Title :
A direct digital synthesizer with a tunable error feedback structure
Author_Institution :
Lab. of Signal Process. & Comput. Technol., Helsinki Univ. of Technol., Espoo, Finland
fDate :
4/1/1997 12:00:00 AM
Abstract :
A basic premise for a direct digital synthesizer (DDS) with error feedback (EF) is that the output frequency being generated is low with respect to the clock frequency used. This is necessary because the transfer function of the EF has zero(s) at DC. In the proposed architecture the clock frequency need only be much greater than the bandwidth of the output signal, whereas the output frequency could be any frequency up to somewhat below the Nyquist frequency. In this novel method, the coefficients of the EF filter are tuned according to the output frequency
Keywords :
circuit feedback; circuit tuning; direct digital synthesis; poles and zeros; transfer functions; Nyquist frequency; architecture; clock frequency; direct digital synthesizer; error feedback filter coefficients; output frequency; output signal bandwidth; transfer function; tunable error feedback structure; Clocks; Costs; Filters; Frequency synthesizers; Output feedback; Quantization; Read only memory; Registers; Sampling methods; Transfer functions;
Journal_Title :
Communications, IEEE Transactions on
