JPH05168020A - Detection circuit for fm modulated wave - Google Patents

Detection circuit for fm modulated wave

Info

Publication number
JPH05168020A
JPH05168020A JP3335148A JP33514891A JPH05168020A JP H05168020 A JPH05168020 A JP H05168020A JP 3335148 A JP3335148 A JP 3335148A JP 33514891 A JP33514891 A JP 33514891A JP H05168020 A JPH05168020 A JP H05168020A
Authority
JP
Japan
Prior art keywords
energy
detection circuit
wave
controlled oscillator
voltage controlled
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
JP3335148A
Other languages
Japanese (ja)
Inventor
Yuji Sakai
裕司 酒井
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.)
Sony Corp
Original Assignee
Sony 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 Sony Corp filed Critical Sony Corp
Priority to JP3335148A priority Critical patent/JPH05168020A/en
Publication of JPH05168020A publication Critical patent/JPH05168020A/en
Pending legal-status Critical Current

Links

Landscapes

  • Picture Signal Circuits (AREA)
  • Two-Way Televisions, Distribution Of Moving Picture Or The Like (AREA)

Abstract

PURPOSE:To provide a detection circuit to satisfactorily detect energy diffused FM modulated waves like the broadcasting waves of satellite broadcasting. CONSTITUTION:This circuit is provided with phase locked loop (PLL) circuits 2, 3 and 4 to detect the energy diffused FM modulated waves, detecting means 11, 12 and 13 to detect the energy diffused component of the FM modulated waves, and a pseudo diffused waveform generating means 14 corresponding to the energy diffused component and based on the outputs of the detecting means 11, 12 and 13, the pseudo diffused waveform outputted by the generating means 14 is adjusted. With this adjusted pseudo diffused waveform signal, the oscillation frequency range of a voltage controlled oscillator 3 constituting the PLL circuit is controlled.

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【産業上の利用分野】本発明は衛星放送受信機に適用し
て好適なエネルギー拡散されたＦＭ変調波の検波回路に
関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a detection circuit for energy-modulated FM-modulated wave, which is suitable for a satellite broadcasting receiver.

【０００２】[0002]

【従来の技術】近年、衛星放送と称する静止衛星からの
放送波を使用した放送システムが実用化されている。こ
の衛星放送の場合には、地上で使用されている同じ周波
数帯の信号との干渉を少なくするために、ＦＭ変調波
（周波数変調波）にエネルギー拡散を施して、変調され
た放送波の周波数スペクトルを分散させている。このエ
ネルギー拡散としては、例えば１５Ｈｚで変化する対称
三角波をＦＭ変調波に重畳して、周波数偏移量が６００
ｋＨｚ（システムによっては周波数偏移量が数ＭＨｚの
ものもある）となるようにしてある。2. Description of the Related Art In recent years, a broadcasting system called a satellite broadcast using a broadcast wave from a geostationary satellite has been put into practical use. In the case of this satellite broadcasting, in order to reduce the interference with the signal of the same frequency band used on the ground, energy is spread to the FM modulated wave (frequency modulated wave) and the frequency of the modulated broadcast wave is applied. The spectrum is dispersed. For this energy diffusion, for example, a symmetrical triangular wave changing at 15 Hz is superimposed on the FM modulated wave, and the frequency shift amount is 600.
kHz (the frequency shift amount may be several MHz depending on the system).

【０００３】[0003]

【発明が解決しようとする課題】このようにエネルギー
拡散された放送波は、周波数偏移量が６００ｋＨｚある
ため、衛星放送を受信する場合には、このエネルギー拡
散に対応した受信処理を行う必要がある。例えば、受信
した衛星放送波を検波するＦＭ検波回路として、広帯域
のものを必要とする。Since the broadcast wave thus energy-spread has a frequency shift amount of 600 kHz, when satellite broadcasting is received, it is necessary to perform reception processing corresponding to this energy spread. is there. For example, a wideband FM detection circuit is required as an FM detection circuit for detecting the received satellite broadcast wave.

