JPS61111226U - - Google Patents
Info
- Publication number
- JPS61111226U JPS61111226U JP20018684U JP20018684U JPS61111226U JP S61111226 U JPS61111226 U JP S61111226U JP 20018684 U JP20018684 U JP 20018684U JP 20018684 U JP20018684 U JP 20018684U JP S61111226 U JPS61111226 U JP S61111226U
- Authority
- JP
- Japan
- Prior art keywords
- frequency
- pulse signal
- signal
- output
- intermediate frequency
- 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
- 238000001514 detection method Methods 0.000 claims 3
- 230000010355 oscillation Effects 0.000 claims 3
- 238000006243 chemical reaction Methods 0.000 claims 1
- 238000010586 diagram Methods 0.000 description 7
Landscapes
- Channel Selection Circuits, Automatic Tuning Circuits (AREA)
Description
第１図はこの考案に係る自動周波数制御回路の
一実施例を示すブロツク回路構成図、第２図は同
実施例の動作を説明するための出力波形図、第３
図はＡＦＣ回路で得られるＩＦ信号の特性を示す
波形図、第４図は従来のＡＦＣ回路の構成を示す
ブロツク回路図、第５図はＡＦＣ回路の周波数弁
別器入出力特性を示す特性図、第６図はＡＦＣ回
路の局部発振器入出力特性を示す特性図、第７図
は従来のＡＦＣ回路に生じていた問題を説明する
ための動作説明図である。
１１……空中線、１２……サーキユレータ、１
３……送信機、１４……受信機、１４１……ＲＦ
増幅器、１４２……混合器、１４３……局部発振
器、１４４，１４９……ＩＦ増幅器、１４５……
振幅制限器、１４６……周波数弁別器、１４７…
…パルス積分器、１４８……ビデオ増幅器、１４
ａ……サンプルホールド回路、１４ｂ……アナロ
グスイツチ、１４ｃ……バンドパスフイルタ、１
４ｄ……検波器、１４ｅ……サンプルホールド回
路、１４ｆ……コンパレータ、１４ｇ……鋸歯状
波信号発生器。
FIG. 1 is a block circuit configuration diagram showing an embodiment of the automatic frequency control circuit according to this invention, FIG. 2 is an output waveform diagram for explaining the operation of the embodiment, and FIG.
Figure 4 is a waveform diagram showing the characteristics of the IF signal obtained by the AFC circuit, Figure 4 is a block circuit diagram showing the configuration of a conventional AFC circuit, Figure 5 is a characteristic diagram showing the frequency discriminator input/output characteristics of the AFC circuit, FIG. 6 is a characteristic diagram showing the local oscillator input/output characteristics of the AFC circuit, and FIG. 7 is an operation explanatory diagram for explaining the problems that have occurred in the conventional AFC circuit. 11...Antenna, 12...Circulator, 1
3...Transmitter, 14...Receiver, 141...RF
Amplifier, 142... Mixer, 143... Local oscillator, 144, 149... IF amplifier, 145...
Amplitude limiter, 146... Frequency discriminator, 147...
... Pulse integrator, 148 ... Video amplifier, 14
a...Sample hold circuit, 14b...Analog switch, 14c...Band pass filter, 1
4d...Detector, 14e...Sample and hold circuit, 14f...Comparator, 14g...Sawtooth wave signal generator.
Claims (1)
局部発振信号を混合することにより中間周波パル
ス信号を得る周波数変換装置に用いられ、前記中
間周波パルス信号の周波数を自動的に一定制御す
る自動周波数制御回路において、前記中間周波パ
ルス信号の振幅を一定にする振幅制限器と、この
振幅制限器の出力信号を入力し前記中間周波パル
ス信号の周波数変動に応じて出力電圧を変化させ
る周波数弁別器と、この周波数弁別器の出力を直
流化するサンプルホールド回路と、前記中間周波
パルス信号の周波数が前記局周波数弁別器の周波
数範囲からはずれたことを検出する検出回路と、
前記局部発振器の発振周波数を広範囲に可変する
鋸歯状波信号を発生する鋸歯状波信号発生器と、
前記検出回路の検出結果に基づいて前記サンプル
ホールド回路の出力及び前記鋸歯状波信号発生器
の出力を選択的に導出するスイツチ回路とを具備
し、このスイツチ回路で導出された信号を前記局
部発振器の同調電圧入力端子に供給してその発振
周波数を前記中間周波パルス信号の周波数が一定
となるように制御するようにした自動周波数制御
回路。 In an automatic frequency control circuit that is used in a frequency conversion device that obtains an intermediate frequency pulse signal by mixing a high frequency pulse signal with a local oscillation signal output from a local oscillator, and that automatically controls the frequency of the intermediate frequency pulse signal to a constant value. , an amplitude limiter that keeps the amplitude of the intermediate frequency pulse signal constant; a frequency discriminator that receives the output signal of the amplitude limiter and changes the output voltage according to frequency fluctuations of the intermediate frequency pulse signal; a sample hold circuit that converts the output of the discriminator into a direct current; a detection circuit that detects that the frequency of the intermediate frequency pulse signal deviates from the frequency range of the station frequency discriminator;
a sawtooth signal generator that generates a sawtooth signal that varies the oscillation frequency of the local oscillator over a wide range;
a switch circuit that selectively derives the output of the sample and hold circuit and the output of the sawtooth signal generator based on the detection result of the detection circuit, and the signal derived by the switch circuit is connected to the local oscillator. an automatic frequency control circuit configured to control the oscillation frequency of the intermediate frequency pulse signal by supplying it to a tuning voltage input terminal of the intermediate frequency pulse signal so that the frequency of the intermediate frequency pulse signal is constant.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1984200186U JPH0349472Y2 (en) | 1984-12-25 | 1984-12-25 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1984200186U JPH0349472Y2 (en) | 1984-12-25 | 1984-12-25 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS61111226U true JPS61111226U (en) | 1986-07-14 |
| JPH0349472Y2 JPH0349472Y2 (en) | 1991-10-22 |
Family
ID=30760798
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1984200186U Expired JPH0349472Y2 (en) | 1984-12-25 | 1984-12-25 |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0349472Y2 (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS50128966A (en) * | 1974-03-29 | 1975-10-11 |
-
1984
- 1984-12-25 JP JP1984200186U patent/JPH0349472Y2/ja not_active Expired
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS50128966A (en) * | 1974-03-29 | 1975-10-11 |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0349472Y2 (en) | 1991-10-22 |
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