JPS61256803A - Voltage controlled oscillator - Google Patents

Voltage controlled oscillator

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Publication number
JPS61256803A
JPS61256803A JP7796386A JP7796386A JPS61256803A JP S61256803 A JPS61256803 A JP S61256803A JP 7796386 A JP7796386 A JP 7796386A JP 7796386 A JP7796386 A JP 7796386A JP S61256803 A JPS61256803 A JP S61256803A
Authority
JP
Japan
Prior art keywords
collector
current source
terminal
transistor
circuit
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
JP7796386A
Other languages
Japanese (ja)
Inventor
Hidekazu Ishii
英一 石井
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
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 filed Critical NEC Corp
Priority to JP7796386A priority Critical patent/JPS61256803A/en
Publication of JPS61256803A publication Critical patent/JPS61256803A/en
Pending legal-status Critical Current

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Abstract

PURPOSE:To obtain a voltage controlled oscillator whose control characteristic has excellent linearity by connecting in common emitters of transistors (TR) whose bases are connected respectively to collectors, to a variable current source and connecting a parallel resonance circuit to the one collector. CONSTITUTION:The emitters of the TRs 1, 2 whose bases are connected respectively to the collectors are connected in common to the variable current source 12. The collector of the TR 1 is connected to a DC power supply terminal 4 and the collector of the TR 1 is connected to a DC power supply terminal 4 and the collector of the TR 2 is connected to the power terminal 4 through the parallel resonance circuit comprising a coil 5 and a capacitor 6. The output of the variable current source 12 is varied depending on the input from a control input terminal 10. Since the oscillating frequency is changed by varying the current of the variable current source 12, no varactor diode is required. Thus, the advantages are given that circuit integration is attained easily and the linearity of the control characteristic of the oscillating frequency is improved.

Description

【発明の詳細な説明】 本発明は電圧制御発振器に関するものである〇従来の技
術の1例を第1図によって説明する。
DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a voltage controlled oscillator. An example of a conventional technique will be explained with reference to FIG.

ベースとコレクタを、それぞれ他のトランジスタのコレ
クタとベースに接続したトランジスタ1.2のエミッタ
を共通接続して電流源8に接続する。トランジスタ1の
コレクタは、直接電源端+4に接続し、トランジスタ2
のコレクタは、コイル5とコンデンサ6からなる並列共
振回路を通して電源端子4に接続する。トランジスタ2
のコレクタからコンデンサ7を通して可変容量ダイオー
ド8に接続し、可変容量ダイオードの反対側はGND(
接地端子)9に接続する。
The emitters of transistors 1.2 whose bases and collectors are connected to the collectors and bases of other transistors, respectively, are connected in common and connected to a current source 8. The collector of transistor 1 is directly connected to the power supply terminal +4, and the collector of transistor 2
The collector of is connected to the power supply terminal 4 through a parallel resonant circuit consisting of a coil 5 and a capacitor 6. transistor 2
The collector of is connected to the variable capacitance diode 8 through the capacitor 7, and the opposite side of the variable capacitance diode is connected to GND (
Connect to ground terminal (ground terminal) 9.

制御入力端子lOから抵抗11を通して、上記コンデン
サ7と可変容量ダイオード8の接続点へ接続する。
The control input terminal IO is connected to the connection point between the capacitor 7 and the variable capacitance diode 8 through the resistor 11.

この電圧制御発振器の発振周波数fa8cはfomc=
%7rfL了C+CD)  −”” (1)で与えられ
る。ただし、C? B CD 、 R,1>> 2Tf
 osc L。
The oscillation frequency fa8c of this voltage controlled oscillator is fomc=
%7rfL C+CD) −”” (1). However, C? B CD , R, 1 >> 2Tf
osc L.

C:コンデンサ6の容量、 cD :可変容量ダイオード8の容量、R11:抵抗1
1の大きさ。
C: capacitance of capacitor 6, cD: capacitance of variable capacitance diode 8, R11: resistor 1
The size of 1.

ここで、可変容量ダイオード8の容tCDは制御入力電
圧によって変化させられるので、発振周波数が変化でき
る。
Here, since the capacitance tCD of the variable capacitance diode 8 is changed by the control input voltage, the oscillation frequency can be changed.

