题目/Title：A 54.4-mW 4th-order Quadrature Bandpass CT ΣΔ Modulator with 33-MHz BW and 10-bit ENOB for a GNSS receiver

作者/Author：张俊峰,张泽宏,续阳,池保勇
                        Junfeng Zhang,Zehong Zhang,Yang Xu,Baoyong Chi

会议/Conference：RFIC 2015

地点/Location：Phoenix，Arizona，USA

年份/Issue Date：2015.17-19 May

页码/pages：

摘要/Abstract：
A 4th-order quadrature bandpass continuous-time sigma-delta modulator for a GNSS receiver is presented. With significantly wide bandwidth, the modulator is able to digitalize the down-conversed GNSS signals in two adjacent signal bands simultaneously. This makes it possible to realize simultaneous dual-frequency reception from two satellite systems with one receiver channel instead of two independent channels. A direct RZ feedback is introduced into the input of the last integrator to realize ELD compensation. Power-efficient amplifiers are employed in the active RC integrators, and self-calibrated comparators are used to implement the low-power 3-bit quantizers. Implemented in 180nm CMOS, the modulator achieves 62.1dB peak SNDR, 64dB DR and 59.3dB image rejection ratio (IRR), and consumes 54.4mW from a 1.8V power supply.