DARC DARC DARC SIGNAL DEMODULATION CIRCUIT ARRANGEMENT AND METHOD FOR OPERATING SAME

摘要

The DARC signal demodulation circuit device 100 for recovering the DARC signal W containing the DARC data data from the FM multiplex transmission signal MPX is synchronized with the stereo pilot tones included in the FM multiplex transmission signal, A pilot tone control loop 101 configured to obtain a first oscillation ps19 and a second oscillation pc19 and a third oscillation ps76 orthogonal to each other including a frequency quadrupled compared to the stereo pilot tone, A first multiplication stage 103 for obtaining a first multiplication signal from an FM multiplex transmission signal and a third oscillation and a second multiplication stage 103 for obtaining an FM multiplex transmission signal and a fourth oscillation A second multiplication stage 104 for obtaining a second multiplication signal, a first low-pass filter 105 for obtaining a first DARC signal component Q by low-pass filtering the first multiplication signal, A second low pass filter 106 for obtaining a second DARC signal component I by low pass filtering and an FM demodulation stage 107 for obtaining a DARC signal from the frequency demodulation of the first and second DARC signal components, . The way in which this DARC signal demodulation circuit arrangement as well as the DARC signal demodulation circuit arrangement is improved and simplified.