上記のように、従来はコイルとコンデンサで構成される
共振回路を用いた電圧制御発振器では、可変容量ダイオ
ードを用いて発振周波数を変化させていた。しかし、こ
の回路構成では可変容量ダイオードの容量変化幅の大き
さ、制御幅に対する容量変化の直線性、同調容量として
のQ特性が要求されるためコストが高くなシ、又、集積
回路化が困難な回路構成である欠点があった。
As mentioned above, in conventional voltage controlled oscillators using a resonant circuit composed of a coil and a capacitor, a variable capacitance diode was used to change the oscillation frequency. However, this circuit configuration requires a large capacitance change width of the variable capacitance diode, linearity of capacitance change with respect to control width, and Q characteristics as a tuning capacitor, so it is expensive and difficult to integrate. The disadvantage was that the circuit configuration was complicated.

本発明は、これらの欠点を除くため可変容置ダイオード
を用いずに、発振周波数に対して制御特性の直線性がよ
く変化幅がひろく、又、集積回路化するに容易な回路の
電圧制御発振器を構成するものである。
In order to eliminate these drawbacks, the present invention provides a voltage controlled oscillator that does not use a variable capacity diode, has good linearity of control characteristics with respect to the oscillation frequency, has a wide variation range, and is easy to integrate into an integrated circuit. It constitutes.

本発明を因習を用いて説明する。The present invention will be explained using convention.

第2図に示すように、それぞれベースをコレクタに互い
に接続したトランジスタ1.2のエミッタを共通接続し
て可変電流源12に接続する。トランジスタlのコレク
タは、直接電源端子4に接続し、トランジスタ2のコレ
クタは、コイル5とコンデンサ6からなる並列共娠回路
を通して、電源端+4に接続する。可変電流源12の大
きさは、制御入力端子10からの人力によって変化でき
る。
As shown in FIG. 2, the emitters of transistors 1.2 whose bases are connected to their collectors are commonly connected to a variable current source 12. The collector of the transistor 1 is directly connected to the power supply terminal 4, and the collector of the transistor 2 is connected to the power supply terminal +4 through a parallel circuit consisting of a coil 5 and a capacitor 6. The magnitude of the variable current source 12 can be changed by manual input from the control input terminal 10.

次に、この回路の発振周波数が可変電流源12の電流値
に依在することを示す。
Next, it will be shown that the oscillation frequency of this circuit depends on the current value of the variable current source 12.

第3図は、第2図に示される発振回路の発振周波数を計
算するための等何回略図であって、それぞれベースをコ
レクタに互いに接続し、共通エミッタ接続したトランジ
スタ1.2をハイブリッドT形等価回路で表わしている
。端子18.14および15は、それぞれトランジスタ
1のコレクタ、ベースおよびエミッタ端子に相当し、端
子16.17および18は、それぞれトランジスタ2の
コレクタ、ベースおよびエミッタ端子に相当する。又、
トランジスタ1および2のベース抵抗は、等価抵抗19
および20、入力抵抗は等価抵抗21および22で示さ
れ、エミッタ、ベース接合の空乏層容量は、等価容景2
8および24、エミッタ拡散容量は等価容[25および
26、コレクタ、ベース接合の空乏層容量は等価容t2
7および28、従属電源は29および80でそれぞれ示
す。
FIG. 3 is a schematic diagram for calculating the oscillation frequency of the oscillation circuit shown in FIG. It is expressed as an equivalent circuit. Terminals 18.14 and 15 correspond to the collector, base and emitter terminals of transistor 1, respectively, and terminals 16.17 and 18 correspond to the collector, base and emitter terminals of transistor 2, respectively. or,
The base resistance of transistors 1 and 2 is equal to the equivalent resistance 19
and 20, the input resistance is shown by the equivalent resistances 21 and 22, and the depletion layer capacitance of the emitter and base junctions is the equivalent resistance 2
8 and 24, the emitter diffusion capacitance is the equivalent capacitance [25 and 26, the depletion layer capacitance of the collector and base junctions is the equivalent capacitance t2
7 and 28, and auxiliary power supplies are shown at 29 and 80, respectively.

