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1.
The accurate measurement of small discontinuities in microstrip by conventional means is limited by the imperfections of the microstrip to coaxial transition. By using a resonant technique where such imperfections cause only 2nd-order errors, the equivalent circuit of microstrip discontinuities can be measured. To demonstrate the method, a 90° corner, with and without a chamfer, has been measured. 相似文献
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全等宽平行耦合微带线带通滤波器的设计 总被引:8,自引:1,他引:7
半波长平行耦合微带线带通滤波器由于其结构紧凑,第二通带的中心频率3倍于主通带中心频率,因而在微波集成电路中获得广泛应用。本文提出一种新的设计方法:耦合线节级联直接设计法。这一方法比传统设计方法简便,适用相对带宽范围较宽,为30~80%,而且可以采用全等宽耦合线,因而滤波器结构简洁。 相似文献
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本文以平面微带线为中介使用保角变换法研究了非平面圆柱型微带线的准静态特性。文中给出了特性分析公式,并确定了用二分法进行尺寸综合要求的操作区间和目标函数。最后,进行了数值结果比较,效果良好。 相似文献
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A numerical code has. been developed for the full-wave determination of the resonant frequencies and quality factors of microstrip patches with right-angle corners of arbitrary shape in the case in which the substrate of the patches is a magnetized ferrite with arbitrarily oriented bias magnetic field. The code is based on the solution of an electric-field integral equation by means of Galerkin's method in the spectral domain. The evaluation of the infinite integrals arising from the application of the numerical method is efficiently carried out by means of a technique based on the interpolation of the spectral dyadic Green's function. The numerical results obtained indicate that microstrip patches fabricated on ferrite substrates present cutoff frequency regions in which resonances cannot occur owing to the excitation of magnetostatic modes. The limits of these cutoff regions are shown to be dependent on the orientation and the magnitude of the bias magnetic field, on the shape of the patches, and even on the nature of every particular resonant mode. The numerical results also show that the resonant frequencies of microstrip patches. on magnetized ferrites can always be tuned over a wide frequency range provided the orientation of the bias magnetic field is suitably chosen 相似文献
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In this paper, we carry out a full-wave analysis of shielded two-port microstrip circuits, in which the metallizations are embedded in a multilayered substrate that may contain isotropic dielectrics and/or anisotropic dielectrics. The Galerkin's method in the spectral domain is applied for determining the current density on the metallizations of the circuits when their feeding lines are excited by means of delta-gap generators, and the matrix pencil technique is subsequently used for deembedding the scattering parameters from the computed current densities. Results are presented for the scattering parameters of some microstrip discontinuities and filters printed on both isotropic dielectric substrates and anisotropic dielectric substrates. These results show that when substrate dielectric anisotropy is ignored, errors arise when computing the scattering parameters of microstrip discontinuities and when predicting the operating frequency band of microstrip filters 相似文献
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This paper demonstrates a novel means of achieving cophasal far-field radiation for a circularly polarized microstrip reflectarray with elements having variable rotation angles. Two Ka-band half-meter microstrip reflectarrays have been fabricated and tested. Both are believed to be the electrically largest reflectarrays ever developed using microstrip patches. One, a conventional design, has identical square patches with variable-length microstrip phase-delay lines attached. The other has identical square patches with identical microstrip phase-delay lines but different element rotation angles. Both antennas demonstrated excellent performance with more than 55% aperture efficiencies, but the one with variable rotation angles resulted in better overall performance. A brief mathematical analysis is presented to validate this “rotational element” approach. With this approach, a means of scanning the main beam of the reflectarray over a wide angular region without any RF beamformer by using miniature or micromachined motors is viable 相似文献
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G. G. Grachev V. V. Shevchenko 《Journal of Communications Technology and Electronics》2007,52(6):641-644
Excitation of a microstrip waveguide by means of a microstrip line and waveguide transitions between microstrip waveguides characterized by different parameters are investigated theoretically. 相似文献
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The equivalent circuit and the scattering parameters of the orthogonal microstrip crossover discontinuity are determined by assuming that the conducting strips are embedded in a multilayered substrate which may contain both anisotropic dielectrics and materials with a nonnegligible conductivity. The equivalent circuit of the crossover is obtained in terms of the complex excess charge densities on the strips. These excess charge densities are computed by means of the Galerkin method in the spectral domain. Comparison is carried out with previously existing results for microstrip crossovers on lossless isotropic substrates and original results are presented for crossovers on anisotropic and lossy substrates 相似文献
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《Antennas and Propagation, IEEE Transactions on》2003,51(9):2218-2226
