Developing Three-Dimensional Beamshaping Techniques on Volumetric Random Arrays to Suppress Array Sidelobes

This paper proposes a three-dimensional (3-D) amplitude tapering technique on volumetric random arrays to minimize array sidelobes and emulate phased array operations on mobile platforms. Our ultimate goal is to realize wireless phased array applications carried out by mobile platforms;in this paper, we focus on the development of collaborative beamforming algorithms. This beamshaping technique mitigates the discontinuity of the current distribution along the array aperture and lower array sidelobe level (SLL) by specially paying attention to the array element’s depth deviation. In this work, step by step amplitude tapering procedures are clearly illustrated. Further, a reconfigurable phased array with sixteen patch antennas is tested to verify the fidelity of the 3-D beamshaping algorithm. Measured and simulated radiation patterns are benchmarked to evaluate the sidelobe suppression results, and the best sidelobe suppressed region is around the array’s main beam.

THE LIMITATION OF MUTUAL IMPEDANCE PRECISION TO THE SIDELOBE LEVEL OF ARRAY ANTENNA

Accurate mutual coupling correction is necessary for an array antenna to reach ultra-low sidelobe level.If the mutual impedance or mutual coupling coefficient matrix of an array isperfectly known,theoretically,one can compensate the effects of mutual coupling completelyand realize the desired low sidelobe level.However,the mutual impedance matrix obtainedwhether by calculation or by measurement has limited precision,which limits the effectiveness ofcompensation.This paper deals with the requirements on the precision of mutual impedance forcompensation in ultra-low sidelobe array antennas.The relationship between mutual impedanceerrors and the amplitude and phase errors of an array is derived,by which the relationship betweenthe mutual impedance errors and the sidelobe level is obtained.

Antenna Sidelobe Canceller of Kalman Filter

The adaptive array antenna may be considered as a general sidelobe canceller. Directional interference suppression is based on a recursive state estimation of Kalman filter. For the stationary filter,this leads to an iterative solution of Wiener Hops matrix equation. The performance of sidelobe canceller are studied by computer simulation. The result of simulation shows that the sidelobe canceller may be regarded as a special case of an adaptive array atenna.

COMPUTER SIMULATION FOR AN ULTRA-LOW RANGE SIDELOBE PULSE COMPRESSION SCHEME

A canceling range sidelobes scheme has been suggested by Yang Guangzheng, et al.,(1997) this technology is based on the fact that all sidelobe of group correlation function of ideal sets are zero. At first, this paper gives the best ideal sets (i. e. the best biphase code sets whose maximal sidelobe not more than 2) for all code length N≤12, which have been obtained from binary sequences by means of the best codes sieving method suggested by Yang Guangzheng, et al.(1997) Computer simulation for group correlation property of best ideal sets for code length N=12 on various conditions is made. Simulation result shows that the sidelobe level of best ideal set with no weighting is zero, under condition of zero-Doppler shift and has ultra-low sidelobe on Doppler up to 5kHz with no weighting and whose tolerance of phase and amplitude distortion is bigger too.

Design of a low-sidelobe-level and wideband dielectric resonator antenna array for 60 GHz millimeter wave communication

A low-sidelobe-level( SLL) and wideband linear dielectric resonator antenna( DRA) array is proposed for 60 GHz millimeter wave communication. The array consists of 10 wideband DRAs which work at 60 GHz and it is fed by a Chebyshev feeding network to get a low SLL. To avoid the influence from the feeding network,a U-shaped substrate and a conformal ground are used,which can separate the DRA array and the feeding network. The parameter analysis and simulated results are presented.

高增益低旁瓣宽扇形波束脊形波导缝隙天线阵列设计

提出了一种具有高增益低副瓣的脊形波导缝隙阵列天线,中心工作频率为24.125 GHz,其包括一个八路馈电网络和一个尺寸为400 mm×65 mm的8×40辐射缝隙。通过波束合成方法提取天线阵列的期望激励分布,采用截止模式功率分配器灵活控制功率比。使用三维电磁仿真软件HFSS综合仿真计算,在中心频率处,获得仰角平面上的旁瓣电平(sidelobe level,SLL)和半功率波束宽度(half power beam width,HPBW)分别为-20.9 dB和54.5°、方位角平面上的SLL和HPBW分别为-27.8 dB和2.5°、峰值增益为23.2 dBi,仿真结果与理论分析一致。此天线可以同时实现低旁瓣的宽扇形波束,覆盖较宽的检测范围,并减轻来自其他方向的干扰,具有应用于空中探测、反无人机、气象雷达和成像雷达的潜力。

