A Compact SAW-less Multiband WCDMA/GPS Receiver Front-End with Translational Loop for Input Matching

📋 论文概要

针对WCDMA系统中强TX泄漏导致的SAW滤波器需求和传统LNA电感退化匹配带来的片外组件过多问题，提出了一种基于translational loop实现输入匹配的紧凑型无SAW多频段WCDMA/GPS接收机前端。该设计通过环路替代电感匹配，降低了芯片尺寸和外部元件数量，同时满足多频段接收需求。

💡 主要创新点

• 采用translational loop实现输入匹配，替代传统的电感退化结构，显著减少片外匹配组件和芯片面积。
• 实现无SAW滤波器的多频段WCDMA/GPS接收前端，解决FDD系统中TX泄漏对线性度的苛刻要求。

🏷 关键词

📄 原文摘要

In FDD systems such as WCDMA, strong TX leakage presented at RX imposes stringent RX out-of-band (OOB) IIP3 and IIP2 requirements in addition to low noise figure (NF) requirement, usually necessitating an inter-stage SAW filter in the RX chain. In a GPS receiver that co-exists with cellular applications in the same platform, such a filter is also often needed. Furthermore, to achieve low NF, conventional receivers adopt LNAs with inductive degeneration for input matching. This substantially increases the number of off-chip matching components as well as the chip size in multiband cellular applications. Another drawback is that the LNA current has to be fixed to provide a constant gm over different gains for input matching, even when the wanted signal is strong. SAW-less receiver design has been addressed in [1-6]. [1] and [2] rely on either an extra bonding wire or an additional Q-enhanced LC resonator to filter the

👥 作者与机构

Xin He, Harish Kundur

NXP Semiconductors, Eindhoven, The Netherlands