JPH0136337Y2 - - Google Patents
Info
- Publication number
- JPH0136337Y2 JPH0136337Y2 JP1982181048U JP18104882U JPH0136337Y2 JP H0136337 Y2 JPH0136337 Y2 JP H0136337Y2 JP 1982181048 U JP1982181048 U JP 1982181048U JP 18104882 U JP18104882 U JP 18104882U JP H0136337 Y2 JPH0136337 Y2 JP H0136337Y2
- Authority
- JP
- Japan
- Prior art keywords
- signal
- transmission frequency
- oscillator
- self
- phase
- 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.)
- Expired
Links
- 230000005540 biological transmission Effects 0.000 claims description 22
- 230000010355 oscillation Effects 0.000 claims description 12
- 230000002194 synthesizing effect Effects 0.000 claims 1
- 239000003990 capacitor Substances 0.000 description 5
- 230000006866 deterioration Effects 0.000 description 3
- 238000000034 method Methods 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
- 238000010586 diagram Methods 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 230000005236 sound signal Effects 0.000 description 1
Landscapes
- Amplitude Modulation (AREA)
Description
【考案の詳細な説明】
〔考案の技術分野〕
この考案はPWM（パルス幅変調）方式による
振幅変調装置の改良に関する。[Detailed description of the invention] [Technical field of the invention] This invention relates to an improvement of an amplitude modulation device using a PWM (pulse width modulation) method.
周知のように、PWM方式による振幅変調装置
はPWM変調器および被変調器から構成されてい
る。第１図は従来のPWM変調器を示すものであ
り、１１は自励発振器である。この発振器１１の
出力信号は三角波形成器１２に供給され三角波と
される。また、入力端子１３より供給される変調
信号例えば音声信号aは増幅器１４を介して前
記三角波とともに比較器１５に供給される。この
比較器１５より出力されるPWM信号は前置増幅
器１６、終段増幅器１７、ダイオードＤ、コイル
Ｌ、コンデンサＣよりなる低域通過フイルタ１８
を介して出力される。この出力された信号、即
ち、変調信号は図示せぬ被変調器に供給され、こ
の被変調器において送信周波数信号と合成されて
出力される。
As is well known, an amplitude modulation device using the PWM method is composed of a PWM modulator and a modulated device. FIG. 1 shows a conventional PWM modulator, and 11 is a self-excited oscillator. The output signal of this oscillator 11 is supplied to a triangular waveformer 12 and converted into a triangular wave. Further, a modulated signal such as an audio signal a supplied from the input terminal 13 is supplied to a comparator 15 together with the triangular wave via an amplifier 14. The PWM signal output from this comparator 15 is passed through a low-pass filter 18 consisting of a preamplifier 16, a final stage amplifier 17, a diode D, a coil L, and a capacitor C.
Output via . This output signal, ie, the modulated signal, is supplied to a modulator (not shown), where it is combined with a transmission frequency signal and output.
また、第２図は前記自励発振器１１を示すもの
であり、この自励発振器１１は発振器１１1、こ
の発振器１１1の発振周波数を決定する抵抗RT、
コンデンサCT、前記発振器１１1の出力信号によ
つて動作されるフリツプフロツプ（FF）回路１
１2、このフリツプフロツプ回路１１2の出力信号
が供給されるノア回路１１3、このノア回路１１3
の出力信号によつてオンオフ制御されるトランジ
スタTr等により構成されている。 FIG. 2 shows the self-excited oscillator 11, which includes an oscillator 11 1 , a resistor R T that determines the oscillation frequency of the oscillator 11 1 , and
capacitor C T , a flip-flop (FF) circuit 1 operated by the output signal of the oscillator 11 1 ;
1 2 , a NOR circuit 11 3 to which the output signal of this flip-flop circuit 11 2 is supplied, this NOR circuit 11 3
It is composed of a transistor Tr, etc., which is turned on and off by the output signal of the Tr.