基于无人机电力巡检的椭圆稀布阵列天线优化方法研究

为了提高电力巡检无人机的电磁检测性能,提出了一种基于无人机电力巡检的椭圆稀布阵列天线优化方法。阵列天线的阵列单元稀布排列,能够在保证阵列天线性能的同时,减少阵列单元的数目,从而减少馈电单元的数目。每个阵列单元等幅馈电,可以有效降低馈电网络设计的复杂程度,这些都能够在一定程度上降低阵列天线的功耗,提高无人机的巡检时间。利用改进智能优化算法,通过优化阵列单元的位置,使方向图的最高旁瓣电平(peak sidelobe level,PSLL)尽量低,因此文中设计的阵列天线具有较低的最高旁瓣电平,从而具有很好的环境抗干扰能力。仿真结果表明,在给定阵列单元数目、最小间距约束和阵列天线尺寸的情况下,提出的方法能够有效降低阵列天线方向图的最高旁瓣电平,对具有41个阵列单元的椭圆阵列天线进行优化,优化后的阵列天线方向图的最高旁瓣电平在-24dB以下。

基于改进型灰狼优化算法和窗函数加权的稀布矩形平面阵列天线综合

针对在阵列孔径、阵元数目、最小阵元间距等多约束条件下的稀布矩形平面阵列天线优化问题,提出了基于改进型灰狼优化(improved grey wolf optimizer,IGWO)算法和窗函数加权的稀布矩形平面阵列天线综合方法。首先,利用Tent混沌映射、非线性收敛因子、优势狼动态置信策略和对立学习策略对灰狼优化(grey wolf optimizer,GWO)算法进行改进,增加算法的种群多样性和跳出局部最优的能力。然后,利用窗函数对阵列单元进行加权,生成位置分布矩阵,减少稀疏矩阵优化时间,提高优化效率。最后,利用位置分布矩阵生成稀疏阵列,再运用IGWO算法进行多约束条件的稀布优化。为验证所提方法的有效性进行了仿真实验,实验结果表明,本文方法可以有效提高阵列天线的性能,降低峰值旁瓣电平,对于解决在多约束条件下的阵列分布问题,具有一定的工程意义和参考价值。

基于脊间隙波导的低副瓣多波束阵列天线设计

为了克服毫米波频段传统多波束阵列天线损耗高、效率低以及等幅激励情况下副瓣电平较高的问题,该文提出了一种基于间隙波导技术的低副瓣多波束阵列天线设计方法。首先,设计了基于巴特勒矩阵的双层多波束馈电网络拓扑结构,将传统巴特勒矩阵的4个输出端口与不等功分器相连,拓展为8个输出端口,实现输出功率的重新分配,以达到低副瓣设计的目的。接着,设计了基于脊间隙波导的双层和单层定向耦合器、交叉结和不等功分器,完成了低副瓣多波束阵列天线的整体设计。最后,进行了天线实物加工和测试,测试与仿真结果较为吻合,副瓣电平得到了有效降低,验证了所提出的低副瓣多波束阵列天线的性能。

Ku波段高增益波导缝隙阵列天线

文章设计了在Ku频段窄边开缝的行波阵波导缝隙天线。首先设计了单根的开槽缝隙天线,其增益可达23.69dB以上,在方位面波束宽度为1.4°,副瓣电平均低于-15dB。64根开槽缝隙天线组阵后能够在4%的带宽内实现增益大于41.88dB,波束宽度在1.4°左右,副瓣电平均低于-13dB。仿真与测试结果均可以表明,该天线能够在Ku波段实现高增益和低副瓣、指向性好,并具有低剖面的优点。

改进哈里斯鹰算法用于阵列天线方向图赋形

由于目前群智能优化算法在解决直线阵列天线方向图的旁瓣电平抑制和零陷控制问题时容易陷入局部最优以及收敛速度较慢的问题,提出了一种改进哈里斯鹰优化算法。该算法首先引入单鹰探索策略来扩大算法的全局搜索范围,然后引入自适应控制理论,用以提高算法的搜索精度并加快算法的收敛。仿真结果表明,与粒子群算法、布谷鸟搜索算法、蚁群优化算法以及标准哈里斯鹰优化算法相比,所提算法在压低直线形阵列天线方向图的旁瓣电平和控制零陷方面更具优越性。