【０００４】図４は、従来の衛星放送用受信装置に使用
されるＦＭ検波回路の構成を示す図で、図中１は衛星放
送の受信信号の入力端子を示し、この入力端子１には受
信回路で選択された所望のチャンネルの放送波が供給さ
れる。そして、この入力端子１に得られる受信信号を、
フェーズ・ロックド・ループ回路（ＰＬＬ回路）を構成
する位相比較器２に供給し、この位相比較器２で電圧制
御発振器３の発振信号と受信信号との位相差を検出す
る。そして、この差信号を、ループフィルタ４を介して
電圧制御発振器３に戻し、電圧制御発振器３を受信信号
の周波数に応じた周波数で発振させる。そして、ループ
フィルタ４の出力をアンプ５を介して検波信号出力端子
６に取り出し、この出力端子６に得られる電圧信号を、
受信信号の周波数に対応して電位が変化する検波信号と
する。FIG. 4 is a diagram showing the structure of an FM detection circuit used in a conventional satellite broadcast receiving apparatus. In the figure, reference numeral 1 denotes an input terminal of a satellite broadcast reception signal. The broadcast wave of the desired channel selected by the circuit is supplied. Then, the received signal obtained at this input terminal 1 is
It is supplied to the phase comparator 2 which constitutes a phase locked loop circuit (PLL circuit), and this phase comparator 2 detects the phase difference between the oscillation signal of the voltage controlled oscillator 3 and the reception signal. Then, this difference signal is returned to the voltage controlled oscillator 3 via the loop filter 4, and the voltage controlled oscillator 3 is oscillated at a frequency corresponding to the frequency of the received signal. Then, the output of the loop filter 4 is taken out to the detection signal output terminal 6 via the amplifier 5, and the voltage signal obtained at this output terminal 6 is
The detection signal is one in which the potential changes according to the frequency of the received signal.

【０００５】ここで、この図４に示す検波回路の電圧制
御発振器３としては、放送波本来の周波数偏移量だけで
なく、エネルギー拡散用の三角波の周波数偏移量も含め
た広帯域の周波数偏移に対応させる必要がある。即ち、
図５のＡに示す電圧制御発振器３の発振周波数範囲に対
応した電圧・周波数変換特性曲線ａ（いわゆるＳ字特
性）として、エネルギー拡散用の三角波により周波数偏
移量（ｆ0 ±Δｆ）が大きくされた放送波ｂ（図５のＢ
参照）をカバーできる特性とする必要がある。なお、図
５に示す例では、ｆ0 を入力ＦＭ変調波の中心周波数と
すると、エネルギー拡散用の三角波で±Δｆとして示す
周波数偏移が行われている。Here, as the voltage controlled oscillator 3 of the detection circuit shown in FIG. 4, not only the frequency deviation of the original broadcast wave but also the frequency deviation of a wide band including the frequency deviation of the triangular wave for energy diffusion is used. It is necessary to correspond to the move. That is,
As the voltage-frequency conversion characteristic curve a (so-called S-shaped characteristic) corresponding to the oscillation frequency range of the voltage controlled oscillator 3 shown in A of FIG. 5, the frequency deviation amount (f 0 ± Δf) is large due to the triangular wave for energy diffusion. Broadcast wave b (B in FIG. 5)
It is necessary to have a characteristic that can cover (see). In the example shown in FIG. 5, assuming that f 0 is the center frequency of the input FM-modulated wave, the frequency shift shown as ± Δf in the triangular wave for energy diffusion is performed.

【０００６】このように周波数偏移に対応させた広帯域
のものとするためには、それだけＰＬＬ回路の構成部品
として特性の良いものを使用する必要があった。In order to obtain a wide band corresponding to the frequency shift as described above, it is necessary to use components having good characteristics as constituent parts of the PLL circuit.

【０００７】また、このようにエネルギー拡散された信
号を検波した場合には、検波回路の出力にそのままエネ
ルギー拡散成分が含まれ、検波回路の後段に接続された
クランプ回路で、エネルギー拡散成分を除去する必要が
あった。Further, when the energy-spread signal is detected, the output of the detection circuit contains the energy-spread component as it is, and the energy-spread component is removed by the clamp circuit connected to the subsequent stage of the detection circuit. Had to do.

