A Pulling Mitigation Technique for Direct-Conversion Transmitters

📋 论文概要

该论文提出了一种用于直接变频发射机的牵引缓解技术，解决了功率放大器通过电磁或电容耦合干扰本地振荡器的问题，从而改善发射机EVM和频谱掩模。

💡 主要创新点

• 提出一种新的电路技术来抑制PA对VCO的牵引效应，无需依赖耗时且不可预测的布局优化。
• 通过主动补偿或隔离机制，减少耦合路径对振荡器频谱的污染。

🏷 关键词

📄 原文摘要

Despite versatility and low power consumption, direct-conversion transmitters suffer from a fundamental drawback: the local oscillator disturbance by the power amplifier, through unwanted electromagnetic or capacitive coupling [1,2]. As shown in Fig. 21.8.1, the pulled oscillator spectrum is no longer a single-tone sinusoid, which can drastically degrade the transmitter EVM or spectrum mask. To alleviate this, time-consuming and often unpredictable optimization of the floor plan, package, and PCB is required to maximize the isolation between the PA and VCO. Ultimately, this issue may prohibit the use of this architecture for many applications, leading to higher power consumption. Moreover, in many modern radios it is common to have more than one VCO on-chip (Fig. 21.8.1) to support various features such as FDD, carrier aggregation, or coexistence, further exacerbating the problem through multiple-VCO cross-coupling. To

👥 作者与机构

Ahmad Mirzaei, Mohyee Mikhemar, Hooman Darabi

Broadcom, Irvine, CA