Electromagnetic bandgap phased array antenna controlled by piezoelectric transducer

The optimal performance of a phased array antenna controlled by a piezoelectric transducer, having an electromagnetic bandgap (EBG) structure in the ground plane of the feed microstrip lines, is illustrated. The EBG presence increases by about 10/spl deg/ the beam scanning angle achieved by the multiline phase shifter.     

Pattern synthesis of the offset reflector antenna system with lesscomplicated phased array feed

The performance degradation of an offset reflector antenna with off-axis scanning feed and distorted reflector surface can be improved by using a phased array feed. Generally, both analog attenuators and phase shifters are used in phased array feed. Yet, it seems to make the feed system very complicated. In this paper, a phase-only gradient search (POGS) algorithm is developed to optimize the performance of offset reflector antenna systems using phased array feed that is equipped with phase shifters only. This technique not only can greatly simplify the complexity of phased array feed, but also can provide the reflector antenna with better antenna gain and sidelobe level control capability. Simulation and experimental results are presented to illustrate the excellent performance of offset reflector, with limited beam scanning capability, can be obtained by using this less complicated phased array feed     

啁啾光纤光栅移相器在相控阵天线中的应用

本文首先介绍了相控阵天线中的移相器和延时线，然后从啁啾光纤光栅的相位匹配条件出发推导出这种光栅的时延特性近似表达式，并提出将啁啾光纤光栅作为延时线应用于相控阵开线，然后给出了不同光波波长条件下的相移特性。     

Tunable Chirped Fiber Grating Based Variable Time-Delay Network for Phased-Array Antenna Beamforming

In this paper, we present a photonics continuous beamforming system for optically controlled phased-array antenna based on a tunable fiber ring laser source and a novel variable true-time delay network consisting of one single-mode fiber delay line and four tunable chirped grating delay lines. The chirp rate of each chirped grating is tuned by bending a uniform fiber Bragg grating (FBG) bonded at a slant onto the lateral surface of a simply supported beam. This kind of variable true-time delay network can provide five-channel time-delayed signals that can be fed to an antenna array to achieve continuously beam scanning. The proposed true-time-delay unit with 5-element phased array steerer is suitable for phased-array antenna beamforming at frequencies up to 12 GHz.     

A low-cost 8 to 26.5 GHz phased array antenna using a piezoelectrictransducer controlled phase shifter

A new phased array antenna of wide bandwidth and good beam scanning angle has been developed using a low cost multiline phase shifter controlled by a piezoelectric transducer (PET) and a stripline fed Vivaldi antenna array. The multiline progressive PET phase shifter has a low perturbation loss of less than 2 dB and a total loss of less than 4 dB up to 40 GHz with a maximum phase shift of 480°. The proposed phased array antenna consists of four E- or H-plane Vivaldi antennas, a PET phase shifter, and a power divider. The phased array shows a wide beam scanning capability of ±27° over a wide bandwidth from 8 to 26.5 GHz covering X, Ku, and K bands     

双圆极化共形相控阵天线研究

设计了一种基于十字缝隙耦合双圆极化微带共形相控阵天线。首先设计了微带天线单元,分析了天线各结构参数对天线性能的影响。通过电桥向偏馈于十字缝隙上的馈线馈电,实现等幅、相差90°馈电,电桥的两个端口分别获得旋向相反的圆极化信号。然后对天线单元进行了测量,结果表明天线轴比小于3dB 的带宽为16%,驻波小于1.5 的带宽 为17%,波束宽度大于87°。最后对5×5 共形相控阵天线进行了仿真与测量,结果显示天线可以扫描60°,适合用作载体共形的卫星通信天线。     

A new Millimeter-wave printed dipole phased array antenna using microstrip-fed coplanar stripline tee junctions

A new millimeter-wave printed twin dipole phased array antenna is developed at Ka band using a new microstrip-fed CPS tee junction, which does not require any bonding wires, air bridges, or via holes. The phased array used a piezoelectric transducer (PET) controlled tunable multitransmission line phase shifter to accomplish a progressive phase shift. A progressive phase shift of 88.8/spl deg/ is achieved with the 5 mm of perturber length when the PET has full deflection. Measured return loss of the twin dipole antenna is better than 10 dB from 29.5 to 30.35 GHz. Measured return loss of better than 15 dB is achieved from 30 to 31.5 GHz for a 1/spl times/8 phased array. The phased array antenna has a measured antenna gain of 14.4 dBi with 42/spl deg/ beam scanning and has more than 11 dB side lobe suppression across the scan.     

