نوع مقاله : مقاله پژوهشی
نویسندگان
دانشگاه شهید ستاری
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
In this paper, a second order discrete-time quadrature delta sigma modulator for GSM / EDGE receivers is designed. By reducing the OSR in the designed modulator, its operating frequency is decreased. This frequency reduction has led to the use of smaller bandwidth-based op-amps in this modulator that work at lower frequencies with less power consumption. A three-bit quantizer is used to achieve the desired signal to noise ratio (SNR). A 3-bit quantizer is used To achieve the desired SNR, and consequently it has a 3-bit DAC at the feedback paths of modulator. The mismatch of its cells is one of the problems of multi bit modulators. Another problem with quadrature modulators is the mismatch between paths I and Q. A complex DEM block is designed to correct the DAC cells error mismatch in each path and between I and Q paths. The designed modulator is implemented in CMOS-180nm technology. The designed modulator is implemented in CMOS-180nm technology. The SNR of the output spectrum of this modulator is obtained 86dB with a sampling rate of 50 and a power consumption of 5.58mw.
کلیدواژهها [English]