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1.
A design procedure is given for a microstrip phase-trim device using a dielectric overlay on a conventional microstrip line. The physical operation of the device is based on the change in the effective dielectric constant of the microstrip line caused by the presence of the dielectric layer on top of the microstrip line. The amount of phase trim produced by the device can be selected by the appropriate choice of dielectric constant, height, and length of the dielectric overlay. An approximate expression is given for the effective dielectric constant of the microstrip line as a function of the dielectric constant and height of the overlay. Measured results at 10 GHz are compared with predicted performance 相似文献
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《Microwave Theory and Techniques》2009,57(7):1714-1723
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针对传统贴片天线检测频率有限(2~35 GHz)且由于增益低导致检测结果不明显的问题,文中提出了以聚苯乙烯作为介质基板构建微带天线的解决方案。在以介电材料玻璃超细纤维为介质基板的理论基础上,采用高分子材料Polysty作为介质基板构建微带天线模型。结合经典天线理论计算辐射贴片以及介质基板尺寸;基于HFSS搭建Polysty作为介质基板的模型并根据微带天线特性将理论设计的微带天线参数进行优化,最终得到在1 GHz时微带天线的最佳尺寸。仿真及实验结果表明,Polysty作为介质基板的微带天线中心频率可以达到1 GHz,增益高并且检测角度范围大。 相似文献
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Resonant frequency characteristics of rectangular resonators in a generalized shielded suspended substrate line are analysed using a rigorous spectral domain technique. The computed dominant mode resonant frequency of rectangular resonators in a suspended microstrip with centred dielectric, inverted microstrip and suspended microstrip are presented as a function of various structural parameters. These characteristics are distinct from those obtained for a conventional microstrip rectangular resonator. Experiments are carried out in the frequency range 4-18 GHz to verify the computed resonant frequencies for a suspended microstrip with a centred dielectric using first-order basis functions. The results should find applications in the design of inverted microstrip and suspended microstrip passive microwave and millimetre wave integrated circuits. 相似文献
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A. V. Zakharov S. A. Rozenko 《Journal of Communications Technology and Electronics》2012,57(6):649-655
A microstrip duplexer for a modification of a PCS communication system operating at frequencies of 1.84?C1.87 and 1.75?C1.78 GHz is described. The duplexer containing microstrip bandpass filters on high dielectric constant substrates (? r = 92) are compared with duplexers manufactured on microwave ceramic materials with high values of ? r . The microstrip bandpass filters use stepped-impedance resonators placed one near another with a gap of 0.1?C0.2 mm. It is shown that the microstrip duplexer has slightly lower insertion loss and occupies smaller volume than a duplexer using coaxial dielectric resonators having a rectangular cross section of 3 × 3 mm and ? r = 92. 相似文献
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M. Gallitre B. Blampey A. Farcy C. Bermond J. Torres 《Microelectronic Engineering》2007,84(11):2744-2749
With the dimensions scaling down at each new technology node, introduction of porous dielectric materials is required to reduce the interconnect capacitance. Nevertheless, these materials are very prone to damage during integration, thus increasing their K-value (2.5 as deposited for the 45 nm node) in the final circuit. In order to characterize these effects, high-frequency measurements and electromagnetic simulations were carried out on specific microstrip structures. Taking into account typical circuit characteristics, time-domain extraction of delay values and crosstalk levels were then performed, enabling a precise analysis of moisture uptake effects from a performance point of view. 相似文献
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微带电路无源互调产生机制尚无定论并且缺乏可靠的理论预测方法,本文基于等效受控源模型,建立了基于介电非线性机制的微带线无源互调的解析计算模型,同时,通过对比测试聚四氟乙烯玻纤布介质微带线和空气介质微带线的三阶互调规律验证了介质非线性是微带电路无源互调的一种主要非线性来源,并提取了非线性参数.实验结果显示聚四氟乙烯玻纤布介质微带线比空气介质微带线的传输互调高了约20dB,反射互调高了约15dB,表明介质非线性是聚四氟乙烯玻纤布介质微带线互调的主要来源.同时,根据本文建立的微带线互调计算解析模型,提取聚四氟乙烯玻纤布介质基板的三阶非线性相对介电常数.本文研究方法可以进一步用于其它微带电路无源互调规律计算研究. 相似文献
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The microstrip loaded inset dielectric waveguide has been proposed as a transmission medium alternative to microstrip, and as a useful antenna medium at X-band and millimetric frequencies. In the present analysis we consider the case where a multi-layer, multi-conductor microstrip circuit may be housed within inset dielectric waveguide. A generalised transverse resonance diffraction method is developed in the space domain for analyzing such structures. Experimental and theoretical results for the propagation characteristics of the fundamental and first higher order mode of a few different configurations are presented showing good agreement 相似文献
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《Microwave Theory and Techniques》1993,41(6):1037-1043
The quasi-TEM characteristics of a class of cylindrical microstrip lines are rigorously determined. The class of microstrip lines considered consists of multiple infinitesimally thin strips on a multilayered dielectric substrate on a perfectly conducting wedge. Expressions for the potential distribution inside and outside the dielectric substrate, charge distribution on the strips, and capacitance matrix of the microstrip lines are derived. The problems of a microstrip line on a cylindrically capped wedge and on a cylindrical dielectric substrate on perfectly conducting core are also considered as special cases. Sample numerical results based on the derived expressions are given and discussed 相似文献
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Electromagnetic coupling of coplanar waveguides and microstriplines to highly lossy dielectric media 总被引:1,自引:0,他引:1
