A design of front-end compatible with PAL & DVB-C

This paper discusses the design on the front-end that is compatible with analog modulation signal (compliance with PAL) and digital modulation signal (compliance with DVB-C). Although the PAL signal and the DVB-C signal are two signals with different types of modulation, they can use one RF tuner together to save the cost. These two signals have different spectrum characteristics, so they need different in-band response of the channel filter to satisfy the receiving requirement. Meanwhile, we choose two appropriate intermediate frequencies to make them in the same range. We design a programmable intermediate frequency (IF) and a switching circuit for the IF signal.