HYBRID DIGITAL DIGITAL/ANALOG FM MULTIPLEXER/TRANSMITTER

摘要

An audio circuit digitizes raw analog input and uses a digital signal processor (DSP) to filter, modulate, and mix the input to produce a multiplex composite signal. The multiplex composite signal is output from the DSP through a digital/analog converter (DAC), and modulates a conventional FM RF stage. In a first preferred, hydrid embodiment, the composite signal is output from the DSP through a digital/analog converter (DAC), and modulates a conventional FM RF stage. In a second preferred, fully digital embodiment, carrier modulation takes place in the DSP, and FM modulated RF is output via a fast DAC for final filtering and radiation.