Direction de recherche : Alain GREINER

Co-encadrement : ABOUSHADY Hassan

Modulateurs Sigma Delta LC Monobloc d'Ordre Élevé

Software-Defined Radio (SDR) was envisioned in the late 1990’s. Since then, a lot of effort has been done to implement such a radio transceiver, where most of the analog functions such as down-conversion and channel-selection are moved to the digital domain. With these features a SDR could be easily programmed and adapted to new standards. However, its implementation using a Nyquist-rate Analog-to-Digital Converter (ADC) has been challenging and very power hungry, making it inappropriate for mobile applications.
Bandpass Sigma-Delta Modulator (SDM) using LC resonators are well suited for that purpose, as they can convert a narrow band around an Radio Frequency (RF) center frequency.
High-order LC-based SDMin the literature use the nodes between the LC tanks either for feedforward or feedback coefficients in order to obtain the desired Noise Transfer Function (NTF). These nodes are usually a source of additional noise, non-linearity and power consumption to the overall performance of the SDM.
In this work, a methodology to design high-order LC-Based single-block SDM is introduced. This opens the door to unexplored filter topologies such as high-order passively coupled LC filters and Microelectromechanical Systems (MEMS) filters.
The main contributions of his work can be summarized in the following points:
- Design Methodology for LC-Based Single-Block Sigma-Delta Modulators
- Undersampled 4th order Capacitively-Coupled Sigma-Delta
- Systematic design procedures for the RF building blocks
- Design and Implementation of the first 4th Order Capacitively-Coupled LC-Based SDM

Publications 2009-2018

• 2018
  • D. Haghighitalab, D. Belfort, A. Kilic, A. Benlarbi‑Delai, H. Aboushady : “A 2.4 GHz ISM-band Highly Digitized Receiver based on a Variable Gain LNA and a Subsampled ADC”, Analog Integrated Circuits and Signal Processing, vol. 95 (2), pp. 259-270, (Springer Verlag) (2018)
• 2017
  • D. Belfort, Sebastian Y.C. Catunda, H. Aboushady : “4^th order capacitively-coupled LC-based Σ Δ modulator”, Microelectronics Journal, vol. 62, pp. 99-107, (Elsevier) (2017)
• 2015
  • Ah. Ashry, D. Rodrigues Belfort, H. Aboushady : “Phase Noise Effect on Sine-Shaped Feedback DACs Used in Continuous-Time Sigma-Delta ADCs”, IEEE Transactions on Circuits and Systems Part 1 Fundamental Theory and Applications, vol. 62 (3), pp. 717-724, (Institute of Electrical and Electronics Engineers (IEEE)) (2015)
• 2014
  • D. Rodrigues Belfort, Sebastian Y. C. Catunda, H. Aboushady : “Design of RF BAW-based ΣΔ Modulators”, IEEE 5^th Latin American Symposium on Circuits and Systems (LASCAS), 2014, Santiago, Chile, pp. 1-4 (2014)
• 2012
  • D. Rodrigues Belfort : “Modulateurs Sigma Delta LC Monobloc d’Ordre Élevé”, soutenance de thèse, soutenance 26/11/2012, direction de recherche Greiner, Alain, co-encadrement : Aboushady, Hassan (2012)
• 2010
  • D. Belfort, H. Aboushady : “Automatic Design of RF Linear Transconductor”, LASCAS IEEE Circuits and Systems Society Latin American Symposium on Circuits and Systems, Foz do Iguaçu, Brazil (2010)
• 2009
  • D. Belfort, N. Beilleau, H. Aboushady, M.‑M. Louërat, Sebastian Y. C. Catunda : “A Q-enhanced LC bandpass filter using CAIRO+”, IEEE International Conference on Electronic Circuits and Systems, (ICECS), Hammamet, Tunisia, pp. 860-863, (IEEE) (2009)