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Abstract：
A design method for an ultra-wideband coplanar-stripline-based vertical transition that can be used for ultra-high-speed digital interfaces is proposed. A conventional via structure, based on a differential line (DL), inherently possesses performance limitations (<10 GHz) due to difficulties in maintaining constant line impedance and smooth electric field transformation, in addition to the effects of signal skews, FR4 fiber weave, and unbalanced EM interferences. DL-based digital interfaces may not meet the demands of ultra-high-speed digital data transmission required for the upcoming 6G communications. The use of a coplanar stripline (CPS), a type of planar balanced line (BL), for the vertical transition, along with the ultra-wideband DL-to-CPS transition, mostly removes the inherent and unfavorable issues of the DL and enables ultra-high-speed digital data transmission. The design process of the transition is simplified using the analytical design formulas, derived using the conformal mapping method, of the transition. The characteristic line impedances of the transition are calculated and found to be in close agreement with the results obtained from EM simulations. Utilizing these results, the CPS-based vertical transition, maintaining the characteristic line impedance of 100 Ω, is designed and fabricated. The measured results confirm its ultra-wideband characteristics, with a maximum of 1.6 dB insertion loss and more than 10 dB return loss in the frequency range of DC to 30 GHz. Therefore, the proposed CPS-based vertical transition offers a significantly wider frequency bandwidth, i.e., more than three times that of conventional DL-based via structures.
摘要：
提出了一种可用于超高速数字接口的超宽带共面带状线垂直过渡的设计方法。传统的通孔结构，基于差分线(DL)，由于难以保持恒定的线路阻抗和平滑的电场转换，固有地具有性能限制（<10GHz），除了信号偏斜的影响，FR4纤维编织，和不平衡的电磁干扰。基于DL的数字接口可能无法满足即将到来的6G通信所需的超高速数字数据传输的需求。使用共面带状线(CPS)，一种平面平衡线(BL)，对于垂直过渡，随着超宽带DL到CPS的过渡，大部分消除了DL的固有和不利问题，并实现了超高速数字数据传输。使用分析设计公式简化了过渡的设计过程，使用共形映射方法导出，的过渡。计算过渡的特征线阻抗，并发现与EM模拟获得的结果非常吻合。利用这些结果，基于CPS的垂直过渡，保持100Ω的特性线路阻抗，是设计和制造的。测量结果证实了其超宽带特性，在DC至30GHz的频率范围内，最大插入损耗为1.6dB，回波损耗超过10dB。因此,拟议的基于CPS的垂直过渡提供了明显更宽的频率带宽，即，是传统的基于DL的通孔结构的三倍以上。
