DK162000C - NOISE REDUCTION SYSTEM, FOR FM RADIO RECEIVERS, AT LOW SIGNAL LEVELS. - Google Patents

NOISE REDUCTION SYSTEM, FOR FM RADIO RECEIVERS, AT LOW SIGNAL LEVELS.

Info

Publication number
DK162000C
DK162000C DK200886A DK200886A DK162000C DK 162000 C DK162000 C DK 162000C DK 200886 A DK200886 A DK 200886A DK 200886 A DK200886 A DK 200886A DK 162000 C DK162000 C DK 162000C
Authority
DK
Denmark
Prior art keywords
intermediate frequency
phase
locked loop
band
noise reduction
Prior art date
Application number
DK200886A
Other languages
Danish (da)
Other versions
DK200886A (en
DK200886D0 (en
DK162000B (en
Inventor
Bernhard-Michael Katzy
Original Assignee
Bosch Gmbh Robert
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
Family has litigation
First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=6269616&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=DK162000(C) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Application filed by Bosch Gmbh Robert filed Critical Bosch Gmbh Robert
Publication of DK200886D0 publication Critical patent/DK200886D0/en
Publication of DK200886A publication Critical patent/DK200886A/en
Publication of DK162000B publication Critical patent/DK162000B/en
Application granted granted Critical
Publication of DK162000C publication Critical patent/DK162000C/en

Links

Classifications

    • 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
    • H03D3/001—Details of arrangements applicable to more than one type of frequency demodulator
    • H03D3/003—Arrangements for reducing frequency deviation, e.g. by negative frequency feedback
    • H03D3/004—Arrangements for reducing frequency deviation, e.g. by negative frequency feedback wherein the demodulated signal is used for controlling an oscillator, e.g. the local oscillator
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03J—TUNING RESONANT CIRCUITS; SELECTING RESONANT CIRCUITS
    • H03J7/00—Automatic frequency control; Automatic scanning over a band of frequencies
    • H03J7/02—Automatic frequency control
    • H03J7/04—Automatic frequency control where the frequency control is accomplished by varying the electrical characteristics of a non-mechanically adjustable element or where the nature of the frequency controlling element is not significant
    • H03J7/06—Automatic frequency control where the frequency control is accomplished by varying the electrical characteristics of a non-mechanically adjustable element or where the nature of the frequency controlling element is not significant using counters or frequency dividers
    • H03J7/065—Automatic frequency control where the frequency control is accomplished by varying the electrical characteristics of a non-mechanically adjustable element or where the nature of the frequency controlling element is not significant using counters or frequency dividers the counter or frequency divider being used in a phase locked loop

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Superheterodyne Receivers (AREA)
  • Input Circuits Of Receivers And Coupling Of Receivers And Audio Equipment (AREA)
  • Circuits Of Receivers In General (AREA)
  • Noise Elimination (AREA)

Abstract

1. An FM radio receiver having a mixing- and oscillator circuit for forming an intermediate frequency, an intermediate frequency band-pass filter (12), an intermediate frequency amplifier (13), a demodulator (13) for demodulating the intermediate frequency and a first (17) and second phase-locked loop (33), wherein a voltage-controlled oscillator (38) of the second phase-locked loop forms the oscillator of the mixing- and oscillator circuit, characterised in that the first phase-locked loop (17) between the intermediate frequency band-pass filter (12) and the intermediate frequency amplifier (13) is connected in series with a second band-pass filter (26) which is a narrow band filter compared with the first intermediate frequency signal, wherein the first phase-locked loop contributing to the reduction of the noise level of the intermediate frequency signal supplies its output signal to a first input (31) of a phase detector (32) which forms part of the second phase-locked loop (33) and the second input (34) of which carries a reference frequency signal, and that the second phase-locked loop readjusts the intermediate frequency to the midband of the narrow band filter.
DK200886A 1985-05-02 1986-05-01 NOISE REDUCTION SYSTEM, FOR FM RADIO RECEIVERS, AT LOW SIGNAL LEVELS. DK162000C (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19853515746 DE3515746A1 (en) 1985-05-02 1985-05-02 FM RADIO RECEIVER
DE3515746 1985-05-02

Publications (4)

Publication Number Publication Date
DK200886D0 DK200886D0 (en) 1986-05-01
DK200886A DK200886A (en) 1986-11-03
DK162000B DK162000B (en) 1991-09-02
DK162000C true DK162000C (en) 1992-02-10

Family

ID=6269616

Family Applications (1)

Application Number Title Priority Date Filing Date
DK200886A DK162000C (en) 1985-05-02 1986-05-01 NOISE REDUCTION SYSTEM, FOR FM RADIO RECEIVERS, AT LOW SIGNAL LEVELS.

Country Status (4)

Country Link
EP (1) EP0199887B1 (en)
AT (1) ATE45450T1 (en)
DE (2) DE3515746A1 (en)
DK (1) DK162000C (en)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2596220A1 (en) * 1986-03-21 1987-09-25 Portenseigne FREQUENCY DEMODULATOR
US4939789A (en) * 1987-01-20 1990-07-03 Matsushita Electric Industrial Co., Ltd. Signal receiver for terrestrial and satellite broadcastings
CA2071421C (en) * 1991-06-19 2000-08-08 Yoshiaki Kumagai Automatic frequency control circuit
CH702685B1 (en) * 1999-10-06 2011-08-31 Richemont Int Sa frequency modulation receiver, particularly an RDS application.

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3530383A (en) * 1966-11-18 1970-09-22 Itt Ultra-sensitive receiver
JPS5643809A (en) * 1979-09-19 1981-04-22 Hitachi Ltd Automatic gain controller
GB2079552B (en) * 1980-07-02 1984-02-01 Philips Electronic Associated Double phase lock loop
DE3231708A1 (en) * 1982-08-26 1984-03-01 Robert Bosch Gmbh, 7000 Stuttgart Filter and demodulation circuit

Also Published As

Publication number Publication date
DK200886A (en) 1986-11-03
DK200886D0 (en) 1986-05-01
EP0199887A3 (en) 1987-12-23
DE3515746A1 (en) 1986-11-06
DE3664990D1 (en) 1989-09-14
EP0199887A2 (en) 1986-11-05
DK162000B (en) 1991-09-02
ATE45450T1 (en) 1989-08-15
EP0199887B1 (en) 1989-08-09

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Legal Events

Date Code Title Description
PBP Patent lapsed