JPH01202013A - Local oscillation circuit - Google Patents
Local oscillation circuitInfo
- Publication number
- JPH01202013A JPH01202013A JP63026856A JP2685688A JPH01202013A JP H01202013 A JPH01202013 A JP H01202013A JP 63026856 A JP63026856 A JP 63026856A JP 2685688 A JP2685688 A JP 2685688A JP H01202013 A JPH01202013 A JP H01202013A
- Authority
- JP
- Japan
- Prior art keywords
- diode
- circuit
- local oscillation
- variable capacitance
- fine tuning
- 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.)
- Granted
Links
- 230000010355 oscillation Effects 0.000 title claims abstract description 51
- 238000006073 displacement reaction Methods 0.000 abstract description 6
- 239000003990 capacitor Substances 0.000 description 21
- 238000010586 diagram Methods 0.000 description 8
- 230000000694 effects Effects 0.000 description 4
- 230000000903 blocking effect Effects 0.000 description 2
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03J—TUNING RESONANT CIRCUITS; SELECTING RESONANT CIRCUITS
- H03J7/00—Automatic frequency control; Automatic scanning over a band of frequencies
- H03J7/02—Automatic frequency control
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03B—GENERATION OF OSCILLATIONS, DIRECTLY OR BY FREQUENCY-CHANGING, BY CIRCUITS EMPLOYING ACTIVE ELEMENTS WHICH OPERATE IN A NON-SWITCHING MANNER; GENERATION OF NOISE BY SUCH CIRCUITS
- H03B5/00—Generation of oscillations using amplifier with regenerative feedback from output to input
- H03B5/08—Generation of oscillations using amplifier with regenerative feedback from output to input with frequency-determining element comprising lumped inductance and capacitance
- H03B5/12—Generation of oscillations using amplifier with regenerative feedback from output to input with frequency-determining element comprising lumped inductance and capacitance active element in amplifier being semiconductor device
- H03B5/1231—Generation of oscillations using amplifier with regenerative feedback from output to input with frequency-determining element comprising lumped inductance and capacitance active element in amplifier being semiconductor device the amplifier comprising one or more bipolar transistors
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03B—GENERATION OF OSCILLATIONS, DIRECTLY OR BY FREQUENCY-CHANGING, BY CIRCUITS EMPLOYING ACTIVE ELEMENTS WHICH OPERATE IN A NON-SWITCHING MANNER; GENERATION OF NOISE BY SUCH CIRCUITS
- H03B5/00—Generation of oscillations using amplifier with regenerative feedback from output to input
- H03B5/08—Generation of oscillations using amplifier with regenerative feedback from output to input with frequency-determining element comprising lumped inductance and capacitance
- H03B5/12—Generation of oscillations using amplifier with regenerative feedback from output to input with frequency-determining element comprising lumped inductance and capacitance active element in amplifier being semiconductor device
- H03B5/1203—Generation of oscillations using amplifier with regenerative feedback from output to input with frequency-determining element comprising lumped inductance and capacitance active element in amplifier being semiconductor device the amplifier being a single transistor
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03B—GENERATION OF OSCILLATIONS, DIRECTLY OR BY FREQUENCY-CHANGING, BY CIRCUITS EMPLOYING ACTIVE ELEMENTS WHICH OPERATE IN A NON-SWITCHING MANNER; GENERATION OF NOISE BY SUCH CIRCUITS
- H03B5/00—Generation of oscillations using amplifier with regenerative feedback from output to input
- H03B5/08—Generation of oscillations using amplifier with regenerative feedback from output to input with frequency-determining element comprising lumped inductance and capacitance
