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1.
Analytic design of conformal slot arrays 总被引:1,自引:0,他引:1
Westerman C. Harrington V. Pyong Park 《Antennas and Propagation, IEEE Transactions on》1983,31(4):668-672
A completely analytic design process has been developed for small slot arrays which accounts for the varying effect of mutual coupling as a function of element position. A previously developed theory for the design of small arrays has been extended to include conformal dielectric-filled waveguide slot arrays. Computer software has been assembled which enables calculation of the slot geometries required to implement a specified aperture distribution and input impedance condition. The slot self- and mutual admittances are calculated numerically, thus eliminating the traditional measured slot data from the design process. This design technique has been applied to conformalX -band slot arrays on cylinders of a few wavelengths diameter. The arrays consist of multiple dielectric-filled waveguides, each of which is a narrow-band standing-wave linear array of longitudinal shunt slots. The computerized design process adjusts the length and offset of each slot in the total array until the desired aperture distribution and impedance match are achieved. A flow diagram of the design program and test results from experimental arrays are presented. 相似文献
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提出了一种新的矩形波导缝隙阵列的单元形式-宽边偏置交叉缝,并采用全域正弦基Galerkin法对其散射特性和谐振特性进行了理论分析。数值结果表明,这种缝隙单元的散射作用与宽边偏置纵缝相似,二者均可以用等效传输线上的一个并联导纳来表示,但交叉缝的谐振长度比纵缝显著缩短,因而交叉缝阵列中单元间的互耦相对较弱,频带相对较宽。理论计算结果与实验测量数据的良好吻合验证了上述分析方法的准确性。 相似文献
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Wu Ren Ben-Qing Gao Zheng-Hui Xue Wei-Ming Li Bo Liu 《Antennas and Propagation, IEEE Transactions on》2004,52(9):2436-2444
A rigorous analysis of the resonant characteristics for a broad wall waveguide slot by using the finite-difference time-domain method is presented. Four types of slots including a radiating longitudinal shunt slot, a longitudinal/transverse coupling slot, a centered-inclined coupling slot and a compound coupling slot are analyzed. Lots of slot characteristics such as the resonant length, scattering parameters and normalized admittance in different offsets, tilt angles or slot sizes are obtained. Because the shape of slots is a rectangle with rounded ends in practical fabrication, an accurate modeling and computation for the slots with rounded ends is implemented, and the resonant lengths calculated coincide well with the Stegen's measured data and method of moments results. From these computed results, it is found that all the resonant characteristics of the slots with rounded ends are significantly different from those with normal rectangular ends. 相似文献
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Tzung-Fang Huang Shih-Wen Lu Powen Hsu 《Antennas and Propagation, IEEE Transactions on》1999,47(10):1560-1565
A method for analyzing and designing the slot antenna array excited by a coplanar waveguide (CPW) is presented. The slots are etched on the conducting plane of the CPW and placed in the direction perpendicular to the transmission line. Moment-method analysis and matrix-pencil approach are adopted to calculate the scattering parameters and hence the self-admittance of each slot. The mutual admittances between the slots are calculated from the formulas derived for the complementary strip dipoles based on the reciprocity theorem and via Booker's relation. Then the transmission line theory is used to calculate the input impedance of the array, and an iterative process is employed to obtain a matched design for a desired slot-voltage distribution. A four-element slot array is fabricated and measured using this design procedure. Calculated results are in good agreement with measurements 相似文献
5.
A resonant slot array with a bidirectional radiation pattern and an impedance bandwidth of more that 15% has been realized by measuring the admittance of a couple of longitudinal shunt slots on the opposite walls of the waveguide, and then optimizing the reflection coefficient of the equivalent network of the array in the desired frequency range. 相似文献
6.
Resonant length of longitudinal slots and validity of circuit representation: Theory and experiment 总被引:4,自引:0,他引:4
Pertinent theory for the design of longitudinal slot arrays is reviewed and its dependence on the dominant mode scattering off a single slot is pinpointed. The critical need to know resonant length versus slot offset is emphasized and the desirability of determining this information theoretically rather than experimentally is argued. Then method of moments solutions are used to calculate resonant length versus slot offset for given waveguide dimensions and frequency. These theoretical results are compared to new, carefully obtained experimental data. Agreement is found to be so good, it is concluded that one can dispense with the costly gathering of experimental input data when designing longitudinal slot arrays fed by standard rectangular waveguide. A critical look is taken at the validity of representing the longitudinal slot as a shunt element on an equivalent transmission line. This assumption is found to be more and more questionable as theb dimension is reduced. For quarter-height guide, an alternate design procedure is suggested as being more accurate. 相似文献
7.
Analysis of longitudinal slots in rectangular waveguides 总被引:4,自引:0,他引:4
An accurate computation of the admittance characteristics of longitudinal shunt slots in a rectangular waveguide is presented. A moment method with entire basis functions is used for solving the electric field in the slot. The waveguide wall thickness is accounted for by introducing higher order waveguide modes in the short waveguide connecting the inner and outer regions. Particular attention is given to the resonant length of the slot, which is a critical parameter in the design of waveguide slot array antennas. Computed resonant lengths compare very well with measured results. 相似文献
8.
