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Radiated emissions and immunity of microstrip transmission lines:theory and reverberation chamber measurements 总被引:3,自引:0,他引:3
Hill D.A. Camell D.G. Cavcey K.H. Koepke G.H. 《Electromagnetic Compatibility, IEEE Transactions on》1996,38(2):165-172
The increasing complexity of electronic systems has introduced an increased potential for electromagnetic interference (EMI) between electronic systems. We analyze the radiation from a microstrip transmission line and calculate the total radiated power by numerical integration. Reverberation chamber methods for measuring radiated emissions and immunity are reviewed and applied to three microstrip configurations. Measurements from 200 to 2000 MHz are compared with theory, and excellent agreement is obtained for two configurations that minimize feed cable and finite ground plane effects. Emissions measurements are found to be more accurate than immunity measurements because the impedance mismatch of the receiving antenna cancels when the ratio of the microstrip and reference radiated power measurements is taken. The use of two different receiving antenna locations for emissions measurements illustrates good field uniformity within the chamber 相似文献
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Effect of substrate on the efficiency of an arbitrarily shaped microstrip patch antenna 总被引:1,自引:0,他引:1
A general approach is presented for the determination of power radiated via the space wave and surface wave from the aperture of an arbitrarily shaped microstrip antenna. The magnetic current model is used for this, and the analysis is carried out in the Fourier domain to determine the effect of the substrate. It has been shown that, in the Fourier domain, the longitudinal components of electric and magnetic displacement vectors follow the transmission line equation and can be solved by inspection. An expression for total radiated power has been derived. The singularities of the integral for power radiation indicate the presence of surface wave modes, and the associated power has been obtained using a singularity extraction technique. The effect of the substrate on space wave power has also been determined. This theory has been applied to a rectangular patch antenna. The results are in conformity with those reported in the literature. It has been found that for the frequency range (h/lambda, < 0.02 ), the effect of dielectric substrate can be neglected. 相似文献
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A. A. Vertiy S. P. Gavrilov S. Aydinlik S. Samedov 《Journal of Infrared, Millimeter and Terahertz Waves》1996,17(10):1613-1637
In millimeter wave lengths region semiconductor generators, amplifiers, mixers and other solid state UHF devices find a wide application. In our work, we suggested to use aCircular Through-Shaped Resonator for obtaining power combination using active elements at frequency region Δf≈20–40 GHz. The resonator is formed by two plane aluminum reflectors. The first reflector has a circular groove. The second reflector has coupling elements. The first and the second reflectors are considered as a ring groove shaped waveguide. A resonator spectrum was calculated and analyzed in the frequency range Δf ≈20–40 GHz. It is showed that, in the given frequency range the resonator spectrum has a complicated structure and is formed by a series of spectrum lines; a frequency range between the series increases with the frequency increasing. We studied on transmission coefficient of the resonator, frequency shifts of spectrum lines when inserting a thin (t/λ≈0.003) dielectric substrates into the resonator, and also attenuation constants of waves propagating in circular groove (due to losses in metal). 相似文献
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文中提出了一种基于折叠型SIR 谐振器的双通带频率可控的微带滤波器,它由SIR 谐振器特性结合
传输线理论实现。该滤波器设计为具有两个自由度,调节谐振器的导带宽度可以对两个通带之间的频率及其间隔
进行调节。文中还研究了调整谐振器导带长度对滤波器频率特性的影响。测试结果表明,该微带滤波器有两个通
带,其中心频率分别为2. 79 GHz 和3. 90 GHz,带内最小插入损耗分别为-0. 96 dB 和-3. 0 dB,带内最小回波损耗分
别为-42 dB 和-18 dB,相对带宽分别为5. 7%和6. 7%。仿真和测试结果的一致性证实了滤波器设计的有效性。 相似文献
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The method uses the resonant frequencies of a simple straight microstrip resonator, short-circuited at both ends. It is excited by passing a current through one of the short circuits. Graphs of effective relative permittivity against frequency are given for resonators on alumina and quartz substrates, with an error of within only ±0.1%. 相似文献
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《Microwave Theory and Techniques》1978,26(11):893-894
The radiation from a microstrip Y junction is calculatcd as a function of angle. It is shown that the radiated power increases monotonically with the Y angle, decreases inversely as the dielectric constant of the substrate for large permittivities, and increases as the square of the substrate thickness for thin substrates. 相似文献