The spectral-domain technique is utilized to analyze the coupling characteristics of coplanar waveguides and microstrip lines coupled with multilayer lossy dielectric media. Numerical results illustrating the dispersion characteristics of coplanar and microstrip lines, as well as the various electric field components coupled to highly lossy dielectric media, are presented. It is shown that the presence of a superstrate of lossless dielectric between the coplanar waveguide and the lossy medium plays a key role in setting up an axial electric field component that facilitates leaky-wave-type coupling to the lossy medium. The thickness of the superstrate relative to the gap width in the coplanar waveguide is important in controlling the magnitude of this axial electric field component. The coupling characteristics of the microstrip and coplanar lines are compared, and results generally show improved coupling if coplanar waveguides are utilized. Values of the attenuation constant α are higher for coplanar waveguide than for microstrip line, and for both structures α decreases with frequency 相似文献
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Development of a successful remote sensing instrument for soil moisture relies on the accurate knowledge of the soil dielectric constant (ϵsoil) to its moisture content. Two existing methods for measurement of dielectric constant of soil at low and high frequencies are, respectively, the time domain reflectometry and the reflection coefficient measurement using an open-ended coaxial probe. The major shortcoming of these methods is the lack of accurate determination of the imaginary part of Esoil. In this paper, a microstrip ring resonator is proposed for the accurate measurement of soil dielectric constant. In this technique the microstrip ring resonator is placed in contact with soil medium and the real and imaginary parts of Esoil are determined from the changes in the resonant frequency and the quality factor of the resonator, respectively. The solution of the electromagnetic problem is obtained using a hybrid approach based on the method of moments solution of the quasistatic formulation in conjunction with experimental data obtained from reference dielectric samples. Also, a simple inversion algorithm for Esoil=E'r-jϵE"r based on regression analysis is obtained. It is shown that the wide dynamic range of the measured quantities provides excellent accuracy in the dielectric constant measurement. A prototype microstrip ring resonator at L-band is designed and measurements of soil with different moisture contents are presented and compared with other approaches 相似文献
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The charge and the potential at every point in the cross-section of the elementary cell of a microstrip delay line are determined under the quasitem approximation. The authors solve a first order Fredholm type integral equation in the complex plane for a general phase shift of θper cell to get the charge density of the two conductors in the elementary cell. Knowing this, the characteristic impedance, the phase velocity and the effective dielectric constant are determined for the fundamental modes of propagation. From a detailed study of the characteristic parameter variations with the geometry of the line, a general law of coupling is deduced. The dispersion diagram and the iterative impedance of the lines are then determined by considering the boundary conditions of each structure. In addition to the classical meander line, they have studied the interdigital line, these lines having many dielectric layers. They present curves of practical interest in as much as coupling is concerned and an extension of Weiss’ theory, presented in to treat multilayered structures. 相似文献
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Microstrip lines are attractive for the lower millimeter-wave ranges, but use of relatively thick substrates would be desirable in order to minimize losses. On such substrates the usual types of microstrip narrowband bandpass filters (formed from, e.g. coupled line segments with open ends) tend to radiate strongly giving very poor performance. It has been found that a grating technique initially developed for use with dielectric waveguides can be adapted for microstrips to obtain narrowband millimeter-wave microstrip filters with little radiation and strong filter characteristics. The stopbands are broad, the second passband occurring at three times the frequency of the first passband. These filters use parallel-coupled gratings with a single grating in cascade at each end. The modifications to the dielectric waveguide filter theory that are necessary for use with microstrips are detailed. Experimental results from microstrip realizations, which demonstrate their potential for millimeter-wave microstrip applications, are also presented 相似文献
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R. S. Tomar K. V. S. Rao P. Bhartia 《Journal of Infrared, Millimeter and Terahertz Waves》1988,9(9):813-821
Accurate dispersion data for open inverted microstrip is presented. Two most commonly used substrate materials, namely, RT-duroid (dielectric constant 2.22) and fused quartz (dielectric constant 3.78) are considered. The work is a continuation of the earlier reported data on a similar structure, called suspended microstrip, and will be an useful addition to the millimeter-wave designer's library. 相似文献
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The X -band microstrip slot antenna array is described as an attempt to achieve moderate bandwidth and overcome the problems of radiation from microstrip feed lines and surface waves in the dielectric. The discussion covers development of a mathematical simulation that computes the radiation pattern of a single microstrip slot and the feeding microstripline; construction of a uniform broadband microstrip slot antenna array; development of a mathematical simulation that computes the radiation pattern in the H - and E -planes; and investigation of the mutual coupling between the slots. A comparison is made between computed and measured results at X -band frequencies 相似文献
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Koscica T.E. Babbitt R. Hendrickson M. 《Applied Superconductivity, IEEE Transactions on》1992,2(3):186-188
A means for increasing the effective dielectric quality factor by selective removal of dielectric from a microstrip resonator is discussed. Methods for determining the impedance and effective dielectric constant are included. The reduction in loss compared with an equivalent microstrip resonator is presented 相似文献