さらに、第３図は前記PWM変調器と被変調器
を複数個用いた振幅変調装置を示すものであり、
３１1〜３１3はそれぞれPWM変調器、３２1〜３
２3は被変調器、３３は送信周波数発振器（C.
O.），３４は合成器、３５は電源入力端子、３６
は変調信号入力端子、３７は出力端子である。 Furthermore, FIG. 3 shows an amplitude modulation device using a plurality of the PWM modulators and modulated devices,
31 1 to 31 3 are PWM modulators, 32 1 to 3 respectively
2 3 is a modulated device, 33 is a transmission frequency oscillator (C.
O.), 34 is a synthesizer, 35 is a power input terminal, 36
37 is a modulation signal input terminal and an output terminal.
ところで、前記PWM変調器３１1〜３１3の後
段増幅器１７は高出力のフイツチング増幅器であ
り、この増幅器１７からは電源ラインおよび各配
線間の結合容量を介して自励発振信号の数次の高
調波信号が漏洩することがあり、この信号と送信
周波数信号との相互干渉によつてビート信号を発
生することがある。このビート信号が変調信号帯
域内にある場合、装置の総合的なＳ／Ｎ比が劣化
するものであり、除去する必要がある。しかし、
第３図に示す如くPWM変調器が複数個用いられ
る場合、発生するビート信号は単一のものではな
く、各自励発振周波数との相互干渉から任意なも
のとなり、除去することが極めて困難となる。 Incidentally, the amplifier 17 after the PWM modulators 31 1 to 31 3 is a high-output switching amplifier, and the amplifier 17 outputs several harmonics of the self-oscillation signal through the power supply line and the coupling capacitance between each wiring. The wave signal may leak, and mutual interference between this signal and the transmission frequency signal may generate a beat signal. If this beat signal is within the modulation signal band, it degrades the overall S/N ratio of the device and must be removed. but,
When multiple PWM modulators are used as shown in Figure 3, the generated beat signal is not a single one, but becomes arbitrary due to mutual interference with each individual's own excitation oscillation frequency, and is extremely difficult to eliminate. .
この考案は上記事情に基づいてなされたもの
で、その目的とするところはPWM変調器の自励
発振信号と送信周波数信号との相互干渉によるビ
ート信号の発生を防止してＳ／Ｎ比の劣化を抑え
ることが可能な振幅変調装置を提供しようとする
ものである。
This invention was made based on the above circumstances, and its purpose is to prevent the generation of beat signals due to mutual interference between the self-oscillation signal of the PWM modulator and the transmission frequency signal, and the deterioration of the S/N ratio. The present invention aims to provide an amplitude modulation device that can suppress the
この考案はPWM変調器における自励発振信号
を送信周波数信号に位相ロツクすることによりビ
ート信号の発生を防止するものである。
This idea prevents the generation of beat signals by locking the phase of the self-excited oscillation signal in the PWM modulator to the transmission frequency signal.
以下、この考案の一実施例について図面を参照
して説明する。尚、第４図中第３図と同一部分に
は同一符号を付す。
An embodiment of this invention will be described below with reference to the drawings. Note that the same parts in FIG. 4 as in FIG. 3 are given the same reference numerals.
第４図において、第３図と異なるのはPWM変
調器３１1〜３１3に送信周波数発振器（C.O.）３
３の出力信号を供給し、各自励発振信号を送信周
波数信号に位相ロツクする点である。 In Fig. 4, the difference from Fig. 3 is that the PWM modulators 31 1 to 31 3 are equipped with a transmission frequency oscillator (CO) 3.
3 output signals are supplied, and each self-excited oscillation signal is phase-locked to the transmission frequency signal.
