Evaluation of Digital-to-RF Upconversion Transmitter Using Harmonic Images of DAC Output

Abstract

This letter evaluates a transmitter architecture using harmonic images in D/A conversion for generating RF signals. In generating harmonic images, the problems such as intermodulation distortion of DAC were investigated. We developed an evaluation system with two bandpass filter and a buffer amplifier. It was experimentally found that the RF signal up to around 400MHz can be generated by a commonly used 14-bit DAC at the sampling rates of around 40MHz with EVM less than 6.6%. This letter also presents a more feasible transmitter example having an IF stage with harmonic image extraction scheme and a typical RF upconversion stage.