【０００８】本発明はかかる点に鑑み、衛星放送の放送
波のように、エネルギー拡散されたＦＭ変調波の検波が
良好にできる検波回路を提供することを目的とする。In view of the above point, the present invention has an object to provide a detection circuit capable of favorably detecting an energy-modulated FM modulated wave such as a broadcast wave of satellite broadcasting.

【０００９】[0009]

【課題を解決するための手段】本発明は、例えば図１に
示すように、エネルギー拡散されたＦＭ変調波を検波す
るＰＬＬ回路２，３，４と、ＦＭ変調波のエネルギー拡
散成分を検出する検出手段１１，１２，１３と、エネル
ギー拡散成分に相当する擬似拡散波形の発生手段１４と
を設け、検出手段１１，１２，１３の出力に基づいて、
発生手段１４が出力する擬似拡散波形の調整を行い、こ
の調整された擬似拡散波形信号でＰＬＬ回路を構成する
電圧制御発振器３の発振周波数範囲を制御するようにし
たものである。The present invention detects, for example, as shown in FIG. 1, PLL circuits 2, 3 and 4 for detecting an energy-modulated FM modulated wave and an energy diffused component of the FM modulated wave. The detection means 11, 12, 13 and the pseudo diffusion waveform generation means 14 corresponding to the energy diffusion component are provided, and based on the outputs of the detection means 11, 12, 13,
The pseudo spread waveform output by the generation means 14 is adjusted, and the adjusted pseudo spread waveform signal is used to control the oscillation frequency range of the voltage controlled oscillator 3 constituting the PLL circuit.

【００１０】またこの場合に、電圧制御発振器３での擬
似拡散波形信号による発振周波数範囲の調整により、Ｆ
Ｍ変調波の中心周波数が、発振周波数範囲のほぼ中心に
なるようにしたものである。Further, in this case, by adjusting the oscillation frequency range by the pseudo spread waveform signal in the voltage controlled oscillator 3, F
The center frequency of the M-modulated wave is set to be substantially the center of the oscillation frequency range.

【００１１】[0011]

【作用】このようにしたことで、ＦＭ変調波のエネルギ
ー拡散成分に対応して電圧制御発振器の発振周波数が変
化することになり、検波出力としてエネルギー拡散成分
が除去された信号が得られる。By doing so, the oscillation frequency of the voltage controlled oscillator changes corresponding to the energy diffusion component of the FM modulated wave, and a signal from which the energy diffusion component is removed can be obtained as the detection output.

【００１２】この場合に、ＦＭ変調波の中心周波数が、
電圧制御発振器の発振周波数範囲のほぼ中心になるよう
にしたことで、ＰＬＬ回路を構成する電圧制御発振器の
発振範囲を非常に狭くすることができ、ＦＭ変調波から
エネルギー拡散成分を除去した分だけの発振周波数範囲
で、入力ＦＭ変調波を良好に検波することができる。In this case, the center frequency of the FM modulated wave is
Since the oscillation frequency range of the voltage controlled oscillator is approximately at the center, the oscillation range of the voltage controlled oscillator forming the PLL circuit can be extremely narrowed, and only the amount of energy diffusion component removed from the FM modulated wave can be obtained. The input FM modulated wave can be satisfactorily detected in the oscillation frequency range of.

【００１３】[0013]

【実施例】以下、本発明の一実施例を図１〜図３を参照
して説明する。この図１〜図３において、図４，図５に
対応する部分には同一符号を付し、その詳細説明は省略
する。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 to 3, parts corresponding to those in FIGS. 4 and 5 are designated by the same reference numerals, and detailed description thereof will be omitted.

【００１４】図１は本例のＦＭ検波回路の構成を示す図
で、このＦＭ検波回路は衛星放送の受信装置に適用した
もので、本例の衛星放送受信装置で受信する衛星放送波
は、３０Ｈｚの三角波でエネルギー拡散されたものとす
る。FIG. 1 is a diagram showing the configuration of the FM detection circuit of this example. This FM detection circuit is applied to a satellite broadcast receiving device, and the satellite broadcast wave received by the satellite broadcast receiving device of this example is It is assumed that energy is diffused with a triangular wave of 30 Hz.

