IF exciter for radio transmitter

摘要

A method and apparatus are provided for modulating an intermediate frequency of a radio frequency transmitter with a digital sample stream. The method includes the steps of interpolating the digital sample stream by an over sampling factor and modulating the interpolated digital sample stream to a single bit sample stream, while spreading and shaping quantization noise created by the modulation outside a bandwidth of the intermediate frequency. The method further includes the steps of converting the single bit sample stream to an analog signal and bandpass filtering the analog signal around the intermediate frequency.