超宽带低损耗带状线-共面波导垂直互联设计

Ultra-wideband low-loss stripline-to-GCPW vertical transition

摘要:

随着电子技术向更高集成度和小型化发展，三维电路布局日益普及，其中毫米波信号在表层与内部电路间的有效传输变得尤为关键。本研究设计了一种新型超宽带低损耗的带状线-共面波导垂直互联结构，以应对互联结构中寄生电感和电容引起的信号反射和辐射问题。通过等效电路模型分析和参数初步设计，结合三维场仿真优化，确定了最终设计参数。该互联结构采用0.2 mm直径的通孔实现连接，并具有仅0.8 mm直径的隔离环，保证了结构的简洁性和易于加工的特点。仿真结果表明，该设计可实现DC~80 GHz的宽带覆盖，S₁₁小于-13 dB，S₂₁大于-0.4 dB，显示出优异的性能。为了匹配测试系统，设计了测试板转换至同轴接口的转换结构，使其工作频率达到40 GHz。实际测试结果显示，在DC~40 GHz范围内，回波损耗小于11 dB，插入损耗小于0.4 dB，进一步验证了设计的有效性和实用性。

Abstract:

As electronic technology advances towards higher integration and miniaturization, three-dimensional circuit layouts have become increasingly prevalent, making the effective transmission of millimeter-wave signals between the surface and internal circuits particularly critical. This study presents a novel design for an ultra-wideband, low-loss vertical interconnect structure transitioning from a stripline to a Grounded Coplanar Waveguide(GCPW), aimimg at addressing signal reflection and radiation issues caused by parasitic inductance and capacitance in interconnect structures. Through the analysis of an equivalent circuit model and preliminary parameter design, combined with optimization using three-dimensional field simulation, the final design parameters were determined. The interconnect structure employs a 0.2 mm diameter via for connection and features an isolation ring with a mere 0.8 mm diameter, ensuring the simplicity and ease of fabrication of the structure. Simulation results indicate that the design achieves broadband coverage from DC to 80 GHz, with S₁₁ less than -13 dB and S₂₁ greater than -0.4 dB, demonstrating excellent performance. To interface with the testing system, a test board was designed to convert to a coaxial connector, extending the operating frequency to 40 GHz. Actual test results show that, within the DC to 40 GHz range, return loss is less than 11 dB and insertion loss is less than 0.4 dB, further verifying the effectiveness and practicality of the design.