第５図は各PWM変調器３１1〜３１3における
自励発振器の構成を示すものであり、第５図中第
２図と同一部分には同一符号を付し異なる部分に
ついてのみ説明する。この図において５１は前記
送信周波数信号の入力端子である。この入力端子
５１に供給された送信周波数信号は分周器５２に
おいて１／Ｍに分周される。一方、発振器１１1
の出力信号は分周器５３に供給され、この分周器
５３の出力信号が前記分周器５２の出力信号の周
波数と等しくなるよう１／Ｎに分周される。これ
ら分周器５２，５３の出力信号は位相比較器５４
に供給され、両信号の位相差が検出される。この
比較出力信号は低域通過フイルタ（LPF）５５
を介して直流増幅器５６に供給され、この直流増
幅器５６の出力信号は抵抗Raを介してコンデン
サCa、可変容量ダイオードDvの接続点に供給さ
れる。これらコンデンサCaおよび可変容量ダイ
オードDvの直列回路は前記発振器１１1の発振周
波数を決定するコンデンサCTに並列接続されて
おり、前記直流増幅器５６の出力信号、即ち、自
励発振信号と送信周波数信号の位相差に応じた信
号によつて可変容量ダイオードDvのキヤパシタ
ンスが変化され、自励発振信号の位相が送信周波
数信号の位相にロツクされる。 FIG. 5 shows the configuration of a self-excited oscillator in each of the PWM modulators 31 1 to 31 3. In FIG. 5, the same parts as in FIG. 2 are given the same reference numerals, and only the different parts will be explained. In this figure, 51 is an input terminal for the transmission frequency signal. The transmission frequency signal supplied to this input terminal 51 is frequency-divided by 1/M in a frequency divider 52. On the other hand, oscillator 11 1
The output signal of the frequency divider 53 is supplied to a frequency divider 53, and the frequency is divided by 1/N so that the output signal of the frequency divider 53 becomes equal to the frequency of the output signal of the frequency divider 52. The output signals of these frequency dividers 52 and 53 are sent to a phase comparator 54.
and the phase difference between both signals is detected. This comparison output signal is passed through a low pass filter (LPF) 55
The output signal of the DC amplifier 56 is supplied to the connection point between the capacitor Ca and the variable capacitance diode Dv via the resistor Ra. The series circuit of the capacitor Ca and the variable capacitance diode Dv is connected in parallel to the capacitor C T which determines the oscillation frequency of the oscillator 111 , and the output signal of the DC amplifier 56, that is, the self-excited oscillation signal and the transmission frequency signal. The capacitance of the variable capacitance diode Dv is changed by a signal corresponding to the phase difference between the two, and the phase of the self-oscillation signal is locked to the phase of the transmission frequency signal.
このように、上記実施例によれば自励発振信号
の位相を送信周波数信号の位相にロツクしてい
る。したがつて、これらの信号の相互干渉による
ビート信号の発生を防止でき、Ｓ／Ｎ比の劣化を
抑えることができる。 In this way, according to the above embodiment, the phase of the self-oscillation signal is locked to the phase of the transmission frequency signal. Therefore, generation of beat signals due to mutual interference of these signals can be prevented, and deterioration of the S/N ratio can be suppressed.
また、自励発振信号と送信周波数信号との位相
をロツクする構成であるため、PWM変調器が複
数個用いられた場合においても複雑なビート信号
を容易に除去することが可能である。 Furthermore, since the configuration locks the phase of the self-excited oscillation signal and the transmission frequency signal, it is possible to easily remove complex beat signals even when a plurality of PWM modulators are used.
以上、詳述したようにこの考案によれば、
PWM変調器の自励発振信号と送信周波数信号と
の相互干渉によるビート信号の発生を防止して
Ｓ／Ｎ比の劣化を抑えることが可能な振幅変調装
置を提供できる。
As detailed above, according to this idea,
It is possible to provide an amplitude modulation device that can prevent the generation of beat signals due to mutual interference between the self-excited oscillation signal of the PWM modulator and the transmission frequency signal, and suppress deterioration of the S/N ratio.
