Title :
Design of a wideband transmit delta-sigma DAC
Author :
Neitola, Marko ; Kivi, Arto ; Rahkonen, Timo
Author_Institution :
Dept. of Electr. Eng. & Infotech Oulu, Oulu Univ., Finland
fDate :
6/23/1905 12:00:00 AM
Abstract :
In this paper a wideband CDMA single-carrier transmitter IF digital-to-analog converter (DAC) based on delta-sigma (ΔΣ) modulation is presented. The ΔΣ modulator is a 5-bit 12th order bandpass-type with a sampling frequency of 16 times the chip rate. The implementation consists of FIR interpolation filters, a ΔΣ modulator, a binary weighted D/A converter and an analog postfilter. This paper discusses mainly the digital ΔΣ architecture, and its performance on adjacent channel power ratio (ACPR) and error vector magnitude (EVM). Concerning on the given specifications, also linearity errors due to element mismatch distortion in the D/A conversion are discussed. The modulator is implemented in Xilinx. Virtex 400 series FPGA family
Keywords :
FIR filters; band-pass filters; code division multiple access; delta-sigma modulation; field programmable gate arrays; hardware description languages; logic CAD; radio transmitters; 12th order bandpass-type; FIR interpolation filters; FPGA; IF digital-to-analog converter; Xilinx. Virtex 400; analog postfilter; binary weighted D/A converter; delta-sigma modulation; element mismatch distortion; error vector magnitude; linearity errors; wideband CDMA single-carrier transmitter; Delta modulation; Digital modulation; Digital-analog conversion; Finite impulse response filter; Frequency; Interpolation; Multiaccess communication; Sampling methods; Transmitters; Wideband;
Conference_Titel :
Electronics, Circuits and Systems, 2001. ICECS 2001. The 8th IEEE International Conference on
Print_ISBN :
0-7803-7057-0
DOI :
10.1109/ICECS.2001.957668