- H03B5/12—Generation of oscillations using amplifier with regenerative feedback from output to input with frequency-determining element comprising lumped inductance and capacitance active element in amplifier being semiconductor device
- H03B5/1237—Generation of oscillations using amplifier with regenerative feedback from output to input with frequency-determining element comprising lumped inductance and capacitance active element in amplifier being semiconductor device comprising means for varying the frequency of the generator
- H03B5/124—Generation of oscillations using amplifier with regenerative feedback from output to input with frequency-determining element comprising lumped inductance and capacitance active element in amplifier being semiconductor device comprising means for varying the frequency of the generator the means comprising a voltage dependent capacitance
- H03B5/1243—Generation of oscillations using amplifier with regenerative feedback from output to input with frequency-determining element comprising lumped inductance and capacitance active element in amplifier being semiconductor device comprising means for varying the frequency of the generator the means comprising a voltage dependent capacitance the means comprising voltage variable capacitance diodes
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03B—GENERATION OF OSCILLATIONS, DIRECTLY OR BY FREQUENCY-CHANGING, BY CIRCUITS EMPLOYING ACTIVE ELEMENTS WHICH OPERATE IN A NON-SWITCHING MANNER; GENERATION OF NOISE BY SUCH CIRCUITS
- H03B2200/00—Indexing scheme relating to details of oscillators covered by H03B
- H03B2200/003—Circuit elements of oscillators
- H03B2200/004—Circuit elements of oscillators including a variable capacitance, e.g. a varicap, a varactor or a variable capacitance of a diode or transistor
- H03B2200/0042—Circuit elements of oscillators including a variable capacitance, e.g. a varicap, a varactor or a variable capacitance of a diode or transistor the capacitance diode being in the feedback path
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03B—GENERATION OF OSCILLATIONS, DIRECTLY OR BY FREQUENCY-CHANGING, BY CIRCUITS EMPLOYING ACTIVE ELEMENTS WHICH OPERATE IN A NON-SWITCHING MANNER; GENERATION OF NOISE BY SUCH CIRCUITS
- H03B2201/00—Aspects of oscillators relating to varying the frequency of the oscillations
- H03B2201/02—Varying the frequency of the oscillations by electronic means
- H03B2201/0208—Varying the frequency of the oscillations by electronic means the means being an element with a variable capacitance, e.g. capacitance diode
Landscapes
- Inductance-Capacitance Distribution Constants And Capacitance-Resistance Oscillators (AREA)
- Television Receiver Circuits (AREA)
- Channel Selection Circuits, Automatic Tuning Circuits (AREA)
Abstract
Description
【発明の詳細な説明】
「産業上の利用分野」
この発明は電子同調チューナに係り、特にＡＦＴ（自動
周波数調整）回路を備えた局部発振回路に関する。DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to an electronically tuned tuner, and more particularly to a local oscillator circuit equipped with an AFT (Automatic Frequency Tuning) circuit.
「従来の技術」 第４図は従来の局部発振回路の回路図である。"Conventional technology" FIG. 4 is a circuit diagram of a conventional local oscillation circuit.
この局部発振回路は、増幅回路ｌと帰還回路２と共振回
路３とＡＦ’Ｔ回路４とからなる。This local oscillation circuit includes an amplifier circuit 1, a feedback circuit 2, a resonance circuit 3, and an AF'T circuit 4.
まず、増幅回路ｌの構成を説明する。Ｔｒ、は発振用ト
ランジスタであり、電源電圧Ｖｃｃからバイアス抵抗Ｒ
４、Ｒ６、Ｒ８、Ｒ７を介して直流バイアスが加えられ
ている。コンデンサＣ６は接地コンデンサであり、交流
動作時にトランジスタＴｒ＋のベース端子を等測的に接
地仕しめるものである。First, the configuration of the amplifier circuit l will be explained. Tr is an oscillation transistor, which is connected from the power supply voltage Vcc to the bias resistor R.
4, DC bias is applied via R6, R8, and R7. The capacitor C6 is a grounding capacitor, which isomerically grounds the base terminal of the transistor Tr+ during AC operation.
