JPS5780851A - Fsk demodulating circut - Google Patents

Fsk demodulating circut

Info

Publication number
JPS5780851A
JPS5780851A JP55157193A JP15719380A JPS5780851A JP S5780851 A JPS5780851 A JP S5780851A JP 55157193 A JP55157193 A JP 55157193A JP 15719380 A JP15719380 A JP 15719380A JP S5780851 A JPS5780851 A JP S5780851A
Authority
JP
Japan
Prior art keywords
scf
pass filter
frequency
capacitor
amplifier
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
JP55157193A
Other languages
Japanese (ja)
Inventor
Fumiaki Mukoyama
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.)
Seiko Epson Corp
Suwa Seikosha KK
Original Assignee
Seiko Epson Corp
Suwa Seikosha KK
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 Seiko Epson Corp, Suwa Seikosha KK filed Critical Seiko Epson Corp
Priority to JP55157193A priority Critical patent/JPS5780851A/en
Priority to US06/318,496 priority patent/US4517519A/en
Publication of JPS5780851A publication Critical patent/JPS5780851A/en
Pending legal-status Critical Current

Links

Classifications

    • 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
    • H03H19/004—Switched capacitor networks
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/10—Frequency-modulated carrier systems, i.e. using frequency-shift keying
    • H04L27/14—Demodulator circuits; Receiver circuits
    • H04L27/156—Demodulator circuits; Receiver circuits with demodulation using temporal properties of the received signal, e.g. detecting pulse width
    • H04L27/1563—Demodulator circuits; Receiver circuits with demodulation using temporal properties of the received signal, e.g. detecting pulse width using transition or level detection

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Power Engineering (AREA)
  • Digital Transmission Methods That Use Modulated Carrier Waves (AREA)

Abstract

PURPOSE:To form an FSK demodulating circuit of different specifications by switching clocks, by using a switched capacitor filter (SCF) as a pre-band pass filter. CONSTITUTION:A receiving signal is inputted to an SCR19 through a microphone 15, a high pass filter consisting of a capacitor 16 and a resistance 17, and an amplifier 18. A clock frequency is super-posed onto the output of the SCF in steps, and therefore, the offset due to the operational amplifier of the SCF is eliminated by a buffer 22, a capacitor 23, and a resistance 24 after the output passes through a low pass filter. Next, it is discriminated whether the signal is a mark or a space by an amplifier 25, a limiter 26, a comparator 27, and a demodulating circuit 28 to obtain a digital signal. The clock of the SCF is obtained by an oscillating circuit 30 having two frequency division ratios and a quartz oscillator 29, and a frequency dividing frequency adapted for a high group or a low group is given in accordance with a high-band receiving or a low-band receiving by the input of H or L in respect to the frequency division ratio.
JP55157193A 1980-11-07 1980-11-07 Fsk demodulating circut Pending JPS5780851A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
JP55157193A JPS5780851A (en) 1980-11-07 1980-11-07 Fsk demodulating circut
US06/318,496 US4517519A (en) 1980-11-07 1981-11-05 FSK Demodulator employing a switched capacitor filter and period counters

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP55157193A JPS5780851A (en) 1980-11-07 1980-11-07 Fsk demodulating circut

Related Child Applications (1)

Application Number Title Priority Date Filing Date
JP2076353A Division JPH02276351A (en) 1990-03-26 1990-03-26 Fsk demodulating circuit

Publications (1)

Publication Number Publication Date
JPS5780851A true JPS5780851A (en) 1982-05-20

Family

ID=15644226

Family Applications (1)

Application Number Title Priority Date Filing Date
JP55157193A Pending JPS5780851A (en) 1980-11-07 1980-11-07 Fsk demodulating circut

Country Status (1)

Country Link
JP (1) JPS5780851A (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6162241A (en) * 1984-09-04 1986-03-31 Nec Corp Automatic railway equalizer of switched capacitor
JPS61273009A (en) * 1985-05-28 1986-12-03 Fujitsu Ltd Filter circuit
JPH01280947A (en) * 1988-05-06 1989-11-13 Fujitsu Ltd Hand shake system
JPH031740A (en) * 1989-05-30 1991-01-08 Fuji Electric Co Ltd Data transmission circuit
JP2009261017A (en) * 2001-07-13 2009-11-05 Thomson Licensing Method used for bi-directional communication device, and bi-directional communication device

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6162241A (en) * 1984-09-04 1986-03-31 Nec Corp Automatic railway equalizer of switched capacitor
JPH0511450B2 (en) * 1984-09-04 1993-02-15 Nippon Electric Co
JPS61273009A (en) * 1985-05-28 1986-12-03 Fujitsu Ltd Filter circuit
JPH01280947A (en) * 1988-05-06 1989-11-13 Fujitsu Ltd Hand shake system
JPH031740A (en) * 1989-05-30 1991-01-08 Fuji Electric Co Ltd Data transmission circuit
JP2009261017A (en) * 2001-07-13 2009-11-05 Thomson Licensing Method used for bi-directional communication device, and bi-directional communication device

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