JPH0350459B2 - - Google Patents
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- Publication number
- JPH0350459B2 JPH0350459B2 JP61297157A JP29715786A JPH0350459B2 JP H0350459 B2 JPH0350459 B2 JP H0350459B2 JP 61297157 A JP61297157 A JP 61297157A JP 29715786 A JP29715786 A JP 29715786A JP H0350459 B2 JPH0350459 B2 JP H0350459B2
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- frequency
- spectrum
- center frequency
- received
- fixed
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- Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
Description
【発明の詳細な説明】
〔概要〕
データ通信用モデムに於いて、受信側には受信
信号の劣化を補正・等化するために等化器を設
け、送信側からトレーニング中の或る時間内に、
音声帯域の中心周波数のスペクトラムと中心周波
数の上下のナイキスト点の周波数のスペクトラム
からなる信号を送出し、受信側では此の信号によ
り当該等化器の等化能力をアダプテイブに設定
し、データ伝送中は此の設定を固定して使用す
る。[Detailed Description of the Invention] [Summary] In a data communication modem, an equalizer is provided on the receiving side to correct and equalize the deterioration of the received signal, and the To,
A signal consisting of the spectrum of the center frequency of the voice band and the spectrum of frequencies at the Nyquist points above and below the center frequency is sent out, and on the receiving side, this signal is used to adaptively set the equalization ability of the equalizer, and during data transmission. Use this setting as a fixed value.
本発明はデータ通信用モデムの復調器に於いて
受信信号が回線から受ける劣化を補正する為の等
化器に関するものである。
The present invention relates to an equalizer for correcting deterioration of a received signal from a line in a demodulator of a data communication modem.
データ通信用モデムの復調器は受信信号から再
生用タイミング信号を抽出してデータを再生する
が、受信信号が回線上で劣化（位相・振幅）を受
けるので此の劣化を補正するため通常自動等化器
が設けられる。 The demodulator of a data communication modem extracts the timing signal for reproduction from the received signal and reproduces the data, but since the received signal is subject to deterioration (phase and amplitude) on the line, it usually uses automatic etc. to correct this deterioration. A converter will be provided.
然しながらデータ伝送速度を上げるために回線
の使用帯域をフルに使用しようとすると、帯域の
両端での劣化が激しく、自動等化器だけでは補正
が困難となる。 However, when attempting to make full use of the bandwidth of the line in order to increase the data transmission speed, the deterioration at both ends of the bandwidth becomes severe, making it difficult to correct it using only an automatic equalizer.
此の為自動等化器の負担を減らして等化能力を
向上させる等化方法が必要となつて来る。 Therefore, there is a need for an equalization method that reduces the load on the automatic equalizer and improves its equalization ability.
第７図は従来の受信部のブロツク図の一例であ
る。
FIG. 7 is an example of a block diagram of a conventional receiving section.
図中、１はＡ−Ｄ変換器、２はAGC回路、３
は復調器、４はロールオフフイルタ、５は自動等
化器、６はCAPC回路、７はコード変換器であ
る。 In the figure, 1 is an A-D converter, 2 is an AGC circuit, and 3
4 is a roll-off filter, 5 is an automatic equalizer, 6 is a CAPC circuit, and 7 is a code converter.
従来の9600bps〜14400bps迄の通信速度を有す
るデータ通信用モデムの受信部は第７図に示す様
に、受信信号をＡ−Ｄ変換器１によりサンプリン
グ系列データに変換した後、AGC回路２により
其のレベルを一定としてから復調器３によりベー
スバンドに変換する。変換後、ロールオフフイル
タ４を通して自動等化器５に入力し、此処で回線
歪の自動等化をした後CAPC回路６により位相補
正を自動的に行い、コード変換器７により受信デ
ータを作成する手順を採るのが普通である。 As shown in FIG. 7, the receiving section of a conventional data communication modem having a communication speed of 9,600 bps to 14,400 bps converts the received signal into sampling series data by an A-D converter 1, and then converts the received signal into sampling series data by an AGC circuit 2. After making the level constant, the demodulator 3 converts it to baseband. After conversion, the signal is input to the automatic equalizer 5 through the roll-off filter 4, where the line distortion is automatically equalized, the phase correction is automatically performed by the CAPC circuit 6, and the received data is created by the code converter 7. It is common to take steps.