トランジスタＴｒ、のエミッタ端子はコンデンサＣ４を
介して出力端子２１に接続される。また、出力端子２１
には、一端が接地されたコンデンサＣ７が負荷として接
続される。そして、この増幅回路ｌの入力端（トランジ
スタＴｒ＋のコレクタ端子）は、共振用インダクタンス
Ｌ１を介して後述する共振回路３と結合されており、こ
のインダクタンスし、の両端に発生する信号を増幅して
、出力端子２Ｉに出力する。The emitter terminal of the transistor Tr is connected to the output terminal 21 via a capacitor C4. In addition, the output terminal 21
A capacitor C7, one end of which is grounded, is connected as a load. The input terminal of this amplifier circuit l (collector terminal of transistor Tr+) is coupled to a resonant circuit 3, which will be described later, via a resonant inductance L1, and the signal generated across this inductance is amplified. , output to output terminal 2I.
次に、帰還回路２の構成を説明する。増幅回路１の出力
端子２１には帰還用可変容量ダイオードＤ、のアノード
が接続されている。そして、この可変容量ダイオードＤ
２のアノードは抵抗Ｒ８を介して接地され、また、カソ
ードは共振回路３の節点ａに接続される。この結果、出
力端子２１に出力される増幅回路Ｉの出力信号は可変容
量ダイオードＤ２を介して共振回路３の節点ａに帰還さ
れる。Next, the configuration of the feedback circuit 2 will be explained. The output terminal 21 of the amplifier circuit 1 is connected to the anode of a feedback variable capacitance diode D. And this variable capacitance diode D
The anode of No. 2 is grounded via a resistor R8, and the cathode is connected to node a of the resonant circuit 3. As a result, the output signal of the amplifier circuit I output to the output terminal 21 is fed back to the node a of the resonant circuit 3 via the variable capacitance diode D2.
次に、共振回路３の構成を説明する。共振回路３は前述
の通り増幅回路ｌの入力側に接続され、構成される。す
なわち、節点ａには共振用可変８墳ダイオードＤ３のカ
ソードとコンデンサＣ３の一端が接続され、可変容量ダ
イオードＤ３のアノードには一端が接地されたコンデン
サＣ７および抵抗Ｒ３の他端が接続され、コンデンサＣ
３の他端はインダクタンスし、とコンデンサＣ６とを直
列に介して接地される。そして、共振回路３は前述の通
りインダクタンスＬ、により増幅回路ｌと結合される。Next, the configuration of the resonant circuit 3 will be explained. The resonant circuit 3 is connected to the input side of the amplifier circuit 1 and configured as described above. That is, the cathode of the variable capacitance diode D3 for resonance and one end of the capacitor C3 are connected to the node a, and the anode of the variable capacitance diode D3 is connected to the capacitor C7 whose one end is grounded and the other end of the resistor R3. C
The other end of C.3 has an inductance and is connected to ground through a capacitor C6 in series. The resonant circuit 3 is coupled to the amplifier circuit l through the inductance L, as described above.
また、この共振回路３の節点ａは抵抗Ｒ７を介して局発
周波数制御端子１１に接続されている。Further, the node a of this resonant circuit 3 is connected to the local frequency control terminal 11 via a resistor R7.
従って、可変容量ダイオードＤ３は、抵抗Ｒ７、Ｒ５を
介して、この局発周波数制御端子１１の局発周波数制御
電圧ＶＴＵによる直流バイアスを受け、容量値が制御さ
れる。この結果、この局発周波数が制御され、この局部
発振回路が使用されているチューナにおける選局が行わ
れる。Therefore, the variable capacitance diode D3 receives a DC bias from the local frequency control voltage VTU of the local frequency control terminal 11 via the resistors R7 and R5, and its capacitance value is controlled. As a result, this local oscillation frequency is controlled, and tuning is performed in a tuner using this local oscillation circuit.