Cheng-Geng Jan Powen Hsu Ruey-Beei Wu 《Antennas and Propagation, IEEE Transactions on》1993,41(4):488-492
An analysis for calculating the mutual impedance between two edge slots in a linear slotted waveguide array is presented. The analysis uses a 90° wedge Green's function to account for the influence of the waveguide corners on the evaluation of the external mutual coupling. A novel asymptotic formula for the 90° wedge Green function's is derived to expedite the numerical analysis for slots with large separation. Numerical results show that the phase of mutual impedance retards linearly with slot separation and the magnitude decays as the separation is increased. However, the mutual impedance of edge slots is larger and decays more slowly than that of longitudinal slots or other slots in a large ground plane. The distinguished characteristics can be attributed to the energy guiding effect of the waveguide corners, which is discovered and verified mathematically and numerically. Also shown in the numerical calculations are the incremental conductances of the individual slots in a linear edge slot array, which are compared, and found to be in good agreement, with the available experimental data 相似文献
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Improved coupling for aperture coupled microstrip antennas 总被引:3,自引:0,他引:3
An aperture shape that gives significantly improved coupling for an aperture coupled microstrip antenna is described. This 'dogbone' aperture consists of the usual rectangular slot augmented with loading slots at each end. Measured data show an increase of more than three for the resonant input impedance of an antenna using the dogbone-shaped aperture, as compared with the input impedance of the same antenna with a rectangular slot of the same overall length. The field distributions of both slots are also measured, and compared.<> 相似文献
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针对耦合波导缝隙馈电时波导内电磁场复杂且不利于工程应用的问题,提出一种耦合波导缝隙有源阻抗计算方法.根据耦合波导端口处S矩阵与端口处输入阻抗矩阵的关系建立关于耦合波导缝隙有源阻抗方程,且采用牛顿法求解此非线性高阶分式方程,得到计及缝隙间互耦的耦合波导缝隙有源阻抗值.通过提取HFSS软件中耦合缝隙馈电的裂缝天线S矩阵进行仿真计算,结果表明该计算耦合缝隙有源阻抗的方法是有效的且适合大型裂缝天线耦合裂缝设计. 相似文献
15.
非对称单脊波导裂缝阵天线分析 总被引:5,自引:1,他引:4
将Elliott关于矩形波导缝阵理论推广运用到非对称单脊波导裂缝阵天线上,在考虑了裂缝外部互耦影响的情况下,给出相应的两个设计方程,同时给出8单元谐振裂缝线阵的具体计算和设计方法。加工样品的近场和远场测试结果证明了本文理论和设计方法是正确有效的。 相似文献
16.
The efficient and accurate evaluation of external mutual coupling between compound broad-wall slots cut in rectangular waveguides is addressed. The special case of longitudinal slots is also considered. Errors introduced by approximations used in some mutual coupling expressions are investigated and numerical results are presented for a range of waveguide and slot parameters. It is shown that for most applications, mutual coupling expressions can be determined in terms of single numerical integrals 相似文献
17.
The design of large waveguide arrays of shunt slots 总被引:3,自引:0,他引:3
It is shown that the method of moments (MM) solution can determine the active admittance of each slot in a finite array and that the infinite array model is quite accurate for the design of large waveguide arrays of shunt slots. Active admittances computed by an infinite array model agree favorably with that of slots in sufficiently large finite arrays. Measured results verify the MM solution, thereby validating the infinite array model accuracy 相似文献
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An overview of the theory, properties, and potential applications of compound slots is given. Methods for analyzing compound slots are discussed. Scattering properties of the compound slot are examined, covering resonance and the equivalent circuit model, resonant length scattering in the main waveguide, the aperture electric field, and off-resonant characteristics. Array characteristics are also considered, including external mutual coupling, internal higher order mode coupling, and some factors to consider in designing array configurations. Problems remaining to be solved are indicated 相似文献
19.
An analytical design method is presented which enables determination of the length of each slot in a collinear array and the tilt angle of the strip relative to each slot for a specified aperture distribution and input impedance, in the presence of external mutual coupling. The theory uses an extension of Stevenson's approach to relate the TEM mode current in the boxed stripline to the slot-voltage, and a geometrical theory of diffraction (GTD) expression for the external coupling between slot elements. A novel method is introduced to constrain resonant slot lengths to practical values. An array constructed to validate the theory has given good results. 相似文献
20.
An analysis is presented of the characteristics of a broad wall radiating slot, offset from the center line and tilted with respect to the longitudinal axis of a rectangular waveguide. Pertinent integral equations are developed, taking into account finite wall thickness, and are solved for the slot aperture E -field using the method of moments. Compound slot characteristics are then deduced, including resonant length and dominant mode scattering. Numerical results for the scattering from resonant slots are presented over a range of offsets, tilt angles, frequencies and waveguide dimensions. For resonant compound slots, offset and tilt are shown to control the aperture electric-field amplitude with a phase variability of 360°. The results have significant applications in the design of compound slot arrays 相似文献