Wideband Signal Synthesis Using Interleaved Partial-Order Hold Current-Mode Digital-to-Analog Converters

We describe how a zero-order hold digital-to-analog converter (DAC) followed by a windowed-integration-based filter results in a novel partial-order hold (POH) DAC architecture with the ability of broadband image reduction between 1.5 and two times the sampling frequency while also providing a flat-group delay. Interleaving two such POH-DACs results in a DAC with an excellent output signal reconstruction whereby the broadband sampling images below two times the sampling frequency in the output signal spectrum are strongly reduced. Some implementation techniques are proposed and the effect of implementation nonidealities is evaluated.