定常発振時には、ループ利得が1と小さく又、コレクタ
、ベース接合の空乏層容t27および28は小さいので
同容量は無視できる。又、回路の対称性よシ第3図を書
き直すと、等側口路第4図を得る。
During steady oscillation, the loop gain is as small as 1, and the depletion layer capacitances t27 and 28 of the collector and base junctions are small, so they can be ignored. Also, if we rewrite FIG. 3 to improve the symmetry of the circuit, we obtain the isolateral path in FIG. 4.

ここで、トランジスタ1.2のコレクタ間のインピーダ
ンスを求めると ただし、fT)fO 2:トランジスタ1,2のコレクタ間のインピーダンス
、 L :コイル5のインダクタンス、 C:コンデンサ6の容量、 Cb:等価容景23と等価容量25の容量の和、 二等価容t24と等価容t26の容 量の和、 rb:等価抵抗19.20の値、 rπ :等価抵抗21.22の値、 fT :Iβl=1となる周波数、 β :エミッタ接地電流増幅率。
Here, to find the impedance between the collectors of transistors 1 and 2, fT) fO 2: impedance between the collectors of transistors 1 and 2, L: inductance of coil 5, C: capacitance of capacitor 6, Cb: equivalent capacitance The sum of the capacitances of the two equivalent capacitances 23 and 25, the sum of the capacitances of the two equivalent capacitances t24 and t26, rb: value of equivalent resistance 19.20, rπ: value of equivalent resistance 21.22, fT: Iβl=1. β: common emitter current amplification factor.

発振周波域において2は、位相負零の純抵抗となるので
(2の虚数部)=Oとおいて(3)式を得る。
In the oscillation frequency range, 2 is a pure resistance with a negative phase of zero, so (imaginary part of 2) is set as =O to obtain equation (3).

これよシ発振周波数が求まって、 fosc:発振周波数、k:ボルツマン定数、q:電子
の電荷、T:絶対温1.、Io:可変電流源12の電流
の大きさ ただし、fT>> fosc、 C)Ch、  rff
 >> rb(。
Now that the oscillation frequency has been found, fosc: oscillation frequency, k: Boltzmann constant, q: electron charge, T: absolute temperature 1. , Io: magnitude of current of variable current source 12, where fT>> fosc, C) Ch, rff
>> rb(.

となる。上記(4)式は、可変電流源12の電流の大き
さ工0 を変えることによって、発振周波数を変化でき
ることを示している。
becomes. Equation (4) above indicates that the oscillation frequency can be changed by changing the magnitude of the current of the variable current source 12.

以上説明したように、本発明によれば可変電流源12の
電流の大きさを変化させることばよって、発振周波数を
変化させられるので可変容量ダイオードを用いなくてよ
いため、集積回路化しやすい効果がある。又、(4)式
に示されるように、発振周波数の変化は可変電流源12
の電流の大きさIoに比例するので、発振周波数の制御
特性の直線性をよくする効果がある。
As explained above, according to the present invention, since the oscillation frequency can be changed by changing the magnitude of the current of the variable current source 12, there is no need to use a variable capacitance diode, which has the effect of making it easier to integrate the circuit. . Furthermore, as shown in equation (4), the change in the oscillation frequency is caused by the variable current source 12.
Since it is proportional to the magnitude of the current Io, it has the effect of improving the linearity of the control characteristics of the oscillation frequency.

以上のように優れた特長をもっているので、本発明を位
相同期回路の電圧制御発振器として用いてFM検波もし
くはPM検波させると検波歪が小さい検波回路が実現で
きる。
Because of the excellent features described above, when the present invention is used as a voltage controlled oscillator in a phase-locked circuit for FM detection or PM detection, a detection circuit with small detection distortion can be realized.

第5図は、本発明の具体的な一実施例の回路接続図であ
る。
FIG. 5 is a circuit connection diagram of a specific embodiment of the present invention.

