Direct digital synthesizer with tunable delta sigma modulator

Author

Vankka, Jouko ; Lindeberg, Jonne ; Halonen, Kari

Author_Institution

Electron. Circuit Design Lab., Helsinki Univ. of Technol., Espoo, Finland

Volume

1

fYear

2003

fDate

25-28 May 2003

Abstract

In direct digital synthesizer (DDS) applications, the drawback of the conventional delta sigma (ΔΣ) modulator structure is that its signal band is fixed. In the proposed architecture, the signal band of the ΔΣ modulator is tuned according to the DDS output frequency. We use a hardware efficient phase-to-sine amplitude converter in the DDS that approximates the first quadrant of the sine function with sixteen equal length piecewise cubic segments. The DDS is capable of frequency, phase, and quadrature amplitude modulation. Two DDSs with tunable 1 bit ΔΣ D/A converters (real and complex) were designed and implemented on a programmable logic device (PLD); experimental results show their desired operation and performance.

Keywords

circuit tuning; delta-sigma modulation; direct digital synthesis; frequency modulation; logic design; phase modulation; programmable logic devices; quadrature amplitude modulation; 1 bit; DDS output frequency; PLD; direct digital synthesizer; frequency modulation; modulator signal band tuning; phase modulation; phase-to-sine amplitude converter; piecewise cubic segments; programmable logic device; quadrature amplitude modulation; sine function first quadrant approximation; tunable delta sigma modulator; Analog-digital conversion; Delta modulation; Delta-sigma modulation; Digital modulation; Frequency conversion; Quadrature amplitude modulation; Quantization; Sampling methods; Synthesizers; Tunable circuits and devices;

fLanguage

English

Publisher

ieee

Conference_Titel

Circuits and Systems, 2003. ISCAS '03. Proceedings of the 2003 International Symposium on

Print_ISBN

0-7803-7761-3

Type

conf

DOI

10.1109/ISCAS.2003.1205714

Filename

1205714