A SAW-Less Direct-Digital RF Modulator with Tri-Level Time-Approximation Filter and Reconfigurable Dual-Band Delta-Sigma Modulation

📋 论文概要

该论文提出了一种无SAW的直接数字射频调制器，采用三电平时间逼近滤波器和可重构双频带Delta-Sigma调制器，解决了5G多频段多标准应用中高带内动态范围和特定带外低噪声的需求。通过可调操作频带设计，实现了更优的实现权衡。

💡 主要创新点

• 提出三电平时间逼近滤波器，有效抑制带外噪声并降低功耗。
• 采用可重构双频带Delta-Sigma调制器，支持多频段操作且无需SAW滤波器。
• 实现直接数字射频调制架构，简化模拟前端并提高灵活性。

🏷 关键词

📄 原文摘要

A key aspect of 5G systems is supporting multiband and multistandard applications. Depending on operating conditions, this requires high in-band dynamic range and/or low noise floor at specific out-of-band (OOB) frequencies, e.g. the receiver band of an FDD system or radio coexistence. For a transmitter to implement instantaneous bandwidth covering all communication bands while maintaining sufficient dynamic range is usually not cost efficient, and a directdigital RF modulator (DDRM) with tunable operational band is a potential solution, providing better implementation tradeoff [1-4]. However, a conventional DDRM typically incurs an overhead of RF bandpass filtering for signal reconstruction and noise/spur suppression due to the lack of a baseband reconstruction filter between the DAC and mixer. To relax the filter requirement, a bandpass delta-sigma modulator (DSM) [1] is used to create spectral notches for suppressing OOB

👥 作者与机构

Shiyu Su, Mike Shuo-Wei Chen

University of Southern California, Los Angeles, CA