ところで、前述した帰還回路２の可変容量ダイオードＤ
、もカソードが共振回路３の節点ａに接続されているの
で、抵抗Ｒ２、Ｒ８を介して、局発周波数制御電圧ＶＴ
Ｕによる直流バイアスを受け、容量値が制御される。す
なわち、可変容量ダイオードＤ、とＤ３とは、同一の局
発周波数制御電圧ＶＴＵによって容量値が制御される。By the way, the variable capacitance diode D of the feedback circuit 2 mentioned above
, the cathode is connected to the node a of the resonant circuit 3, so the local oscillation frequency control voltage VT is applied via the resistors R2 and R8.
The capacitance value is controlled by receiving a DC bias from U. That is, the capacitance values of the variable capacitance diodes D and D3 are controlled by the same local frequency control voltage VTU.
このようにする事で、バンドの全域に渡って帰還量がよ
り均一になり発振を安定化さ仕る事が可能となる。By doing this, the amount of feedback becomes more uniform over the entire band, making it possible to stabilize the oscillation.
次に、ＡＦＴ回路４の構成を説明する。ＡＦＴ回路４は
共振回路３と並列に接続され、構成される。Next, the configuration of the AFT circuit 4 will be explained. The AFT circuit 4 is connected and configured in parallel with the resonant circuit 3.
すなわち、節点ａにはコンデンサＣＩの一端が接続され
、コンデンサＣ８の他端には、アノードが接地された微
同調用可変容量ダイオードＤ、のカソードが接続され、
さらに抵抗Ｒ１を介して微同調制御端子Ｉ２に接続され
る。ここで、可変容量ダイオードＤ１は、カソードに抵
抗Ｉ？、を介して、微同調制御端子１２の自動微同調電
圧Ｖ ＡＦＴを受け、容量値が制御される。That is, one end of the capacitor CI is connected to the node a, and the cathode of a fine tuning variable capacitance diode D whose anode is grounded is connected to the other end of the capacitor C8.
Furthermore, it is connected to a fine tuning control terminal I2 via a resistor R1. Here, the variable capacitance diode D1 has a resistor I? at the cathode. , the automatic fine tuning voltage V AFT of the fine tuning control terminal 12 is received, and the capacitance value is controlled.
以上要約すると、この局部発振回路はコルピッツ型発振
回路の共振回路３に並列にＡＰＴ回路４が接続された構
成になっている。To summarize above, this local oscillation circuit has a configuration in which an APT circuit 4 is connected in parallel to a resonance circuit 3 of a Colpitts type oscillation circuit.
次に、この局部発振回路の動作を説明する。第５図は、
第４図の局部発振回路における直流バイアス用抵抗およ
び直流阻止用コンデンサを省略して、発振動作時の等価
回路を表したものである。Next, the operation of this local oscillation circuit will be explained. Figure 5 shows
This figure shows an equivalent circuit during oscillation operation, with the DC bias resistor and DC blocking capacitor in the local oscillation circuit of FIG. 4 omitted.
この回路において、コンデンサＣｆｌは第４図の帰還用
可変容量コンデンサＤｔに対応し、コンデンサＣｒｔは
第４図のコンデンサＣ９に対応し、コンデンサＣＴＵは
第４図の共振用可変８債ダイオードＤ３に対応し、コン
デンサＣＡＰＴは第４図の微同調用可変容量ダイオード
Ｄ１に対応し、インダクタンスＬ１は第４図の共振用イ
ンダクタンスＬ＋に対応する。この等価回路図によれば
、この局部発振回路の局発周波数ｆは次式で表される。In this circuit, capacitor Cfl corresponds to feedback variable capacitor Dt in Figure 4, capacitor Crt corresponds to capacitor C9 in Figure 4, and capacitor CTU corresponds to resonance variable 8-bond diode D3 in Figure 4. The capacitor CAPT corresponds to the fine tuning variable capacitance diode D1 in FIG. 4, and the inductance L1 corresponds to the resonance inductance L+ in FIG. According to this equivalent circuit diagram, the local oscillation frequency f of this local oscillation circuit is expressed by the following equation.
