Title :
A new direct digital transmitter architecture for constant envelope modulation
Author :
Finateu, Thomas ; Belot, Didier ; Badets, Franck ; Bégueret, Jean-Baptiste ; Deval, Yann
Author_Institution :
FTM, Crolles
Abstract :
A high speed direct digital synthesizer (DDS) based transmitter architecture is presented. The DDS driven by a sigma delta (SigmaDelta) locks by injection an LC-tank oscillator on an upper harmonic. Moreover, the injection locked oscillator (ILO) provides a band-pass filtering within its locking range which rejects out of band SigmaDelta quantization noise. The DDS is detailed in order to explain how to design an output signal frequency close to the clock frequency. Then the architecture is modulated thanks to constant envelope modulation. Finally, ILO output is compared to high constraint mask such as GSM/DCS in order to simulate architecture capability.
Keywords :
band-pass filters; clocks; direct digital synthesis; injection locked oscillators; quantisation (signal); radio transmitters; band-pass filtering; clock frequency; constant envelope modulation; direct digital synthesizer; direct digital transmitter architecture; injection locked oscillator; quantization noise; Band pass filters; Delta-sigma modulation; Digital modulation; Filtering; Frequency; Injection-locked oscillators; Power harmonic filters; Quantization; Synthesizers; Transmitters; 802.11; Band-pass filtering; Direct Digital Synthesizer (DDS); GSM/DCS; Injection Locked Oscillator (ILO); Phase Accumulator (PACC); Phase Interpolator (PI); Sigma Delta (ΣA); Transmitter Architecture;
Conference_Titel :
Information, Communications & Signal Processing, 2007 6th International Conference on
Conference_Location :
Singapore
Print_ISBN :
978-1-4244-0982-2
Electronic_ISBN :
978-1-4244-0983-9
DOI :
10.1109/ICICS.2007.4449823
