The Design And Physical Implenentation Of14-bits Direct Digital Frequency Synthesizer Based On Muilti-cjannle Interpolation

With the rapid development of modern communication、radar and informationtechnology, high quality signal sources are becoming more and more important in thefields of digital communication, space communication, radar measurements, electronicwarfare and satellite navigation. The direct digital frequency synthesizer (DDS) hasbeen widely used in the design of high quality signal sources for its outstanding featuresof fine frequency discrimination, fast frequency hopping, stable phase and continuousphase changes.This thesis presents a multi-channel interpolated DDS that works on differentialCORDIC algorithm. This thesis details the principle of differential CORDIC algorithm,multi-channel interpolatioin technology and physical design of the DDS. As a new typeof CORDIC algorithm, the differential CORDIC algorithm is used to realize thephase-amplitude mapping logic. Compared with conventional CORDIC algorithm, theSFDR of the output of DDS improves by3.77dB. To increase the sampling clockfrequency,4-channel interpolation technology is used. As we can see in this thesis, thesampling clock frequency is4times higher than the conventional single-channel DDS.In addition, the spur characteristic of low frequency output is improved. Using thecontrol signal imported through serial peripheral interface, we can modulate theamplitude, frequency and phase of the DDS output signal.The physical design and timing analysis of DDS are based on SMIC0.18μm1P6Mstandard CMOS process library. Final analysis reveals that it has a maximum samplingfrequency of800MHz, and its frequency resolution is32-bits. When output signalfrequency reaches91.56MHz, the SFDR of the design is84.57dB. The power of thedesign is543.8mw with an area of2.15mm2. The design can meet the requirements ofradar and communication application with stable and reliable functionality.