・・・・・・（１）
この局部発振回路は上式（１）の局発周波数ｆで発振し
、その発振出力は出力端子２Ｉを介して後続の混合器に
供給される。混合器ではチューナの入力信号周波数と局
発周波数との差が検出され、これが規定値になるように
第４図の局部発振回路の微同調制御端子１２に自動微同
調制御電圧Ｖ ＡＦＴが送られ、局発周波数の自動微調
整が行われる。(1) This local oscillation circuit oscillates at the local oscillation frequency f expressed by the above equation (1), and its oscillation output is supplied to the subsequent mixer via the output terminal 2I. The mixer detects the difference between the input signal frequency of the tuner and the local oscillation frequency, and an automatic fine tuning control voltage V AFT is sent to the fine tuning control terminal 12 of the local oscillation circuit shown in FIG. 4 so that this becomes the specified value. , automatic fine adjustment of the local oscillator frequency is performed.
「発明が解決しようとする課題」
ところで、従来の局部発振回路では共振用可変容量ダイ
オードと並列に微同調用可変容量ダイオードが接続され
ているため、共振用可変容量ダイオードの容量値が小さ
い場合、すなわち発振周波数が高い場合には、微同調用
可変容量ダイオードの容量値変化が発振周波数に及ぼす
影響が太き過ぎ、逆に、同調用可変容量ダイオードの容
量値が大きい場合、すなわち発振周波数が低い場合には
、微同調用可変容量ダイオードの容簗値変化が発振周波
数に及ぼず影響が小さ過ぎる。従って、この局部発振回
路のバンド内において、高域と低域とで、自動微同調電
圧に対する局発周波数の変位量に大きな周波数偏差が生
じてしまうという問題があった。"Problems to be Solved by the Invention" By the way, in conventional local oscillation circuits, a fine tuning variable capacitance diode is connected in parallel with a resonant variable capacitance diode, so if the capacitance value of the resonant variable capacitance diode is small, In other words, when the oscillation frequency is high, the effect of the capacitance change of the fine tuning variable capacitance diode on the oscillation frequency is too large, and conversely, when the capacitance value of the tuning variable capacitance diode is large, that is, the oscillation frequency is low. In this case, the change in the capacitance value of the fine tuning variable capacitance diode does not affect the oscillation frequency, and the influence is too small. Therefore, within the band of this local oscillation circuit, there is a problem in that a large frequency deviation occurs in the amount of displacement of the local oscillation frequency with respect to the automatic fine tuning voltage between the high range and the low range.
この発明は上述した事情に鑑みてなされたもので、自動
微同調電圧に対する局発周波数の変位量の偏差が小さい
局部発振回路を提供することを目的としている。The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a local oscillation circuit in which the deviation of the local oscillation frequency with respect to the automatic fine tuning voltage is small.
「課題を解決するための手段」
この発明は、
（ａ）局発周波数制御電圧を与えられて電極間容量が制
御される共振用可変容量ダイオードを有する共振回路と
、
（ｂ） 前記共振回路の出力信号を増幅する増幅回路と
、
（Ｃ）前記局発周波数制御電圧によって電極間容量が制
御され、前記増幅回路の出力信号を前記同調回路に帰還
する帰還用可変８惧ダイオードと、（ｄ）前記増幅回路
の出力端と接地間に介挿されて、自動微同調電圧を与え
られて電極間容量が制御される微同調用可変容量ダイオ
ードと
を具備する事を特徴としている。"Means for Solving the Problems" The present invention comprises: (a) a resonant circuit having a resonant variable capacitance diode whose inter-electrode capacitance is controlled by applying a local frequency control voltage; an amplifier circuit that amplifies the output signal; (C) a variable feedback diode whose interelectrode capacitance is controlled by the local frequency control voltage and which feeds back the output signal of the amplifier circuit to the tuning circuit; (d) The present invention is characterized by comprising a variable capacitance diode for fine tuning, which is inserted between the output end of the amplifier circuit and ground, and whose interelectrode capacitance is controlled by applying an automatic fine tuning voltage.
