JPS6053856A - Noise measuring apparatus - Google Patents

Noise measuring apparatus

Info

Publication number
JPS6053856A
JPS6053856A JP16140983A JP16140983A JPS6053856A JP S6053856 A JPS6053856 A JP S6053856A JP 16140983 A JP16140983 A JP 16140983A JP 16140983 A JP16140983 A JP 16140983A JP S6053856 A JPS6053856 A JP S6053856A
Authority
JP
Japan
Prior art keywords
noise
transistor
switch
input
change
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
Application number
JP16140983A
Other languages
Japanese (ja)
Inventor
Yoshifumi Tatebayashi
舘林 美史
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.)
NEC Corp
Original Assignee
NEC Corp
Nippon Electric 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 NEC Corp, Nippon Electric Co Ltd filed Critical NEC Corp
Priority to JP16140983A priority Critical patent/JPS6053856A/en
Publication of JPS6053856A publication Critical patent/JPS6053856A/en
Pending legal-status Critical Current

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  • Testing Of Individual Semiconductor Devices (AREA)
  • Amplifiers (AREA)

Abstract

PURPOSE:To enable the rapid measurement of noise, by making the change-over operations of an input signal change-over switch and a bias change-over switch same. CONSTITUTION:The collector of a transistor 6 is connected to a voltage source 40 along with the other terminal of a constant current source 10 to constituted a bias power source circuit and the emitter of the transistor 6 is connected to the bases of the transistors 19, 20 of a preamplifier 1 through a switch 12. In this case, the change-over operations of an input signal change-over switch 4 and a bias change-over switch 12 are made same. As a result, by appropriately determining the values of the resistors 7, 8 of a bias power source circuit, the scaleover of a noise meter 36 is eliminated and a noise measuring time can be shortened.

Description

【発明の詳細な説明】 本発明は、入力切換スイッチを備えたプリアンプ等の雑
音測定装置に関するものである。
DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a noise measuring device such as a preamplifier equipped with an input selector switch.

第1図は、従来の雑音測定装置および測定すべきプリア
ンプの回路図である。第1図において、低雑音トランジ
スタ19.20のそれぞれのペースには、入力インピー
ダンスを決定する抵抗13゜14及び2つの入力端子3
2.33のうちどちらの入力を選択するかの切換用スイ
ッチとしてトランジスタ17.38のコレクタが接続さ
れ、さらに、入力信号を印加するためのコンデンサ2,
3が接続される。前記抵抗13と14の他端は共通接続
され、ダイオード15のアノードに接続され、さらに定
電流源16が接続される。ダイオード15のカソード側
は接地雷1位50に接続する。前記トランジスタ19.
20のコl/クタは共通接続され、抵抗27とトランジ
スタ230ペースに接続され、抵抗27の他端は電圧源
40に接続される。トランジスタ23のエミッタは抵抗
28とトランジスタ240ベースに接続され、抵抗28
の他端及びトランジスタ24のエミッタは共に接地電位
50に接続される。トランジスタ23のコレクタとトラ
ンジスタ24のコレクタは接続され、さらに抵抗26と
トランジスタ25のベースも接続されている。抵抗26
の他端とトランジスタ25のコレクタは共に電圧源40
に接続される。トランジスタ25のエミッタは出力端3
1と抵抗22に接続きれ、抵抗22の他端は抵抗21と
トランジスタ20のエミッタに接続されている。
FIG. 1 is a circuit diagram of a conventional noise measuring device and a preamplifier to be measured. In FIG. 1, each of the low noise transistors 19, 20 has a resistor 13, 14 which determines the input impedance and two input terminals 3.
The collectors of transistors 17 and 38 are connected as a switch for selecting which input among 2.33, and furthermore, capacitors 2 and 38 are connected to each other for applying input signals.
3 is connected. The other ends of the resistors 13 and 14 are connected in common, connected to the anode of a diode 15, and further connected to a constant current source 16. The cathode side of the diode 15 is connected to the first earth mine 50. The transistor 19.
The 20 collectors are commonly connected and connected to a resistor 27 and a transistor 230 pace, and the other end of the resistor 27 is connected to a voltage source 40. The emitter of transistor 23 is connected to resistor 28 and the base of transistor 240, and resistor 28
The other end and the emitter of transistor 24 are both connected to ground potential 50 . The collector of the transistor 23 and the collector of the transistor 24 are connected, and the resistor 26 and the base of the transistor 25 are also connected. resistance 26
The other end and the collector of the transistor 25 are both connected to a voltage source 40.
connected to. The emitter of transistor 25 is output terminal 3
The other end of the resistor 22 is connected to the resistor 21 and the emitter of the transistor 20.