それぞれベースをコレクタに互いに接続した、トランジ
スタ1,2のエミッタを共通接続してトランジスタ80
のコレクタに接続する。トランジスタ1のコレクタは、
直接電源端子4へ接続1.、トランジスタ2のコレクタ
は、コイル5とコンデンサ6で構成する並列共振回路の
コイルに中間接続点を設けて接続し、並列共振回路の1
端は電源端子4に接続する。トランジスタ81のベース
は、制御入力端子10に接続し、エミッタは抵抗8zを
通してGND端子9に接続する。
A transistor 80 is formed by connecting the emitters of transistors 1 and 2 in common, each having its base connected to its collector.
Connect to the collector of The collector of transistor 1 is
Connect directly to power terminal 4 1. , the collector of the transistor 2 is connected to the coil of a parallel resonant circuit composed of a coil 5 and a capacitor 6 through an intermediate connection point, and
The end is connected to the power supply terminal 4. The base of the transistor 81 is connected to the control input terminal 10, and the emitter is connected to the GND terminal 9 through a resistor 8z.

トランジスタ88のベースをトランジスタ2のコレクタ
に、コレクタを電源端子4にエミッタを出力端子84に
、それぞれ接続するとともにエミッタを抵抗85を通し
てGND端子9に接続する。第5図に示す本例は、位相
同期回路の電圧制御発振器として用いた例であって、可
変周波数幅がひろがりすぎるのをさけるため、共振回路
のコイル51C中間接続点を設けて用いている。コイル
5の全体に対して、中間点までの巻数比が1:mである
とすると、等測的に同調容量が1/m’倍になるため発
振周波数は、(0<m<1) 1、、ニドランジス:4!81のコレクタ電流となって
、発掘周波数変化は(4)式に比較しM倍に小さくなっ
ている。
The base of the transistor 88 is connected to the collector of the transistor 2, the collector is connected to the power supply terminal 4, the emitter is connected to the output terminal 84, and the emitter is connected to the GND terminal 9 through the resistor 85. The present example shown in FIG. 5 is an example in which it is used as a voltage controlled oscillator of a phase-locked circuit, and in order to avoid the variable frequency width from becoming too wide, an intermediate connection point of the coil 51C of the resonant circuit is provided. Assuming that the turns ratio up to the midpoint of the entire coil 5 is 1:m, the tuning capacitance is isometrically increased by 1/m', so the oscillation frequency is (0<m<1) 1 , Nidorangis: The collector current is 4!81, and the excavation frequency change is M times smaller than in equation (4).

第6図に示すのは、本発明の具体的な他の実施例であっ
て、上記実施例とは抵抗86 、87が、それぞれトラ
ンジスタ1.Bのエミッタに接続された点が異なってい
る。この場合の発振周波数は、抵抗86および87の抵
抗値をReで表わすと、 となる。この式は、エミッタに抵抗が入ったことにより
、発振周波数のトランジスタ81のコレクタ電流に対す
る依存性が小さくなることを示しているが、反面トラン
ジスタ1.2のパラメータのバラツキに対して、発振器
の特性がバックのを押える効果がある。又、本発明では
、第1および第2のトランジスタの各エミッタ電流は、
電流源となる第3のトランジスタからのみ供給するので
、周波数の増減が任意に設定できる。
FIG. 6 shows another specific embodiment of the present invention, in which resistors 86 and 87 are replaced by transistors 1 and 1, respectively. The difference is that it is connected to the emitter of B. The oscillation frequency in this case is as follows, where the resistance values of the resistors 86 and 87 are expressed as Re. This equation shows that the dependence of the oscillation frequency on the collector current of the transistor 81 becomes smaller due to the inclusion of a resistor in the emitter, but on the other hand, the oscillator's characteristics has the effect of suppressing the back. Further, in the present invention, each emitter current of the first and second transistors is
Since the current is supplied only from the third transistor serving as the current source, the frequency can be increased or decreased as desired.