【００１５】図１において１は入力端子を示し、この入
力端子１に得られる衛星放送の受信信号（ＦＭ変調波）
を位相比較器２に供給し、電圧制御発振器３が出力する
周波数信号と位相比較する。そして、位相比較器２の位
相差信号をループフィルタ４に供給し、このループフィ
ルタ４の出力を、電圧制御発振器３の制御電圧入力端子
に供給すると共に、アンプ５を介して出力端子６に供給
する。この構成により、位相比較器２と電圧制御発振器
３とループフィルタ４とで、ＰＬＬ回路（フェーズ・ロ
ックド・ループ回路）が構成され、入力ＦＭ変調波の周
波数に対応した検波信号が出力端子６に得られる。In FIG. 1, reference numeral 1 denotes an input terminal, and a satellite broadcast reception signal (FM modulated wave) obtained at the input terminal 1.
Is supplied to the phase comparator 2 for phase comparison with the frequency signal output from the voltage controlled oscillator 3. Then, the phase difference signal of the phase comparator 2 is supplied to the loop filter 4, and the output of the loop filter 4 is supplied to the control voltage input terminal of the voltage controlled oscillator 3 and the output terminal 6 via the amplifier 5. To do. With this configuration, the phase comparator 2, the voltage controlled oscillator 3, and the loop filter 4 constitute a PLL circuit (phase locked loop circuit), and a detection signal corresponding to the frequency of the input FM modulated wave is output to the output terminal 6. can get.

【００１６】そして本例においては、位相比較器２が出
力する位相差信号を、ループフィルタ１１に供給する。
このループフィルタ１１は、３０Ｈｚ以下の低域だけを
通過させる狭帯域のフィルタとしてある。そして、この
ループフィルタ１１の出力を交流成分検出回路１２に供
給し、ループフィルタ１１に含まれる交流成分を検出さ
せ、この検出した交流成分を振幅検出回路１３に供給す
る。この振幅検出回路１３としては、例えばピークホー
ルド回路が適用される。In this example, the phase difference signal output from the phase comparator 2 is supplied to the loop filter 11.
The loop filter 11 is a narrow band filter that passes only a low frequency band of 30 Hz or less. Then, the output of the loop filter 11 is supplied to the AC component detection circuit 12, the AC component contained in the loop filter 11 is detected, and the detected AC component is supplied to the amplitude detection circuit 13. A peak hold circuit, for example, is applied as the amplitude detection circuit 13.

【００１７】また、図中１４は三角波発生器を示し、こ
の三角波発生器１４は衛星放送波のエネルギー拡散用に
使用される拡散波と同様の周波数（３０Ｈｚ），振幅の
三角波（以下擬似拡散波形信号と称する）を発生させる
回路で、振幅検出回路１３での振幅検出状態に応じて擬
似拡散波形信号の出力位相を調整させる。そして、この
三角波発生器１４が出力する擬似拡散波形信号を、ゲイ
ン調整回路１５に供給する。このゲイン調整回路１５
は、振幅検出回路１３での振幅検出状態に応じて、擬似
拡散波形信号のゲイン調整が行われる回路である。Reference numeral 14 in the drawing denotes a triangular wave generator. This triangular wave generator 14 has a triangular wave of the same frequency (30 Hz) and amplitude as the spread wave used for energy diffusion of satellite broadcast waves (hereinafter, pseudo spread waveform). Signal), and adjusts the output phase of the pseudo spread waveform signal according to the amplitude detection state of the amplitude detection circuit 13. Then, the pseudo spread waveform signal output from the triangular wave generator 14 is supplied to the gain adjusting circuit 15. This gain adjustment circuit 15
Is a circuit in which the gain of the pseudo spread waveform signal is adjusted according to the amplitude detection state of the amplitude detection circuit 13.

