Increasing the Order of Quadrature Delta Sigma Modulator without Addition of Active Blocks for Wide band Radio Receivers

Document Type : Original Article

Author

Department of Electrical Engineering, Shahid Sattari Aeronautical University of Science and Technology, Tehran, Iran

Abstract

Signal bandwidth (BW) is one of the most important factors in transmitting and receiving rate of information in portable radio receiver systems in advanced defense science .Therefore, it is desire to design different parts of these systems with a larger bandwidth and less power consumption. In this paper, self-coupling method is applied to the quadrature modulator in order increase its bandwidth. In this approach, without the addition of active blocks, modulator’s order is increased and its bandwidth is also improved which results in power saving. Utilizing this method increases the number of zeros in quadrature modulator transfer function and results in a higher order modulator performance. The proposed method is applied to a three-order quadrature modulator, and it is significantly increased the bandwidth. The purposed method results in a 0.05fs bandwidth and a signal-to-noise ratio (SNR) of 91.25 dB which is improved by 25% compare to the results obtained in a modulator without the self-coupling( BW=0.04fs and SNR= 92.86dB). 

Keywords


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