New Researches in Electronic Defense Systems

New Researches in Electronic Defense Systems

Efficiency increasing of the Continuous Time quadrature Delta Sigma Modulator by applying Error-Feedback technique for radar receivers

Document Type : Original Article

Author
alireza shamsi
air univercity
10.22034/joeds.2025.493621.1071
Abstract
In this paper, a FF, three-order, 3-bit continuous time quadrature delta-sigma modulator by applying error-feedback method is designed for a wideband radar receiver. In this method, the quantization noise of the modulator is extracted then injected to the output of the loop filter by a transfer function consist of delays in the z domain. The proposed method adds a zero to the modulator’s NTF that increases the modulator’s order without adding active blocks. The first, the primary NTF zeros are located at the pass band, and then applying the error-feedback method adds a zero in DC, which increases the bandwidth and SNR of the modulator. Bandwidth, center frequency and SNR of conventional modulator are 0.03Fs, 0.029Fs and 76.48dB, respectively then for proposed structure are 0.044Fs and 0.0215Fs and 86.52dB, respectively. Comparison of the results shows that the bandwidth and SNR of the proposed structure increased by more than 30 and 10 percent, respectively, compared with the conventional structure.
Keywords
radar receiver
quadrature delta-sigma modulator
error-feedback
wideband
New Researches in Electronic Defense Systems
Volume 5, Issue 15
Summer 2026
Pages 34-37