用复合谐振腔法测量介质谐振器材料的介电特性

本文根据Barlow提出的在TE(01n)模谐振腔上耦合一段截止波导构成复合腔的原理，首次在C波段对介质谐振器材料的介电性能进行了测量，并从理论上证明了该方法对相对介电系数有很高的测试灵敏度，本文给出了几种介质谐振器材料的测试结果，最后就样品厚度对测试精度的影响作了分析。     

测量多层薄膜材料复介电系数的准光腔技术

本文提出用准光腔测薄膜材料复介电系数的新技术，根据双层介质的测量原理，把多层薄膜叠加起来并压上一块介电特性已知的平板样品以消除空气间隙及平整卷曲材料，推导了双层介质的正确理论计算公式，更正了以往文献中的失误之处，采用简易的变腔长法，对几种薄膜材料进行了测量，取得了满意的结果。     

A Sensitive Method for Measuring Complex Permittivity with a Microwave Resonator

The proposed method was carried out to make easier dielectric studies em powders under controlled pressure when the frequency varies. A TE/sub 01n/-mode resonator is needed. The substance under test is contained in a tube of quartz, placed along the axis of a cylindrical cavity. The mathematical formulation for the complex permittivity is given in rigorously accounting for the presence of the tube. Typical ditticulties are discussed, and experimental results given. The absolute precision of the measurement can be compared with that of the classicrd method (/spl plusmn/2 percent for /spl epsi/' and /spl plusmn/ 10 percent for /spl epsi/'). The greatest error arises from an insufficiently precise determination of the geometrical and electrical characteristics of the quartz tube. This error is systematic, and thus it is possible to demonstrate the very small permittivity variations (/spl plusmn/ 0.3 percent for /spl epsi/' and /spl plusmn/ 5 percent for /spl epsi/').     

用谐振腔-截止波导技术测量介质谐振器的复介电常数

在TE01n模谐振腔的一个端面中央,开一圆孔,连接一根等直径、适当长度的截止波导,当截止波导中置入介质谐振器时,使含介质段对TE01模呈传输态。介质谐振器的前向波导段用于调节耦合强弱,足够长度的背向波导段则形成匹配电抗终端或置入金属场构成短路终端。这两种安排都能使置入介质谐振器前后的谐振腔产生相当大的谐振长度和Q因子的变化,从而能获得准确的介质谐振器无载Q因子和介电常数。在X频段对陶瓷谐振器进行测量,获得满意的结果。     

一种求解微波介质谐振器复介电常数的方法

根据微波谐振系统中电场的波动方程,采用复频率和有耗导体的边界条件,导出以被测介质的复介电常数为本征值的微分和变分方程。使用MATLAB软件中的PDE工具箱,只要是能以二维形式作图表现的微波介质谐振器,都可以求解出其复介电常数,且与实验数据及不同方法计算的结果相吻合,该方法适用面广、计算精确、简洁方便。     

用H01型圆柱谐振腔测量介质材料介电常数的原理及方法

讨论H01型圆柱谐振腔的测试原理;详细介绍了用圆柱谐振腔测量介质材料相对介电常数及损耗角正切的方法.     

A Quasi-Optical Method for Measuring the Complex Permittivity of Materials

A quasi-optical method for measuring the complex permittivity of materials is described. The determination is derived from measurements of the transmission of a perpendicularly polarized wave through a dielectric slab at different angles of incidence. This relatively simple method is quite sensitive. Accurate estimates of the relative permittivity and the loss tangent can be obtained by accurately measuring the frequency of the signal and by the use of large, precisely machined Fabry-Perot plates. Estimates of the standard errors in the determinations are obtained by using a bootstrap resampling technique. The measurements here are made at a frequency of 93.788 GHz at ambient temperature.     

开口波导法无损测量微波集成电路基片复介电常数

提出一种测量微波集成电路基片复介电常数的新方法。通过测量贴于开口矩形波导外的介质基片的反射系数,可计算得基片的介电常数和损耗角。经过理论分析,给出求解复介电常数的计算公式和优化算法。对一些基片的复介电常数进行了实际测量,结果表明该测量方法运算量小,精度高,且具有设备简单,不需对样品进行特殊加工或破坏样品等优点。     

A Fast and Accurate Amplitude-Only Transmission-Reflection Method for Complex Permittivity Determination of Lossy Materials

Complex scattering parameter measurements using expensive vector network analyzers make microwave techniques inconvenient for industrial-based applications. In industry, accurate and fast evaluation of materials' properties using a relatively inexpensive measurement setup is a key issue. In this paper, we derive an objective function for fast and accurate complex permittivity ($varepsilon$) determination of lossy materials using amplitude-only reflection and transmission scattering parameter measurements. The measurements can be carried out by relatively inexpensive microwave instruments such as a scalar network analyzer. The domain for computations of the $varepsilon$ is significantly reduced to facilitate rapid $varepsilon$ determination. The objective function is verified by measurements of a commercially available antifreeze solution and binary mixture of ethyl alcohol and water solution.      

复介电常数测量方法——同轴探针法再构建与修正

为提高同轴探针法测量介质的复介电常数的精度,重新对介质的阻抗模型—电容模型进行构建和修正,再分别用修正后的模型和原模型对同一样品进行测量并比较。结果显示两种方法对生物样品的测量结果差别不大,但对虚部较小的介质测量结果有一定的差别。修正后的模型提高了甲醇复介电常数虚部的测量精度,表明该模型比较适合测量虚部较小的介质,在一定程度上扩展了原有模型的适用范围。     

Quasi-Optical Method for Measuring the Complex Permittivity of Materials (Corrections)

In the above paper, in Column 1 of Table II on page 663, Reference [9] should read [10] and Reference [10] should read [12].     