非规则子阵阵列天线仿真与性能分析

文中设计了一种超宽带Vivaldi天线,并对其组成的16×16阵列按照划分设计的最优子阵方案进行仿真。通过均匀加权与低副瓣加权对天线阵列进行了波束偏转分析,从不同频点和偏转角度对波束扫描进行了分析,并仿真分析了天线的差波束及赋形波束,结果良好;同时对子阵级别的扰动进行了敏感度分析,发现在不同相位干扰下,干扰范围越大相位干扰对主瓣波束影响越大,主瓣增益降低和副瓣电平升高越明显,幅度干扰和幅相干扰也有同样结论。实际非规则子阵阵列天线在应用时,子阵级的相位误差在一定范围内对天线的影响不大,幅度误差对天线的整体影响也不大,即子阵级干扰对非规则子阵阵列天线扫描角度的影响不大,但对主波束的影响随干扰范围的增大而增大。本文的仿真分析可为非规则子阵阵列天线的设计和加工提供参考,丰富和拓展非规则子阵阵列天线设计仿真和性能分析领域,节省实际加工和应用的成本。

Thinned array antenna synthesis using modified binary particle swarm optimization with minimization of sidelobes

Purpose-The purpose of this paper is to propose radiating system by avoiding electromagnetic interference in unwanted directions and to radiate the energy in the required direction with an optimization technique.Design/methodology/approach-Practically,multiple,incompatible variables require concurrent boost on a synthesis of systematic antenna assemblage.The authors have worked out the main statistic penalty function to ensure all the restrictions.Here,MBPSO(Modified Binary Particle Swarm Optimization)is developed and introduced thin planar synthesis restriction.The sigmoid function is used to update the particle position.Different analytical demonstrations have been carried out,and the exhibited methods are predominant than the algorithms.Findings-A 20310 planar antenna array is synthesized using modified BPSO.The authors have suppressed the PSLL in two principal planes and as well as in the entire f plane.Numerical results state that MBPSO outperforms the other binary BPSO,BCSO,ACO,RGA,GAoptimization techniques.MBPSO achieved a
51.84 dB PSLL level,whereas BPSO achieved
48.57 dB with the same 50%thinning.Originality/value-Planar array antenna formation is one of the most complex syntheses because the array gets filled with more antenna elements.The machine-like complication and implementation of such an antenna arrangement with a broad opening would be expensive.It is not easy to control the required radiation patterns shape by using a uniform feeding network.To get better flexibility for sustaining the sidelobe levelheaded along with consistent amplitude distribution.So as far as prominence has been given to the evolutionary algorithm,find an ideal solution for objective array combinational problems.

Beam shaping with limited amplitude weight values for satellite active phased array antenna

To gain the tradeoff between lower sidelobe and higher power amplifiers efficiency,a transmitting beam shaping scheme with limited amplitude weight values for satellite active phased array antenna is presented. The scheme is implemented by a dual coding genetic algorithm(GA). Phase and amplitude of array weight vectors for beam shaping are encoded by real coding and finite length binary coding,respectively,which,maintaining accuracy of results,reduces the amplitude dynamic range and improves the efficiency of power amplifiers. The presented algorithm,compared with complex-coded GA,increases the convergence rate due to the search space's decrease. In order to overcome the prematurity and obtain better global optimization or quasi-global optimization,a new dual coding GA based on "species diversity retention" strategy and adaptive crossover and mutation probability are presented.

DESIGN AND ANALYSIS OF MULTI-STEP AMPLITUDE QUANTIZATION WEIGHTED 2-D SOLID-STATE ACTIVE PHASED ARRAY ANTENNAS

An aperture design technique using multi-step amplitude quantization for two-dimensional solid-state active phased arrays to achieve low sidelobe is described. It can be applied to antennas with arbitrary complex aperture. Also, the gain drop and sidelobe degradation due to random amplitude and phase errors and element (or T/R module) failures are investigated.

