FR2451661A1 - DIGITAL FREQUENCY DEMODULATION CIRCUIT FOR SOUND REPRODUCTION IN A RADIO OR TELEVISION RECEIVER, IN PARTICULAR A COLOR TELEVISION RECEIVER - Google Patents

DIGITAL FREQUENCY DEMODULATION CIRCUIT FOR SOUND REPRODUCTION IN A RADIO OR TELEVISION RECEIVER, IN PARTICULAR A COLOR TELEVISION RECEIVER

Info

Publication number
FR2451661A1
FR2451661A1 FR8005738A FR8005738A FR2451661A1 FR 2451661 A1 FR2451661 A1 FR 2451661A1 FR 8005738 A FR8005738 A FR 8005738A FR 8005738 A FR8005738 A FR 8005738A FR 2451661 A1 FR2451661 A1 FR 2451661A1
Authority
FR
France
Prior art keywords
frequency
television receiver
clock
audio signal
demodulation circuit
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
FR8005738A
Other languages
French (fr)
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.)
TDK Micronas GmbH
ITT Inc
Original Assignee
Deutsche ITT Industries GmbH
ITT Industries Inc
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 Deutsche ITT Industries GmbH, ITT Industries Inc filed Critical Deutsche ITT Industries GmbH
Publication of FR2451661A1 publication Critical patent/FR2451661A1/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00—Details of television systems
    • H04N5/44—Receiver circuitry for the reception of television signals according to analogue transmission standards
    • H04N5/60—Receiver circuitry for the reception of television signals according to analogue transmission standards for the sound signals
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03D—DEMODULATION OR TRANSFERENCE OF MODULATION FROM ONE CARRIER TO ANOTHER
    • H03D3/00—Demodulation of angle-, frequency- or phase- modulated oscillations
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03D—DEMODULATION OR TRANSFERENCE OF MODULATION FROM ONE CARRIER TO ANOTHER
    • H03D7/00—Transference of modulation from one carrier to another, e.g. frequency-changing

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Analogue/Digital Conversion (AREA)
  • Color Television Systems (AREA)
  • Amplifiers (AREA)

Abstract

CIRCUIT DE DEMODULATION NUMERIQUE D'UNE ONDE PORTEUSE RADIOELECTRIQUE A MODULATION ANALOGIQUE DE FREQUENCE PAR UN SIGNAL AUDIO. LA PORTEUSE MODULEE FM MISE SOUS FORME RECTANGULAIRE EST APPLIQUEE A UNE BASCULE D4 SYNCHRONISEE PAR UNE PREMIERE HORLOGE F1 DE FREQUENCE F F (FREQUENCE PORTEUSE) 2 FG (FREQUENCE MAXIMALE DU SIGNAL AUDIO) 2 DF (ECART MAXIMAL DE FREQUENCE DE MODULATION). LA DEMI-PERIODE DU SIGNAL DE MELANGE 59 ECHANTILLONNE 5 PAR UNE SECONDE HORLOGE F2 DE FREQUENCE 2 FG EST MESUREE PAR UN COMPTEUR NUMERIQUE 31 AU MOYEN D'UNE TROISIEME HORLOGE F3 ET UN CONVERTISSEUR 6 EN DEDUIT LA VALEUR ABSOLUE DE L'ECART DE FREQUENCE INSTANTANE DF ET LE SIGNE DE DF. UN SIGNAL Q8 MODULE EN LARGEUR D'IMPULSIONS EN FONCTION DE DF ET LE SIGNE DE DF SERVENT A RECONSTITUER LE SIGNAL AUDIO VIA DES ELEMENTS DE LOGIQUE 11 A 14, DES TRANSISTORS MOS DE PUISSANCE 15, 16, UN FILTRE 17 ET LE HAUT-PARLEUR. APPLICATION PARTICULIERE AU CIRCUIT DE SON D'UN RECEPTEUR DE TELEVISION EN COULEUR.DIGITAL DEMODULATION CIRCUIT OF A RADIOELECTRIC CARRIER WAVE WITH ANALOGUE FREQUENCY MODULATION BY AN AUDIO SIGNAL. THE FM MODULATED CARRIER SET IN A RECTANGULAR SHAPE IS APPLIED TO A D4 ROCKER SYNCHRONIZED BY A FIRST CLOCK F1 OF FREQUENCY F F (CARRIER FREQUENCY) 2 FG (MAXIMUM FREQUENCY OF AUDIO SIGNAL) 2 DF (MAXIMUM MODULATION FREQUENCY DIFFERENCE). THE HALF PERIOD OF THE MIXING SIGNAL 59 SAMPLE 5 BY A SECOND CLOCK F2 OF FREQUENCY 2 FG IS MEASURED BY A DIGITAL COUNTER 31 BY MEANS OF A THIRD CLOCK F3 AND A CONVERTER 6 DEDUCTS THE ABSOLUTE VALUE OF THE FREQUENCY DIFFERENCE INSTANTANE DF AND THE SIGN OF DF. A Q8 SIGNAL IN PULSE WIDTH MODULE DEPENDING ON DF AND THE SIGN OF DF ARE USED TO RECONSTITUTE THE AUDIO SIGNAL VIA LOGIC ELEMENTS 11 TO 14, POWER MOS TRANSISTORS 15, 16, A FILTER 17 AND THE LOUDSPEAKER . SPECIAL APPLICATION TO THE SOUND CIRCUIT OF A COLOR TELEVISION RECEIVER.