微波光子技术相控阵雷达天线现场校准系统

研究了基于微波光子技术的相控阵雷达天线现场校准技术。介绍了微波光子技术进行相控阵天线现场校准的基本原理,通过利用架设在相控阵天线阵面上的光学探针中的电光晶体的泡克尔斯效应,使得自探针反射的光学信号携带有天线单元的近场辐射信息,在将其进行光电转换后采用外差相干检测的方法来获得信号中所携带的天线单元的幅相信息,便可实现对天线阵面天线单元辐射场信息的快速检测,实验验证系统的电场幅度和相位测量精度可以分别达到0.3 dB和2,同时该方法对被测天线单元具有侵入性低、抗干扰能力强、体积小等优点,满足相控阵天线现场校准的实际需要,具有很强的工程实用价值。     

Partial adaptive nulling on a monopulse phased array antenna system

A partial phase-only nulling (PPON) algorithm has been developed and evaluated on a 496-element monopulse phased array antenna system which employs five-bit phase shifters. Using this PPON algorithm allows nulls in the far-field pattern to be steered to the desired directions for a phased array equipped with low-resolution phase shifters to perform simultaneous nulling in the sum and two difference patterns in the environment of multiple jammers. Simulated and experimental patterns are illustrated     

以循环移位控制为基础的相控阵天线快速测量方法研究

为了解决相控阵天线快速测试问题,本文研究了一种相控阵天线测量的新方法。该方法中相控阵天线和测试探头均不动,利用相控阵天线中各移相器的移相状态可循环移位控制的特点和相控阵天线一些已知可信的信息,从而使测量具有极高的效率。文中对一相控阵天线模型采用该测量方法的测量全过程进行模拟,验证了该方法的正确性和高效性。     

相控阵体制SAR系统的误差建模与补偿方法

在基于相控阵天线体制的合成孔径雷达(SAR)系统中,中央电子设备和相控阵天线的非理想特性,会引入幅相误差,造成SAR信号幅相特性畸变,影响SAR图像等数据产品的质量。本文建立了相控阵体制SAR系统误差的模型,并设计了误差校正方法。研究结果表明：雷达中央电子设备的非理想特性会引入固定的幅频、相频误差;相控阵天线的非理想特性所引入的幅频、相频误差会随着波束指向的变化而变化,该误差主要根源于有源器件在不同频点处的性能差异,并会受到T/R模块移相衰减量的调制;可通过测量或分析计算对相控阵SAR的系统误差进行提取,并在SAR成像处理阶段实施误差补偿。     

Microstrip circular phased array design and development using microwave antenna CAD tools

The complex design and development of a planar multilayer phased array antenna in microstrip technology can be simplified using two commercially available design tools (1) Ansoft Ensemble and (2) HP-EEsof Touchstone. In the approach presented here, Touchstone is used to design RF switches and phase shifters whose scattering parameters are incorporated in Ensemble simulations using its black box tool. Using this approach, Ensemble is able to analyze fully the performance of the radiating and beamforming layers of a phased array prior to its manufacture. This strategy is demonstrated in a design example of a 12-element linearly-polarized circular phased array operating at L band. A comparison between theoretical and experimental results of the array is demonstrated.     

渐变巴伦馈电的超宽带天线单元及阵列研究

为了满足超宽带电子系统对天线的需求, 研究了强互耦超宽带天线单元及阵列.首先设计了能够满足强耦合线极化的天线单元, 然后研究了超宽带相控阵天线阵, 设计了10×10天线单元组成的阵列.以此为基础, 利用高频电磁场仿真软件在二维周期环境中模拟了无限大周期阵列.结果表明, 在满足尺寸约束的前提下实现了二维周期边界下超宽带阵列的功能要求, 同时, 解决了强互耦效应下超宽带无限大偶极子相控阵进行全阵列仿真耗时极多、难度极大的问题.为了解决阵列单元如何有效馈电的问题, 在分析了天线单元结构设计的基础上, 研究了渐变结构巴伦的馈电特性, 并将这种馈电结构与上述强耦合超宽带天线单元相结合, 对单元结构和馈电方式进行了优化, 实现了超宽带馈电的效果.加工了天线阵列并在微波暗室中对不同频点进行了测试, 测试结果与仿真结果吻合.从测试结果可以看出, 主平面辐射方向图在不同频点内的最大扫描角波束峰值增益均大于5 dBi, 最大达到20 dBi, 满足设计要求.说明所设计的阵列天线能够应用于实际微波系统中.     

