A low-power and high-SFDR Direct Digital Frequency Synthesizer based on adaptive recoding CORDIC

Abstract

Direct Digital Frequency Synthesizer (DDS) plays an important role in communication systems. In this paper, we propose a novel DDS architecture. Compared with the conventional lookup table (LUT) based DDS, the proposed one adopts the coordinate rotation digital computer (CORDIC) algorithm to accomplish phase-to-amplitude conversion. Due to the poor accuracy of the conventional CORDIC, an adaptive recoding CORDIC is proposed. To verify the correctness and evaluate the performance, the proposed DDS is validated on a Virtex 5 FPGA development platform. Compared with a commercial implementation of DDS, the power dissipation of the proposed DDS is reduced by 21.5% at the same toggle rate. Compared to the latest CORDIC based DDS, the spurious free dynamic range (SFDR) of the proposed DDS achieves 91.67 dBc and exceeds nearly 5 dBc.