Radio Data System (RDS) demodulator for receiving broadcast programmes carrying both Radio Data signals and ARI signals, comprising a digital filter means for obtaining a high attenuation of ARI signals

摘要

An RDS data demodulator includes an analog-to-digital converter for converting an analog FM signal into a digital FM modulation signal; a first filter having a transfer zero point at a predetermined frequency, for receiving the digital FM modulation signal and for attenuating an information modulation signal; a second filter having a pass band characteristic at the predetermined frequency, for receiving a filter output signal from the first filter and for extracting an RDS modulation signal; and RDS demodulating means for demodulating the RDS modulation signal from the second filter to output both an RDS data signal and a reproduction clock signal used to demodulate the RDS data signal.