An improved architecture of building a delta-sigma modulator, which is the
basis of fully digital transmitter operating at gigahertz carrier, is presented.
A block diagram of signal processing is represented, a polyphase decomposition of
DSM modulators 1 and 2 orders is carried out. DSM 1 and 2 orders are
implemented in chip Kintex 7 firm Xilinx, using polyphase conception. Logic
optimization is executed for each modulator. The high frequency architecture of
DSM 1 order, which is obtained on optimization, excludes feedback in an
explicit form, has less complexity of combinational logic. The scheme allows to
create logic with 4, 8 and more phases without decreasing clock frequency. The
maximum frequency of realization for standart architecture with 4 phases is
194Mhz, for high frequency architecture with 8 phases – 316Mhz. Optimization
architecture DSM 2 order is made by additional parallelization of calculations
using multiplexer. As
a result, the maximum frequency of the standard architecture for phases 4 is
119 MHz, high-frequency architecture for 4 phases - 223MGts, 8 phases - 134
MHz. The results of the implementation of a polyphase and high-frequency
circuits, including DSM noise, are represented for oversampling ratios 64 and
DSM, polyphaser decomposition, high-frequency architecture, OSR.
1. Nielsen M. and Larsen T. A
transmitter architecture based on delta-sigma modulation and switch-mode power
amplification. IEEE Trans. Circuits Syst. II: Exp. Briefs, vol. 54, no. 8, pp.
735–739, Aug. 2007.
2. Wagh P., Midya P., Rakers P.,
Caldwell J., Schooler T. An all digital universal RF transmitter. in Proc.
IEEE Custom Integr. Circuits
Conf., Oct. 2004, pp. 549–552.
3. Helaoui M., Hatami S., Negra R.,
Ghannouchi F. A Novel Architecture of Delta-Sigma Modulator Enabling
All-Digital Multiband Multistandard RF Transmitters Design. IEEE Trans. ON Circuits Syst. II: Exp.
Briefs, vol. 55, no. 11, pp.1129-33, nov. 2008.
R., Temes G.C. Understanding Delta-Sigma Data Converters. Wiley-IEEE Press, pp. 36-39, Nov. 2004
5. Morin M. A. A 1.6 Gb/s
delta-sigma modulator with integrated wideband mixer for RF applications. in
Proc. Bipolar/BiCMOS Circuits Technol. Meeting, pp.148–151,Sep.1998.
6. Jerng A. and Sodini C. G. A wideband delta-sigma
digital-RF modulator for high data rate transmitters. IEEE J. Solid-State
Circuits, vol.42, no. 8, pp. 1710–1722, Aug. 2007
7. Vaidyanathan P.P. Multirate
digital filters, filter banks, polyphase networks, and applications: a
tutorial. Proceedings of the IEEE, VOL. 78, NO. 1, pp. 56-93, Jan. 1990