An accurate and efficient method that combines the precorrected fast Fourier transform (FFT) method and the discrete complex image method (DCIM) is presented to characterize the scattering and radiation properties of arbitrarily shaped microstrip patch antennas. In this method, the mixed potential integral equation (MPIE) is discretized in the spatial domain by means of the discrete complex image method. The resultant system is solved iteratively using the generalized conjugate residual method (GCR) and the precorrected-FFT technique is used to speed up the matrix-vector multiplication. The precorrected-FFT eliminates the need to generate and store the usual square impedance matrix and thus leads to a significant reduction in memory requirement and computational cost. Numerical results are presented for arbitrarily shaped microstrip antenna arrays to demonstrate the accuracy and efficiency of this technique. 相似文献
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Marques R. Rafii-El-Idrissi R. Mesa F. Medina F. 《Microwave Theory and Techniques》2002,50(8):1935-1941
The propagation of leaky forward magnetostatic (MS) volume waves along ferrite-loaded microstrip and slot lines is analyzed. This phenomenon is studied by means of a numerical approach based on the residue calculus technique because of its good numerical convergence and stability. The proposed method allows for a quick and accurate computation of the phase and attenuation constants of the leaky MS modes. A comparative analysis between both microstrip lines and slot lines is carried out, and some new physical effects, such as MS resonances in the radiation loss, are reported. The advantages of the proposed method of analysis over other numerical methods, such as Galerkin's or moment methods, are also discussed. 相似文献
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设计了工作于毫米波频段的基片集成波导(SIW),阐述了基片集成波导及其微带过渡的原理和结构,公式推导出过渡结构中各种参数的计算方法,通过HFSS软件进行仿真,制作了SIW与微带过渡的样品并测试,结果表明在35.5~37.5GHz范围内,波导插损为-1~-2dB,回波损耗小于-10dB,性能良好。 相似文献
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A 90° microstrip bend is characterized using a time-frequency method based on the finite-difference-time-domain (FDTD) method. Time evolution of the currents generated by FDTD are Fourier transformed to lead to S-parameters and the radiated powers characteristic of the microstrip bend. The method for calculating both radiation and surface wave losses is developed for microstrip structures. The results of the 90° microstrip bend are compared with the results of the mitered microstrip bend 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
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The authors present a set of experimental results which demonstrate that it is possible to control the level of harmonic and spurious radiation emitted from a microstrip patch oscillator by means of at least two mechanisms. A discussion of these mechanisms is included, and it is also argued that an unambiguous method of classifying similar results is required 相似文献
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《Microwave Theory and Techniques》1968,16(8):529-535
A theoretical method is presented by which microstrip-like transmission lines can be analyzed. These transmission lines are characterized by conducting strips, large ground planes, multi-dielectric-layer insulation, and planar geometry. The method is essentially based on a variational calculation of the line capacitance in the Fourier-transformed domain and on the charge density distribution as a trial function. A shielded double-layer microstrip line is analyzed by this method. Derived formulas for this structure are also applicable to simpler structures: a double-layer microstrip line, a shielded microstrip line, and a microstrip line. The calculated values of the line capacitance and the guide wavelength are compared with the measured values where possible. Oxide-layer effects on a silicon microstrip line and shielding effects on a sapphire microstrip line are also discussed based on this theory. The limitations and possible applications of this method are described. 相似文献
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本文利用并矢格林函数获得了准光腔中的电磁场积分方程。利用矩量法导出了被一个轴向电流源激励的单微带贴片腔的输入阻抗的计算公式。利用本方法对矩形微带贴片的输入阻抗进行了讨论。其结果与微带天线很类似。这对设计微带型准光振荡器有重要的参考价值。 相似文献
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B. M. Levin 《Journal of Communications Technology and Electronics》2007,52(2):121-130
A planar reflection array consisting of a primary radiator and an array of secondary microstrip radiators such that the phases of the fields generated by these radiators are identical in the direction of radiation is considered. This identity is attained by means of a forced phase step of the reradiated field. An approximate method for calculating the phase step of the reflected field relative to the phase of the incident field that arises during reradiation of the incident signal by an element of the reflection array is proposed. The method is based on the theory of dipoles and the reciprocity theorem. Dependences of the phase step on the dimensions of the antenna and the reactive stub, as well as the capacitance of the capacitor formed by the slot cut in the antenna, are studied. The calculation method is extended to the case of a two-stack microstrip antenna. A method is proposed for setting the maximum of the radiation pattern of this reflection array in a specified direction via the use of an electric signal to control the capacitances of the capacitors in the array elements. 相似文献
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《Microwave Theory and Techniques》1976,24(1):47-48
A method of obtaining an improved transition, from 0.141-in (3.55-mm) semirigid coaxial to microstrip is described. Further improvements by means of compensation include two fixed types having a reflection coefficient less than 0.005 and an adjustable form capable of producing a "transparent" transition. 相似文献