JPS5840931A - Afc type frequency oscillating circuit - Google Patents
Afc type frequency oscillating circuitInfo
- Publication number
- JPS5840931A JPS5840931A JP13906381A JP13906381A JPS5840931A JP S5840931 A JPS5840931 A JP S5840931A JP 13906381 A JP13906381 A JP 13906381A JP 13906381 A JP13906381 A JP 13906381A JP S5840931 A JPS5840931 A JP S5840931A
- Authority
- JP
- Japan
- Prior art keywords
- frequency
- discriminator
- filter
- output
- narrow band
- 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
Links
- 230000010355 oscillation Effects 0.000 claims description 19
- 239000002253 acid Substances 0.000 claims description 12
- 238000001914 filtration Methods 0.000 abstract description 3
- 239000013078 crystal Substances 0.000 description 2
- 230000003321 amplification Effects 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 230000035939 shock Effects 0.000 description 1
- 238000005728 strengthening Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03L—AUTOMATIC CONTROL, STARTING, SYNCHRONISATION OR STABILISATION OF GENERATORS OF ELECTRONIC OSCILLATIONS OR PULSES
- H03L7/00—Automatic control of frequency or phase; Synchronisation
- H03L7/02—Automatic control of frequency or phase; Synchronisation using a frequency discriminator comprising a passive frequency-determining element
Landscapes
- Stabilization Of Oscillater, Synchronisation, Frequency Synthesizers (AREA)
Abstract
Description
【発明の詳細な説明】
本発明は、広帯域形周波数弁別器並びに狭帯域フィルタ
と組合せた狭帯酸形周波数弁別器により、電圧制御発振
器（ＶＣＯ）の発振周波数を高安定化したＡＦＣ形周波
数発振回路に関する。Detailed Description of the Invention The present invention provides an AFC type frequency oscillation system in which the oscillation frequency of a voltage controlled oscillator (VCO) is highly stabilized by a narrow band frequency discriminator and a narrow band acid type frequency discriminator combined with a narrow band filter. Regarding circuits.
この種のＡＦＣ形周波数発振回路は、ＶＣＯの発振周波
数（自走周波数）をキャプチャレンジ内にとり込むこと
を可能とするために”、周波数弁別器は広帯域形を必要
とする。This type of AFC frequency oscillation circuit requires a wideband frequency discriminator in order to capture the oscillation frequency (free-running frequency) of the VCO within the capture range.
この広帯域形周波数弁別器は、水晶振動子あるいはセラ
ミック共振子等一般に温度変化、振動衝撃等に対して安
定であるといわれている素子を使用して構成したとして
も、弁別器自身の周波数安定度は時によって問題となる
。すなわち、ＡＦＣ形周波数発振回路の周波数安定度は
、周波数混合器に注入される外部周波数成分を除外して
考えだ場合、周波数弁別器の周波数安定度で支配される
。Even if this broadband frequency discriminator is constructed using elements such as crystal oscillators or ceramic resonators that are generally said to be stable against temperature changes, vibration shocks, etc., the frequency stability of the discriminator itself becomes a problem from time to time. That is, the frequency stability of the AFC type frequency oscillation circuit is dominated by the frequency stability of the frequency discriminator when considering excluding the external frequency component injected into the frequency mixer.
例えば、広帯域形周波数弁別器のみで構成したＡＦＣ形
周波数発振回路をＶＨＦあるいはＵＨＦ等のＦＭ無線機
に使用した場合、弁別器自身の周波数安定度が無線機の
実用性を著しく低下させることになる。For example, if an AFC frequency oscillation circuit consisting only of a wideband frequency discriminator is used in an FM radio such as VHF or UHF, the frequency stability of the discriminator itself will significantly reduce the practicality of the radio. .
