JPS648751A - Demodulation system - Google Patents

Demodulation system

Info

Publication number
JPS648751A
JPS648751A JP16446487A JP16446487A JPS648751A JP S648751 A JPS648751 A JP S648751A JP 16446487 A JP16446487 A JP 16446487A JP 16446487 A JP16446487 A JP 16446487A JP S648751 A JPS648751 A JP S648751A
Authority
JP
Japan
Prior art keywords
mixers
local oscillation
demodulation
reception signal
branching device
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
JP16446487A
Other languages
Japanese (ja)
Inventor
Tomozo Ota
Kazutada Azuma
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.)
Sharp Corp
Original Assignee
Sharp Corp
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 Sharp Corp filed Critical Sharp Corp
Priority to JP16446487A priority Critical patent/JPS648751A/en
Publication of JPS648751A publication Critical patent/JPS648751A/en
Pending legal-status Critical Current

Links

Landscapes

  • Digital Transmission Methods That Use Modulated Carrier Waves (AREA)

Abstract

PURPOSE:To surely enable demodulation regardless of height of the carrier frequency by mixing local oscillation signals having a different phase by 90 deg. to a reception signal, demodulating the result by 2-system of demodulation circuits and adding the result. CONSTITUTION:A radio wave modulated by a responding device 2 is received by a transmission/reception antenna 101 of a questionnaire device 1 and led to mixers 107a, 107b via a circulator 102 and a branching device 106. Moreover, a branching device 103 branches a part of a high frequency power as a local oscillation signal and it is branched into two signals having a different phase of 90 deg. by a branching device 105 and injected to the mixers 107a, 107b. The local oscillation signal and the reception signal are mixed in the mixers 107a, 107b. The output is demodulated respectively by an FSK demodulator or detectors 108a, 108b and added to an adder circuit 109 via LPFs 110a, 110b to obtain information. Thus, the intermission of the reception signal is avoided. Thus, the demodulation is ensured regardless of the height of the carrier frequency.
JP16446487A 1987-06-30 1987-06-30 Demodulation system Pending JPS648751A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP16446487A JPS648751A (en) 1987-06-30 1987-06-30 Demodulation system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP16446487A JPS648751A (en) 1987-06-30 1987-06-30 Demodulation system

Publications (1)

Publication Number Publication Date
JPS648751A true JPS648751A (en) 1989-01-12

Family

ID=15793673

Family Applications (1)

Application Number Title Priority Date Filing Date
JP16446487A Pending JPS648751A (en) 1987-06-30 1987-06-30 Demodulation system

Country Status (1)

Country Link
JP (1) JPS648751A (en)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5819038A (en) * 1981-07-16 1983-02-03 インタ−ナシヨナル・スタンダ−ド・エレクトリツク・コ−ポレイシヨン Radio receiver for frequency transient modulation signal
JPS58106469A (en) * 1981-12-21 1983-06-24 Nec Corp Digital sine wave level detecting circuit
JPS58120334A (en) * 1982-01-12 1983-07-18 Oki Electric Ind Co Ltd Narrow-band acoustic signal reception system
JPS5928750A (en) * 1982-08-09 1984-02-15 Mitsubishi Electric Corp Switching device of demodulator
JPS60100859A (en) * 1983-11-08 1985-06-04 Nec Corp Frequency detector

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5819038A (en) * 1981-07-16 1983-02-03 インタ−ナシヨナル・スタンダ−ド・エレクトリツク・コ−ポレイシヨン Radio receiver for frequency transient modulation signal
JPS58106469A (en) * 1981-12-21 1983-06-24 Nec Corp Digital sine wave level detecting circuit
JPS58120334A (en) * 1982-01-12 1983-07-18 Oki Electric Ind Co Ltd Narrow-band acoustic signal reception system
JPS5928750A (en) * 1982-08-09 1984-02-15 Mitsubishi Electric Corp Switching device of demodulator
JPS60100859A (en) * 1983-11-08 1985-06-04 Nec Corp Frequency detector

Similar Documents

Publication Publication Date Title
SE9703617D0 (en) Methods and apparatus for radio communication systems
KR960001578B1 (en) Method and circuit for receiving radio wave
TW341013B (en) Wide band zero if quadrature demodulator using an intermediate frequency and a single local oscillator
MY103727A (en) Arrangement for filtering a received fm signal
SE9102317D0 (en) MIXERS FOR DIRECT CONVERSION RECEIVERS
EP0528443A3 (en) Circuit for receiving radio waves of the vhf-field in vehicles
CA2104729A1 (en) Quadrature Modulation Circuit for Use in a Radio Transmitter
KR980007140A (en) Transmitter / receiver of time division full duplex spread spectrum communication system
US4605903A (en) FSK demodulator with high noise immunity digital phase detector
JPS648751A (en) Demodulation system
JPH0415429B2 (en)
EP1224730A1 (en) Fsk demodulator using a frequency conversion stage with three parallel mixers
JPS55161429A (en) Signal transmitting and receiving system
BG102091A (en) Method for modulation and circuit for the transmission of data-containing signals
JPS55117314A (en) Fm demodulator
JPS5459811A (en) Receiver
JPS614330A (en) Radio equipment
JPS54126412A (en) Multi-station transmission system
JPS5579540A (en) Fsk radio unit
JPS5580948A (en) Fsk radio equipment
JPH04276926A (en) Polarized wave modulation method
JPS6457832A (en) Switching device for transmission line
JPS5586240A (en) Antenna feeding unit
JPS55120229A (en) Set stand-by reception system for frequency-modulated wave
JPS6411448A (en) Receiving device