JPH0758637A - Frequency synthesizer - Google Patents
Frequency synthesizerInfo
- Publication number
- JPH0758637A JPH0758637A JP5222213A JP22221393A JPH0758637A JP H0758637 A JPH0758637 A JP H0758637A JP 5222213 A JP5222213 A JP 5222213A JP 22221393 A JP22221393 A JP 22221393A JP H0758637 A JPH0758637 A JP H0758637A
- Authority
- JP
- Japan
- Prior art keywords
- frequency
- vco
- control voltage
- capacitor
- capacitance
- 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
- 239000003990 capacitor Substances 0.000 claims abstract description 17
- 230000010355 oscillation Effects 0.000 abstract description 14
- 238000010586 diagram Methods 0.000 description 4
- 230000035945 sensitivity Effects 0.000 description 2
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03C—MODULATION
- H03C3/00—Angle modulation
- H03C3/02—Details
- H03C3/09—Modifications of modulator for regulating the mean frequency
- H03C3/0908—Modifications of modulator for regulating the mean frequency using a phase locked loop
- H03C3/095—Modifications of modulator for regulating the mean frequency using a phase locked loop applying frequency modulation to the loop in front of the voltage controlled oscillator
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03C—MODULATION
- H03C3/00—Angle modulation
- H03C3/02—Details
- H03C3/09—Modifications of modulator for regulating the mean frequency
- H03C3/0908—Modifications of modulator for regulating the mean frequency using a phase locked loop
- H03C3/0916—Modifications of modulator for regulating the mean frequency using a phase locked loop with frequency divider or counter in the loop
- H03C3/0925—Modifications of modulator for regulating the mean frequency using a phase locked loop with frequency divider or counter in the loop applying frequency modulation at the divider in the feedback loop
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03C—MODULATION
- H03C3/00—Angle modulation
- H03C3/02—Details
- H03C3/09—Modifications of modulator for regulating the mean frequency
- H03C3/0908—Modifications of modulator for regulating the mean frequency using a phase locked loop
- H03C3/0941—Modifications of modulator for regulating the mean frequency using a phase locked loop applying frequency modulation at more than one point in the loop
-
- 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
- H03L7/06—Automatic control of frequency or phase; Synchronisation using a reference signal applied to a frequency- or phase-locked loop
- H03L7/08—Details of the phase-locked loop
- H03L7/099—Details of the phase-locked loop concerning mainly the controlled oscillator of the loop
-
- 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
- H03L7/06—Automatic control of frequency or phase; Synchronisation using a reference signal applied to a frequency- or phase-locked loop
- H03L7/16—Indirect frequency synthesis, i.e. generating a desired one of a number of predetermined frequencies using a frequency- or phase-locked loop
- H03L7/18—Indirect frequency synthesis, i.e. generating a desired one of a number of predetermined frequencies using a frequency- or phase-locked loop using a frequency divider or counter in the loop
- H03L7/183—Indirect frequency synthesis, i.e. generating a desired one of a number of predetermined frequencies using a frequency- or phase-locked loop using a frequency divider or counter in the loop a time difference being used for locking the loop, the counter counting between fixed numbers or the frequency divider dividing by a fixed number
- H03L7/187—Indirect frequency synthesis, i.e. generating a desired one of a number of predetermined frequencies using a frequency- or phase-locked loop using a frequency divider or counter in the loop a time difference being used for locking the loop, the counter counting between fixed numbers or the frequency divider dividing by a fixed number using means for coarse tuning the voltage controlled oscillator of the loop
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03L—AUTOMATIC CONTROL, STARTING, SYNCHRONISATION OR STABILISATION OF GENERATORS OF ELECTRONIC OSCILLATIONS OR PULSES
- H03L2207/00—Indexing scheme relating to automatic control of frequency or phase and to synchronisation
- H03L2207/06—Phase locked loops with a controlled oscillator having at least two frequency control terminals
Landscapes
- Stabilization Of Oscillater, Synchronisation, Frequency Synthesizers (AREA)
- Digital Transmission Methods That Use Modulated Carrier Waves (AREA)
Abstract
Description
【0001】[0001]
【産業上の利用分野】本発明は周波数シンセサイザに関
し、特にディジタル変復調を行う無線通信に用いる周波
数シンセサイザに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a frequency synthesizer, and more particularly to a frequency synthesizer used for wireless communication for digital modulation / demodulation.
【0002】[0002]
【従来の技術】周波数シンセサイザは、その内部に備え
た電圧制御発振器(以下VCOという)への制御電圧を
調節することによって所望周波数の信号を出力するもの
である。2. Description of the Related Art A frequency synthesizer outputs a signal of a desired frequency by adjusting a control voltage to a voltage controlled oscillator (hereinafter referred to as VCO) provided therein.
【0003】図3は従来の周波数シンセサイザのブロッ
ク図である。FIG. 3 is a block diagram of a conventional frequency synthesizer.
【0004】周波数シンセサイザ1aは、基準信号を発
振する基準発振器9と、要求される周波数に基づいて分
周器7の分周数Nを指定する制御部5aと、制御部5a
で指定された分周数Nでバッファアンプ6からの信号を
分周する分周器7と、基準発振器9からの信号の位相と
分周器7からの信号の位相とを比較し比較結果を出力す
る位相比較器8と、位相比較器8の出力に基づいて位相
の進み/遅れの量を電圧に変換するチャージポンプ4
と、チャージポンプ4からの電圧のうち直流成分以外を
除去するローパスフィルタ3と、ローパスフィルタ3か
らの制御電圧に応じた周波数の信号を出力するVCO2
aと、VCO2aからの信号を増幅するバッファアンプ
6および10とから成る。The frequency synthesizer 1a includes a reference oscillator 9 that oscillates a reference signal, a control unit 5a that specifies the frequency division number N of the frequency divider 7 based on a required frequency, and a control unit 5a.
The frequency divider 7 that divides the signal from the buffer amplifier 6 by the frequency division number N specified in step 1 and the phase of the signal from the reference oscillator 9 and the phase of the signal from the frequency divider 7 are compared, and the comparison result is shown. A phase comparator 8 for outputting and a charge pump 4 for converting the amount of lead / lag of the phase into a voltage based on the output of the phase comparator 8.
And a low-pass filter 3 that removes components other than the DC component of the voltage from the charge pump 4, and a VCO 2 that outputs a signal having a frequency according to the control voltage from the low-pass filter 3.
a and buffer amplifiers 6 and 10 for amplifying the signal from the VCO 2a.
【0005】VCO2aは、可変容量ダイオード23a
と、コンデンサ22a、と発振部21aとから成り、端
子27aに印加される制御電圧に応じて可変容量ダイオ
ード23aのキャパシタンスを変化させ、発振する周波
数を変化させる。The VCO 2a is a variable capacitance diode 23a.
The capacitor 22a and the oscillator 21a change the capacitance of the variable capacitance diode 23a according to the control voltage applied to the terminal 27a to change the oscillation frequency.
【0006】図4は、図3に示したVCO2aの制御電
圧−発振周波数特性を示すグラフである。FIG. 4 is a graph showing control voltage-oscillation frequency characteristics of the VCO 2a shown in FIG.
【0007】図4において、横軸は端子27aに印加さ
れる制御電圧であり、縦軸は端子26aから出力する信
号の発振周波数である。図4に示すように、制御電圧を
V1からV2 へと変化させると、発振周波数はf1 から
f2 へと変化する。In FIG. 4, the horizontal axis is the control voltage applied to the terminal 27a, and the vertical axis is the oscillation frequency of the signal output from the terminal 26a. As shown in FIG. 4, when the control voltage is changed from V 1 to V 2 , the oscillation frequency changes from f 1 to f 2 .
【0008】[0008]
【発明が解決しようとする課題】最近では、周波数シン
セサイザを使用する無線機において、広帯域のものが求
められている。このため周波数シンセサイザも1つで広
帯域の周波数を発振するものが求められる。Recently, a wireless device using a frequency synthesizer is required to have a wide band. Therefore, one frequency synthesizer is required to oscillate a wide band frequency.
【0009】ところで、図4に示したように、従来の周
波数シンセサイザはVCOの発振周波数と制御電圧が1
対1に対応しているので、発振周波数の帯域を広くする
ためには、制御電圧−発振周波数特性の曲線の傾き、す
なわち変調感度を大きくし制御電圧が少し変化しただけ
で発振周波数が大きく変化するようにする必要がある。By the way, as shown in FIG. 4, in the conventional frequency synthesizer, the oscillation frequency of the VCO and the control voltage are 1.
Since it corresponds to 1: 1, in order to widen the oscillation frequency band, the slope of the curve of the control voltage-oscillation frequency characteristic, that is, the modulation sensitivity is increased and the oscillation frequency changes greatly even if the control voltage slightly changes. Need to do.
【0010】しかし、このような周波数シンセサイザで
は、VCOの制御電圧ラインから廻り込んでくるノイズ
がそのままVCOの出力の位相ノイズとなって現れてし
まい、この位相ノイズの影響はQPSK(四相差動位相
変調)やMSK(最小偏移変調)等のディジタル変調を
行う無線機にとっては致命的な問題である。However, in such a frequency synthesizer, the noise sneaking from the control voltage line of the VCO appears as the phase noise of the output of the VCO as it is, and the influence of this phase noise is QPSK (four-phase differential phase). This is a fatal problem for a wireless device that performs digital modulation such as modulation) or MSK (minimum shift keying).
【0011】本発明は上記の点にかんがみてなされたも
ので、広い周波数帯域を確保しつつVCOの制御電圧ラ
インから廻り込んでくるノイズの影響による位相ノイズ
を低減した周波数シンセサイザを提供することを目的と
する。The present invention has been made in view of the above points, and it is an object of the present invention to provide a frequency synthesizer which secures a wide frequency band and reduces the phase noise due to the influence of noise sneaking from the control voltage line of the VCO. To aim.
【0012】[0012]
【課題を解決するための手段】本発明は上記の目的を達
成するために、供給される制御電圧に応じて可変容量ダ
イオードのキャパシタンスを変化させることでキャパシ
タンス成分を変化させ周波数を可変発振する電圧制御発
振器を有する周波数シンセサイザにおいて、前記制御電
圧による前記可変容量ダイオードのキャパシタンス変化
とは別に、前記電圧制御発振器の前記キャパシタンス成
分を変化させるキャパシタンス可変手段を設けた。SUMMARY OF THE INVENTION In order to achieve the above object, the present invention changes the capacitance of a variable capacitance diode according to a supplied control voltage to change a capacitance component and oscillate a frequency variably. In a frequency synthesizer having a controlled oscillator, a capacitance varying means for varying the capacitance component of the voltage controlled oscillator is provided in addition to the capacitance variation of the variable capacitance diode due to the control voltage.
【0013】[0013]
【作用】本発明は以上の構成によって、キャパシタンス
可変手段により電圧制御発振器のキャパシタンス成分を
変化させることにより、制御電圧の変化による発振周波
数の変化幅が小さくても広帯域の周波数を発振すること
ができる。According to the present invention, by changing the capacitance component of the voltage controlled oscillator by the capacitance varying means, it is possible to oscillate a wide band frequency even if the change width of the oscillation frequency due to the change of the control voltage is small. .
【0014】[0014]
【実施例】以下本発明を図面に基づいて説明する。DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.
【0015】図1は本発明による周波数シンセサイザの
ブロック図である。FIG. 1 is a block diagram of a frequency synthesizer according to the present invention.
【0016】周波数シンセサイザ1は、基準信号を発振
する基準発振器9と、要求される周波数に基づいて分周
器7の分周数Nを指定するとともにVCO2内のスイッ
チ25のON/OFF制御を行う制御部5と、制御部5
で指定された分周数Nでバッファアンプ6からの信号を
分周する分周器7と、基準発振器9からの信号の位相と
分周器7からの信号の位相とを比較し比較結果を出力す
る位相比較器8と、位相比較器8の出力に基づいて位相
の進み/遅れの量を電圧に変換するチャージポンプ4
と、チャージポンプ4からの電圧のうち直流成分以外を
除去するローパスフィルタ3と、ローパスフィルタ3か
らの制御電圧に応じた周波数の信号を出力するVCO2
と、VCO2からの信号を増幅するバッファアンプ6お
よび10とから成る。The frequency synthesizer 1 designates a reference oscillator 9 which oscillates a reference signal, a frequency division number N of the frequency divider 7 based on a required frequency, and controls ON / OFF of a switch 25 in the VCO 2. Control unit 5 and control unit 5
The frequency divider 7 that divides the signal from the buffer amplifier 6 by the frequency division number N specified in step 1 and the phase of the signal from the reference oscillator 9 and the phase of the signal from the frequency divider 7 are compared, and the comparison result is shown. A phase comparator 8 for outputting and a charge pump 4 for converting the amount of lead / lag of the phase into a voltage based on the output of the phase comparator 8.
And a low-pass filter 3 that removes components other than the DC component of the voltage from the charge pump 4, and a VCO 2 that outputs a signal having a frequency according to the control voltage from the low-pass filter 3.
And buffer amplifiers 6 and 10 for amplifying the signal from the VCO 2.
【0017】VCO2は、可変容量ダイオード23と、
コンデンサ22と、発振部21と、発振部21とコンデ
ンサ22との間に一端が接続されたコンデンサ24と、
コンデンサ24とアースとの間に接続されたスイッチ2
5とから成り、端子27に印加される制御電圧を調整す
ることにより可変容量ダイオード23のキャパシタンス
を変化させ、発振する周波数を変化させる。The VCO 2 has a variable capacitance diode 23,
A capacitor 22, an oscillating unit 21, a capacitor 24 having one end connected between the oscillating unit 21 and the capacitor 22,
Switch 2 connected between capacitor 24 and ground
5, the capacitance of the variable capacitance diode 23 is changed by adjusting the control voltage applied to the terminal 27, and the oscillation frequency is changed.
【0018】図2は、図1に示したVCO2の制御電圧
−発振周波数特性を示すグラフである。FIG. 2 is a graph showing the control voltage-oscillation frequency characteristic of the VCO 2 shown in FIG.
【0019】図2において、横軸は端子27に印加され
る制御電圧であり、縦軸は端子26から出力する信号の
発振周波数である。曲線aはスイッチ25がONのとき
の特性を示し、曲線bはスイッチ25がOFFのときの
特性を示す。In FIG. 2, the horizontal axis is the control voltage applied to the terminal 27, and the vertical axis is the oscillation frequency of the signal output from the terminal 26. The curve a shows the characteristic when the switch 25 is ON, and the curve b shows the characteristic when the switch 25 is OFF.
【0020】VCO2が発振する周波数は、制御部5が
要求される周波数に応じて端子28を介してスイッチ2
5をONにした場合には、図2の曲線aに示すように制
御電圧をV1 からV2 へと変化させたときf1 からf4
へと変化し、制御部5が要求される周波数に応じて端子
28を介してスイッチ25をOFFにした場合には、図
2の曲線bに示すように制御電圧をV1 からV2 へと変
化させたとき発振周波数はf3 からf2 へと変化する。The frequency at which the VCO 2 oscillates depends on the frequency required by the control section 5 and the switch 2 via the terminal 28.
When 5 is turned on, when the control voltage is changed from V 1 to V 2 as shown by the curve a in FIG. 2, f 1 to f 4
When the control unit 5 turns off the switch 25 via the terminal 28 according to the required frequency, the control voltage is changed from V 1 to V 2 as shown by the curve b in FIG. When changed, the oscillation frequency changes from f 3 to f 2 .
【0021】すなわち、本実施例においては、スイッチ
25がONかOFFかによってVCO2のキャパシタン
ス成分を異ならせ、1つの周波数シンセサイザで2種類
の制御電圧−発振周波数特性を有するようにし、この2
種類の制御電圧−発振周波数特性でf1 からのf2 まで
の周波数帯域をカバーしている。That is, in this embodiment, the capacitance component of the VCO 2 is made different depending on whether the switch 25 is ON or OFF so that one frequency synthesizer has two kinds of control voltage-oscillation frequency characteristics.
The control voltage-oscillation frequency characteristics of various types cover the frequency band from f 1 to f 2 .
【0022】なお、本実施例では、コンデンサ24を発
振部21とコンデンサ22との間に接続したが、本発明
はこれに限らずスイッチ25のON/OFFでVCO2
のキャパシタンス成分を変化させることができればよ
い。In the present embodiment, the capacitor 24 is connected between the oscillator 21 and the capacitor 22, but the present invention is not limited to this, and the VCO2 can be turned ON / OFF by the switch 25.
It suffices if the capacitance component of can be changed.
【0023】また、本実施例では、スイッチ(スイッチ
25)のOFFで回路から切り離されるコンデンサ(コ
ンデンサ24)を1つだけ設けたが、本発明は、このよ
うなスイッチとコンデンサとを2組以上設けて3種類以
上の制御電圧−発振周波数特性を有するようにしてもよ
い。この制御電圧−発振周波数特性の種類を多くすれば
するほど個々の制御電圧−発振周波数特性の傾きを小さ
くすることができる。Further, in the present embodiment, only one capacitor (capacitor 24) which is disconnected from the circuit when the switch (switch 25) is turned off is provided, but the present invention provides two or more sets of such switch and capacitor. It may be provided so as to have three or more kinds of control voltage-oscillation frequency characteristics. The slope of each control voltage-oscillation frequency characteristic can be made smaller as the number of types of the control voltage-oscillation frequency characteristic is increased.
【0024】さらに、スイッチ25は機械的スイッチで
あっても電子的スイッチであってもかまわない。Further, the switch 25 may be a mechanical switch or an electronic switch.
【0025】[0025]
【発明の効果】以上説明したように、本発明によれば、
VCO内のスイッチのON/OFFによりVCOの発振
周波数をシフトさせることで、同じ制御電圧に対して複
数の発振周波数を設定できるので、要求される周波数帯
域のすべてを単一の制御電圧−発振周波数特性でカバー
する従来の周波数シンセサイザに比べてVCOの制御電
圧−発振周波数特性の曲線の傾き、すなわち変調感度を
小さく設定することができ、VCOの制御電圧ラインか
ら廻り込んでくるノイズがVCOの出力の位相ノイズと
なって現れるのを低減することができる。As described above, according to the present invention,
Since multiple oscillation frequencies can be set for the same control voltage by shifting the oscillation frequency of the VCO by turning ON / OFF the switch in the VCO, all required frequency bands are controlled by a single control voltage-oscillation frequency. The slope of the curve of the control voltage-oscillation frequency characteristic of the VCO, that is, the modulation sensitivity can be set smaller than that of the conventional frequency synthesizer covered by the characteristics, and the noise sneaking in from the control voltage line of the VCO is output by the VCO. It is possible to reduce the appearance of the phase noise of.
【0026】このように、本発明によれば、周波数シン
セサイザの出力の位相ノイズを低減することができるの
で、QPSKやMSK等のディジタル変調を行う無線機
に適した周波数シンセサイザを実現することができる。As described above, according to the present invention, since the phase noise of the output of the frequency synthesizer can be reduced, it is possible to realize a frequency synthesizer suitable for a radio device for performing digital modulation such as QPSK or MSK. .
【図1】本発明による周波数シンセサイザのブロック図
である。FIG. 1 is a block diagram of a frequency synthesizer according to the present invention.
【図2】図1に示したVCOの制御電圧−発振周波数特
性を示すグラフである。FIG. 2 is a graph showing control voltage-oscillation frequency characteristics of the VCO shown in FIG.
【図3】従来の周波数シンセサイザのブロック図であ
る。FIG. 3 is a block diagram of a conventional frequency synthesizer.
【図4】図3に示したVCOの制御電圧−発振周波数特
性を示すグラフである。FIG. 4 is a graph showing control voltage-oscillation frequency characteristics of the VCO shown in FIG.
1 周波数シンセサイザ 2 VCO 3 ローパスフィルタ 4 チャージポンプ 5 制御部 6 バッファアンプ 7 分周器 8 位相比較器 9 基準発振器 10 バッファアンプ 11 端子 21 発振部 22 コンデンサ 23 可変容量ダイオード 24 コンデンサ 25 スイッチ 26 端子 27 端子 28 端子 1 Frequency Synthesizer 2 VCO 3 Low Pass Filter 4 Charge Pump 5 Control Section 6 Buffer Amplifier 7 Frequency Divider 8 Phase Comparator 9 Reference Oscillator 10 Buffer Amplifier 11 Terminal 21 Oscillation Section 22 Capacitor 23 Variable Capacitance Diode 24 Capacitor 25 Switch 26 Terminal 27 Terminal 28 terminals
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.6 識別記号 庁内整理番号 FI 技術表示箇所 9297−5K H04L 27/00 Z ─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. 6 Identification number Office reference number FI technical display location 9297-5K H04L 27/00 Z
Claims (2)
イオードのキャパシタンスを変化させることでキャパシ
タンス成分を変化させ周波数を可変発振する電圧制御発
振器を有する周波数シンセサイザにおいて、 前記制御電圧による前記可変容量ダイオードのキャパシ
タンス変化とは別に、前記電圧制御発振器の前記キャパ
シタンス成分を変化させるキャパシタンス可変手段を設
けたことを特徴とする周波数シンセサイザ。1. A frequency synthesizer having a voltage controlled oscillator for varying a capacitance component by varying a capacitance of the variable capacitance diode according to a supplied control voltage to variably oscillate a frequency, the variable capacitance diode according to the control voltage. In addition to the capacitance change, the frequency synthesizer is provided with capacitance changing means for changing the capacitance component of the voltage controlled oscillator.
圧制御発振器のキャパシタンス成分を構成するコンデン
サと、ON時に前記コンデンサを前記電圧制御発振器に
接続しOFF時に前記コンデンサを前記電圧制御発振器
から切離すスイッチ回路と、該スイッチ回路のON/O
FFを制御するスイッチ制御手段とから成ることを特徴
とする請求項1に記載の周波数シンセサイザ。2. The capacitance varying means includes a capacitor that constitutes a capacitance component of the voltage controlled oscillator, and a switch circuit that connects the capacitor to the voltage controlled oscillator when turned on and disconnects the capacitor from the voltage controlled oscillator when turned off. And ON / O of the switch circuit
The frequency synthesizer according to claim 1, further comprising switch control means for controlling the FF.
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP5222213A JPH0758637A (en) | 1993-08-13 | 1993-08-13 | Frequency synthesizer |
GB9525281A GB2294830A (en) | 1993-08-13 | 1994-08-12 | Frequency synthesizer |
GB9416381A GB2282285A (en) | 1993-08-13 | 1994-08-12 | VCO; Frequency synthesizers |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP5222213A JPH0758637A (en) | 1993-08-13 | 1993-08-13 | Frequency synthesizer |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH0758637A true JPH0758637A (en) | 1995-03-03 |
Family
ID=16778910
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP5222213A Pending JPH0758637A (en) | 1993-08-13 | 1993-08-13 | Frequency synthesizer |
Country Status (2)
Country | Link |
---|---|
JP (1) | JPH0758637A (en) |
GB (1) | GB2282285A (en) |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0812066A4 (en) * | 1995-12-25 | 1999-03-24 | Matsushita Electric Ind Co Ltd | High-frequency device |
JP3488180B2 (en) * | 2000-05-30 | 2004-01-19 | 松下電器産業株式会社 | Frequency synthesizer |
GB2370167B (en) * | 2000-12-18 | 2005-01-05 | Texas Instruments Ltd | Improvements in or relating to phase locked loops |
DE10122194A1 (en) | 2001-05-08 | 2002-11-28 | Infineon Technologies Ag | Phase-locked loop |
US6873214B2 (en) | 2002-05-03 | 2005-03-29 | Texas Instruments Incorporated | Use of configurable capacitors to tune a self biased phase locked loop |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5676639A (en) * | 1979-11-27 | 1981-06-24 | Trio Kenwood Corp | Synthesizer receiver |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2511563B1 (en) * | 1981-08-14 | 1986-05-16 | Trt Telecom Radio Electr | PHASE LOCKING DEVICE FOR PROVIDING SIGNALS WHOSE FREQUENCY MAY VARY ON A WIDE RANGE |
GB2120478B (en) * | 1982-04-22 | 1985-10-16 | Standard Telephones Cables Ltd | Voltage controlled oscillator |
US4510465A (en) * | 1983-08-12 | 1985-04-09 | Motorola, Inc. | Linear gain voltage controlled oscillator with modulation compensation |
-
1993
- 1993-08-13 JP JP5222213A patent/JPH0758637A/en active Pending
-
1994
- 1994-08-12 GB GB9416381A patent/GB2282285A/en not_active Withdrawn
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5676639A (en) * | 1979-11-27 | 1981-06-24 | Trio Kenwood Corp | Synthesizer receiver |
Also Published As
Publication number | Publication date |
---|---|
GB9416381D0 (en) | 1994-10-05 |
GB2282285A (en) | 1995-03-29 |
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