AM, FM, FM STEREO INTEGRATION MODULATION APPARATUS AND METHOD

摘要

An AM, FM, FM stereo integration modulation apparatus and a modulation method thereof are provided to reduce a size of device in a system using various modulation methods by simplifying a composition thereof. A microprocessor(102) scales an input signal according to a modulation mode selected from AM, FM, FM stereo modulation modes, and generates a control command for controlling an output frequency and an output amplitude according to the scaled signal variably. A DDS(Direct Digital frequency Synthesizer)(104) generates an output signal for varying an output frequency or an output amplitude according to the scaled signal which is controlled by the microprocessor. The microprocessor sets an output frequency of the DDS as a carrier frequency according to the selection of an AM modulation mode. The microprocessor generates a control command for varying an amplitude resistor value of the DDS.