本発明は、前記の広帯域形周波数弁別器のみで構成した
ＡＦＣ形周波数発振回路が有する周波数安定度が悪いと
いう欠点に鑑みて提案されたものであシ、その目的とす
るところは、広帯域形周波数弁別器によりキャプチャレ
ンジ内にとり込まれた電圧制御発振器（ＶＣＯ）の発振
周波数（自走周波数）を、高い周波数安定度が容易に得
られる狭帯域フィルタ並びに狭帯酸形周波数弁別器によ
り、ＶＣＯの発振周波数を高安定化したＡＦＣ形周波数
発振回路を提供するにある。The present invention was proposed in view of the drawback that the AFC type frequency oscillation circuit, which is composed only of the above-mentioned wideband frequency discriminator, has poor frequency stability. The oscillation frequency (free-running frequency) of the voltage controlled oscillator (VCO) captured within the capture range by the discriminator is detected by a narrow-band filter and narrow-band acid type frequency discriminator that can easily obtain high frequency stability. An object of the present invention is to provide an AFC type frequency oscillation circuit in which the oscillation frequency is highly stabilized.
次に、本発明に係るＡＦＣ形周波数発振回路の実施例に
つき添付図面を参照して説明する０第１図は本発明に係
るＡＦＣ形周波数発振回路の構成を示すものである０す
なわち、第１図において、１は広帯域形周波数弁別器、
２はアクティブフィルタ、３は狭帯域フィルタ、４は狭
帯酸形周波数弁別器、５はアクティブフィルタ、６は電
圧制御発振器（ＶＣＯ）、７は周波数混合器、８は分周
器をそれぞれ示す。第１図に示す回路において、電圧制
御発振器（ＶＣＯ）は、広帯域形周波数弁別器１の出力
をアクティブフィルタ２を介しＦ波して得た出力と、狭
帯域フィルタ３を介して狭帯酸形周波数弁別器４より得
られ出力をアクティブフィルタ５を介しｒ波して得た出
力とにより、制御される。この場合、ＶＣＯの出力の一
部を周波数混合器７において他の周波数信号と共に混合
し、次いで分周器８によシ分周して得た出力信号を前記
広帯域形周波数弁別器１および狭帯域フィルタ３に供給
する。この結果、広帯域形周波数弁別器１によシキャプ
チャレンジ内にとシ込んだｖＣＯの発振周波数（自走周
波数）は、狭帯域フィルタ３と組合せた狭帯酸形周波数
弁別器４により高安定化することができる。Next, an embodiment of the AFC type frequency oscillation circuit according to the present invention will be explained with reference to the attached drawings. Fig. 1 shows the configuration of the AFC type frequency oscillation circuit according to the present invention. In the figure, 1 is a broadband frequency discriminator;
2 is an active filter, 3 is a narrow band filter, 4 is a narrow band acid type frequency discriminator, 5 is an active filter, 6 is a voltage controlled oscillator (VCO), 7 is a frequency mixer, and 8 is a frequency divider. In the circuit shown in FIG. 1, a voltage controlled oscillator (VCO) uses an output obtained by converting the output of a broadband frequency discriminator 1 into an F wave via an active filter 2, and a narrow band acid type output via a narrow band filter 3. It is controlled by the output obtained from the frequency discriminator 4 and the output obtained by converting the output from the frequency discriminator 4 into r-waves via the active filter 5. In this case, a part of the output of the VCO is mixed with other frequency signals in the frequency mixer 7, and then divided by the frequency divider 8, and the resulting output signal is sent to the broadband frequency discriminator 1 and the narrowband Supplied to filter 3. As a result, the oscillation frequency (free-running frequency) of the vCO, which is injected into the capture range by the broadband frequency discriminator 1, is highly stabilized by the narrowband acid frequency discriminator 4 combined with the narrowband filter 3. can do.
次に、訂゛記回路構成からなる本発明ＡＦＣ形周波数発
振回路の作用につき、第２図および第３図に示す特性曲
線を参照して説明する。Next, the operation of the AFC type frequency oscillation circuit of the present invention having the circuit configuration as described above will be explained with reference to the characteristic curves shown in FIGS. 2 and 3.
