GB1044091A - Creación de Inventos y Patentes con Inteligencia Artificial

GB1044091A – Improvements in or relating to circuit arrangements for restoring the missing sideband portion of a partially single-sideband electrical signal
– Google Patents

GB1044091A – Improvements in or relating to circuit arrangements for restoring the missing sideband portion of a partially single-sideband electrical signal
– Google Patents
Improvements in or relating to circuit arrangements for restoring the missing sideband portion of a partially single-sideband electrical signal

Info

Publication number
GB1044091A

GB1044091A
GB887/64A
GB88764A
GB1044091A
GB 1044091 A
GB1044091 A
GB 1044091A
GB 887/64 A
GB887/64 A
GB 887/64A
GB 88764 A
GB88764 A
GB 88764A
GB 1044091 A
GB1044091 A
GB 1044091A
Authority
GB
United Kingdom
Prior art keywords
sideband
signal
frequency
double
circuit
Prior art date
1963-01-11
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.)

Expired

Application number
GB887/64A
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.)

Philips Electronics UK Ltd

Original Assignee
Philips Electronic and Associated Industries Ltd
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.)
1963-01-11
Filing date
1964-01-08
Publication date
1966-09-28

1964-01-08
Application filed by Philips Electronic and Associated Industries Ltd
filed
Critical
Philips Electronic and Associated Industries Ltd

1966-09-28
Publication of GB1044091A
publication
Critical
patent/GB1044091A/en

Status
Expired
legal-status
Critical
Current

Links

Espacenet

Global Dossier

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Classifications

H—ELECTRICITY

H04—ELECTRIC COMMUNICATION TECHNIQUE

H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION

H04N11/00—Colour television systems

H04N11/06—Transmission systems characterised by the manner in which the individual colour picture signal components are combined

H04N11/12—Transmission systems characterised by the manner in which the individual colour picture signal components are combined using simultaneous signals only

H04N11/14—Transmission systems characterised by the manner in which the individual colour picture signal components are combined using simultaneous signals only in which one signal, modulated in phase and amplitude, conveys colour information and a second signal conveys brightness information, e.g. NTSC-system

H04N11/146—Decoding means therefor

H—ELECTRICITY

H04—ELECTRIC COMMUNICATION TECHNIQUE

H04B—TRANSMISSION

H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 – H04B13/00; Details of transmission systems not characterised by the medium used for transmission

H04B1/06—Receivers

H04B1/16—Circuits

H04B1/30—Circuits for homodyne or synchrodyne receivers

H04B1/302—Circuits for homodyne or synchrodyne receivers for single sideband receivers

H—ELECTRICITY

H04—ELECTRIC COMMUNICATION TECHNIQUE

H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION

H04N11/00—Colour television systems

H04N11/06—Transmission systems characterised by the manner in which the individual colour picture signal components are combined

H04N11/12—Transmission systems characterised by the manner in which the individual colour picture signal components are combined using simultaneous signals only

Abstract

1,044,091. Colour television. PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd. Jan. 8, 1964 [Jan.11, 1963]. No. 887/64. Headings H3Q and H4F. In a single-sideband transmission system, the messing sideband is restored at the receiver before demodulation by heterodyning the received single-side band signal with an oscillation of twice the carrier frequency and adding the resultant difference-frequency signals to the received signals. The system may be extended to convert received vestigial-sideband signals into double-sideband signals and finds particular application in the reception of colour-television signals transmitted according to the N.T.S.C. system. Basically, received signals E 2 , Fig. 1, are applied to a mixer 1 where they are heterodyned with oscillations of twice carrier frequency derived by a narrow-band filter 4 tuned to the carrier frequency and a frequency doubler 5. Signals corresponding to the messing sideband are generated in the mixer and combined with directly transmitted signals to produce a double-sideband signal E 01 at the output, unwanted results of the mixing being eliminated by a filter 7 and the direct and conversion gains of the mixer 1 being chosen to give equal amplitudes for the two sidebands. If, however, the received signal includes a vestigial sideband, this will be added to the full sideband reconstituted by the mixer 1 and the sideband reconstituted therefrom will be added to the original full sideband, causing the resulting signal to be of excessive amplitude over the lower-frequency sideband portions. In this event the further circuitry shown in Fig. 1 is required. Bandpass filter 2 extracts that portion of the receiver signal Ei which is effectively a double-sideband signal, i.e. the vestigial sideband, carrier and as much of the full sideband as corresponds with the vestigial one. This is heterodyned in mixer 3, with an oscillation of twice carrier frequency of opposite phase from that applied to mixer 1. Thus a further signal E 03 consisting of the lowerfrequency portions of the sidebands is developed in a phase opposite to E 01 so that, provided the relative amplitudes of the signals are correctly chosen, they may be added to give rise to a double sideband signal E 0t in which the lowerfrequency portions of the sidebands are not emphasized at the expense of the higher-frequency portions. In the N.T.S.C. colour television system the modulation applied for transmission according to vestigial-sideband techniques upon a radiofrequency carrier itself comprises a sub-carrier double-sideband modulated by a narrow-band Q component and vestigial-sideband modulated by a wider-band I component in quadrature with the Q-component modulation. Hence after demodulation of the received radio-frequency transmission converted to double-sideband modulation by the circuit of Fig. 1, further conversion of the I-component modulation to double-sideband is desirable. In the circuit of Fig. 5 the luminance component of the demodulated signal is applied through amplifier 10 to the cathodes of a three-gun tube 11. The chrominance component, extracted by filter 12 is applied to a circuit operating similarly to the circuit of Fig. 1 and comprising mixers 1, 3 having equivalent functions to the mixers 1, 3 of Fig. 1 so that there is produced at the output of filter 7 a double-sideband chrominance signal having both I and Q components in correct phase and amplitude. In this circuit the double-carrier-frequency oscillation from circuit 5 is generated in an oscillator 16 which is synchronized by a comparison of the carrierfrequency output thereof with the reference oscillation derived in circuit 14 from the back porch of the line synchronizing pulses by means of gating pulses 15. Phase detector 151 produces a control voltage to maintain oscillator 16 in synchronism with the oscillation bursts carried on the back porch. Oscillations of subcarrier frequency from oscillator 16 are applied in appropriate phase to synchronous detectors 18, 19 to derive respective outputs R – Y, B – Y which applied to circuit 23 develops output G – Y, these three outputs being applied to respective control grids of the colour tube 11. A delay line 13 is introduced between filter 12 and mixer 1 to compensate for delay introduced by filter 2. In an alternative form of circuit employing a single-gun tube such as a chromatron or Lawrence tube, the output from filter 7 is applied to an elliptical amplifier which so modifies the signal that when suitably compounded with the luminance component it becomes equivalent to a dot-sequential signal suitable for use in a single-gun tube, Fig. 7 (not shown). In a modified version of this circuit, Fig. 8 (not shown), the mixing in mixers 1 and 3 is done with local oscillations containing a subcarrier-frequency component as well as a double-frequency component and the amplitudes and phases are so chosen that an effect equivalent to elliptical amplification is obtained before the filter 7, the output from which after being compounded with the luminance signal is thus a dot-sequential signal which may be applied directly to a single-gun tube.

