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1.
The rectangular cavity backed slot is excited by a current source connected across its center. The longitudinal voltage variation across the slot is obtained from the variational solution of an integral equation. For shallow and narrow cavities the slot appears inductive and the voltage is rapidly attenuated along the slots. The slot may resonate for deeper and/or wider cavities, when the voltage along the slot is approximated by a half-cycle of a sine wave. The resonant cavity depth and the antenna bandwidth are examined for various cavity and Slot parameters. Dielectric cavity loading is shown to decrease both the resonant cavity depth and the antenna bandwidth.  相似文献   

2.
In this paper we use a hybrid method to calculate the admittance of a longitudinal slot (of finite length) in a rectangular waveguide, when the slot radiates into a cylindrical outer structure of arbitrary finite cross section. The analysis takes advantage of a Fourier transformation along the cylinder axis, by which the computational effort is drastically reduced. The harmonic spectral currents on the structure are expanded in subsectional triangular basis functions and determined using an electric field integral equation (EFIE) and the moment method. These currents and the corresponding fields are inverse Fourier transformed and matched over the slot to the fields inside the waveguide by an additional moment method approach using entire domain basis functions for the slot field. The calculated slot admittance has good accuracy when compared with measurements on a chosen geometry  相似文献   

3.
The admittance of a half-wavelength slot antenna in a two-layer lossy plasma is shown to be greatly affected by moderate electron temperatures (T_{e} leq 1 eV) when the plasma is overdense. The effects of slot width and electron collision frequency upon the slot admittance also are investigated.  相似文献   

4.
An experiment to determine the input admittance of a slot antenna after r.f. voltage breakdown outside the aperture has occurred is described. It is found that the conductance decreases and the susceptance increases with input-power level.  相似文献   

5.
An efficient method of computing resonant length and admittance characteristics of an isolated broad-wall shunt slot radiating between baffles of finite height is presented. The outer three-dimensional (3D) field problem associated with this geometry is reduced to a two-dimensional (2D) one via a Fourier transformation with respect to the longitudinal z direction. For each value of the longitudinal wave number kz an integral equation is solved for the E field in the mouth of the plates using the method of moments. This procedure is repeated for several discrete values of kz, to obtain a spectrum of 2D solutions which are then inverse-transformed to construct the 3D solution in the spatial domain for the exterior baffle region and the half space. The slot aperture field is determined by the conventional moment method solution to the integral equation that enforces the continuity of the H field across the slot. Scattering properties of the slot are then deduced. Numerical results for the resonant length and resonant conductance are presented. Computer results are found to be in good agreement with experimentally measured data  相似文献   

6.
An analysis of a wide rectangular radiating slot excited by a microstrip line is described. Coupled integral equations are formulated to find the electric current distribution on the feed line and the electric field in the aperture. The solution is based on the method of moments and using the space domain Sommerfeld-type Green's function. The information about the input impedance or reflection coefficient is extracted from the electric current distribution on the microstrip line utilizing the matrix pencil technique. The theoretical analysis is described and data are presented and compared with other theoretical and experimental results  相似文献   

7.
讨论了圆极化向线缝隙天线的几何结构,口径场分布、缝隙对设计。在此基础上,讨论了慢波结构和波导结构关系,分析了慢波结构对天线的影响,完成了该天线的计算机辅助设计和绘图,使用该方法给天线设计带来了方便,能灵活地调整缝隙排列、优化排列结构,具有直观和精度高的优点。  相似文献   

8.
The authors provide a clarification of a decoupling method employed in the analysis of multiconductor transmission lines. They show that the use of a similarity transformation yields more efficient and stable numerical algorithms for computation of eigenvalues and characteristic impedance/admittance matrices of the telegrapher's equations than those based on a congruence transformation. The algorithms are easy to implement in existing software and, thus, their utilization is recommended  相似文献   

9.
The resonant characteristics and end effects of a rectangular-slot resonator in unilateral fin line are presented for centered as well as off-centered fin locations in the guide. Sample theoretical results on the resonant frequency are verified through experiment at the Ka-band.  相似文献   

