JPS57178435A - Fm transmitter and receiver - Google Patents

Fm transmitter and receiver

Info

Publication number
JPS57178435A
JPS57178435A JP56062899A JP6289981A JPS57178435A JP S57178435 A JPS57178435 A JP S57178435A JP 56062899 A JP56062899 A JP 56062899A JP 6289981 A JP6289981 A JP 6289981A JP S57178435 A JPS57178435 A JP S57178435A
Authority
JP
Japan
Prior art keywords
synthesizer
digital frequency
vco25
transmission
reception
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
JP56062899A
Other languages
Japanese (ja)
Inventor
Yukio Fukumura
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.)
NEC Corp
Original Assignee
NEC Corp
Nippon Electric 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 NEC Corp, Nippon Electric Co Ltd filed Critical NEC Corp
Priority to JP56062899A priority Critical patent/JPS57178435A/en
Publication of JPS57178435A publication Critical patent/JPS57178435A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03J—TUNING RESONANT CIRCUITS; SELECTING RESONANT CIRCUITS
    • H03J5/00—Discontinuous tuning; Selecting predetermined frequencies; Selecting frequency bands with or without continuous tuning in one or more of the bands, e.g. push-button tuning, turret tuner
    • H03J5/02—Discontinuous tuning; Selecting predetermined frequencies; Selecting frequency bands with or without continuous tuning in one or more of the bands, e.g. push-button tuning, turret tuner with variable tuning element having a number of predetermined settings and adjustable to a desired one of these settings
    • H03J5/0245—Discontinuous tuning using an electrical variable impedance element, e.g. a voltage variable reactive diode, in which no corresponding analogue value either exists or is preset, i.e. the tuning information is only available in a digital form
    • H03J5/0272—Discontinuous tuning using an electrical variable impedance element, e.g. a voltage variable reactive diode, in which no corresponding analogue value either exists or is preset, i.e. the tuning information is only available in a digital form the digital values being used to preset a counter or a frequency divider in a phase locked loop, e.g. frequency synthesizer

Abstract

PURPOSE:To set a transmission and a reception frequency independently by improving spurious characteristics, by providing digital frequency synthesizers for transmission and reception, respectively. CONSTITUTION:A digital frequency synthesizer 24 composed of a VCO25, a variable frequency divider 26, a phase comparator 27, and an LPF28 is provided on a transmitting circuit side. This synthesizer 24 is constituted by using a control part 3 and a reference oscillator 5 in common to a digital frequency synthesizer 8. Then, a demosulated signal collected by a microphone 23 is processed by amplification 17 and then applied to the VCO25 to impose FM modulation upon a transmitted signal.
JP56062899A 1981-04-24 1981-04-24 Fm transmitter and receiver Pending JPS57178435A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP56062899A JPS57178435A (en) 1981-04-24 1981-04-24 Fm transmitter and receiver

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP56062899A JPS57178435A (en) 1981-04-24 1981-04-24 Fm transmitter and receiver

Publications (1)

Publication Number Publication Date
JPS57178435A true JPS57178435A (en) 1982-11-02

Family

ID=13213549

Family Applications (1)

Application Number Title Priority Date Filing Date
JP56062899A Pending JPS57178435A (en) 1981-04-24 1981-04-24 Fm transmitter and receiver

Country Status (1)

Country Link
JP (1) JPS57178435A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH021626A (en) * 1988-06-09 1990-01-05 Matsushita Electric Ind Co Ltd Outdoor communication equipment
JPH0626329U (en) * 1992-09-02 1994-04-08 株式会社田村電機製作所 Wireless device

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS49131717A (en) * 1973-04-23 1974-12-17

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS49131717A (en) * 1973-04-23 1974-12-17

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH021626A (en) * 1988-06-09 1990-01-05 Matsushita Electric Ind Co Ltd Outdoor communication equipment
JPH0626329U (en) * 1992-09-02 1994-04-08 株式会社田村電機製作所 Wireless device

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