FR8005738A 1979-03-14 1980-03-14 DIGITAL FREQUENCY DEMODULATION CIRCUIT FOR SOUND REPRODUCTION IN A RADIO OR TELEVISION RECEIVER, IN PARTICULAR A COLOR TELEVISION RECEIVER Pending FR2451661A1 (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19792909921 DE2909921A1 (en) 1979-03-14 1979-03-14 SOUND CHANNEL SWITCHING FOR FREQUENCY MODULATED SIGNALS

Publications (1)

Publication Number Publication Date
FR2451661A1 true FR2451661A1 (en) 1980-10-10

Family

ID=6065307

Family Applications (1)

Application Number Title Priority Date Filing Date
FR8005738A Pending FR2451661A1 (en) 1979-03-14 1980-03-14 DIGITAL FREQUENCY DEMODULATION CIRCUIT FOR SOUND REPRODUCTION IN A RADIO OR TELEVISION RECEIVER, IN PARTICULAR A COLOR TELEVISION RECEIVER

Country Status (3)

Country Link
DE (1) DE2909921A1 (en)
FR (1) FR2451661A1 (en)
GB (1) GB2046543B (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2599575A1 (en) * 1986-05-29 1987-12-04 Inst Radioveschatel Prie Method of receiving frequency-modulated analog signals with digital processing and device for carrying out this method
EP0614268A1 (en) * 1993-03-04 1994-09-07 Nokia Mobile Phones Ltd. Method and apparatus for producing a difference signal between signal frequencies, and for detection of modulation
US5732108A (en) * 1993-03-04 1998-03-24 Nokia Mobile Phones Ltd. Method and apparatus for producing a difference signal between two signal frequencies, and for detection of modulation

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3819660A1 (en) * 2019-11-05 2021-05-12 NXP USA, Inc. Radar transmitter module for digital modulation

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1137132A (en) * 1965-02-04 1968-12-18 Emi Ltd Improvements in or relating to frequency modulation receivers
US3548328A (en) * 1969-01-13 1970-12-15 Honeywell Inc Digital fm discriminator
US3628165A (en) * 1968-09-19 1971-12-14 Anderson Jacobson Inc Digital frequency discriminator
GB1434450A (en) * 1973-07-03 1976-05-05 Gardner Denver Co Rate measurement circuit
GB1509162A (en) * 1975-08-27 1978-04-26 Siemens Ag Pulsing rate indicator

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1137132A (en) * 1965-02-04 1968-12-18 Emi Ltd Improvements in or relating to frequency modulation receivers
US3628165A (en) * 1968-09-19 1971-12-14 Anderson Jacobson Inc Digital frequency discriminator
US3548328A (en) * 1969-01-13 1970-12-15 Honeywell Inc Digital fm discriminator
GB1434450A (en) * 1973-07-03 1976-05-05 Gardner Denver Co Rate measurement circuit
GB1509162A (en) * 1975-08-27 1978-04-26 Siemens Ag Pulsing rate indicator

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2599575A1 (en) * 1986-05-29 1987-12-04 Inst Radioveschatel Prie Method of receiving frequency-modulated analog signals with digital processing and device for carrying out this method
EP0614268A1 (en) * 1993-03-04 1994-09-07 Nokia Mobile Phones Ltd. Method and apparatus for producing a difference signal between signal frequencies, and for detection of modulation
US5732108A (en) * 1993-03-04 1998-03-24 Nokia Mobile Phones Ltd. Method and apparatus for producing a difference signal between two signal frequencies, and for detection of modulation

Also Published As

Publication number Publication date
GB2046543A (en) 1980-11-12
DE2909921A1 (en) 1980-09-25
GB2046543B (en) 1983-06-15

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