第２図は、周波数弁別器の入出力特性を示すもので、特
性曲線Ｉは広帯域形周波数弁別器１の入出力特性を示し
、特性曲線■は狭帯酸形周波数弁別器４の入出力特性を
示す０第３図は、周波数弁別器とアクティブフィルタを
組合せた場合の入出力特性を示し、特性曲線Ｉは広帯域
形周波数弁別器１とアクティブフィルタ２とによる入出
力特性を示し、特性臼−■は狭帯酸形周波数弁別器４と
アクティブフィルタ５とによる入出力特性を示す。FIG. 2 shows the input/output characteristics of the frequency discriminator. Characteristic curve I shows the input/output characteristics of broadband frequency discriminator 1, and characteristic curve ■ shows the input/output characteristics of narrowband acid frequency discriminator 4. Figure 3 shows the input/output characteristics when the frequency discriminator and active filter are combined, and the characteristic curve I shows the input/output characteristics of the broadband frequency discriminator 1 and the active filter 2. 3 shows the input/output characteristics of the narrow band acid type frequency discriminator 4 and the active filter 5.
なお、第３図に示す特性曲線において、第２図に示す周
波数弁別器の８字特性に、比べ、直線部分の傾斜角が太
きくなシ、シかも８字特性のピーク部分については平坦
になっているのは、増幅度を有するアクティブフィルタ
によるものである。また、第３図に示す特性曲線Ｉ、Ｉ
Ｉは、第２図に示す特性曲線１．Ｕとそれぞれ比較し、
逆相の関係にあるが、これもアクティブフィルタによる
ものである０逆相にした理由は、ＡＦＣループを構成す
るためである０
今、ＶＣＯの発振周波数（自走周波数）の広帯域形周波
数弁別器１側入力端における周波数が、第３図の特性曲
線Ｉ−の１点−におったとする。この場合、ＡＦＣ効果
により、前記周波数は、中心周波数方向に引き込まれて
いく。この過程において、狭帯域フィルタの帯域内に入
る（第３図の特性曲線■参照）。このようにして、前記
周波数が狭帯域フィルタの帯域内に入ると、その時点に
おいてｖＣＯに対し狭帯酸形周波数弁別器４が作用する
Ｏこのように、狭帯酸形周波数弁別器４を経た■ＣＯ制
御信号は、広帯域形周波数弁別器１を経たｖＣＯ制御信
号に比較し、■ＣＯ制御力を強くすることにより、ｖＣ
Ｏの発振周波数安定度は狭帯酸形周波数弁別器の周波数
安定度でほぼ決定されることになる。In addition, in the characteristic curve shown in Figure 3, compared to the figure 8 characteristic of the frequency discriminator shown in Figure 2, the slope angle of the straight line part is not thicker, but the peak part of the figure 8 characteristic is flat. This is due to the active filter having amplification. In addition, the characteristic curves I and I shown in FIG.
I is the characteristic curve 1. shown in FIG. Compare each with U,
They have a reverse phase relationship, but this is also due to the active filter.The reason for the reverse phase is to configure the AFC loop. Assume that the frequency at the first input terminal is at one point on the characteristic curve I in FIG. In this case, the frequency is pulled toward the center frequency due to the AFC effect. In this process, it enters the band of the narrowband filter (see characteristic curve ◯ in Fig. 3). In this way, when said frequency falls within the band of the narrow band filter, at that point the narrow band acid type frequency discriminator 4 acts on vCO. ■The CO control signal is compared to the vCO control signal that has passed through the broadband frequency discriminator 1, and ■By strengthening the CO control force, the vCO control signal is
The oscillation frequency stability of O is approximately determined by the frequency stability of the narrow band acid type frequency discriminator.
なお、アクティブフィルタのろ波作用は、ＶＣＯの出力
の搬送波対雑音比（Ｃ／Ｎ）の改善にある０前述した実
施例から明らかなように、本発明によれば、従来の広帯
域形周波数弁別器を使用するＡＦＣ形周波数発振回路に
おいて、狭帯域フィルりおよび狭帯酸形周波数弁別器を
追加するのみで、高安定度のＡＦＣ形周波数発振回路を
容易に構成することができる。Note that the filtering action of the active filter is to improve the carrier-to-noise ratio (C/N) of the output of the VCO.As is clear from the embodiments described above, according to the present invention, the conventional broadband frequency discrimination A highly stable AFC type frequency oscillation circuit can be easily constructed by simply adding a narrow band filter and a narrow band acid type frequency discriminator.
