Direct Digital Synthesizers (DDS) are known to be very spurious due to the use of Digital-to-Analog Convertors (DAC). This paper presents the phase behaviour of spurs of the AD9912 DDS and its SpurKiller cancellation system. A great variation in spur phase and a variation in increased spurious-free dynamic range (SFDR) was observed. As a result, an adaptive system is proposed using a Double Quadrature Mixer and a variable phase LO. The system is tested at the Intermediate Frequency (IF) of 1.2 GHz, simulating an Ultra-Wideband (UWB) radio. In simulation, an increase in SFDR of 29 dB resulted. In system prototype, an increase in SFDR of 10 dB resulted.

Additional Metadata
Keywords cancellation, interference, mixers, phase modulation, Signal synthesis
Persistent URL dx.doi.org/10.1109/RWS.2015.7129780
Conference 2015 IEEE Radio and Wireless Symposium, RWS 2015 - RWW 2015
Citation
Mack, S. (Simon), & Wight, J. S. (2015). Double Quadrature Mixer for adaptive spur cancellation in ultra-wideband radios. In IEEE Radio and Wireless Symposium, RWS (pp. 78–81). doi:10.1109/RWS.2015.7129780