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在接收阵天线中,提高信/噪比,即最大化增益并有效地抑制干扰一直成为研究的中心课题。本文围绕着这个中心,提出了振子型合成元三维相控阵天线辐射空间多重控制理论。它包括:合成元三维阵远区辐射场表达式;合成元在三维空间辐射场型最大方向可控性质;阵辐射场图型多重零点控制的基本关系;在多重零点控制强制条件下,合成元三维相控阵天线方向增益最大化。 相似文献
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介绍一种试验性质和截获雷达天线,该天线采用相控阵技术,经济实用,天线阵用带有移相器的裂缝波导阵实现波束的方位面扫描,通过配置在裂缝阵前面的Radant透镜进行波束的俯仰面扫描,这样就避免在每个辐射单元后面使用移相器或T/R组件,从而利用行0-列相位控制简化对波束的控制,降低天线阵的成本,与每个辐射单元后面使用移相器或T/R组件的同样尺寸的天线阵相比,该天线阵的生产费用估计不到前者的1/3 相似文献
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Liu Zhenwei 《电子科学学刊(英文版)》1984,1(4):217-224
The antenna array pattern null steering is one of the important current topics in the array synthesis theory, due to it's
very effectiveness to suppress the interfering signals. Thus in this paper the problem of forming nulls in the radiational
pattern of three-dimensional arrays is discussed.
This paper deals with the following aspects: The essential relations forming multi-nulls in the arrays are analysed by the
method of vector space. A method forming multi-null regions is presented in terms of the extensive property of null itself.
The resolvent formulation of the radiational pattern of multi-null steering is derived. The numerical results are given and
discussed. The resolvent formulation is analogous to the one of the adaptive arrays. 相似文献
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任意形状旁瓣波束形成技术研究 总被引:2,自引:0,他引:2
在自适应零陷形成的基础上,提出了一种自适应加权算法,用于任意阵型阵列构成具有任意形状旁瓣的波束图,并考虑基元方向性对波束图的影响.给出了实现自适应加权算法的三个步骤,预先设定所需旁瓣形状及旁瓣级,采用循环,最终使旁瓣与预设形状吻合.将该算法用于均匀线阵和抛物线阵,均得到期望的结果,并与道夫-切比雪夫加权作了相应比较.研究表明,基元的方向性对该算法波束形成的影响很小,新算法可以消除基元宽带方向性对波束的影响. 相似文献
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在粒子群算法优化阵列天线方向图时,适应值函数的选取对算法收敛和优化效率都有着至关重要的影响。针对复杂多指标方向图优化容易早熟收敛,提出了一种分步的适应值函数策略,通过分阶段提高优化指标,可以更好地促进算法收敛和提升优化效率。仿真结果表明:将此适应值策略应用于天线方向图综合中,在不改变算法本身的同时,可以在多零点和低旁瓣约束情况下取得更好的优化效果。 相似文献
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A general formulation for the analysis of a phased array of waveguide apertures in a common ground plane has been given for finite number of elements and nonuniform spacings based on network representation of the system. The analysis yields the radiation pattern, reflection coefficient, and aperture field in each waveguide. The pattern of an array of physically identical elements is expressed as superposition of patterns of infinite number of arrays. The formulation, when applied to single and two aperture cases, confirms the known results. It is then applied to investigate the properties of the element position modulated phased array of 15 rectangular waveguide apertures excited by uniform incident waves. Uniformly spaced arrays are also analyzed for comparison. The dominant mode and one higher order evanescent mode are included in the computations. The results show that the overall power reflection coefficient of the nonuniform array does not undergo any peaks over a wide scan range. It is concluded that the advantages of nonuniformly spaced arrays in suppressing grating lobes and eliminating blind spots are physically realizable. 相似文献
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In antenna arrays, the number of nulls that can be formed independently is equal to or less than the number of array elements minus one. Therefore, if the number of interferences exceeds the number of freedom for pattern synthesis in adaptive arrays, nulls in the radiation pattern can not be steered toward each interference direction. To clarify the behavior of the adaptive array in such an environment, an analysis is made for the case where two interferences are impinging on the two-element directionally constrained adaptive array. As a result, it is proved that the adaptive array acts to reduce the undesired noise power at the array output. However, improvement in output signal-to-noise ratio is insufficient because of the limitation in null formation. 相似文献
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Blind spots observed in structures consisting of a slot array and parasitic straight wire arrays are investigated. Each blind spot is found to be associated with either a pattern null or the excitation of a surface wave on the corrugated structure consisting of the parasitic wires and conducting screen, with the slots shorted. The plane-wave-expansion technique is used to evaluate the coupling between arrays. It is shown analytically that for structures consisting of a single wire array, the blind spot can exist only at broadside, where there is a pattern null for the parasitic wires. For structures with two-wire arrays, such as an array of Clavin elements, a surface wave can be excited at a particular scan angle provided a certain uniformity condition in the structure is satisfied. The information presented is relevant to the incorporation of parasitic wire arrays for scan compensation 相似文献
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Basic array theory 总被引:10,自引:0,他引:10
Kummer W.H. 《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》1992,80(1):127-140
Basic antenna array theory is outlined with major emphasis on pattern analysis and synthesis for periodic linear and planar arrays, phased arrays, and conformal arrays. Extension is made to synthesis techniques which use computer algorithms. These include arbitrary sidelobe control, shaped beams, and phase-only null steering. The subjects of random errors and phased array quantization errors are outlined 相似文献
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Ishimaru A. Coe R. Miller G. Geren W. 《Antennas and Propagation, IEEE Transactions on》1985,33(11):1213-1220
There are two conventional techniques dealing with mutual coupling problems for antenna arrays. The "element-by-element" method is useful for small to moderate size arrays. The "infinite periodic structure" method deals with one cell of infinite periodic structures, including all the mutual coupling effects. It cannot, however, include edge effects, current tapers, and nonuniform spacings. A new technique called the "finite periodic structure" method, is presented and applied to represent the active impedance of an array, it involves two operations. The first is to convert the discrete array problem into a series of continuous aperture problems by the use of Poisson's sum formula. The second is to use spatial Fourier transforms to represent the impedance in a form similar to the infinite periodic structure approach. The active impedance is then given by a convolution integral involving the infinite periodic structure solution and the Fourier transform of the equivalent aperture distribution of the current over the entire area of the array. The formulation is particularly useful for large finite arrays, and edge effects, current tapers, and nonuniform spacings can also be included in the general formulation. Although the general formulation is valid for both the free and forced modes of excitation, the forced excitation problem is discussed to illustrate the method. 相似文献
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This paper presents an efficient method, based on the modified touring ant colony optimization algorithm, for null steering of linear antenna arrays by controlling both the amplitude and the phase of array elements. The maximum sidelobe level, the null depth level and the dynamic range ratio are taken into account in the pattern synthesis. Simulation results for Chebyshev patterns with the imposed single, multiple and broad nulls are given to show the effectiveness of the proposed method. 相似文献