尚第７図はタイミング抽出関係の回路は省略し
てある。 Note that in FIG. 7, circuits related to timing extraction are omitted.
然しながら通信速度を上げると信号のエネルギ
ーは音声帯域一杯に拡がる。データ伝送に使用す
る通信線路の音声帯域（0.3KHz〜3.4KHz）の内、
0.3KHz近傍、3.4KHz近傍は歪が多いので、高速
度のデータ伝送の場合には此れ等低周波、及び高
周波の補正を正確に行わないと確実な受信を行う
ことは出来ない。
However, increasing the communication speed spreads the energy of the signal to fill the voice band. Within the voice band (0.3KHz to 3.4KHz) of communication lines used for data transmission,
There is a lot of distortion around 0.3KHz and 3.4KHz, so in the case of high-speed data transmission, reliable reception cannot be achieved unless these low and high frequencies are corrected accurately.
従つて通信速度の低いデータ伝送用モデムの様
に自動等化器５により前記補正を行うと、データ
伝送時の歪補正を十分に行う余裕がなくなり、結
果的にタイミング抽出が十分に行われなくなり、
良好な通信が出来ないと云う欠点があつた。 Therefore, if the above-mentioned correction is performed using the automatic equalizer 5 as in a modem for data transmission with a low communication speed, there will not be enough room for distortion correction during data transmission, and as a result, timing extraction will not be performed sufficiently. ,
The drawback was that good communication was not possible.
上記問題点は第１図の原理図に示す様にデータ
通信用モデムに於いて、送信側からトレーニング
中の或る時間内に、音声帯域の中心周波数fcのス
ペクトラム、中心周波数fcより低いナイキスト点
の第１周波数f1のスペクトラム、及び中心周波数
fcより高いナイキスト点の第２周波数f2のスペク
トラムからなり、且つ中心周波数fcのスペクトラ
ムと周波数f1及びf2の各スペクトラムのレベル比
が一定である信号を送出し、受信側に、中心周波
数fcのスペクトラムを選択受信する中心周波数選
択受信手段２０、周波数f1のスペクトラムを選択
受信する第１手段３０、周波数f2のスペクトラム
を選択受信する第２手段４０、及び受信した信号
を与えられた補正係数で補正するフイルタ１２を
有するアダプテイブ半固定等化器１０を設けるこ
とにより解決される。
The above problem is as shown in the principle diagram in Figure 1. In a data communication modem, during a certain period of time during training from the transmitting side, the spectrum of the center frequency f c of the voice band is lower than the center frequency f c . Spectrum of first frequency f 1 of Nyquist point and center frequency
A signal consisting of a spectrum of a second frequency f 2 at a Nyquist point higher than f c and in which the level ratio of the spectrum of the center frequency f c and each spectrum of frequencies f 1 and f 2 is constant is transmitted to the receiving side, Center frequency selection receiving means 20 for selectively receiving the spectrum of the center frequency f c , first means 30 for selectively receiving the spectrum of the frequency f 1 , second means 40 for selectively receiving the spectrum of the frequency f 2 , and the received signal This problem is solved by providing an adaptive semi-fixed equalizer 10 having a filter 12 that corrects with a given correction coefficient.
本発明に依ると受信側では前記信号をアダプテ
イブ半固定等化器１０に入力し、アダプテイブ半
固定等化器１０の中心周波数選択受信手段２０に
より受信した中心周波数fcのスペクトラムのレベ
ルと、第１手段３０により受信した周波数f1、及
び第２手段４０により受信した周波数f2の各スペ
クトラムのレベルの比が前記比となる様に補正
し、データ伝送中アダプテイブ半固定等化器１０
の補正状態を固定する。
According to the present invention, on the receiving side, the signal is input to the adaptive semi-fixed equalizer 10, and the level of the spectrum of the center frequency f c received by the center frequency selection receiving means 20 of the adaptive semi-fixed equalizer 10 is determined. The adaptive semi-fixed equalizer 10 corrects the level ratio of each spectrum of the frequency f 1 received by the first means 30 and the frequency f 2 received by the second means 40 to be equal to the ratio.
Fix the correction state.
