JSSC 2007第3期RF & Wireless0.18μm

A 20 mW 3.24 mm/50Fully Integrated GPS Radio for Location

本文提出了一种集成GPS无线电，解决了GPS接收器与蜂窝电话共存的挑战。

0.18μm SiGe, 20mW, 3.24mm²

GPS接收器蜂窝电话SiGe技术低噪声放大器分数-N PLL

▸高度选择性LNA：采用创新的电路设计，显著提高了对1.9 GHz频段手机泄漏信号的抗干扰能力，实现了8 dBm的1 dB增益去敏化，噪声系数低至5 dB，有效解决了GPS接收器与手机共存的干扰问题。

▸新型正交VCO拓扑：提出了一种创新的VCO结构，能够直接驱动正交无源混频器，同时提供高摆幅和低功耗特性，显著降低了系统功耗（仅20 mW），并提升了信号处理效率。

▸分数-N sigma-delta PLL：采用先进的分数-N sigma-delta技术，实现了与任意晶体频率的锁定，提供了更高的频率合成精度和灵活性，同时优化了系统的功耗和面积效率（芯片面积仅3.24 mm²）。

▸全集成GPS射频系统：通过高度集成的设计，将LNA、VCO、混频器、带通滤波器、可变增益放大器、自动增益控制和量化器等模块整合在单一芯片上，实现了高性能（5 dB噪声系数）与低功耗（20 mW）的完美平衡。

Abstract

The challenges in the co-existence of a GPS receiver with cellular phones for Location Based Services are addressed in this paper. A fully integrated GPS radio, realized in a 0.18 m SiGe technology, demonstrates a 1 dB gain desensitization at 1.9 GHz of 8 dBm, a noise ﬁgure of 5 dB, with 20 mW power con- sumption. Chip area is 3.24 mm /50. The receiver includes a highly selective LNA, key to minimize desensitization and reciprocal mixing due to the large cellphone leakage, a novel quadrature VCO topology capable of directly driving quadrature passive mixer with high swing and low power consumption, complex bandpass ﬁlter, variable gain ampliﬁer, automatic gain control, 2–bit quantizer, and a fractional-N sigma-delta-based PLL that can lock to any crystal frequency.