JPS5772434A - Communication system - Google Patents
Communication systemInfo
- 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
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B1/00—Details 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
- H04B1/38—Transceivers, 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
- H04B1/40—Circuits
- H04B1/50—Circuits 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.
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)
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 |
-
1980
- 1980-10-23 JP JP55149007A patent/JPS5772434A/en active Pending
Cited By (2)
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 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
ATE233971T1 (en) | TWO-MODE TRANSMITTER/RECEIVER | |
KR900004119A (en) | LNB for simultaneous reception of C / ku-band satellite broadcasting | |
GB586315A (en) | Improvements in or relating to secret radio communication | |
GB590506A (en) | Radio relay station | |
GB551472A (en) | Improvements in modulated high frequency carrier wave signalling systems | |
ES482039A1 (en) | Multifrequency generator | |
JPS5772434A (en) | Communication system | |
JPS5642437A (en) | Radio receiver | |
JPS57111150A (en) | Radio communication system | |
JPS56103514A (en) | Filter circuit | |
JPS5556743A (en) | Simple privacy telephone set | |
JPS5746551A (en) | Communication device | |
JPS5795729A (en) | Radio transmitter and receiver | |
KR970056176A (en) | Transceiver of Time Division Full Duplex Spread Spectrum Communication | |
JPS56123157A (en) | Heterodyne transmitter-receiver | |
JPS5530257A (en) | Noise suppressing receiver | |
JPS575442A (en) | Fm receiver | |
KR890004512A (en) | Low noise frequency converter for both C-band and Ku-band of satellite broadcasting | |
JPH0516748Y2 (en) | ||
JPS5791040A (en) | Radio communication device | |
JPS55160872A (en) | Doppler speedometer | |
JPS55161430A (en) | Radio communicating system | |
JPS55128928A (en) | Radio communication system | |
JPS5739630A (en) | Radio equipment | |
JPS572135A (en) | Radio telephone system |