13-Bit RF-DAC up to 14GS/s at 3.5 GHz introducing Smart-Switching

This paper presents a radio frequency digital-to-analog converter using Smart Switching to handle glitches. This technique is feasible for I/Q modulator transmitters applying a 25% duty cycle as well as for standalone RF-DACs applying a 50% duty cycle. The approach has been evaluated in schematic simulations as well as in simulations with layouted critical blocks and can, with the current buffer design, support local oscillator frequencies of up to 3.5 GHz and sampling rates of up to 4fLo. Single-tone as well as baseband data have been chosen as inputs. The spurious free dynamic range for the current steering output is 58 dB for 2.4 GS/s at an LO of 2.4 GHz with an input frequency of 5 MHz and ranges from 0 Hz to 4.7 GHz without any filtering at the output.