A Planar 4-Bit Reconfigurable Antenna Array Based on the Design Philosophy of Information Metasurfaces

Inspired by the design philosophy of information metasurfaces based on the digital coding concept,a planar 4-bit reconfigurable antenna array with low profile of 0.15λ0(whereλ0is the free-space wavelength)is presented.The array is based on a digital coding radiation element consisting of a 1-bit magnetoelectric(ME)dipole and a miniaturized reflection-type phase shifter(RTPS).The proposed 1-bit ME dipole can provide two digital states of"0"and"1"(with 0°and 180°phase responses)over a wide frequency band by individually exciting its two symmetrical feeding ports.The designed RTPS is able to realize a relative phase shift of 173°.By digitally quantizing its phase in the range of 157.5°,additional eight digital states at intervals of 22.5°are obtained.To achieve low sidelobe levels,a 1:16 power divider based on the Taylor line source method is employed to feed the array,A prototype of the proposed 4-bit antenna array has been fabricated and tested,and the experimental results are in good agreement with the simulations.Scanning beams within a±45°range were measured with a maximum realized gain of 13.4 dBi at12 GHz.The sidelobe and cross-polarization levels are below-14.3 and-23.0 dB,respectively.Furthermore,the beam pointing error is within 0.8°,and the 3 dB gain bandwidth of the broadside beam is 25%.Due to its outstanding performance,the array holds potential for significant applications in radar and wireless communication systems.

某卫星有源相控阵天线系统在轨失效分析

某卫星有源相控阵天线为首颗成功在轨应用的C频段多极化天线,已在轨运行超过4年,采用有源相控阵天线体制,具有高分辨率、宽覆盖、多极化、多工作模式、高图像质量的特点,波束控制灵活,能够实现聚束模式、超精细条带模式、全极化条带模式、波成像模式、双极化条带模式、双极化扫描模式多种工作模式。相控阵天线的部件失效会造成天线增益、副瓣电平等性能参数的恶化。通过算例仿真,建立部件失效数学模型,天线增益变化与失效比例相关,副瓣抬升和失效模式相关。计算结果可以用于某卫星有源相控阵天线在轨失效后性能分析。

W波段宽带宽角低副瓣类喇叭天线稀布阵

针对大损耗、制作工艺、T/R组件尺寸与通道数量以及位置等因素带来的W波段宽带宽角低副瓣相控阵天线设计难题,文中设计了一款在80~110 GHz频率范围内的宽带类喇叭天线单元,天线驻波比均小于1.8。在充分考虑T/R组件带来的布阵空间限制下,文中仅通过阵元位置优化设计了64元高增益低副瓣宽带宽角阵列天线,并为该阵列设计了小型低剖面空气波导馈电网络。仿真结果表明,64元稀布阵在䥺SymbolqB@40°波束扫描范围内下增益高于22.6 dB,副瓣电平低于-6.2 dB,各阵元有源驻波比均小于2,证实该阵列天线具有宽带宽角、低副瓣、高增益、结构易于加工实现等优点,应用前景良好。

毫米波宽带低副瓣波导缝隙阵列天线设计

本文提出了一种毫米波宽带低副瓣波导缝隙阵列天线。该天线分为上下两层,利用下层的功分器和反相器使电磁波从上层的辐射波导的两端向中心进行馈电,激励12个非均匀波导缝隙辐射单元。该天线呈中心对称结构,结构紧凑,并使得天线的方向图具有稳定性。在辐射波导中引入二阶短路金属阶梯,并且阵列的辐射单元采用非连续的双层缝隙,拓展了天线的工作带宽。所提出的加载二阶金属阶梯双层缝隙阵列天线的阻抗带宽达到16.3%(35.35~41.55 GHz),峰值增益为16 dBi,工作频带内天线的增益下降低于2.5 dBi,副瓣电平低于−20 dB。

一种旁瓣匿影天线系统设计

旁瓣匿影是相控阵雷达采用的一种典型抗干扰技术。天线系统是旁瓣匿影的核心硬件设备,其设计直接关系到匿影波束能否有效压制干扰信号。针对目前旁瓣匿影容易出现的波束覆盖穿刺等问题,文中设计了一种旁瓣匿影天线系统,它包括全向匿影天线、低噪放耦合模块。通过匿影天线与低噪放集成设计提高匿影链路的干噪比。全向匿影天线采用方位全向双极化天线设计,水平极化匿影天线采用扁波导缝隙全向天线,垂直极化匿影天线采用扁平双锥全向天线。仿真结果表明,两种天线可实现方位向水平极化与垂直极化的全向覆盖。经实测验证,匿影波束能完整覆盖主天线副瓣区,可有效提升雷达系统的抗干扰能力。