【００１８】そして、ゲイン調整回路１５でゲイン調整
された擬似拡散波形信号を、電圧制御発振器３に供給す
る。この電圧制御発振器３では、供給される擬似拡散波
形信号により、発振周波数範囲を設定させる。この場
合、ＦＭ変調波の中心周波数が、発振周波数範囲のほぼ
中心になるように、発振周波数範囲を制御させる。Then, the pseudo spread waveform signal whose gain is adjusted by the gain adjusting circuit 15 is supplied to the voltage controlled oscillator 3. In this voltage controlled oscillator 3, the oscillation frequency range is set by the supplied pseudo spread waveform signal. In this case, the oscillation frequency range is controlled so that the center frequency of the FM modulated wave is approximately at the center of the oscillation frequency range.

【００１９】また、交流成分検出回路１２の出力を同期
検出回路１６に供給し、この同期検出回路１６で同期状
態を検出したときには、三角波発生器１４に擬似拡散波
形信号の出力状態を維持させる制御信号を供給する。こ
の場合、同期検出回路１６での同期状態の検出は、交流
成分検出回路１２の出力に含まれる交流分の検出で行わ
れ、交流分が一定値以下になったとき同期状態であると
検出する。Further, the output of the AC component detection circuit 12 is supplied to the synchronization detection circuit 16, and when the synchronization detection circuit 16 detects the synchronization state, the triangular wave generator 14 is controlled to maintain the output state of the pseudo spread waveform signal. Supply a signal. In this case, the synchronization detection circuit 16 detects the synchronization state by detecting the AC component included in the output of the AC component detection circuit 12, and detects that the AC component is in the synchronization state when the AC component becomes a certain value or less. ..

【００２０】次に、このように構成される検波回路の動
作について、図２及び図３を参照して説明すると、まず
或るタイミングで受信したＦＭ変調波が、図２のＡに示
すように、このＦＭ変調波の本来の中心周波数ｆ0 から
Δｆだけエネルギー拡散波により周波数偏移した周波数
ｆ1 の周波数帯に分布しているとする。このとき、電圧
制御発振器３は、三角波発生器１４側から供給される３
０Ｈｚの擬似拡散波形信号により、発振周波数範囲が３
０Ｈｚで絶えず変動するが、３０Ｈｚ以下の低域だけを
通過させる狭帯域のループフィルタ１１の出力に基づい
て、受信信号に含まれるエネルギー拡散波が交流成分検
出回路１２で検出され、このエネルギー拡散波と擬似拡
散波形信号とが同期するように、三角波発生器１４での
発生状態及びゲイン調整回路１５でのゲイン調整が行わ
れる。従って、電圧制御発振器３の発振周波数範囲の３
０Ｈｚでの変動が、最終的に受信信号のエネルギー拡散
波に同期したものになり、図２のＢに示すように、エネ
ルギー拡散波により周波数偏移した周波数ｆ1 が、電圧
制御発振器３の発振周波数範囲の中心Ｖ0 に一致するよ
うになる。この図２では、エネルギー拡散波により下側
に周波数偏移した状態を示したが、エネルギー拡散波に
より上側に周波数偏移した場合も、同様にして発振周波
数範囲の中心Ｖ0 に一致する。Next, the operation of the detection circuit configured as described above will be described with reference to FIGS. 2 and 3. First, the FM modulated wave received at a certain timing is as shown in A of FIG. It is assumed that the FM-modulated wave is distributed in the frequency band of frequency f 1 that is frequency-shifted by Δf from the original center frequency f 0 of the FM-modulated wave. At this time, the voltage controlled oscillator 3 is supplied from the triangular wave generator 14 side.
The oscillation frequency range is 3 by the 0 Hz pseudo spread waveform signal.
The energy spread wave included in the received signal is detected by the AC component detection circuit 12 based on the output of the narrow band loop filter 11 that constantly changes at 0 Hz but passes only the low range of 30 Hz or less. The generation state in the triangular wave generator 14 and the gain adjustment in the gain adjusting circuit 15 are performed so that the and the pseudo spread waveform signal are synchronized with each other. Therefore, in the oscillation frequency range of the voltage controlled oscillator 3,
The fluctuation at 0 Hz finally becomes synchronized with the energy spread wave of the received signal, and as shown in FIG. 2B, the frequency f 1 that is frequency-shifted by the energy spread wave is the oscillation of the voltage controlled oscillator 3. It comes to coincide with the center V 0 of the frequency range. In FIG. 2, the state where the frequency is shifted downward by the energy diffusion wave is shown. However, when the frequency is shifted upward by the energy diffusion wave, the center V 0 of the oscillation frequency range is similarly matched.