かかる構成のプリアンプ1においては、入力端子32.
33のいずれか一方の入力信号、すなわち、切換スイッ
チとしてのトランジスタ17.18のそれぞれのコント
ロール入力端子29.30にコントロール信号が印加さ
れることによって、トランジスタ17.18のいずれか
カットオフしている側の入力信号がトランジスタ19あ
るいハ20のベースに入力される。入力された信号はト
ランジスタ19.20.23.24.25 、抵抗21
゜22.26,27.28から構成されるアンプに入力
され、電圧利得は、抵抗21.22の抵抗値をR21,
R22とすると、約R22/几21倍され出力端31に
出力される。切換時のショック音を和らげるため、本回
路では、切換スイッチトランジスタ17.18のいずれ
か一方がオンの状態からオフの状態になった時、例えば
ここでトランジスタ17がオフになったとすると、入力
抵抗13と、入力コンデ7920時定数により、トラン
ジスタ19のベースがバイアスされるようになる。
In the preamplifier 1 having such a configuration, the input terminals 32.
33, that is, a control signal is applied to each control input terminal 29.30 of the transistor 17.18 as a changeover switch, to cut off one of the transistors 17.18. The input signal on the side is input to the base of the transistor 19 or 20. The input signal is transmitted through transistors 19, 20, 23, 24, 25 and resistor 21.
22.26, 27.28, and the voltage gain is determined by changing the resistance value of resistor 21.22 to R21,
If it is R22, it is multiplied by approximately R22/⇠21 and output to the output terminal 31. In order to reduce the shock noise at the time of switching, in this circuit, when either one of the changeover switch transistors 17 and 18 changes from an on state to an off state, for example, if the transistor 17 is turned off, the input resistance 13 and the input capacitor 7920 time constant causes the base of transistor 19 to be biased.

さらに、vrJI図において、一端が接:IIx電位5
0に接続された信号源抵抗5の他端を、スイッチ4を用
いて入力端子32.33のうち、コントロール入力端子
29.30に印加さtLるコントロール信号によって選
択された側の入力端子に接続されるように切換えて、出
力端子31に出力される雑音を、雑音計36を用いて測
定する。しかし、かかるスイッチ4の切換は、前記で述
べたように、入力抵抗13.14 、結合容[2,3の
時定数で立ち上り時間が決定するため、出力端31に雑
音電圧計36を接続すると目盛がふり切れ°Cしまうの
で雑音が6111定でrするまで時間がかかる。時間を
短縮するため結合容量2.3の答%値を小さくすると、
等測的な信号源の抵抗値が変わっCしまうため、測定価
の値が容量ft&を変えた前後で値が異り1差が太きく
なる。
Furthermore, in the vrJI diagram, one end is connected: IIx potential 5
The other end of the signal source resistor 5 connected to 0 is connected to the input terminal of the input terminal 32.33 selected by the control signal tL applied to the control input terminal 29.30 using the switch 4. Then, the noise output to the output terminal 31 is measured using the noise meter 36. However, as mentioned above, when switching the switch 4, the rise time is determined by the time constants of the input resistance 13, 14 and the coupling capacitance [2, 3]. Since the scale goes off by °C, it takes time for the noise to reach a constant value of 6111°C. If you reduce the answer % value of coupling capacity 2.3 to shorten the time,
Since the resistance value of the isometric signal source changes, the value of the measurement value differs before and after changing the capacitance ft&, and the difference becomes larger by 1.

本発明の目的は、このような、従来回路で雑音の測定を
行うためには測定時間がかかり過ぎるという欠点を改善
し、迅速な測定を可能にした雑音測定装置を提供するこ
とにある。
SUMMARY OF THE INVENTION An object of the present invention is to provide a noise measuring device that can overcome the drawback that it takes too much time to measure noise using a conventional circuit, and can perform quick measurements.

