A 1.25mW 75dB-SFDR CT Filter with In-Band Noise Reduction

📋 论文概要

本文提出一种连续时间滤波器，通过带内噪声降低技术打破噪声与线性度之间的折衷，在1.25mW功耗下实现75dB SFDR，适用于直接转换无线接收机。

💡 主要创新点

• 提出带内噪声降低技术，在不增加电容面积的前提下改善噪声性能。
• 通过电路设计打破传统噪声-线性度折衷，实现低功耗高SFDR。

🏷 关键词

📄 原文摘要

In a direct-conversion wireless receiver the baseband filter should be able to handle large blockers, resulting in a very challenging spurious free dynamic range (SFDR) requirement. In particular, the noise added in-band trades off with the linearity required to handle close out-of-band interferers [1]. Since the integrated noise generally is proportional to kT/C, once the noise floor for the filter is set, the amount of capacitance is roughly defined as well as a lower bound for area and power consumption [2]. The solution presented in this paper aims to break this trade off by inserting an in-band zero in the output noise transfer function to improve the dynamic range. The starting point of this work is the current-driven 1st-order LPF shown in Fig. 19.8.1. In this structure, the high impedance degeneration at low frequencies minimizes the noise injected by the cascode in the filter passband. As an analogy, the current signal flows as in a pipe where only losses or current injection

👥 作者与机构

Antonio Liscidini, Alberto Pirola, Rinaldo Castello

University of Pavia, Pavia, Italy