【００２１】そして、このようにして電圧制御発振器３
の発振周波数範囲が、受信信号のエネルギー拡散波に完
全に同期するようになると、ループフィルタ１１の出力
に含まれる交流成分は少なくなるが、同期検出回路１６
で同期状態を検出すると、この同期検出回路１６による
制御で三角波発生器１４での擬似拡散波形信号の出力状
態が維持され、電圧制御発振器３の発振周波数範囲の変
化が受信信号のエネルギー拡散波に同期して行われ、出
力端子６に得られる検波信号にエネルギー拡散成分が含
まれなくなる。In this way, the voltage controlled oscillator 3
When the oscillating frequency range of 1 becomes completely synchronized with the energy spread wave of the received signal, the AC component contained in the output of the loop filter 11 decreases, but the synchronization detection circuit 16
When the synchronous state is detected by, the output state of the pseudo spread waveform signal in the triangular wave generator 14 is maintained by the control of the synchronous detection circuit 16, and the change of the oscillation frequency range of the voltage controlled oscillator 3 becomes the energy spread wave of the received signal. The detection signal obtained at the output terminal 6 is synchronized and does not include an energy diffusion component.

【００２２】そして、何らかの変動により一時的に同期
状態が維持できなくなったときには、ループフィルタ１
１の出力に含まれる交流成分が増大し、この交流成分を
少なくさせる起動時と同様な制御が行われ、再度同期状
態にさせる制御が行われる。When the synchronization state cannot be maintained temporarily due to some fluctuation, the loop filter 1
The AC component included in the output of No. 1 increases, the same control as that at the time of startup for reducing this AC component is performed, and the control for bringing the synchronized state again is performed.

【００２３】ここで、電圧制御発振器３の発振周波数範
囲の変化状態を図３に示すと、エネルギー拡散波の中心
周波数からの最大周波数偏移量を±Δｆとすると、ＦＭ
変調波の本来の中心周波数ｆ0 を中心とした発振周波数
範囲ｘから上下に±Δｆだけ周波数偏移した発振周波数
範囲ｙ，ｚが下限及び上限の発振周波数範囲となる。こ
の図３に破線で示す発振周波数範囲ａは、発振周波数範
囲を可変にしない従来の場合の例（図５のＡ参照）で、
従来はエネルギー拡散による周波数偏移を全て含んだ範
囲の広い単一の発振周波数範囲ａを設定する必要がある
のに比べ、各発振周波数範囲ｘ，ｙ，ｚを非常に狭く設
定させることができる。Here, FIG. 3 shows a change state of the oscillation frequency range of the voltage controlled oscillator 3. If the maximum frequency deviation from the center frequency of the energy diffusion wave is ± Δf, FM
Oscillation frequency ranges y and z, which are vertically shifted by ± Δf from the oscillation frequency range x centered on the original center frequency f 0 of the modulated wave, are the lower and upper oscillation frequency ranges. The oscillation frequency range a indicated by the broken line in FIG. 3 is an example of a conventional case where the oscillation frequency range is not variable (see A in FIG. 5).
Conventionally, it is necessary to set a single oscillating frequency range a having a wide range including all frequency deviations due to energy diffusion, whereas each oscillating frequency range x, y, z can be set extremely narrow. ..