なお、本発明ＡＦＣ形周波周波数発振回路周波シンプレ
ックスの送受信機に利用した場合、送受信用の水晶発振
子を共用することができる。ただし、この場合、周波数
混合器の出力周波数を受信部中間周波数と同一にする必
要がある。Note that when the AFC type frequency oscillator circuit of the present invention is used in a frequency simplex transmitter/receiver, the crystal oscillator for transmitting and receiving can be shared. However, in this case, it is necessary to make the output frequency of the frequency mixer the same as the receiver intermediate frequency.
また、本発明発振回路においては、周波数混合器または
分周器を省略することも可能である０Furthermore, in the oscillation circuit of the present invention, it is also possible to omit the frequency mixer or frequency divider.
テイプフィルタを組合せた場合の入出力特性面、ｒ：
。
図である。 刈・本
１・・・脅帯域形周波数弁別器
２・・・アクティブフィルタ
３・・・狭帯域フィルタ
４・・・狭帯酸形周波数弁別器
５・・・アクティブフィルタ
６・・・電圧制御発振器（ＶＣＯ）
７・・・周波数混合器
８・・・分周器
特許出願人 日本無線株式会社Input/output characteristics when tape filters are combined, r:
. It is a diagram. Kari・moto 1... Threat band type frequency discriminator 2... Active filter 3... Narrow band filter 4... Narrow band acid type frequency discriminator 5... Active filter 6... Voltage controlled oscillator (VCO) 7... Frequency mixer 8... Frequency divider Patent applicant Japan Radio Co., Ltd.
Claims (1)
するアクティブフィルタと、狭帯域フィルタおよび該フ
ィルタの出力を弁別する狭帯域形縄波数弁別器並びに該
弁別器の出力をｐ波するアクティブフィルタと、前記両
アクティブフィルタの出力によシ制御される電圧制御発
振器とからなり、該電圧制御発振器の出力を周波数混合
器および／を特徴とするＡ、 Ｆ Ｃ形周波数発振回路
。 （２、特許請求の範囲第１項記載のＡＦＣ形周波数発振
回路において、電圧制御発振器を制御する狭帯酸形周波
数弁別器を経た出力信号を広帯域形周波数弁別器を経た
出力信号に対し制御力を強く設定してなるＡＦＣ形周波
数発振回路。[Claims] 0) A wideband frequency discriminator, an active filter that filters the output of the discriminator, a narrowband filter, a narrowband frequency discriminator that discriminates the output of the filter, and the discriminator. It consists of an active filter that outputs P waves, and a voltage controlled oscillator that is controlled by the outputs of both of the active filters, and the output of the voltage controlled oscillator is converted into an A, F C type frequency converter characterized by a frequency mixer and/or a frequency mixer. Oscillation circuit. (2. In the AFC type frequency oscillator circuit according to claim 1, the output signal that has passed through the narrow band acid type frequency discriminator that controls the voltage controlled oscillator is controlled by the output signal that has passed through the wide band type frequency discriminator. An AFC type frequency oscillation circuit with a strong setting.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13906381A JPS5840931A (en) | 1981-09-03 | 1981-09-03 | Afc type frequency oscillating circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13906381A JPS5840931A (en) | 1981-09-03 | 1981-09-03 | Afc type frequency oscillating circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS5840931A true JPS5840931A (en) | 1983-03-10 |
Family
ID=15236622
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP13906381A Pending JPS5840931A (en) | 1981-09-03 | 1981-09-03 | Afc type frequency oscillating circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5840931A (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS50128966A (en) * | 1974-03-29 | 1975-10-11 | ||
| JPS5463873A (en) * | 1977-10-31 | 1979-05-23 | Koito Mfg Co Ltd | Frequency tracer |
-
1981
- 1981-09-03 JP JP13906381A patent/JPS5840931A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS50128966A (en) * | 1974-03-29 | 1975-10-11 | ||
| JPS5463873A (en) * | 1977-10-31 | 1979-05-23 | Koito Mfg Co Ltd | Frequency tracer |
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