Title:
BEACON RECEIVER
Document Type and Number:
Japanese Patent JP3205232
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide a beacon receiver for surely performing AM demodulation irrespective of the receiving strength of an FM-AM composite modulation wave transmitted from a road station.
SOLUTION: A beacon receiver 1 is provided with an FM demodulation system composed of a limiter amplifier 21 and a frequency detector 22 and two AM demodulation systems. A first AM demodulation system is composed of the limiter amplifier 21 and a DC prevention circuit 31 and a weak composite modulation wave is AM demodulated based on a RSSI signal produced by the limiter amplifier 21. A second AM demodulation system is composed of a diode flow rectifying type amplitude detector 33 and a strong composite modulation wave is AM demodulated by envelope detection. An AM demodulation signal is obtained by adding these outputs to an adder 34 and its phase is compared with that of an FM demodulation signal by a phase determination circuit 44. In order to acquire synchronism between FM demodulation and AM demodulation and between the two AM demodulation systems, delay circuits 23 and 32 are provided.
Inventors:
Kaoru Okabe
Application Number:
JP26847195A
Publication Date:
September 04, 2001
Filing Date:
October 17, 1995
Export Citation:
Assignee:
Sharp Corporation
International Classes:
G01S1/68; H03D5/00; (IPC1-7): G01S1/68; H03D5/00
Domestic Patent References:
| JP5314393A | ||||
| JP63292805A | ||||
| JP526997A | ||||
| JP526998A | ||||
| JP581596A |
Attorney, Agent or Firm:
Shizuo Sano
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