GB1321848A - Selective frequency-sensitive circuit arrangements - Google Patents

Selective frequency-sensitive circuit arrangements

Info

Publication number
GB1321848A
GB1321848A GB1321848DA GB1321848A GB 1321848 A GB1321848 A GB 1321848A GB 1321848D A GB1321848D A GB 1321848DA GB 1321848 A GB1321848 A GB 1321848A
Authority
GB
United Kingdom
Prior art keywords
output
period
frequency
count
circuit arrangements
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.)
Expired
Application number
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.)
BAE Systems Electronics Ltd
Original Assignee
Marconi Co 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.)
Filing date
Publication date
Application filed by Marconi Co Ltd filed Critical Marconi Co Ltd
Publication of GB1321848A publication Critical patent/GB1321848A/en
Expired legal-status Critical Current

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
    • H03D3/02—Demodulation of angle-, frequency- or phase- modulated oscillations by detecting phase difference between two signals obtained from input signal
    • H03D3/04—Demodulation of angle-, frequency- or phase- modulated oscillations by detecting phase difference between two signals obtained from input signal by counting or integrating cycles of oscillations
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H19/00—Networks using time-varying elements, e.g. N-path filters
    • H03H19/002—N-path filters

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Measuring Frequencies, Analyzing Spectra (AREA)

Abstract

1321848 Frequency detectors MARCONI CO Ltd 7 Sept 1971 [11 Dec 1970] 58914/70 Heading H3A An arrangement for detecting the presence of a predetermined frequency at the output of an n-path filter comprises a reference time period source and means for comparing the period of the filter output with the reference period. The output signal from the filter 2 is examined by detector 6 which responds to the required frequency to trigger reference period source 11 to feed signals of the required frequency to counter 8. At the end of the count period a decoder 14 examines the count attained and provides an output if the count indicates that the correct signal is present.
GB1321848D 1970-12-11 1970-12-11 Selective frequency-sensitive circuit arrangements Expired GB1321848A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB5891470 1970-12-11

Publications (1)

Publication Number Publication Date
GB1321848A true GB1321848A (en) 1973-07-04

Family

ID=10482676

Family Applications (1)

Application Number Title Priority Date Filing Date
GB1321848D Expired GB1321848A (en) 1970-12-11 1970-12-11 Selective frequency-sensitive circuit arrangements

Country Status (1)

Country Link
GB (1) GB1321848A (en)

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Legal Events

Date Code Title Description
PS Patent sealed
PCNP Patent ceased through non-payment of renewal fee