「作用」
上記構成によれば、微同調用可変容量ダイオードが帰還
用可変容量ダイオードの容量値に略比例して共振用可変
容量ダイオードに結合され、局発周波数を決定せしめる
。しかも、この時の帰還用可変容量ダイオードの容量値
は、共振用可変容重ダイオードの容量値に連動して制御
される。従って、微同調用可変容量ダイオードは、共振
用可変容量ダイオードの容量値に略比例した割合て共振
用可変容重ダイオードに結合される。"Operation" According to the above configuration, the fine tuning variable capacitance diode is coupled to the resonance variable capacitance diode in substantially proportion to the capacitance value of the feedback variable capacitance diode, thereby determining the local oscillation frequency. Furthermore, the capacitance value of the feedback variable capacitance diode at this time is controlled in conjunction with the capacitance value of the resonance variable capacitance diode. Therefore, the fine tuning variable capacitance diode is coupled to the resonant variable capacitance heavy diode at a rate approximately proportional to the capacitance value of the resonant variable capacitance diode.
「実施例」
以下、図面を参照して本発明の一実施例について説明す
る。"Embodiment" Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
第１図はこの発明の一実施例による局部発振器の回路図
である。この局部発振回路は、第４図に示す従来の局部
発振回路においてＡＰＴ回路４が共振回路３に並列に接
続されていたのに対し、ＡＦＴ回路４が増幅回路ｌの出
力端子２１に接続されている点のみが異なる。FIG. 1 is a circuit diagram of a local oscillator according to an embodiment of the present invention. In this local oscillation circuit, whereas the APT circuit 4 was connected in parallel to the resonant circuit 3 in the conventional local oscillation circuit shown in FIG. 4, the AFT circuit 4 is connected to the output terminal 21 of the amplifier circuit l. The only difference is that
次に、この局部発振回路の動作を説明する。第２図は、
第１図の局部発振回路におけろ直流バイアス用抵抗およ
び直流阻止用凸ンデンサを省略して、発振動作時の等両
回路を表したものである。Next, the operation of this local oscillation circuit will be explained. Figure 2 shows
In the local oscillation circuit of FIG. 1, the DC bias resistor and the DC blocking convex capacitor are omitted to illustrate both circuits during oscillation operation.
この回路において、コンデンサＣｆ、、コンデンサＣｒ
ｔ、コンデンサＣＴＯ，コンデンサＣＡＰＴ、インダク
タンスし、は前述した第５図と同じものである。この等
価回路図によれば、この局部発振回路の局発周波数ｆは
次式で表される。In this circuit, capacitor Cf, capacitor Cr
t, capacitor CTO, capacitor CAPT, and inductance are the same as in FIG. 5 described above. According to this equivalent circuit diagram, the local oscillation frequency f of this local oscillation circuit is expressed by the following equation.
・・・・・・（２）
式（２）により、微同調用可変容量ダイオードＤ１の容
量値ＣＡＦＴが△ＣＡＦＴだけ変化したとすると、その
局発周波数ｒへの影響は帰還用可変吉川ダイオードＤ！
の容量値Ｃｒ１の値に応じて制御される事がわかる。......(2) According to equation (2), if the capacitance value CAFT of the fine tuning variable capacitance diode D1 changes by △CAFT, the effect on the local oscillation frequency r will be as follows: !
It can be seen that the capacitance value Cr1 is controlled according to the value of the capacitance value Cr1.