つぎに本発明を実施例により説明する。Next, the present invention will be explained by examples.

第2図は本発明の一実施例と、雑音を測定すべきプリア
ンプを示す回路図である。第2図において、カソードを
接地電位50に接続したダイオード11のアノードは、
抵抗8とダイオード9のカソードに接続し、ダイオード
9のアノードには定電流源10と抵抗7を接続し、抵抗
7と抵抗8は接続し、さらにこの接続点にトランジスタ
6のベースヲ接続し、トランジスタ6のコレクタは定電
流源10の他端と共に電圧源40に接続してバイアス電
源回路を構成し、かかるバイアス電源回路の出力である
トランジスタ6のエミッタはスイッチ12に接続され、
トランジスタ19.20のベースからそれぞれ出した端
子34.35のいずれか一方にスイッチ12で接続され
るようになって5− いる。
FIG. 2 is a circuit diagram showing an embodiment of the present invention and a preamplifier whose noise is to be measured. In FIG. 2, the anode of the diode 11 whose cathode is connected to the ground potential 50 is
A resistor 8 is connected to the cathode of a diode 9, a constant current source 10 and a resistor 7 are connected to the anode of the diode 9, a resistor 7 and a resistor 8 are connected, and the base of a transistor 6 is connected to this connection point. The collector of the transistor 6 is connected to the voltage source 40 together with the other end of the constant current source 10 to form a bias power supply circuit, and the emitter of the transistor 6, which is the output of the bias power supply circuit, is connected to the switch 12.
The terminals 5- are connected by a switch 12 to either one of terminals 34 and 35 extending from the bases of the transistors 19 and 20, respectively.

ここでスイッチ4と12の切換動作を同一にし、今、ト
ランジスタ]7がオン状態からオフ状態になると、トラ
ンジスタ19のベースが抵抗13と入力コンデンサ2の
時定数で持ち上るとすると、この時スイッチ12けトラ
ンジスタ19のペース側に接続し、バイアス電源の出力
で急速に入力コンデンサ2を充電するため、抵抗7,8
の値、すなわちバイアス電源の出力電圧を適切な値に決
定すれば、雑音計36の目盛がふり切れることがないた
め雑音測定時間を短縮できる。
Now, if we make the switching operations of switches 4 and 12 the same and assume that when transistor 7 changes from on to off, the base of transistor 19 is lifted by the time constant of resistor 13 and input capacitor 2. Resistors 7 and 8 are connected to the pace side of the 12-channel transistor 19 to quickly charge the input capacitor 2 with the output of the bias power supply.
If the value of , that is, the output voltage of the bias power supply, is determined to an appropriate value, the scale of the noise meter 36 will not go off, so the noise measurement time can be shortened.

本発明にかかるプリアンプの例として入力抵抗13.1
4は88にΩ、入力コンデンサ2,3は10μFとする
。入力トランジスタ19(又は20)が動作時には、ベ
ースのバイアスは約0.6V、)ランジスタ19(又は
20)がカットオフ時は、ベースのバイアスが約76m
V近辺になる。しかし、トランジスタ19(又は20)
が動作状態時にトランジスタ6はオフ状態にならなけれ
ばならないので、ダイオード9の導通状態での電圧を約
−6= 0.7vとした時、抵抗7,8によってダイオード9の
カソードから0.4 V近辺にバイアスを設定するため
、抵抗値を上記の理由より、R,:R8=7.2にΩ:
10にΩとする。
Input resistance 13.1 as an example of the preamplifier according to the present invention
4 is 88Ω, and input capacitors 2 and 3 are 10 μF. When the input transistor 19 (or 20) is in operation, the base bias is about 0.6V, and when the transistor 19 (or 20) is cut off, the base bias is about 76V.
It will be around V. However, transistor 19 (or 20)
Since the transistor 6 must be in the off state when the transistor 6 is in the operating state, when the voltage when the diode 9 is in the conductive state is approximately -6 = 0.7 V, the voltage from the cathode of the diode 9 is 0.4 V by the resistors 7 and 8. In order to set the bias in the vicinity, the resistance value was set to R:R8=7.2Ω: for the above reason.
Let Ω be 10.

