ 上記コンデンサに並列に接続された帰還抵抗
器とスイツチとから成る直列回路と、 Ｃ 上記演算増幅器の出力電圧を初期電圧にリセ
ツトするリセツト手段と、 を具備し、上記演算増幅器から直線型の掃引電圧
を出力する時は上記スイツチを開き、ステツプ型
の掃引電圧を出力する時は上記スイツチを閉じて
上記可変電圧源の出力電圧を順次変化させていく
と共に、演算増幅器の出力電圧が所定値に達した
時、上記リセツト手段を動作させて初期電圧に戻
すようにしたことを特徴とする掃引電圧発生回
路。[Claims for Utility Model Registration] A: an operational amplifier, a variable voltage source, an input resistor connected between the inverting input terminal of the operational amplifier and the variable voltage source, and the inverting input terminal of the operational amplifier; B. A series circuit consisting of a feedback resistor and a switch connected in parallel to the capacitor; C. Resets the output voltage of the operational amplifier to the initial voltage. and a reset means for opening the switch when outputting a linear sweep voltage from the operational amplifier and closing the switch when outputting a step sweep voltage, thereby adjusting the output voltage of the variable voltage source. 1. A sweep voltage generating circuit characterized in that when the output voltage of the operational amplifier reaches a predetermined value, the reset means is operated to return the voltage to the initial voltage.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13838286U JPH036035Y2 (en) | 1986-09-09 | 1986-09-09 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13838286U JPH036035Y2 (en) | 1986-09-09 | 1986-09-09 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6344531U JPS6344531U (en) | 1988-03-25 |
| JPH036035Y2 true JPH036035Y2 (en) | 1991-02-15 |
Family
ID=31043312
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP13838286U Expired JPH036035Y2 (en) | 1986-09-09 | 1986-09-09 |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH036035Y2 (en) |
-
1986
- 1986-09-09 JP JP13838286U patent/JPH036035Y2/ja not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6344531U (en) | 1988-03-25 |
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