第３図は、第１図に示すこの発明の一実施例による局部
発振回路と第４図に示す従来の局部発振回路とで、微同
調制御電圧Ｖ ＡＰＴに対する微同調周波数変位量△ｆ
を示したものである。この図より、本発明の局部発振回
路の方が全バンド内において微同調制御電圧Ｖ ＡＦＴ
に対する微同調周波数変位量△ｆが安定している事がわ
かる。FIG. 3 shows the amount of fine tuning frequency displacement Δf with respect to the fine tuning control voltage V APT in the local oscillation circuit according to the embodiment of the present invention shown in FIG. 1 and the conventional local oscillation circuit shown in FIG.
This is what is shown. From this figure, the local oscillation circuit of the present invention has a higher fine tuning control voltage V AFT in all bands.
It can be seen that the fine tuning frequency displacement amount Δf is stable.
「発明の効果」
以上説明したように、この発明によれば、微同調用可変
容量ダイオードは、共振用可変容量ダイオードに連動し
て容量値が制御される帰還用可変容量ダイオードを介し
て共振用可変容量ダイオードに結合されるため、その結
合度は共振用可変容量ダイオードの容量値に略比例した
ものとなる。"Effects of the Invention" As explained above, according to the present invention, the fine tuning variable capacitance diode is connected to the resonance variable capacitance diode through the feedback variable capacitance diode whose capacitance value is controlled in conjunction with the resonance variable capacitance diode. Since it is coupled to the variable capacitance diode, the degree of coupling is approximately proportional to the capacitance value of the resonant variable capacitance diode.
従って、局発周波数全域において自動微同調電圧に対す
る局発周波数変位量を安定化する事ができる効果がある
。Therefore, there is an effect that the local oscillator frequency displacement amount with respect to the automatic fine tuning voltage can be stabilized over the entire local oscillator frequency range.
第１図はこの発明の一実施例による局部発振回路の構成
図、第２図は同実施例の局部発振回路の発振時の等価回
路図、第３図はこの発明の一実施例による局部発振回路
および従来の局部発振回路における自動微同調電圧に対
する局発周波数の変化を示す図、第４図は従来の局部発
振回路の構成図、第５図は従来の局部発振回路の発振時
の等価回路図である。
Ｄ、・・・・・・微同調用可変容重ダイオード、Ｄ、・
・・・・・帰還用可変容量ダイオード、Ｄ３・・・・・
・共振用可変容量ダイオード。
出願人 アルプス電気株式会社
代表各 片間 勝太部
第１図
且
第２図
ｈ
第３図
ｘ−−−−−Ｘ 本（うにの局部す答払Ｕ回路第４図
第５図
Ｃｆ＋FIG. 1 is a block diagram of a local oscillation circuit according to an embodiment of the present invention, FIG. 2 is an equivalent circuit diagram of the local oscillation circuit according to the same embodiment during oscillation, and FIG. 3 is a diagram of a local oscillation circuit according to an embodiment of the present invention. Figure 4 shows the configuration of the conventional local oscillator circuit, and Figure 5 shows the equivalent circuit during oscillation of the conventional local oscillator circuit. It is a diagram. D,...Variable capacitance heavy diode for fine tuning, D,...
...Feedback variable capacitance diode, D3...
・Variable capacitance diode for resonance. Applicant Alps Electric Co., Ltd. Representative Katama Katsutabe Figures 1 and 2 h Figure 3
Claims (1)
御される共振用可変容量ダイオードを有する共振回路と
、 （ｂ）前記共振回路の出力信号を増幅する増幅回路と、 （ｃ）前記局発周波数制御電圧によって電極間容量が制
御され、前記増幅回路の出力信号を前記共振回路に帰還
する帰還用可変容量ダイオードと、（ｄ）前記増幅回路
の出力端と接地間に介挿されて、自動微同調電圧を与え
られて電極間容量が制御される微同調用可変容量ダイオ
ードと を具備する事を特徴とする局部発振回路。[Claims] (a) A resonant circuit having a resonant variable capacitance diode whose interelectrode capacitance is controlled by applying a local frequency control voltage; (b) An amplifier circuit that amplifies the output signal of the resonant circuit. (c) a feedback variable capacitance diode whose interelectrode capacitance is controlled by the local frequency control voltage and which feeds back the output signal of the amplifier circuit to the resonant circuit; and (d) an output terminal of the amplifier circuit and ground. A local oscillation circuit characterized by comprising: a fine tuning variable capacitance diode inserted between the electrodes and having an interelectrode capacitance controlled by applying an automatic fine tuning voltage.