【図面の簡単な説明】 第1図は、従来の電圧制御発振器を説明する回路接続図
、第2図は本発明の一実施例の回路接続図、第3図は、
前記実施例の発振周波数を求める等価回路図、第4図は
第3図の等価回路図、第5図は本発明の具体的な一実施
例を示す回路後り図、第6図は本発明の他の実施例を示
す回路接続図である。 1,2,81.88・・・・・・トランジスタ、8・・
・電流源、4・・・・・・電源端子、5・・・・・・コ
イル、6゜7・・・・・・コンデンサ、8・・・・・・
可変容量ダイオード、9・・・・・・GND端子、10
・・・・・・制御入力端子、11.82.85.86.
37・・・・・・抵抗、12・・・・・・可変電流源、
18.16・・・・・・コレクタ端子、14.1’7・
・・・・・ベース端子、15 、1 s・・・・・・エ
ミッタ端子、19.20,21.22・・・・・・等価
抵抗、23.24,25.26.27.28・・・等価
容量、29.80・・・・・・従R@流源、84・・・
出力端子。 第71B f−2已 第3 圀 γ 第 4 目 f″S 第 、5 図
[Brief Description of the Drawings] Fig. 1 is a circuit connection diagram explaining a conventional voltage controlled oscillator, Fig. 2 is a circuit connection diagram of an embodiment of the present invention, and Fig. 3 is a circuit connection diagram illustrating a conventional voltage controlled oscillator.
4 is an equivalent circuit diagram of FIG. 3, FIG. 5 is a circuit diagram showing a specific embodiment of the present invention, and FIG. 6 is a circuit diagram of the present invention. It is a circuit connection diagram which shows another Example. 1, 2, 81.88...transistor, 8...
・Current source, 4...Power terminal, 5...Coil, 6゜7...Capacitor, 8...
Variable capacitance diode, 9...GND terminal, 10
...Control input terminal, 11.82.85.86.
37...Resistor, 12...Variable current source,
18.16... Collector terminal, 14.1'7.
...Base terminal, 15, 1 s...Emitter terminal, 19.20, 21.22...Equivalent resistance, 23.24, 25.26.27.28...・Equivalent capacity, 29.80... Sub-R@flow source, 84...
Output terminal. 71B f-2 3rd area γ 4th f″S 5th figure

Claims (1)

【特許請求の範囲】[Claims] エミッタが互いに接続され、一方のベースが他方のコレ
クタに他のベースが一方のコレクタに、それぞれ接続さ
れた第1および第2のトランジスタと、これら第1と第
2のトランジスタのコレクタ間に接続された共振回路と
、前記第1および第2のトランジスタのエミッタ結合点
に接続された第3のトランジスタと、制御信号に応答し
て前記第3のトランジスタに流れる電流を制御する手段
とを有し、前記第1および第2トランジスタの各エミッ
タ電流は、前記第3のトランジスタからのみ供給される
ことを特徴とする電圧制御発振器。
first and second transistors whose emitters are connected to each other, one base to the collector of the other, and the other base to the collector of the other, and between the collectors of the first and second transistors; a third transistor connected to an emitter junction of the first and second transistors; and means for controlling a current flowing through the third transistor in response to a control signal; A voltage controlled oscillator, wherein each emitter current of the first and second transistors is supplied only from the third transistor.
JP7796386A 1986-04-04 1986-04-04 Voltage controlled oscillator Pending JPS61256803A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP7796386A JPS61256803A (en) 1986-04-04 1986-04-04 Voltage controlled oscillator

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP7796386A JPS61256803A (en) 1986-04-04 1986-04-04 Voltage controlled oscillator

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
JP52147542A Division JPS6022845B2 (en) 1977-12-07 1977-12-07 voltage controlled oscillator

Publications (1)

Publication Number Publication Date
JPS61256803A true JPS61256803A (en) 1986-11-14

Family

ID=13648618

Family Applications (1)

Application Number Title Priority Date Filing Date
JP7796386A Pending JPS61256803A (en) 1986-04-04 1986-04-04 Voltage controlled oscillator

Country Status (1)

Country Link
JP (1) JPS61256803A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0324806A (en) * 1989-06-21 1991-02-01 Matsushita Electric Ind Co Ltd Oscillator

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3963996A (en) * 1974-09-05 1976-06-15 Zenith Radio Corporation Oscillation system for integrated circuit

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3963996A (en) * 1974-09-05 1976-06-15 Zenith Radio Corporation Oscillation system for integrated circuit

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0324806A (en) * 1989-06-21 1991-02-01 Matsushita Electric Ind Co Ltd Oscillator

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