A both Gaussian and sinusoidal phase-to-amplitude converter for low-power ultra-high-speed direct digital synthesizers

This paper introduces a new bipolar differential pair topology for both Gaussian and sinusoidal signal shaping, to be used as a phase-to-amplitude converter alternative in low-power ultra-high-speed DDS. A DDS using this converter, with a 9-bit frequency resolution and an 8-bit amplitude resolution has been designed in a 0.13 μm SiGe BiCMOS technology, with f_t/f_max of 200/250 GHz, and simulated up to a 20 GHz operating clock frequency. It consumes 585 mW under a 2.8 V power supply. Simulated triangle shape allows an optimal SFDR of -44.5 dBc in sinus mode and a SLRR of -43.5 dBc in Gaussian mode.