GB887/64A
1963-01-11
1964-01-08
Improvements in or relating to circuit arrangements for restoring the missing sideband portion of a partially single-sideband electrical signal

Expired

GB1044091A
(en)

Applications Claiming Priority (1)

Application Number
Priority Date
Filing Date
Title

NL287701

1963-01-11

Publications (1)

Publication Number
Publication Date

GB1044091A
true

GB1044091A
(en)

1966-09-28

Family
ID=19754342
Family Applications (1)

Application Number
Title
Priority Date
Filing Date

GB887/64A
Expired

GB1044091A
(en)

1963-01-11
1964-01-08
Improvements in or relating to circuit arrangements for restoring the missing sideband portion of a partially single-sideband electrical signal

Country Status (10)

Country
Link

US
(1)

US3294897A
(en)

AT
(1)

AT240927B
(en)

BE
(1)

BE642320A
(en)

CH
(1)

CH450501A
(en)

DE
(1)

DE1270629B
(en)

DK
(1)

DK109152C
(en)

ES
(1)

ES295153A1
(en)

GB
(1)

GB1044091A
(en)

NL
(1)

NL287701A
(en)

SE
(1)

SE301662B
(en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party

Publication number
Priority date
Publication date
Assignee
Title

US3466548A
(en)

1966-10-03
1969-09-09
Conrac Corp
Method and apparatus for regenerated vestigial sideband reception

Family Cites Families (3)

* Cited by examiner, † Cited by third party

Publication number
Priority date
Publication date
Assignee
Title

US2890273A
(en)

1954-12-14
1959-06-09
Hazeltine Research Inc
Wave-signal modifying apparatus

US2987617A
(en)

1956-10-19
1961-06-06
Hazeltine Research Inc
Apparatus for converting a vestigialside-band carrier to a double-sideband carrier

NL260429A
(en)

1961-01-24

NL
NL287701D
patent/NL287701A/xx
unknown

1963

1963-12-23
US
US332761A
patent/US3294897A/en
not_active
Expired – Lifetime

1964

1964-01-07
DE
DEP1270A
patent/DE1270629B/en
active
Pending

1964-01-08
DK
DK8864AA
patent/DK109152C/en
active

1964-01-08
SE
SE173/64A
patent/SE301662B/xx
unknown

1964-01-08
GB
GB887/64A
patent/GB1044091A/en
not_active
Expired

1964-01-08
AT
AT10164A
patent/AT240927B/en
active

1964-01-08
CH
CH19464A
patent/CH450501A/en
unknown

1964-01-09
BE
BE642320A
patent/BE642320A/xx
unknown

1964-01-09
ES
ES0295153A
patent/ES295153A1/en
not_active
Expired

Also Published As

Publication number
Publication date

US3294897A
(en)

1966-12-27

ES295153A1
(en)

1964-04-01

DE1270629B
(en)

1968-06-20

NL287701A
(en)

SE301662B
(en)

1968-06-17

CH450501A
(en)

1968-01-31

AT240927B
(en)

1965-06-25

BE642320A
(en)

1964-07-09

DK109152C
(en)

1968-03-25

Información de contacto