第１図は従来のPWM変調器の構成を示す図、
第２図は第１図に示す自励発振器の構成を示す
図、第３図は従来の振幅変調装置の構成を示す
図、第４図はこの考案に係わる振幅変調装置の一
実施例を示す構成図、第５図はこの考案に適用さ
れる自励発振器の一例を示す構成図である。
１１……自励発振器、１２……三角波形成器、
１５……比較器、１７……スイツチング増幅器、
３１1〜３１3……PWM変調器、３２1〜３２3…
…被変調器、３３……送信周波数発振器、５２，
５３……分周器、５４……比較器、５５……低域
通過フイルタ、５６……直流増幅器、Dv……可
変容量ダイオード。
Figure 1 shows the configuration of a conventional PWM modulator.
FIG. 2 shows the configuration of the self-excited oscillator shown in FIG. 1, FIG. 3 shows the configuration of a conventional amplitude modulation device, and FIG. 4 shows an embodiment of the amplitude modulation device according to this invention. FIG. 5 is a block diagram showing an example of a self-excited oscillator applied to this invention. 11...Self-excited oscillator, 12...Triangle waveformer,
15... comparator, 17... switching amplifier,
31 1 to 31 3 ... PWM modulator, 32 1 to 32 3 ...
...Modulated device, 33...Transmission frequency oscillator, 52,
53... Frequency divider, 54... Comparator, 55... Low pass filter, 56... DC amplifier, Dv... Variable capacitance diode.
Claims (1)
と、それぞれ自励発振器を備え、その発振信号に
基づいて三角波を生成し、この三角波と被変調信
号とを比較してパルス幅変調信号を生成する複数
のパルス幅変調器と、これら複数のパルス幅変調
器に対応して設けられ、それぞれパルス幅変調器
の出力信号を前記送信周波数発振器で発生される
送信周波数信号で振幅変調する複数の被変調器
と、これら複数の被変調器の各出力信号を合成す
る合成器とを有する振幅変調装置において、前記
自励発振器毎に設けられ、その発振信号と前記送
信周波数発振器で発生される送信周波数信号とを
位相比較し、その比較結果に基づいて前記自励発
振器の発振周波数を制御して、発振信号の位相を
送信周波数信号の位相に一致させる複数の位相ロ
ツク手段を具備したことを特徴とする振幅変調装
置。 A transmission frequency oscillator that generates a transmission frequency signal, and a plurality of pulses that each include a self-excited oscillator, generate a triangular wave based on the oscillation signal, and generate a pulse width modulated signal by comparing the triangular wave and the modulated signal. a width modulator, and a plurality of modulated devices provided corresponding to the plurality of pulse width modulators, each of which amplitude modulates the output signal of the pulse width modulator with a transmission frequency signal generated by the transmission frequency oscillator; In an amplitude modulation device having a synthesizer for synthesizing each output signal of the plurality of modulated devices, the amplitude modulation device is provided for each of the self-excited oscillators, and the oscillation signal and the transmission frequency signal generated by the transmission frequency oscillator are phase-shifted. An amplitude modulation device characterized by comprising a plurality of phase locking means for comparing and controlling the oscillation frequency of the self-excited oscillator based on the comparison result to match the phase of the oscillation signal with the phase of the transmission frequency signal. .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18104882U JPS5984909U (en) | 1982-11-30 | 1982-11-30 | amplitude modulator |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18104882U JPS5984909U (en) | 1982-11-30 | 1982-11-30 | amplitude modulator |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5984909U JPS5984909U (en) | 1984-06-08 |
| JPH0136337Y2 true JPH0136337Y2 (en) | 1989-11-06 |
Family
ID=30392409
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP18104882U Granted JPS5984909U (en) | 1982-11-30 | 1982-11-30 | amplitude modulator |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5984909U (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5582516A (en) * | 1978-12-19 | 1980-06-21 | Toshiba Corp | Amplitude modulator |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS51131166U (en) * | 1975-04-15 | 1976-10-22 |
-
1982
- 1982-11-30 JP JP18104882U patent/JPS5984909U/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5582516A (en) * | 1978-12-19 | 1980-06-21 | Toshiba Corp | Amplitude modulator |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5984909U (en) | 1984-06-08 |
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