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为了使微带均衡器满足衰减特性与给定的误差曲线逐点拟和的要求,就必须使其频率可调、衰减可调、品质因数可调。因此,本文通过大量仿真和实验,研究了加载了薄膜电阻的微带谐振器及其在微带均衡器中的应用,研究分析了薄膜电阻对微带均衡器传输特性及驻波特性的影响。研究结果表明将薄膜电阻加载到微带谐振器上构造微带均衡器,可以通过改变谐振器的尺寸使其频率可调,通过改变电阻阻值及位置使其衰减可调、品质因数可调。大量HFSS仿真及实验证明这种方式很适合微带均衡器的设计制造。本文利用这种结构设计制作出了一个宽带微带均衡器,得到了很好的实验结果。 相似文献
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Although more rigorous treatments have been developed for mutual coupling between microstrip antennas, the purpose of this transmission line model is to provide a numerically efficient substitute for them. Therefore, two approximations have been introduced: first, the surface waves have been neglected and second, each rectangular resonator is replaced by two equivalent radiating slots. In most practical cases the approximations are acceptable; this has been proved while comparing the transmission line model with other published results. It is obvious that the efficieney of the transmission model and can be used to include mutual coupling in practical analysis or synthesis routines for arrays of rectangular microstrip antennas. 相似文献
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《Microwave Theory and Techniques》1976,24(7):409-415
An equivalent model is presented for evaluating the fringing-field effects in edge-guided waves (EGW) propagating along ferrite microstrip circuits. It is based on the approximate model developed by Getsinger for nonferromagnetic microstrip circuits. Fringing-field effects are characterized by a fringing-field parameter b/b' whose numerical value is determined by experiment. Measurements are made on EGW resonators of various shapes for different values of the applied magnetic bias. Finally, the fringing-field parameter is used to evaluate the ratio between the reactive power stored in the fringing fields and the RF power in the ferrite under the strip conductor in a disk resonator. 相似文献
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In this paper simple closed form expressions of surface wave fields for microstrip dipoles on grounded substrates are presented. The surface power, radiated power and radiation efficiency are calculated. It is shown that the radiation efficiency decreases with the increase of substrate electrical thickness. Hence new type antennas are needed to radiate millimeter wave because of the effect of the surface waves in substrate. 相似文献
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基于印刷电路板的辐射抑制分析 总被引:1,自引:0,他引:1
使用矩量法研究印刷电路板上微带线的辐射干扰及其抑制方法。给出微带线辐射效应的模型,并利用数值算法分析单微带线和有屏蔽线的单微带线的辐射功率。仿真结果显示,加入匹配屏蔽线的单微带线辐射功率明显小于未加屏蔽线时的功率。因此,在数字电路的电磁兼容设计中,对强信号线加匹配屏蔽线能有效地降低对外界的辐射干扰。 相似文献
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《Microwave Theory and Techniques》1970,18(7):373-376
In a lens waveguide with a curved axis, light beams appreciably different in frequency split and take different paths due to the effect of chromatic aberration of lens. The deviation from a main beam can grow cumulatively through the curved lens waveguide. This effect knits permissible bandwidth to be transmitted without loss of beams. For bends having tilts and offsets at the connections to the straight waveguides, the deviation of the light beam from the guide axis due to the effect of chromatic aberration is derived. With random circular bends the bandwidth is inversely proportional to the square root of the number of bends and proportional to the average radius of curvature. For a normal design of the curved waveguide the allowable bandwidth is expected to be sufficiently broad for signal transmission, but it is narrow in the sense of optical frequency. 相似文献
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A novel dual-mode microstrip square loop resonator is proposed using the slow-wave and dispersion features of the microstrip slow-wave open-loop resonator. It is shown that the designed and fabricated dual-mode microstrip filter has a wide stopband including the first spurious resonance frequency. Also, it has a size reduction of about 50% at the same center frequency, as compared with the dual-mode bandpass filters such as microstrip patch, cross-slotted patch, square loop, and ring resonator filter. 相似文献
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A theoretical study on the problem of surface wave excitation of microstrip disk antennas is presented. The cavity model with magnetic sidewalls and dyadic Green's functions in stratified media is used to obtain the radiated fields in an integral form. Lossless media are assumed such that there is no cross coupling between the powers in the space (P_{SP} ) and surface (P_{SU} ) waves. The separate contributions of these two powers is examined. With the assumption thatP_{SU} does not contribute to the main radiation patterns of the antenna an efficiency of space wave launching and a corresponding antenna directivity are defined. Values of efficiency and directivity as functions of the dimensions of the antenna and for two values of dielectric constants of the substrate are shown. Agreement of these results with some of the available data is observed. It is worth noting thatP_{SU} may correspond to an appreciable portion of the total radiated power. 相似文献