Full-wave simulation,design and implementation of a new combination of antenna array feed network integrated in low profile microstrip technology

In this paper, a new modified combination of antenna and array feed network integrated in low thickness microstrip technology is presented. A concept similar to the concept of coherently radiating periodic structures is used to feed a 4-element antenna array. In the feed network, a new combination of Gysel-based 3 and 5 port components as power dividers/combiners is employed to propagate the power into the antenna array so that the desired Gaussian-like amplitudes and linear phase distributions can be obtained. These multi-port components are modified to design the feed network by single-layer microstrip technology without the matching and isolation circuits and through-substrate vias. Therefore, the manufacturing cost and difficulty and design complexity are reduced, considerably. Full-wave simulations of the feed network, unit cells and the final integrated antenna array are done, step by step and the results considering all possible losses are presented. To validate the designs, two prototypes, first the feed network and second the integrated module including both antenna array and feed network designed at 3.5 GHz were fabricated and measured and the S parameters (amplitude and phase) were compared with the full-wave simulations. A good agreement between the results including impedance and radiation characteristics is shown.     

相控阵天线时域有限差分计算中激励源分析

在时域有限差分(FDTD)方法用于偶极阵列天线数值计算时,采用带有内电阻的缝隙馈电激励源模型,及选择自由度较大的调制高斯脉冲信号,来提高数值算法迭代计算的收敛速度;在各馈电单元的时域信号中通过引入合适时间延迟,实现对相应单元相位的控制。用二元相控阵列天线模型,验证了算法和程序是正确的;用六元相控圆形阵列天线,分析了该算法在实际相控阵天线问题分析中的应用。     

基于相控电磁表面的W波段雷达系统研究

该文将介绍一种W波段相控电磁表面雷达系统。这种工作在92～96 GHz的相控电磁表面天线,仅利用普通的印刷电路板(PCB)加工工艺及加工精度要求,通过合理的单元设计,可以控制掺杂本征材料的二极管(PIN)实现电流翻转,能轻便地、低成本地在W波段保证稳定的180°调相效果。进一步通过输入合适的空间编码,相控电磁表面天线可以形成具有不同指向的波束。这种具有空间波束扫描能力的透射型相控电磁表面天线,用作雷达系统的接收天线。该文提出的W波段相控电磁表面雷达系统及其加工和测试结果,为后续研究精确制导、目标识别、成像等应用提供了基础。      

Phased array for millimeter wave frequencies

A phased array is presented at a frequency of 70 GHz, consisting of a corporate feed, ferrite phase shifters and dielectric rod antennas. Metal waveguides were utilized to construct the feed network, whereas a special dielectric waveguide structure was employed for the ferrite phase shifter and dielectric rod antenna. Beam scanning can be performed electronically controlled in the horizontal plane.     

A Novel Methodology to Feed Phased Array Antennas

A new methodology to design beam-forming networks (BFN) to feed antenna arrays is introduced. Using this methodology is feasible to reduce the complexity of the associate control of a phased array, since, an N by N antenna array could be controlled to steer the beam using four phase shifters instead of the N² conventionally used. A prototype was designed, built and measured as proof of concept. The prototype consists on 3 by 3 Quasi-Yagi antennas fed by four input-ports. The measurements show that the main beam of an antenna array fed by this BFN can be steered to any desired direction.     

一种双圆极化半球面相控阵天线的优化设计

针对全空域多目标通信的应用需求,设计了一种具有32阵元的双圆极化半球面相控阵天线。为满足低仰角目标通信需求,采用半球加圆柱的布阵方式,通过详细对比分析三种不同阵元排布方式下的天线性能,确定最优的布阵方式。仿真结果表明,该天线从0°~102.5°扫描过程中,天线增益大于13.3 dBi,增益波动小于2.5 dB。该相控阵天线能够适用于全空域多目标通信的场合。     

一种高隔离低交叉极化等相位中心双极化开槽天线设计

设计了一种高隔离度低交叉极化等相位中心双极化开槽天线,通过对馈电巴伦进行改进设计,解决了两个正交极化开槽天线交叉排布时相位中心不一致难题。由于双极化天线的辐射和馈电部分完全对称,该天线可获得良好的端口隔离度和低交叉极化特性。仿真结果表明,与常规双极化开槽天线相比,该双极化天线的交叉极化可改善20 dB,90%频带内的隔离度提高15 dB 以上,并且该双极化开槽天线在数倍频程带宽内具有良好的匹配和辐射特性,能实现大角度二维扫描,适用于未来宽带多极化相控阵天线系统。