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基于场耦合的概念,建立了有源相控阵天线阵面的机电耦合模型。天线阵面的阵元布置为环栅阵,仿真计算了阵面因子方向图和阵面方向图。依据此环栅阵,将结构误差加入机电耦合模型,得到结构变形误差,阵面加工误差,累积安装误差对天线阵面电性能的影响数据。研究分析结构误差对天线增益、栅瓣电平、波束指向和波束宽度等天线阵面电性能指标的影响,可知天线阵面对振动的位移响应对电性能的影响满足系统的指标要求,阵面加工误差和累积安装误差对天线阵面电性能的影响较小。 相似文献
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Bon‐Jun Ku Do‐Seob Ahn Seong‐Pal Lee A.V. Shishlov A.S. Reutov S.A. Ganin A.G. Shubov 《ETRI Journal》2002,24(3):197-204
This paper presents the results of the numerical simulation of a multibeam active phased array antenna for a High Altitude Platform Station (HAPS). The simulation takes into account the random errors caused by the nonidentity of the array elements and the inaccuracy of the antenna calibration. The results of our statistical simulation show that the strict requirements on the sidelobe envelope for HAPSs can be met when the amplitude and phase distribution errors are minor, a condition which may be achieved by using digital beamforming. 相似文献
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在智能天线系统中,由于各阵元之间存在着耦合和激励误差,在对下行波束进行赋形时,这些误差会使产生波束指向严重偏离期望的方向,造成天线增益下降。针对这一问题,提出了一种基于最小二乘支持矢量机(LS_SVM)的下行波束盲校正算法:该算法首先利用发射的训练序列对支持矢量机(SVM)进行训练,然后利用所得的权值补偿耦合和激励误差,使发射波束的指向符合期望的方向,最后采用自适应波束综合算法产生主波束宽度以及副瓣电平符合期望值的方向图。对该方法进行了仿真验证,仿真结果表明,该算法简单易行,具有实时处理的能力。 相似文献
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根据星载SAR天线的特点建立了天线展开误差模型,定义了展开不平直度指标,基于成对回波理论推导了存在展开误差条件下天线方向图函数的表达式,推出单频天线展开误差分量与方位模糊度之间统计关系,给出了天线展开误差影响方位模糊度指标的上界.大量的计算机仿真验证了本文分析方法的正确性. 相似文献
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It is well known that a linear antenna array with equally spaced elements can be represented by a polynomial whose roots correspond to the nulls of its antenna pattern. Since the linear array has equally spaced elements, its polynomial has only integral powers of the variable, so that the array can be represented by aZ transform. Therefore, the effect of moving roots of the polynomial can be represented as a linear sampled-data system problem, which is solved by using a table ofZ transforms or by discrete numerical convolution. In this paper, the quantitative effects on the array and its antenna pattern caused by moving roots of the polynomial are determined, and these effects are utilized for array synthesis to produce desired antenna patterns. Examples illustrating the use of this new synthesis technique include modification of a uniform array to obtain low sidelobes in the antenna pattern and synthesis of an array to produce nulls in its antenna pattern in the directions of discrete and spatially distributed interference sources. 相似文献
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This paper deals with considerations in the design of an electronically steered IFF antenna which is to provide sidelobe suppression through the use of a difference beam with gain higher than that of the sum beam everywhere outside of the mainlobe region. The influence of the suppression requirement upon illumination design tradeoffs in beamwidth, sidelobe levels, and taper efficiency is demonstrated theoretically for an array restricted to 16 elements. The sidelobe suppression performance for this array, with appropriate choices for amplitude taper, number of phase shifter bits and randomizing phase function, is examined in detail for susceptibility to failures in elements, failures in individual phase shifter bits, and random phase and amplitude illumination errors. In the case of random errors, performance variability with steering direction is examined and a criterion involving the radiation patterns at both the transmit and receive RF frequencies is defined as a measure of performance. It is seen that the design analyzed is successful in reducing the corresponding performance degradation to very low levels in even the worst cases. Expressions are presented for estimating the effects of increasing the number of elements upon improvements in performance in the presence of component failures or random errors. 相似文献
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A comparison of time versus frequency domain antenna patterns 总被引:3,自引:0,他引:3