10.
A linearly polarized radial line slot antenna   总被引:2,自引:0,他引:2  
A design for linearly polarized radial line slot antenna (RLSA) is proposed. A novel slot arrangement is presented which couples to the rotationally symmetric guided waves to produce a uniform aperture distribution with linear polarization. Basic characteristics were measured in the 12-GHz band on a model antenna. The radiation patterns indicate a reasonable cross-polarization level more than 15 dB below the copolarization. The poor VSWR response is typical for waveguide broadside arrays. A technique to suppress this reflection is to tilt the beam from the boresight  相似文献   

11.
姬五胜  张玉  Nefyodov E I  郭宏 《电讯技术》2012,52(8):1411-1416
介绍了不对称槽线的特性,分析了以不对称槽线构建的复合环、支线定向耦合器、平衡功率分配器、多层滤波器、多信道功率分配器等组件的性能.这些组件体积小、重量轻、频带宽、电压驻波系数小,并且大多数可应用于毫米波段,是三维微波集成电路中的重要组成部分.研究表明不对称槽线具有优良的特性.  相似文献   

12.
The continuous spectrum of the slot in an infinite ground plane is expressed in terms of the Mathieu functions. The so-called characteristic values and field modes of the slot are stated explicitly  相似文献   

13.
Coupling between slots and slow-wave waveguides in a radial line slot antenna (RLSA) is discussed. Field analysis of the waveguide with a surface impedance wall revealed a considerable change in the propagation constant due to coupling. Experiments were performed to confirm these results and to obtain the surface impedance for actual slots. The change in the propagation constant caused the antenna efficiency to exhibit its maxima at two separated frequencies. An efficiency of 60% and 50% was measured at 11.6 and 12.4 GHz, respectively, which confirms a theoretical prediction. This effect suggests the possibility of broadband planar antennas  相似文献   

14.
Transmission line analysis of nonlinear slot coupled microstrip antenna   总被引:1,自引:0,他引:1  
The transmission line method is used for the analysis of microstrip antennas fed by several nonlinear slots with 'H' shapes or new geometries. This analysis allows the input impedance of nonlinear slot coupled microstrip antennas to be calculated for the four different structures.<>  相似文献   

15.
A fast method for the calculation of the mutual coupling between transmission lines is presented. The method is based on using the convolution of the incident field and the current induced by a Dirac impulse type field. Only first-order coupling between the lines is taken into account. This means that only the current induced by the source line is taken into account and all currents resulting from induction by this induced current are discarded. The technique is orders of magnitude faster than traditional moment method techniques because no large matrix equations need to be solved  相似文献   

16.
A method is described for calculating the input impedance as seen by the detector for a twin slot antenna structure. This technique is then used to analyze several twin slot antenna configurations, leading to improved performance.  相似文献   

17.
The effect of a parasitic dipole above a waveguide slot antenna is shown analytically and verified experimentally. The E-plane radiation pattern is shown to be rather sensitive to the change of dipole length, and an equalised E- and H-plane pattern is obtained by choosing a proper length of dipole.  相似文献   

18.
The spectrum of natural frequencies of the resonator has been calculated. The specified resonator includes a microstrip transmission line with discontinuity in the form of two rectangular coupled slot resonators in the grounding layer. Based on the above spectrum and using the transverse resonance method the scattering matrix of the principal wave of the microstip transmission line on this discontinuity was calculated. The scattering characteristic of the periodic structure consisting of a finite number of cells in the form of coupled slot resonators in the grounding layer of microstrip line indicates that with due regard for their mutual coupling the losses in the first stopband can be reduced by 3–5 dB as compared with the characteristic obtained by tandem connection of the scattering matrices of separate slot resonators in the grounding layer of microstrip line.  相似文献   

19.
Zieniutycz  W. 《Electronics letters》1983,19(4):135-136
Using the singular integral approach the dispersion characteristics of the slot line on a multilayered substrate containing a gyromagnetic medium are calculated. The properties of the modes are then discussed from both the phase constant and attenuation curves.  相似文献   

20.
The author presents an effective method for computation of the transient response of multiple nonuniform transmission lines. This time-domain analysis technique can predict reflections and crosstalk. The proposed spectral technique is used to transform partial differential equations describing a system of transmission lines into a set of linear ordinary differential equations, which can be solved with one of the many well-developed integration techniques. Numerical experiments performed with the prototype program showed that the method can solve specific problems (lossless, uniform lines) just as fast as less general methods based on modal analysis exploiting the particular properties of lines  相似文献   

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