List of Articles Sigma-Delta Open Access Article Abstract Page Full-Text 1 - Improvement of SNDR using Optimization of Feedback Path Coefficients for Second Order CRFB Modulators in Sigma-Delta Analog to Digital Converters Maryam Shahriary Abdolrasool Ghasemi najmeh cheraghi shirazi Open Access Article Abstract Page Full-Text 2 - Δ∑ Fractional-N Synthesizer for GSM-E-900 Frequency Standard Alireza Bagherzadeh Mostafa Yargholi Open Access Article Abstract Page Full-Text 3 - Design and Simulation of Ultra-Low-Power Sigma-Delta Converter Using the Fully Differential Inverter-Based Amplifier for Digital Hearing Aids Application Shima Alizadeh Zanjani Abumoslem Jannesari Pooya Torkzadeh Open Access Article Abstract Page Full-Text 4 - Background Subtraction Techniques Evaluation based on ∑-∆ Algorithm for Motion Detection Mohammadreza Mahvidi Vahid Ghods