第２図ａは本発明によるデータ通信用モデムの
受信部の一実施例である。
FIG. 2a shows an embodiment of the receiving section of the data communication modem according to the present invention.
第２図ｂは本発明に依るアダプテイブ半固定等
化器の一実施例を示す図である。 FIG. 2b shows an embodiment of an adaptive semi-fixed equalizer according to the present invention.
第３図はトレーニング中に送出するスペクトラ
ムを示す図である。 FIG. 3 is a diagram showing a spectrum transmitted during training.
第４図は２次フイルタ１２の特性図である。 FIG. 4 is a characteristic diagram of the secondary filter 12.
第５図は本発明の説明図である。 FIG. 5 is an explanatory diagram of the present invention.
第６図は本発明に依るアダプテイブ半固定等化
器の出力を示す図である。 FIG. 6 is a diagram showing the output of an adaptive semi-fixed equalizer according to the present invention.
図中、１０は本発明によるアダプテイブ半固定
等化器、１１は１次フイルタ、１２は２次フイル
タ、１３1，１３2，１３3は夫々フイルタ、１４
はAGC回路、１５1，１５2は夫々ゲイン・コン
トロール（GC）、１６1，１６2は夫々AGC回路、
１７はテーブル、１２′はメモリ、１２″はスイツ
チである。 In the figure, 10 is an adaptive semi-fixed equalizer according to the present invention, 11 is a primary filter, 12 is a secondary filter, 13 1 , 13 2 , 13 3 are filters, and 14
are AGC circuits, 15 1 and 15 2 are respectively gain control (GC), 16 1 and 16 2 are each AGC circuits,
17 is a table, 12' is a memory, and 12'' is a switch.
本発明に於いてデータ通信用モデムの送信側か
らトレーニング中に第３図に示す様な３本のスペ
クトラム成分を持つ信号を送出する。尚送出する
時期はトレーニング中の如何なる時期でも良い。 In the present invention, a signal having three spectrum components as shown in FIG. 3 is sent out from the transmitting side of the data communication modem during training. Note that the timing may be any time during training.
第３図に於いて、周波数fcは音声帯域の中心周
波数（キヤリア）であり、周波数f1は中心周波数
fcより低いナイキスト点の周波数であり、周波数
f2は中心周波数fcより高いナイキスト点の周波数
であり、両周波数は位相変化最大に対応する周波
数である。 In Figure 3, frequency f c is the center frequency (carrier) of the audio band, and frequency f 1 is the center frequency
f is the frequency of the Nyquist point lower than c , and the frequency
f 2 is the frequency of the Nyquist point higher than the center frequency f c , and both frequencies are frequencies corresponding to the maximum phase change.
尚両ナイキスト点のスペクトラムの大きさは中
心周波数fcのスペクトラムに対し常に或る一定の
比率Ａを保持するものとする。 It is assumed that the magnitude of the spectrum at both Nyquist points always maintains a certain constant ratio A to the spectrum at the center frequency fc .
本発明に依ると受信側に於いては、第２図ａに
示す様にアダプテイブ半固定等化器１０をAGC
回路２と復調器３の間に設ける。此のアダプテイ
ブ半固定等化器１０は第３図に示す信号を受信
し、受信した中心周波数fcのレベルを基準とし
て、受信した周波数f1のレベル、及び周波数f2の
レベルが夫々前記比率Ａになる様に補正を行い、
以後の通信中は此の状態を固定して使用する。 According to the present invention, on the receiving side, the adaptive semi-fixed equalizer 10 is connected to the AGC as shown in FIG.
It is provided between the circuit 2 and the demodulator 3. This adaptive semi-fixed equalizer 10 receives the signal shown in FIG. 3, and with the level of the received center frequency f c as a reference, the level of the received frequency f 1 and the level of the received frequency f 2 are respectively set to the above ratio. Make corrections so that it becomes A,
This state will be fixed and used during subsequent communication.
本発明に依るアダプテイブ半固定等化器１０は
AGC回路２からトレーニング中の或る時期に送
られて来る第３図に示す信号を受信すると、周波
数f1のスペクトラム成分をフイルタ１３1により、
周波数f2のスペクトラム成分をフイルタ１３2に
より、中心周波数fcのスペクトラム成分をフイル
タ１３3により夫々抽出する。 The adaptive semi-fixed equalizer 10 according to the present invention is
When the signal shown in FIG. 3 sent from the AGC circuit 2 at a certain time during training is received, the spectrum component of frequency f 1 is filtered by the filter 13 1 .