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63026856A JP2693959B2 (en) | 1988-02-08 | 1988-02-08 | Local oscillation circuit |
| KR1019880013292A KR910001649B1 (en) | 1988-02-08 | 1988-10-12 | Local oscillator |
| GB8902366A GB2223903B (en) | 1988-02-08 | 1989-02-03 | Local oscillating circuits |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63026856A JP2693959B2 (en) | 1988-02-08 | 1988-02-08 | Local oscillation circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01202013A true JPH01202013A (en) | 1989-08-15 |
| JP2693959B2 JP2693959B2 (en) | 1997-12-24 |
Family
ID=12204919
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63026856A Expired - Fee Related JP2693959B2 (en) | 1988-02-08 | 1988-02-08 | Local oscillation circuit |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JP2693959B2 (en) |
| KR (1) | KR910001649B1 (en) |
| GB (1) | GB2223903B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2004529558A (en) * | 2001-04-11 | 2004-09-24 | キョウセラ ワイヤレス コーポレイション | Tunable voltage controlled oscillator |
| JP2007267353A (en) * | 2005-11-09 | 2007-10-11 | Renesas Technology Corp | Oscillator and information equipment using the same, and voltage controlled oscillator and information equipment using the same |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6801097B2 (en) | 2002-07-18 | 2004-10-05 | Qualcomm Incorporated | Wideband VCO resonant circuit method and apparatus |
| DE102006009467A1 (en) | 2006-03-01 | 2007-09-06 | Rohde & Schwarz Gmbh & Co. Kg | Oscillator with entrained amplifier |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS4846251A (en) * | 1971-10-14 | 1973-07-02 | ||
| JPS5895419A (en) * | 1981-12-01 | 1983-06-07 | Matsushita Electric Ind Co Ltd | Electronic tuning tuner |
| JPS61151415U (en) * | 1985-03-12 | 1986-09-19 |
-
1988
- 1988-02-08 JP JP63026856A patent/JP2693959B2/en not_active Expired - Fee Related
- 1988-10-12 KR KR1019880013292A patent/KR910001649B1/en not_active IP Right Cessation
-
1989
- 1989-02-03 GB GB8902366A patent/GB2223903B/en not_active Expired - Lifetime
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS4846251A (en) * | 1971-10-14 | 1973-07-02 | ||
| JPS5895419A (en) * | 1981-12-01 | 1983-06-07 | Matsushita Electric Ind Co Ltd | Electronic tuning tuner |
| JPS61151415U (en) * | 1985-03-12 | 1986-09-19 |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2004529558A (en) * | 2001-04-11 | 2004-09-24 | キョウセラ ワイヤレス コーポレイション | Tunable voltage controlled oscillator |
| JP4666564B2 (en) * | 2001-04-11 | 2011-04-06 | キョウセラ ワイヤレス コープ． | Tunable voltage controlled oscillator |
| JP2007267353A (en) * | 2005-11-09 | 2007-10-11 | Renesas Technology Corp | Oscillator and information equipment using the same, and voltage controlled oscillator and information equipment using the same |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2223903A (en) | 1990-04-18 |
| GB8902366D0 (en) | 1989-03-22 |
| KR910001649B1 (en) | 1991-03-16 |
| KR890013885A (en) | 1989-09-26 |
| JP2693959B2 (en) | 1997-12-24 |
| GB2223903B (en) | 1992-01-08 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |