JPH04100355A - Modulation circuit - Google Patents
Modulation circuitInfo
- Publication number
- JPH04100355A JPH04100355A JP21730090A JP21730090A JPH04100355A JP H04100355 A JPH04100355 A JP H04100355A JP 21730090 A JP21730090 A JP 21730090A JP 21730090 A JP21730090 A JP 21730090A JP H04100355 A JPH04100355 A JP H04100355A
- Authority
- JP
- Japan
- Prior art keywords
- modulation circuit
- circuit
- data
- power amplifier
- frequency power
- 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
- 230000005540 biological transmission Effects 0.000 claims abstract description 10
- 238000001228 spectrum Methods 0.000 claims description 8
- 238000006243 chemical reaction Methods 0.000 claims description 2
- 230000004044 response Effects 0.000 abstract 2
- 238000010586 diagram Methods 0.000 description 5
- 230000003321 amplification Effects 0.000 description 3
- 238000003199 nucleic acid amplification method Methods 0.000 description 3
- 230000003595 spectral effect Effects 0.000 description 3
- 239000004065 semiconductor Substances 0.000 description 2
- 230000001419 dependent effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000000750 progressive effect Effects 0.000 description 1
Landscapes
- Reduction Or Emphasis Of Bandwidth Of Signals (AREA)
- Digital Transmission Methods That Use Modulated Carrier Waves (AREA)
Abstract
Description
【発明の詳細な説明】
［産業上の利用分野］
この発明は送信データをディジタル信号として伝送する
無線機に使用されるような変調回路に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a modulation circuit used in a radio device that transmits transmission data as a digital signal.
［従来の技術］
第３図および第４図は従来の送信機を示す概略ブロック
図である。第３図を参照して、高周波発振器１は高周波
信号を発生して平衡変調回路２に与える。平衡変調回路
２は高周波発振器１から与えられた高周波信号をディジ
タルでＢＰＳＫ変調し、その変調出力を高周波電力増幅
回路３に与える。高周波電力増幅回路３は変調信号を所
定の送信電力まで増幅し、アンテナ４を介して空間に放
射する。[Prior Art] FIGS. 3 and 4 are schematic block diagrams showing a conventional transmitter. Referring to FIG. 3, high frequency oscillator 1 generates a high frequency signal and supplies it to balanced modulation circuit 2. Referring to FIG. The balanced modulation circuit 2 digitally modulates the high frequency signal given from the high frequency oscillator 1 with BPSK, and supplies the modulated output to the high frequency power amplifier circuit 3. The high frequency power amplification circuit 3 amplifies the modulated signal to a predetermined transmission power and radiates it into space via the antenna 4.
ところで、無線送信機において、有限の周波数を有効に
利用するために、できるだけ狭い周波数帯域幅となるよ
うな手段が必要とされる。このためには、平衡変調回路
２あるいは高周波電力増幅回路３のいずれかあるいは双
方に帯域制限フィルタを設けることが考えられているが
、最近のマイクロ波あるいはこれに近い高い周波数では
必要になる狭い周波数帯域幅のフィルタが実用上実現不
可能である。たとえば、１００１００Ｏの高周波で帯域
幅１００ｋＨｚを得ようとすれば、比帯域幅は１／１０
０００であり、これは実現（７得る帯域幅の温度変化特
性の１／２０００より少なく、実用できない。By the way, in a wireless transmitter, in order to make effective use of limited frequencies, a means for making the frequency bandwidth as narrow as possible is required. To this end, it has been considered to provide a band-limiting filter in either or both of the balanced modulation circuit 2 and the high-frequency power amplification circuit 3. However, with recent microwaves or similar high frequencies, narrow frequency bands are required. Bandwidth filters are not practical. For example, if you try to obtain a bandwidth of 100kHz with a high frequency of 100100O, the fractional bandwidth will be 1/10.
000, which is less than 1/2000 of the temperature change characteristic of the bandwidth obtained (7) and is not practical.
これ以外の方法として、第４図に示すように平衡変調回
路２の出力信号を低域通過フィルタ５を通して変調入力
の帯域幅を制限する方法がある。Another method is to limit the bandwidth of the modulation input by passing the output signal of the balanced modulation circuit 2 through a low-pass filter 5, as shown in FIG.
この場合は、高周波電力増幅回路３が線形でなければな
らない。すなわち、一般に半導体マイクロ波電力増幅回
路は、コスト、安定度および電源効率のために、Ｃ級動
作（非線形動作）を行なうが、平衡変調回路２の出力で
は、スペクトラムが帯域制限されても増幅回路の非線形
動作（進行ひずみ）により再びスペクトラム帯域が拡が
ることになる。In this case, the high frequency power amplifier circuit 3 must be linear. In other words, semiconductor microwave power amplifier circuits generally perform class C operation (nonlinear operation) for reasons of cost, stability, and power efficiency, but with the output of the balanced modulation circuit 2, even if the spectrum is band-limited, the amplifier circuit The spectral band will be broadened again due to the nonlinear operation (progressive distortion) of .
［発明が解決しようとする課８］
前述のごとく、光学的に実現不可能なスペクトラム帯域
制限手段が電力効率のよい（小型軽量で安値な）Ｃ級動
作（非線形動作）の高周波電力増幅回路で実現すること
を見出だす必要がある。なお、一般にそのような非線形
動作は使用する半導体によりばらつきがあり、また温度
や使用電圧への依存性が強いため、これらに対する適用
性を持つ回路であることが必要とされる。[Issue 8 to be solved by the invention] As mentioned above, the spectrum band limiting means, which is optically impossible to realize, can be achieved by using a power-efficient (small, lightweight, and inexpensive) class C operation (nonlinear operation) high-frequency power amplifier circuit. We need to find a way to make it happen. Note that such nonlinear operation generally varies depending on the semiconductor used and is strongly dependent on temperature and voltage used, so a circuit that is applicable to these is required.
それゆえに、この発明の主たる目的は、温度や使用電圧
に適用し、スペクトラム帯域を制限できる変調回路を提
供することである。Therefore, the main object of the present invention is to provide a modulation circuit that can be adapted to temperature and working voltage and to limit the spectral band.
［課題を解決するための手段］
第１ｒｆｌ求項に係る発明は、送信データを平衡変調し
て高周波電力増幅回路に与える変調回路であって、スペ
クトラム帯域幅を制限するために、高周波電力増幅回路
および変調回路の非線形動作を補正したディジタルデー
タを予め記憶する記憶手段と、送信データに応じて記憶
手段からディジタルデータを読出す読出手段と、ディジ
タルデータをアナログ信号に変換して変調回路に与える
変換手段とを備えて構成される。[Means for Solving the Problems] The invention according to the first rfl requirement is a modulation circuit that performs balanced modulation on transmission data and provides it to a high frequency power amplifier circuit, and in order to limit the spectrum bandwidth, the high frequency power amplifier circuit and storage means for pre-storing digital data corrected for non-linear operation of the modulation circuit, reading means for reading out digital data from the storage means in accordance with the transmitted data, and conversion means for converting the digital data into an analog signal and providing it to the modulation circuit. and means.
第２請求項に係る発明は、記憶手段には、高周波電力増
幅回路および変調回路の個々の特性を＃１定したデータ
に対応する補正データが記憶される。In the invention according to claim 2, the storage means stores correction data corresponding to data in which individual characteristics of the high frequency power amplifier circuit and the modulation circuit are #1 determined.
第３請求項に係る発明は、記憶手段には高周波電力増幅
回路および変調回路の温度特性および電源電圧特性に応
じて対応する補正データが記憶される。In the third aspect of the invention, the storage means stores correction data corresponding to the temperature characteristics and power supply voltage characteristics of the high frequency power amplifier circuit and the modulation circuit.
［作用］
この発明に係る変調回路は、送信データに応じて、記憶
手段からスペクトラム帯域幅を制限するために、高周波
電力増幅回路および変調回路の非線形動作を補正したデ
ィジタルデータを読出してアナログ信号に変換して変調
回路に与えることによって、周波数帯域幅を狭くするこ
とができる。[Operation] The modulation circuit according to the present invention reads digital data corrected for the nonlinear operation of the high frequency power amplifier circuit and the modulation circuit and converts it into an analog signal in order to limit the spectrum bandwidth from the storage means according to the transmission data. By converting the signal and applying it to the modulation circuit, the frequency bandwidth can be narrowed.
［発明の実施例］ 第１図はこの発明の一実施例の概略ブロック図である。[Embodiments of the invention] FIG. 1 is a schematic block diagram of an embodiment of the present invention.
第１図を参照して、高周波発振器１と平衡変調回路２と
高周波電力増幅回路３とアンテナ４は前述の第３図およ
び第４図に示したのと同し、である。さらに、この発明
の一実施例では、読出回路６とメモリ７とＤ／Ａ変換器
８とが設けられる。メモリ７はスペクトラム帯域幅を制
限するために、高周波電力増幅回路３および平衡変調回
路２の非線形動作を補正したディジタルデータを予め記
憶している。読出回路６は送信データに応じてメモリ７
からディジタルデータを読出し、Ｄ／Ａ変換器８に与え
る。Ｄ／Ａ変換器８はそのディジタルデータをアナログ
信号に変換して平衡変調回路２に与える。Referring to FIG. 1, a high frequency oscillator 1, a balanced modulation circuit 2, a high frequency power amplification circuit 3, and an antenna 4 are the same as those shown in FIGS. 3 and 4 described above. Further, in one embodiment of the present invention, a readout circuit 6, a memory 7, and a D/A converter 8 are provided. The memory 7 stores in advance digital data corrected for the nonlinear operations of the high frequency power amplifier circuit 3 and the balanced modulation circuit 2 in order to limit the spectrum bandwidth. The reading circuit 6 reads the memory 7 according to the transmitted data.
The digital data is read from the D/A converter 8 and provided to the D/A converter 8. The D/A converter 8 converts the digital data into an analog signal and supplies it to the balanced modulation circuit 2.
第２図は回路の非線形特性による補正した入力波形ｇ
（ｔ）と出力波形ｆ （ｔ）との関係を示す図である。Figure 2 shows the input waveform g corrected due to the nonlinear characteristics of the circuit.
(t) and the output waveform f (t).
次に、第１図および第２図を参照して、この発明の一実
施例の具体的な動作について説明する。Next, with reference to FIG. 1 and FIG. 2, a specific operation of an embodiment of the present invention will be described.
一般にディジタル信号の変調に応じて、矩形波パルス信
号のスペクトラムは無限に拡がるが、矩形波パルス波形
を形成して、たとえば二乗余弦波形ｆ （ｔ）にすれば
、その周波数スペクトラムが最少に留められることがす
でに知られている。たとえば、Ｄｉｇｉｔａｌ ｃｏ
ｍｍｕｎｉｃａｔｉｏｎｓ ｉｎ ５ａｔｅｌｌｉ
ｔｅ、ｂｙＪ、Ｂｅｌｌａｍｙ、Ｊｏｈｎ Ｗｉｌｅ
ｙ ＆ Ｓ。Generally, the spectrum of a square wave pulse signal expands infinitely depending on the modulation of the digital signal, but if the square wave pulse waveform is formed into, for example, a raised cosine waveform f (t), the frequency spectrum can be kept to a minimum. That is already known. For example, Digital co
communications in 5ateli
te, by J, Bellamy, John Wile
y&s.
ｎｓ、Ｉｎｃ、１９８２゜
ｆ （ｔ）−ｉｓ ｉｎ （πｔ／Ｔ） 争ｃｏｓ
（απｔ／Ｔ））／ （πｔ・ ［１−（２αｔ／Ｔ）
２１１
ここで、１／Ｔは信号速度であり、αはロールオフ係数
（１〉α〉０）である。第２図を参照して、高周波電力
増幅回路３の出力において、波形ｆ （ｔ）を得れば、
最少のスペクトラムの拡がりを持つ情報を放射すること
ができる。しかるに、前述のごとく第２図に示したＣ扱
高周波電力増幅回路３を使用するので、その非線形入出
力特性（Ｈ）を補正した入力波形ｇ （ｔ）を高周波電
力増幅回路３に与えることが必要である。このような波
形を達成できるように補正ディジタルデータがメモリ７
に記憶され、送信データに応じて、読出回路６によりメ
モリ７から補正データを読出し、Ｄ／Ａ変換器８によっ
てアナログ信号に変換し、このアナログ信号により高周
波発振器１からの高周波信号を変調することによって、
非線形入出力特性を補正することができる。ns, Inc, 1982゜f (t)-is in (πt/T) conflict cos
(απt/T))/(πt・[1-(2αt/T)
211 Here, 1/T is the signal speed and α is the roll-off coefficient (1>α>0). Referring to FIG. 2, if a waveform f (t) is obtained at the output of the high frequency power amplifier circuit 3,
Information can be emitted with minimal spectral spread. However, as mentioned above, since the C-handling high-frequency power amplifier circuit 3 shown in FIG. is necessary. Correction digital data is stored in memory 7 to achieve such a waveform.
The reading circuit 6 reads the correction data from the memory 7 according to the transmission data, converts it into an analog signal by the D/A converter 8, and modulates the high frequency signal from the high frequency oscillator 1 with this analog signal. By,
Nonlinear input/output characteristics can be corrected.
なお第１図に示したメモリ７に記憶する補正した波形デ
ータは、使用する電力増幅回路３の非線形特性を測定し
て求める以外に、電源電圧や使用温度の補正量を追加し
て使用してもよい。Note that the corrected waveform data stored in the memory 7 shown in Fig. 1 is obtained by measuring the nonlinear characteristics of the power amplifier circuit 3 used, and also by adding correction amounts for the power supply voltage and operating temperature. Good too.
［発明の効果］
以上のように、この発明によれば、高周波電力増幅回路
による非線形動作の補正量を含む成形されたディジタル
データを予め記憶しておき、送信データに応じてこの補
正データを読出してアナログ信号に変換し、変調回路に
加えることによって、周波数帯域幅を狭く制限すること
ができる。[Effects of the Invention] As described above, according to the present invention, shaped digital data including the amount of correction of nonlinear operation by the high-frequency power amplifier circuit is stored in advance, and this correction data is read out in accordance with the transmission data. By converting the signal into an analog signal and applying it to the modulation circuit, the frequency bandwidth can be narrowly limited.
第１図はこの発明の一実施例の概略ブロック図である。
第２図は回路の非線形特性による補正した入力波形ｇ
（ｔ）と出力波形ｆ （ｔ）との関係を示す図である。
第３図は従来のディジタル変調回路を示す概略ブロック
図である。第４図は低域通過フィルタを使用した従来の
ディジタル変調回路を示す概略ブロック図である。
図において、１は高周波発振器、２は平衡変調回路、３
は高周波電力増幅回路、４はアンテナ、６は読出回路、
７はメモリ、８はＤ／Ａ変換器を示す。
第２図
小ｈFIG. 1 is a schematic block diagram of an embodiment of the present invention. Figure 2 shows the input waveform g corrected due to the nonlinear characteristics of the circuit.
(t) and the output waveform f (t). FIG. 3 is a schematic block diagram showing a conventional digital modulation circuit. FIG. 4 is a schematic block diagram showing a conventional digital modulation circuit using a low-pass filter. In the figure, 1 is a high-frequency oscillator, 2 is a balanced modulation circuit, and 3 is a high-frequency oscillator.
is a high frequency power amplifier circuit, 4 is an antenna, 6 is a readout circuit,
7 represents a memory, and 8 represents a D/A converter. Figure 2 small h
Claims (3)
与える変調回路において、 スペクトラム帯域幅を制限するために、前記高周波電力
増幅回路および前記変調回路の非線形動作を補正したデ
ィジタルデータを予め記憶する記憶手段、 前記送信データに応じて、前記記憶手段からディジタル
データを読出す読出手段、および 前記ディジタルデータをアナログ信号に変換して変調回
路に与える変換手段を備えた、変調回路。(1) In a modulation circuit that balance-modulates transmission data and provides it to a high-frequency power amplifier circuit, in order to limit the spectrum bandwidth, digital data that has been corrected for nonlinear operations of the high-frequency power amplifier circuit and the modulation circuit is stored in advance. A modulation circuit comprising: storage means; readout means for reading digital data from the storage means in accordance with the transmission data; and conversion means for converting the digital data into an analog signal and providing it to a modulation circuit.
び前記変調回路の個々の特性を測定したデータに対応す
る補正データが記憶される、請求項第１項記載の変調回
路。(2) The modulation circuit according to claim 1, wherein the storage means stores correction data corresponding to data obtained by measuring individual characteristics of the high frequency power amplifier circuit and the modulation circuit.
び前記変調回路の温度特性および電源電圧特性に応じて
対応する補正データが記憶される、請求項第１項記載の
変調回路。(3) The modulation circuit according to claim 1, wherein the storage means stores correction data corresponding to temperature characteristics and power supply voltage characteristics of the high frequency power amplifier circuit and the modulation circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21730090A JPH04100355A (en) | 1990-08-17 | 1990-08-17 | Modulation circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21730090A JPH04100355A (en) | 1990-08-17 | 1990-08-17 | Modulation circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH04100355A true JPH04100355A (en) | 1992-04-02 |
Family
ID=16701982
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP21730090A Pending JPH04100355A (en) | 1990-08-17 | 1990-08-17 | Modulation circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH04100355A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0865352A (en) * | 1994-08-24 | 1996-03-08 | Yuseisho Tsushin Sogo Kenkyusho | Digital modulator |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58105658A (en) * | 1981-12-17 | 1983-06-23 | Nec Corp | Adaptive type modulating equipment |
| JPS59134950A (en) * | 1983-01-24 | 1984-08-02 | Nippon Telegr & Teleph Corp <Ntt> | Multi-value orthogonal amplitude modulator |
-
1990
- 1990-08-17 JP JP21730090A patent/JPH04100355A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58105658A (en) * | 1981-12-17 | 1983-06-23 | Nec Corp | Adaptive type modulating equipment |
| JPS59134950A (en) * | 1983-01-24 | 1984-08-02 | Nippon Telegr & Teleph Corp <Ntt> | Multi-value orthogonal amplitude modulator |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0865352A (en) * | 1994-08-24 | 1996-03-08 | Yuseisho Tsushin Sogo Kenkyusho | Digital modulator |
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