A spectral component with a frequency f 2 is extracted by a filter 13 2 and a spectral component with a center frequency f c is extracted by a filter 13 3 .
フイルタ１３3により抽出された中心周波数fc
のスペクトラム成分はAGC回路１４に送られ、
此処で基準レベルに設定され、ゲイン・コントロ
ール（GC）１５1，１５2に夫々印加される。 Center frequency f c extracted by filter 13 3
The spectrum component of is sent to the AGC circuit 14,
Here, the reference level is set and applied to gain controls (GC) 15 1 and 15 2 , respectively.
尚ゲイン・コントロール（GC）１５1，１５2
は共に乗算器である。 Gain control (GC) 15 1 , 15 2
are both multipliers.
フイルタ１３1の出力の周波数f1のスペクトラ
ム成分とAGC回路１４出力の基準レベルがゲイ
ン・コントロール（GC）１５1で乗算され、其の
乗算値はAGC回路１６1に入力される。 The spectrum component of the frequency f 1 of the output of the filter 13 1 and the reference level of the output of the AGC circuit 14 are multiplied by a gain control (GC) 15 1 , and the multiplied value is input to the AGC circuit 16 1 .
AGC回路１６1の出力は一定化されるが、其の
時のAGC回路１６1のAGCの制御係数は乗算値に
比例する。 Although the output of the AGC circuit 16 1 is made constant, the AGC control coefficient of the AGC circuit 16 1 at that time is proportional to the multiplication value.
フイルタ１３2の出力周波数f2のスペクトラム
成分に対しても同様な処理が行われてAGC回路
１６2から制御係数が求められる。 Similar processing is performed on the spectrum component of the output frequency f 2 of the filter 13 2 to obtain a control coefficient from the AGC circuit 16 2 .
前述した様に、音声帯域の内、0.3KHz近傍、
3.4KHz近傍は歪が多いので、第５図に示す様に
中心周波数fcのスペクトラム成分に比し、周波数
f1のスペクトラム成分、周波数f2のスペクトラム
成分は実線で示す様により多くの減衰を受ける。
劣化分は点線で示す。 As mentioned above, within the audio band, around 0.3KHz,
Since there is a lot of distortion in the vicinity of 3.4KHz, as shown in Figure 5, the frequency
The spectral component of f 1 and the spectral component of frequency f 2 receive more attenuation as shown by the solid line.
The deterioration is shown by the dotted line.
テーブル１７は例えばROMで構成され、前記
制御係数と２次フイルタ１２の制御量の相関テー
ブルである。 The table 17 is composed of, for example, a ROM, and is a correlation table between the control coefficients and the control amount of the secondary filter 12.
第４図は２次フイルタ１２の特性図である。 FIG. 4 is a characteristic diagram of the secondary filter 12.
２次フイルタ１２は第４図ａに示す特性を有す
る２次フイルタ１２ａと第４図ｂに示す特性を有
する２次フイルタ１２ｂからなり、全体として第
４図ｃに示す特性を有するトランスバーサル形フ
イルタである。 The secondary filter 12 consists of a secondary filter 12a having the characteristics shown in FIG. 4a and a secondary filter 12b having the characteristics shown in FIG. 4b, and is a transversal type filter having the characteristics shown in FIG. 4c as a whole. It is.
AGC回路１６1から求められた制御係数は、受
信した中心周波数fcのスペクトラム成分に対する
周波数f1のスペクトラム成分の比率を示す値であ
るので、此の比率を元の比率Ａに戻す様に、第４
図ａに示す山の高さを加減する。周波数f2の場合
も同様に第４図ｂに示す山の高さを加減する。此
の為スイツチ１２″を介してメモリ１２′にトレー
ニング信号の伝送期間中、全スペクトラムの信号
が受信される期間、即ち、スイツチ１２″が図示
されていない制御部により作動される期間にセツ
トされる。 The control coefficient obtained from the AGC circuit 161 is a value indicating the ratio of the spectrum component of the frequency f1 to the received spectrum component of the center frequency fc , so in order to return this ratio to the original ratio A, Fourth
Adjust the height of the mountain shown in Figure a. In the case of frequency f2 , the height of the peak shown in FIG. 4b is similarly adjusted. For this purpose, during the transmission period of the training signal to the memory 12' via the switch 12'', the switch 12'' is set to a period in which signals of the entire spectrum are received, that is, a period in which the switch 12'' is operated by a control section (not shown). Ru.