聚合物薄片的复介电常数微波测量方法

提出了一种在微波频域测量聚合物样品薄片复介电常数的方法,它利用自动测量线测试系统测量出电压驻波比和相角,然后采用级数各阶次展开方法,由反射系数推导出复介电常数.级数低阶次方法求解厚度较大的被测样品复介电常数时,为确保结果具有较高的精确度,要求测量频率不超过1.5GHz.为了克服这种测量频域的局限性,可采用级数高阶次展开方法来求解复介电常数.用级数展开方法测量聚苯乙烯、多乙酸乙烯酯和聚亚胺酯的复介电常数值,结果与真实值相近,可以和传输/反射法相媲美.     

开口同轴探头测量微波集成电路基片的复介电常数

本文论述了开口同轴（无外加法兰）非破坏测量微波集成电路基片复介电常数的方法。文中阐明了开口同轴FDTD法的建模与测量原理。由于FDTD法建模是一种全波分析方法，出此该模型相当准确。在S和X波段测量了聚四氟乙烯材料和另一种介质基片的复介电常数，所得结果与它们的典型值非常吻合。开口同轴法测量具有非破坏性，适于现场测量，而且具有设备简单、操作方便、测量精度高等优点。     

A New Calibration-Independent Method for Complex Permittivity Extraction of Solid Dielectric Materials

Microwave nonresonant methods generally require some sort of calibration before conducting the measurements. Calibration-independent nonresonant methods are very attractive since they eliminate this need. In the literature, different calibration-independent methods for complex permittivity determination of materials have been proposed. While some of them use uncalibrated $S$-parameter measurements of two identical samples with different lengths, the others utilize the same measurements of one sample. The advantage of the latter methods is that they eliminate any impurity and/or inhomogeneity present in the second sample and avoid any thickness uncertainty that can arise from using the second sample. In the literature, the proposed approaches in latter methods, however, require precise location of the sample inside its cell (a waveguide or coaxial-line section) or exact shifting distance of the sample inside its cell. This letter proposes a method to eliminate these requirements using uncalibrated $S$-parameter measurements of an extra cell (empty) and the cell, in which the sample is arbitrarily located.      

电磁开腔测量多层介质样品复介电常数

本文提出了一种在毫米波和亚毫米波微段利用电磁开腔测量多层介质样品复介电常数的新方法。在ｋａ波段利用特制的开腔装置建立了一套电磁开腔电介质参数测量系统，并对一些多层介质样品进行了实际测量。测量结果与标称值十分吻合。     

Design of Group Delay Time Controller Based on a Reflective Parallel Resonator

In this paper, a group delay time controller (GDTC) is proposed based on a reflection topology employing a parallel resonator as the reflection termination. The design equations of the proposed GDTC have been derived and validated by simulation and experimental results. The group delay time can be varied by varying the capacitance and inductance at an operating frequency. To show the validity of the proposed circuit, an experiment was performed for a wideband code division multiple access downlink band operating at 2.11 GHz to 2.17 GHz. According to the experiment, a group delay time variation of 3±0.17 ns over bandwidth of 60 MHz with excellent flatness is obtained.     

A Measurement of the Complex Permittivity Tensor by a Standing-Wave Method in a Rectangular Waveguide

A rubber sheet manufactured by the rolling process strongly shows an anisotropic property, which is caused by carbon particles or carbon fibers aligned along the rolling direction. The measurement of the complex permittivity tensor in the rubber sheet is studied by a standing-wave method in a rectangular waveguide. The tensor elements, including nondiagonal and principal-direction ones, are measured and discussed. Errors in the measured tensor elements are evaluated.     

Simultaneous Determination of Complex Permittivity and Permeability of Columnar Materials With Arbitrarily Shaped Cross Section

An effective simultaneous evaluation method for the complex permittivity and permeability of lossy materials is proposed by applying it to an arbitrarily shaped cross-sectional post placed in a rectangular waveguide. We use one sample and only measure S ₂₁ parameters for two different locations of the sample. The measurement of complex reflection parameter S ₁₁ is not required in this evaluation method. The scheme of electromagnetic field analysis for the evaluation is based on the extended spectral-domain approach combined with the mode-matching method, which is accurate and efficient, and can be flexibly used for the iterative fitting operation for the estimation of material parameters. Sample preparation and setting is significantly easier in this method compared to conventional methods. The error caused by deviations in the setting of a sample is investigated. The estimated values for the sample material by this procedure show good agreement with the results obtained using the conventional method over the X-band.     

Measurement of Complex Permittivity of Lossy Materials in Free Space Using Matched THz Power Meter

The complex permittivity of lossy materials is measured at 330 GHz by matched THz power meter. Such a power meter operates near the Brewster’s angle of its absorbing film resulting in an own reflection coefficient close to zero. It permits to reduce an uncertainty associated with parasitic reflections created by conventional power meters. The measured power transmission coefficient of the dielectric slab as a function of the incident angle is used for estimating the dielectric constant. Its evaluation is based on the root-finding procedure applied to the proper formulated system of two non-linear equations. Convergence and sensitivity of this system in the space of { e￠_\textr,e"_\textr } \left\{ {{{\varepsilon '}_{\text{r}}},{{\varepsilon '}_{\text{r}}}} \right\} are investigated in order to formulate recommendations how guess values providing the unique solution must be chosen. The results are useful for estimating sheilding effects caused by dielectric losses in the sub-mm range with application to detecting hidden objects as well as other homeland security purposes.     

电磁开腔测量双层介质复介电常数

本文提出了一种利用电磁开腔在微波和毫米波频段测量双层介质复介电常数的新技术。在８ｍｍ频段，利用一套电磁开腔自动测量系统对几种双层介质材料进行了具体测量。最后，对测量误差进行了理论分析，并给出了计算实例。