This paper compares the performance of antenna arrays that use sinusoidal and ultra-short pulse waveforms. There are two parts to the paper: first, a comparison of narrowband versus ultra-wideband linear arrays using an analytic approach and second, a series of computer simulations used to extend the analytic results and to show the characteristics of nonstandard array configurations. Analysis shows that antennas using ultra-short waveforms have highly desirable pattern properties that do not appreciably degrade under conditions of high array sparsity, failed elements, or antenna element position errors. Patterns are given that show these properties directly. These results are of particular importance to the emerging technology of base-band or time-domain communications and remote sensing. It addresses the practical problem of designing extremely large aperture space-based arrays without populating those arrays densely with antenna elements and also reducing the traditional fabrication tolerances. 相似文献
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We present the analysis and experimental results of a beam-steering and -switching antenna array using coupled oscillators and phase-locked loops. With the use of a type-II coupled phase-locked loop array and an external reference signal, the antenna array can steer its beam by a single control voltage, reduce the beam-pointing error arising from the phase errors of the oscillator array, and hold its output frequency stably at the reference signal frequency in operation. Using a double-pole double-throw switch and a difference amplifier at the center element of the antenna array, one can switch the array radiation pattern between the sum pattern and the difference pattern. Moreover, the beam-scanning range is extended to plusmn 90deg by properly using frequency prescalers in the phase-locked loops. The radiation characteristics of a three-element antenna array are measured to verify the array performance. 相似文献
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V. A. Kashin A. E. Tumanskaya V. F. Shumilov 《Journal of Communications Technology and Electronics》2012,57(9):972-982
A method for the control of the transmission coefficients of antenna elements of a system comprising an active phased array antenna (APAA) and a dome lens, which ensures formation of a deep boresight null of the elevation difference pattern, is proposed. The effect of the control method on the characteristics of receiving monopulse channels of the APAA depending on the intrinsic noise of antenna elements is analyzed. The results of the well-known theory of reception of a nonplane wave by an antenna with continuous aperture are extended to the case of an array antenna. 相似文献
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The radiation properties of a spherical phased-array antenna with circularly polarized elements are studied. Each antenna element is assumed to have a cosine type of field pattern. It is found that such an array is capable of providing complete hemispherical coverage without appreciable loss of gain. The radiation produced by the array stays circularly polarized in all directions, and the state of polarization is independent of beam steering. A special distribution of elements on a spherical surface is developed. This considerably suppresses the grating lobes in the pattern and thereby makes the antenna array broadband. Numerical calculations are made to determine the directivity and half-power beamwidth for the radiation patterns produced under various situations. 相似文献
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A 16 x 8 microstrip antenna array with 28 dB of gain at 18 GHz using a parallel-series feed with reduced conductor traces is presented. The feed network connects antenna elements with about 50% reduction in conductor traces compared to conventional arrays with equal numbers of radiating elements. It also enhances the gain-bandwidth performance of the array and maintains a broadside radiation pattern in a wider frequency band. The full-wave simulation results are verified by means of measurements that demonstrate a relative gain-bandwidth of 4.4% with less than 1 dB of gain ripple. 相似文献
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针对有源相控阵天线的雷达散射截面(Radar Cross Section,RCS)计算复杂、缩减困难,以及RCS与辐射性能难以兼顾问题,基于阵面结构变形与安装引起的辐射单元位置偏移分析,利用辐射单元相位误差,建立了有源相控阵天线阵列散射因子RCS的机电耦合模型.并基于该耦合模型,应用粒子群优化算法,优化阵面所有辐射单元的安装高度,以实现有源相控阵天线辐射性能和散射性能的全优.仿真结果表明,所建立的耦合模型及综合优化方法能够在保证有源相控阵天线辐射性能的条件下,有效缩减其RCS,具有重要的工程应用价值. 相似文献
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互耦效应导致阵列天线单元间耦合能量的矢量和随扫描角而变化,在特定频率和方向上可能产生较大的功率反射,并且引起方向图出现虚假波瓣。运用散射参数法对阵列天线单元互耦效应进行理论分析。阐述了其对天线性能的影响,提出了各种指标的实验测试方法。 相似文献
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采用非线性最小二乘法实现圆环天线阵的方向图综合 总被引:3,自引:2,他引:1
为使阵列天线获得圆对称方向图,通常采用环阵的排列方式。本文研究了圆环阵列天线的特殊方向图综合方法,文中采用非线性最小二乘法对影响天线方向图的诸多参数,如单元的幅度和相位、单元间距以及单元在阵中的位置进行了优化设计,使阵列方向图在最小二乘意义上逼近预先给定的理想方向图。仿真结果表明该方法可行、有效。 相似文献
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《Antennas and Propagation, IEEE Transactions on》2009,57(6):1679-1683