尚此のタイミングは制御部が例えば受信キヤリ
アを抽出後の一定時間後にスイツチ１２″を作動
してメモリ１２′に書込みを与えることで達成さ
れる。以後スイツチ１２″を開放することにより
補正係数が固定される。 This timing is achieved, for example, by the control section operating the switch 12'' to write to the memory 12' after a certain period of time after extracting the received carrier. Thereafter, by opening the switch 12'', the correction coefficient is Fixed.
此の結果、２次フイルタ１２の出力、即ち、ア
ダプテイブ半固定等化器１０の出力は第６図に示
す様に送信側と同じ比率Ａを保つことが出来る。
尚本発明では比率Ａを−6dbに設定した。 As a result, the output of the secondary filter 12, ie, the output of the adaptive semi-fixed equalizer 10, can maintain the same ratio A as that on the transmitting side, as shown in FIG.
In the present invention, the ratio A is set to -6 db.
此の様にトレーニング中にアダプテイブ半固定
等化器１０を補正した後、データ伝送中は此の補
正値を固定した侭で使用する。 After the adaptive semi-fixed equalizer 10 is corrected during training in this manner, the correction value is used while being fixed during data transmission.
以上詳細に説明した様に本発明によれば、回線
劣化による影響が前段で改善される為、後段に設
けられた従来の自動等化器の負担が軽くなり、タ
イミング抽出が其れ丈容易になり、より広い周波
数帯域を使用する高速データ伝送が特性の悪い回
線の場合でも十分可能になると云う大きい効果が
ある。
As explained in detail above, according to the present invention, the influence of line deterioration is improved at the front stage, so the burden on the conventional automatic equalizer installed at the rear stage is lightened, and timing extraction becomes easier. This has the great effect of making high-speed data transmission using a wider frequency band possible even in the case of lines with poor characteristics.
第１図は本発明の原理図である。第２図ａは本
発明によるデータ通信用モデムの受信部の一実施
例である。第２図ｂは本発明に依るアダプテイブ
半固定等化器の一実施例を示す図である。第３図
はトレーニング中に送出するスペクトラムを示す
図である。第４図は２次フイルタ１２の特性図で
ある。第５図は本発明の説明図である。第６図は
本発明に依るアダプテイブ半固定等化器の出力を
示す図である。第７図は従来の受信部のブロツク
図の一例である。
図中、１はＡ−Ｄ変換器、２はAGC回路、３
は復調器、４はロールオフフイルタ、５は自動等
化器、６はCAPC回路、７はコード変換器、１０
は本発明に依るアダプテイブ半固定等化器、１１
は１次フイルタ、１２は２次フイルタ、１３1，
１３2，１３3は夫々フイルタ、１４はAGC回路、
１５1，１５2は夫々ゲイン・コントロール
（GC）、１６1，１６2は夫々AGC回路、１７はテ
ーブル、１２′はメモリ、１２″はスイツチ、２０
は中心周波数fcを選択受信する手段、３０は周波
数f1を選択受信する手段、４０は周波数f2を選択
受信する手段である。
FIG. 1 is a diagram showing the principle of the present invention. FIG. 2a shows an embodiment of the receiving section of the data communication modem according to the present invention. FIG. 2b shows an embodiment of an adaptive semi-fixed equalizer according to the present invention. FIG. 3 is a diagram showing a spectrum transmitted during training. FIG. 4 is a characteristic diagram of the secondary filter 12. FIG. 5 is an explanatory diagram of the present invention. FIG. 6 is a diagram showing the output of an adaptive semi-fixed equalizer according to the present invention. FIG. 7 is an example of a block diagram of a conventional receiving section. In the figure, 1 is an A-D converter, 2 is an AGC circuit, and 3
is a demodulator, 4 is a roll-off filter, 5 is an automatic equalizer, 6 is a CAPC circuit, 7 is a code converter, 10
is an adaptive semi-fixed equalizer according to the present invention, 11
is the primary filter, 12 is the secondary filter, 13 1 ,
13 2 and 13 3 are filters, 14 is an AGC circuit,
15 1 and 15 2 are gain controls (GC), 16 1 and 16 2 are AGC circuits, 17 is a table, 12' is a memory, 12'' is a switch, and 20
30 is a means for selectively receiving the frequency f 1 , and 40 is a means for selectively receiving the frequency f 2 .
