A 22.4-to-26.8GHz Dual-Path-Synchronized Quad-Core Oscillator Achieving −138dBc/Hz PN and 193.3dBc/Hz FoM at 10MHz Offset from 25.8GHz If the frequency mismatch exists in the adjacent cores (f1 = f3 > f2 = f4), a strong coupling (k2) between LG13 and LG24 also helps reduce the output amplitude variation. Consequently, the PN penalty of our dual-path-synchronized oscillator is ~0dB at a 5% frequency mismatch, which is even lower than that of the conventional design (0.2dB).

📋 论文概要

本文提出了一种22.4至26.8GHz的双路径同步四核振荡器，通过创新的双路径同步技术和四核耦合架构，有效抑制了频率失配引起的相位噪声恶化，并提升了谐振腔品质因数，最终实现了-138dBc/Hz的相位噪声和193.3dBc/Hz的FoM。

💡 主要创新点

• 提出双路径同步技术，通过连接四个核心的VGP/VGN/VDP/VDN节点，将四核振荡器等效为双核振荡器，简化了设计并降低了相位噪声。
• 利用三线圈变压器和对称位置的双栅电感转换，进一步优化为双线圈结构，通过增大耦合系数k2提升栅电感LG'和谐振腔Q值，从而抑制频率失配导致的相位噪声恶化。

🏷 关键词

📄 原文摘要

four cores and connect VGP1-4 (VGN1-4, VDP1-4, and VDN1-4) together. Then the quad-core oscillator can be equivalent to a dual-core oscillator in Fig. 8.2.3 (top-left). The triplecoil transformer in the dual-core oscillator can be further transferred to a dual-coil one by exploiting the symmetric position between the two gate inductors (Fig. 8.2.3 topright). Here, the loss of each coil and the corresponding capacitor is modeled by RD or RG. Besides suppressing the PN penalty due to the frequency mismatch, a large k2 also boosts LG’ and the tank Q. The contour plot in Fig. 8.2.3 (bottom-left) reveals that the tank Q (QT) is maximized by choosing ξ’ = (4LG’CG)/(LDCD) = 1. In addition, a low PN favors a small RP/QT2, where RP is the parallel tank resistance seen from ports VDP and VDN. Since the contour line of RP/QT2 tends to be parallel with the x-axis when ξ’ > 1, increasing ξ’ marginally reduces RP/QT2 but at the cost of large QT degradation. Besides,

👥 作者与机构

Xiangxun Zhan1, Jun Yin1, Pui-In Mak1, Rui P. Martins1,2, To design the transformer tank, we can assume no frequency mismatches between the