このようにして、雑音の出力端子31に雑音計36を接
続した場合、従来の方法ではメータが振り切れ、雑音測
定値を示すまで4秒かかったが、本発明により、雑音計
36のメータが振り切れることなく2秒程度に押えるこ
とができた。
When the noise meter 36 is connected to the noise output terminal 31 in this way, with the conventional method it took 4 seconds for the meter to break out and indicate the noise measurement value, but with the present invention, the meter of the noise meter 36 I was able to hold it down to about 2 seconds without any problems.

【図面の簡単な説明】[Brief explanation of drawings]

第1図は従来の雑音測定装置と、雑音を測定すべきプリ
アンプの回路図、第2図は本発明の一実施例と雑音を測
定すべきプリアンプの回路図である。 1・・・・・・プリアンプ、2,3・・・・・・入力コ
ンデンサ、4・・・・・・信号源抵抗切換用第1のスイ
ッチ、5・・・・・・信号源抵抗、6・・・・・・バイ
アス回路トランジスタ、7.8−°°・・・バ・イアス
回路分圧抵抗、9.11・・・・・・バイアス回路定電
圧用ダイオード、10・・・・・・定電流源、12・・
・・・・バイアス回路切換用箱2のスイッチ、31・・
・・・・出力端子、32.33・・・・・・入力端子、
36・・・・・・雑音計、40・・・・・・電圧源端子
、50・・・・・・接地電位。
FIG. 1 is a circuit diagram of a conventional noise measuring device and a preamplifier whose noise is to be measured, and FIG. 2 is a circuit diagram of an embodiment of the present invention and a preamplifier whose noise is to be measured. 1... Preamplifier, 2, 3... Input capacitor, 4... First switch for signal source resistance switching, 5... Signal source resistance, 6 ...Bias circuit transistor, 7.8-°°...Bias circuit voltage dividing resistor, 9.11...Bias circuit constant voltage diode, 10... Constant current source, 12...
...Bias circuit switching box 2 switch, 31...
...Output terminal, 32.33...Input terminal,
36... Noise meter, 40... Voltage source terminal, 50... Ground potential.

Claims (1)

【特許請求の範囲】[Claims] 複数の入力信号を切換えるための入力切換スイッチを備
えたプリアンプ等の機器の雑音測定装置において、前記
雑音を測定すべき機器の選択された入力端子に信号源抵
抗を接続するための第1のスイッチ手段と、この第1の
スイッチ手段と連動し、かつ、前記選択された入力端子
の入力コンデンサを急速充電する六、めのバイアス電源
回路の出力を前記入力コンデンサに接続するための第2
のスイッチ手段と、前記機器の出力に接続される雑音計
とを備えたことを特徴とする雑音測定装置。
A first switch for connecting a signal source resistor to a selected input terminal of the device whose noise is to be measured, in a noise measuring device for equipment such as a preamplifier, which is equipped with an input selection switch for switching a plurality of input signals. and a second switch for connecting the output of a sixth bias power supply circuit to the input capacitor, the sixth bias power supply circuit interlocking with the first switch means and for rapidly charging the input capacitor of the selected input terminal.
1. A noise measuring device comprising: a switch means; and a noise meter connected to an output of the device.
JP16140983A 1983-09-02 1983-09-02 Noise measuring apparatus Pending JPS6053856A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP16140983A JPS6053856A (en) 1983-09-02 1983-09-02 Noise measuring apparatus

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP16140983A JPS6053856A (en) 1983-09-02 1983-09-02 Noise measuring apparatus

Publications (1)

Publication Number Publication Date
JPS6053856A true JPS6053856A (en) 1985-03-27

Family

ID=15734540

Family Applications (1)

Application Number Title Priority Date Filing Date
JP16140983A Pending JPS6053856A (en) 1983-09-02 1983-09-02 Noise measuring apparatus

Country Status (1)

Country Link
JP (1) JPS6053856A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0452610U (en) * 1990-09-07 1992-05-06
WO2021246405A1 (en) * 2020-06-01 2021-12-09 国立大学法人大阪大学 Measuring device

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0452610U (en) * 1990-09-07 1992-05-06
WO2021246405A1 (en) * 2020-06-01 2021-12-09 国立大学法人大阪大学 Measuring device

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