This article is a study of dielectric characterization of packaging substrates using a 1.85-mm coaxial airline. To the authors’ knowledge, this is the first time that wideband dielectric properties have been demonstrated up to 67 GHz using a single coaxial airline. The algorithm used to extract the material properties is Chalapat’s reference-plane-invariant (RPI) method. The measurement system and the extraction method are validated using air as the material under test (MUT) with SOLT and offset calibration. Traditionally, a sample length of less than $0.5\lambda $ is recommended for material extraction. However, this lowers the accuracy of the material properties. We utilized the advantage of RPI to stack fixed thickness samples to increase the MUT length. This produces a flat response and improves the accuracy of the extracted dielectric constant and loss tangent. The HFSS simulation and the Debye model have been used to compare dielectric properties with measurement using this airline.

中文翻译：

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使用同轴空气提取堆叠封装基板的宽带介电特性

本文研究了使用 1.85 毫米同轴电缆的封装基板的介电特性。据作者所知，这是第一次使用单个同轴电缆证明高达 67 GHz 的宽带介电特性。用于提取材料属性的算法是 Chalapat 的参考平面不变 (RPI) 方法。使用空气作为被测材料 (MUT) 并通过 SOLT 和偏移校准来验证测量系统和提取方法。传统上，建议使用小于 $0.5\lambda $ 的样本长度进行材料提取。然而，这降低了材料特性的准确性。我们利用 RPI 的优势来堆叠固定厚度的样品以增加 MUT 长度。这会产生平坦的响应并提高提取的介电常数和损耗角正切的准确性。HFSS 模拟和德拜模型已被用于比较介电特性与使用该航空公司的测量结果。