JPS5772434A - Communication system - Google Patents

Communication system

Info

Publication number
JPS5772434A
JPS5772434A JP55149007A JP14900780A JPS5772434A JP S5772434 A JPS5772434 A JP S5772434A JP 55149007 A JP55149007 A JP 55149007A JP 14900780 A JP14900780 A JP 14900780A JP S5772434 A JPS5772434 A JP S5772434A
Authority
JP
Japan
Prior art keywords
signal
amplifier
inputted
frequency
circuit
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
JP55149007A
Other languages
Japanese (ja)
Inventor
Hiromitsu Inoue
Toshio Abiko
Kuniharu Tatezuki
Masayuki Matsuo
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.)
Panasonic Electric Works Co Ltd
Original Assignee
Matsushita Electric Works 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 Matsushita Electric Works Ltd filed Critical Matsushita Electric Works Ltd
Priority to JP55149007A priority Critical patent/JPS5772434A/en
Publication of JPS5772434A publication Critical patent/JPS5772434A/en
Pending legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04BTRANSMISSION
    • H04B1/00Details 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
    • H04B1/38Transceivers, i.e. devices in which transmitter and receiver form a structural unit and in which at least one part is used for functions of transmitting and receiving
    • H04B1/40Circuits
    • H04B1/50Circuits using different frequencies for the two directions of communication

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Transceivers (AREA)

Abstract

PURPOSE:To reduce the number of oscillators, by using signals from oscillators, which are included in a pair of communication devices respectively, as not only a local oscillation frequency in the superheterodyne system but also a transmission carrier wave signal to be modulated. CONSTITUTION:The voice signal from a microphone 1a of a communication device 1 is inputted to a modulating circuit 3a through an amplifier 2a. The first frequency f1 of an oscillator 4a is inputted to the modulating circuit 3a and is modulated by the sound signal. The modulated signal is transmitted through a power amplifier 5a and a transmission antenna 6a. The transmission signal from a communication device 2 is received by a receiving antenna 7a and is inputted to a mixing circuit 9a through an amplifier 8a. Since the oscillation frequency f1 of the oscillator 4a is inputted to the mixing circuit 9a, the output signal of the mixing circuit 9a becomes a signal including an intermediate frequency f, and only the intermediate frequency DELTAf is obtained by a band pass filter 10a. This frequency passes through an intermediate frequency amplifier 11a, a demodulating circuit 12a, and an amplifier 13a to obtain an voice output from a speaker 14a.
JP55149007A 1980-10-23 1980-10-23 Communication system Pending JPS5772434A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP55149007A JPS5772434A (en) 1980-10-23 1980-10-23 Communication system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP55149007A JPS5772434A (en) 1980-10-23 1980-10-23 Communication system

Related Child Applications (1)

Application Number Title Priority Date Filing Date
JP59052861A Division JPS59181729A (en) 1984-03-19 1984-03-19 Comminication system

Publications (1)

Publication Number Publication Date
JPS5772434A true JPS5772434A (en) 1982-05-06

Family

ID=15465623

Family Applications (1)

Application Number Title Priority Date Filing Date
JP55149007A Pending JPS5772434A (en) 1980-10-23 1980-10-23 Communication system

Country Status (1)

Country Link
JP (1) JPS5772434A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58195325A (en) * 1982-05-11 1983-11-14 Hitachi Denshi Ltd Radio equipment
JPS62245730A (en) * 1986-04-18 1987-10-27 Hitachi Ltd Duplex transmitter-receiver

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58195325A (en) * 1982-05-11 1983-11-14 Hitachi Denshi Ltd Radio equipment
JPS62245730A (en) * 1986-04-18 1987-10-27 Hitachi Ltd Duplex transmitter-receiver

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