Claims (1)
心周波数fcより低いナイキスト点の第１周波数f1
のスペクトラム、 及び該中心周波数fcより高いナイキスト点の第
２周波数f2のスペクトラムからなり、 且つ該中心周波数fcのスペクトラムと該第１、
第２周波数f1，f2の各スペクトラムのレベル比が
一定である信号を送出し、 受信側に、 該中心周波数fcのスペクトラムを選択受信する
中心周波数選択手段２０、 該第１周波数f1のスペクトラムを選択受信する
第１手段３０、 該第２周波数f2のスペクトラムを選択受信する
第２手段４０、 及び受信した信号を与えられた補正係数で補正
するフイルタ１２を有するアダプテイブ半固定等
化器１０を設け、 前記受信した信号を該アダプテイブ半固定等化
器１０に入力し、 該アダプテイブ半固定等化器１０の該中心周波
数選択手段２０により受信した該中心周波数fcの
スペクトラムのレベルと、該第１手段３０により
受信した該第１周波数f1、及び該第２手段４０に
より受信した該第２周波数f2の各スペクトラムの
レベルの比が前記比となる様に前記補正係数を補
正し、 データ伝送中該アダプテイブ半固定等化器１０
の補正状態を固定することを特徴とするアダプテ
イブ半固定等化器。[Claims] 1. In a data communication modem, within a certain time during training from the transmitting side, the spectrum of the center frequency f c of the voice band, the first frequency of the Nyquist point lower than the center frequency f c f 1
and a spectrum of a second frequency f 2 of the Nyquist point higher than the center frequency f c , and the spectrum of the center frequency f c and the first,
A center frequency selection means 20 for transmitting a signal in which the level ratio of each spectrum of the second frequencies f 1 and f 2 is constant, and selectively receiving the spectrum of the center frequency f c on the receiving side, the first frequency f 1 Adaptive semi-fixed equalization comprising: a first means 30 for selectively receiving the spectrum of the second frequency f2 ; a second means 40 for selectively receiving the spectrum of the second frequency f2; and a filter 12 for correcting the received signal with a given correction coefficient. inputting the received signal into the adaptive semi-fixed equalizer 10, and comparing the level of the spectrum of the center frequency f c received by the center frequency selection means 20 of the adaptive semi-fixed equalizer 10 with the received signal. , the correction coefficient is corrected so that the ratio of the levels of the spectrums of the first frequency f 1 received by the first means 30 and the second frequency f 2 received by the second means 40 becomes the ratio. and the adaptive semi-fixed equalizer 10 during data transmission.
An adaptive semi-fixed equalizer characterized in that the correction state of is fixed.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61297157A JPS63149949A (en) | 1986-12-12 | 1986-12-12 | Adaptive semi-fixed equalizer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61297157A JPS63149949A (en) | 1986-12-12 | 1986-12-12 | Adaptive semi-fixed equalizer |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63149949A JPS63149949A (en) | 1988-06-22 |
| JPH0350459B2 true JPH0350459B2 (en) | 1991-08-01 |
Family
ID=17842928
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61297157A Granted JPS63149949A (en) | 1986-12-12 | 1986-12-12 | Adaptive semi-fixed equalizer |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63149949A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9069133B2 (en) | 1999-06-10 | 2015-06-30 | Honeywell International Inc. | Anti-reflective coating for photolithography and methods of preparation thereof |
-
1986
- 1986-12-12 JP JP61297157A patent/JPS63149949A/en active Granted
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9069133B2 (en) | 1999-06-10 | 2015-06-30 | Honeywell International Inc. | Anti-reflective coating for photolithography and methods of preparation thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS63149949A (en) | 1988-06-22 |
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