摘要： 传统PCB设计在处理射频滤波线路时主要聚焦阻抗匹配，对电磁耦合路径的约束研究较少，导致滤波单元端口隔离度受限。为此，提出一种基于“场-路-屏”协同设计的PCB高隔离度度实现方法。该方法融合三项核心技术：减薄关键介质层增强垂直场约束；优化共面接地间距抑制同层横向耦合；采用工艺可实现的最小间距高密度过孔阵列构建三维电磁屏蔽墙。通过三维电磁仿真与实物测试验证表明，在1.6~2.1 GHz频段内，协同设计方法将端口间隔离度由67 dB提升至8 3dB以上，改善超过16 dB，且插入损耗变化小于0.1 dB。该方法为射频滤波模块及无源滤波器的封装与电磁兼容设计提供了可量化工程参考。

中图分类号：TN811+.4 文献标志码：A DOI: 10.16157/j.issn.0258-7998.268039
中文引用格式： 杨桃均，向星诚，温桎茹，等. 高隔离射频滤波的PCB设计方法[J]. 电子技术应用，2026，52(7)：24-28.
英文引用格式： Yang Taojun，Xiang Xingcheng，Wen Zhiru，et al. PCB design method for high-isolation RF filters[J]. Application of Electronic Technique，2026，52(7)：24-28.

PCB design method for high-isolation RF filters

Abstract： Traditional PCB design for RF filter circuits primarily focuses on impedance matching, with limited consideration given to the control of electromagnetic coupling paths, which restricts port isolation in filtering units. To address this, a method to achieve high isolation on PCBs based on a "field-circuit-shielding" synergistic design is proposed. This method integrates three core techniques: thinning the critical dielectric layer to enhance vertical field confinement; optimizing the coplanar ground spacing to suppress in-plane lateral coupling; and employing a high-density via array with the minimum process-achievable pitch to construct a 3D electromagnetic shielding wall. Verified through 3D electromagnetic simulation and physical measurements, the synergistic design approach improves the inter-port isolation by over 16 dB within the 1.6~2.1 GHz frequency band, without significant degradation in insertion loss. This method provides a quantitative engineering reference for the packaging and electromagnetic compatibility design of RF filtering modules and passive filters.

Key words : RF filtering；PCB design；high isolation；electromagnetic shielding；via array