【００２４】このように本例の検波回路によると、検波
用のＰＬＬ回路を構成する電圧制御発振器３の発振周波
数範囲を狭くすることができ、電圧制御発振器３の制御
特性の直線性が向上するなどの利益があると共に、出力
端子６に得られる検波信号としてエネルギー拡散成分が
含まれなくなり、後段の回路でエネルギー拡散成分を除
去する必要がなくなり、クランプ回路などが必要なくな
る。この場合、特に本例においては、ＦＭ変調波の中心
周波数が、電圧制御発振器３の発振周波数範囲の中心に
なるように制御したことで、電圧制御発振器３の発振範
囲を非常に狭くすることができ、ＦＭ変調波からエネル
ギー拡散成分を除去した分だけの発振周波数範囲で、入
力ＦＭ変調波を良好に検波することができる。As described above, according to the detection circuit of this example, the oscillation frequency range of the voltage controlled oscillator 3 which constitutes the detection PLL circuit can be narrowed, and the linearity of the control characteristic of the voltage controlled oscillator 3 is improved. In addition to the above advantages, the detection signal obtained at the output terminal 6 does not include the energy diffusion component, so that it is not necessary to remove the energy diffusion component in the subsequent circuit, and the clamp circuit is not required. In this case, in particular, in this example, by controlling the center frequency of the FM-modulated wave to be the center of the oscillation frequency range of the voltage controlled oscillator 3, the oscillation range of the voltage controlled oscillator 3 can be made extremely narrow. Therefore, the input FM modulated wave can be satisfactorily detected within the oscillation frequency range corresponding to the amount of the energy diffusion component removed from the FM modulated wave.

【００２５】なお、上述実施例では衛星放送受信装置の
検波回路に適用したが、他のエネルギー拡散された各種
変調波を検波する回路にも適用できることは勿論であ
る。Although the above-described embodiment is applied to the detection circuit of the satellite broadcast receiving apparatus, it is needless to say that it is also applicable to a circuit for detecting other various energy-modulated modulated waves.

【００２６】[0026]

【発明の効果】本発明によると、ＦＭ変調波のエネルギ
ー拡散成分に対応して電圧制御発振器の発振周波数が変
化することになり、検波出力としてエネルギー拡散成分
が除去された信号が得られ、電圧制御発振器の発振周波
数範囲として比較的狭い範囲で、エネルギー拡散された
ＦＭ変調波の検波が良好にできる。According to the present invention, the oscillation frequency of the voltage controlled oscillator changes in accordance with the energy spread component of the FM modulated wave, so that a signal from which the energy spread component is removed is obtained as the detection output, and the voltage It is possible to favorably detect the FM-modulated wave in which the energy is diffused in a relatively narrow range as the oscillation frequency range of the controlled oscillator.

【図面の簡単な説明】[Brief description of drawings]

【図１】本発明の一実施例を示す構成図である。FIG. 1 is a configuration diagram showing an embodiment of the present invention.

【図２】一実施例の説明に供する周波数特性図である。FIG. 2 is a frequency characteristic diagram for explaining an embodiment.

【図３】一実施例の説明に供する周波数特性図である。FIG. 3 is a frequency characteristic diagram for explaining one embodiment.

【図４】従来のＦＭ検波回路の一例を示す構成図であ
る。FIG. 4 is a configuration diagram showing an example of a conventional FM detection circuit.

【図５】エネルギー拡散されたＦＭ変調波に対する検波
特性を示す特性図である。FIG. 5 is a characteristic diagram showing a detection characteristic for an FM-modulated wave in which energy is diffused.

【符号の説明】[Explanation of symbols]

１ 入力端子 ２ 位相比較器 ３ 電圧制御発振器 ４ ループフィルタ ６ 検波信号出力端子 １１ ループフィルタ １２ 交流成分検出回路 １３ 振幅検出回路 １４ 三角波発生器 １６ 同期検出回路 1 Input Terminal 2 Phase Comparator 3 Voltage Controlled Oscillator 4 Loop Filter 6 Detection Signal Output Terminal 11 Loop Filter 12 AC Component Detection Circuit 13 Amplitude Detection Circuit 14 Triangular Wave Generator 16 Synchronization Detection Circuit

Claims (2)

【特許請求の範囲】[Claims] 【請求項１】 エネルギー拡散されたＦＭ変調波を検波
するフェーズ・ロックド・ループ回路と、上記ＦＭ変調
波のエネルギー拡散成分を検出する検出手段と、上記エ
ネルギー拡散成分に相当する擬似拡散波形の発生手段と
を設け、 上記検出手段の出力に基づいて、上記発生手段が出力す
る擬似拡散波形の調整を行い、この調整された擬似拡散
波形信号で上記フェーズ・ロックド・ループ回路を構成
する電圧制御発振器の発振周波数範囲を制御するように
したＦＭ変調波の検波回路。1. A phase-locked loop circuit for detecting an energy-modulated FM modulation wave, a detection means for detecting an energy diffusion component of the FM modulation wave, and a pseudo-diffusion waveform corresponding to the energy diffusion component. Means for adjusting the pseudo spread waveform output from the generating means on the basis of the output of the detecting means, and the voltage controlled oscillator constituting the phase locked loop circuit with the adjusted pseudo spread waveform signal. An FM-modulated wave detection circuit configured to control the oscillation frequency range of. 【請求項２】 上記電圧制御発振器での擬似拡散波形信
号による発振周波数範囲の調整により、上記ＦＭ変調波
の中心周波数が、上記発振周波数範囲のほぼ中心になる
ようにした請求項１記載のＦＭ変調波の検波回路。2. The FM according to claim 1, wherein the center frequency of the FM modulated wave is adjusted to be substantially at the center of the oscillation frequency range by adjusting the oscillation frequency range by the pseudo spread waveform signal in the voltage controlled oscillator. Modulation wave detection circuit.
JP3335148A 1991-12-18 1991-12-18 Detection circuit for fm modulated wave Pending JPH05168020A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP3335148A JPH05168020A (en) 1991-12-18 1991-12-18 Detection circuit for fm modulated wave

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP3335148A JPH05168020A (en) 1991-12-18 1991-12-18 Detection circuit for fm modulated wave

Publications (1)

Publication Number Publication Date
JPH05168020A true JPH05168020A (en) 1993-07-02

Family

ID=18285302

Family Applications (1)

Application Number Title Priority Date Filing Date
JP3335148A Pending JPH05168020A (en) 1991-12-18 1991-12-18 Detection circuit for fm modulated wave

Country Status (1)

Country Link
JP (1) JPH05168020A (en)

Similar Documents

Publication Publication Date Title
US5600680A (en) High frequency receiving apparatus
US5446411A (en) Frequency tuning for a phase locked loop FM demodulator
JPH0628338B2 (en) Phase locked loop and direct mixed sync AM receiver using the same
KR100256455B1 (en) Receiver
JPH07170127A (en) Fm audio carrier wave demodulation method and demodulator
JPH0715371A (en) Superheterodyne system transmission/reception method and transmitter/receiver
JPH0720017B2 (en) FM demodulator
JPS5997233A (en) Direct mixing synchronous receiver
JPS5912214B2 (en) Synchronous signal generation circuit
US4426627A (en) Phase-locked loop oscillator circuit utilizing a sub-loop with a second phase comparator
JPH05168020A (en) Detection circuit for fm modulated wave
JP3818694B2 (en) Television signal receiving circuit
JP3227358B2 (en) Tuner device
JPS5951182B2 (en) AM receiver
JPH1079666A (en) Phase locked loop oscillation circuit
US3982198A (en) Oscillators
JPH0255988B2 (en)
KR0130840Y1 (en) Frequency sellecting circuit
KR0122005B1 (en) Multi frequency modulation phase locked loop detection apparatus
EP1091487B1 (en) Method and apparatus for eliminating self quieter signals generated in synthesiser receivers
JPH03284075A (en) Video intermediate frequency circuit
JPH09135167A (en) Phase locked loop circuit device
JP2000505962A (en) Voltage controlled crystal oscillator and loop filter
US6201447B1 (en) Phase synchronization circuit with units for setting sweep frequency and control voltage
JPS609204A (en) Detection circuit of television signal