圆口径测距天线时延测量方法

在测距系统中,天线时延初值的测量是很重要的。首先简述了信标塔法和无塔标校法测量圆口径天线时延的原理和方法。提出了利用矢量网络分析仪测量天线时延初值的一种简单方法。实践证明:该方法简单易行,在实际工程测量中,值得推广和应用。     

Phaseless Antenna Characterization by Effective Aperture Field and Data Representations

The problem of antenna characterization from phaseless near-field data is addressed by appropriate use of the available information on the Antenna Under Test (AUT) and on the scanning geometry to provide efficient representations for both the unknowns and the data. Such a strategy allows improving the reliability and the accuracy of the proposed characterization algorithm and, at the same time, shortens the overall measurement process.      

Development and Investigation of an Antenna System With Reconfigurable Aperture

The concept and results of investigation of a waveguide slot antenna with reconfigurable aperture is presented. Solutions are based on the utilized semiconductor material, which allows one to design the electronically reconfigurable antennas. The key element of the reconfigurable antenna is a surface PIN (SPIN) diode whose conductivity changes proportionally to the plasma density. SPIN structures can be activated selectively and cause, in turn, the generation of the desired shapes of radiation pattern. It allows one to extend the function possibilities of waveguide slot antennas compared with the conventional one.      

Novel Broadband Circularly Polarized Cavity-Backed Aperture Antenna With Traveling Wave Excitation

A novel broadband circularly polarized aperture antenna is presented that uses traveling-wave excitation as the design concept. The antenna configuration consists of a circular radiating aperture, a backed cavity, and an equiangular tapered strip outer-fed by a microstrip transmission line. Operating with a traveling wave excitation, the proposed antenna contains inherent broadband characteristics in terms of the impedance, axial ratio, and gain performances. The presented antenna is comprehensively investigated, including the working principles, design consideration, and parametric studies. In addition, the research interests are extended to a 2$,times,$ 2 antenna array. Promising results from the experimental 2$,times,$2 array are achieved, including the 10-dB return loss bandwidth of 70%, the 3-dB axial ratio bandwidth of 50%, and the half-power (3-dB) gain bandwidth of 40% with a maximum gain about 11 dBi. The measured and simulated results are well complied with each other.      

测试场地对大型圆口径天线增益测量影响的研究

本文运用近区功率方程导出了圆口径天线近区增益与测量距离的关系，计算了圆口径改进广义Ｔａｙｌｏｒ位移分布和指数型分布的近场增益误差修正的数值结果，阐述了消除地面反射误差的方法，并提出了在斜测试场中减少地面反射误差的一种简易方法。最后，给出了测试实例，从而验证了理论分析和计算的正确性。     

基于微带天线原理面天线设计的分析与仿真

介绍了应用在航空、航天、卫星和导弹上的面天线结构设计,根据微带天线原理,通过S11参数讨论面天线结构对天线尺寸大小、工作频带和辐射增益的影响,为实际设计天线提供理论数据.特别地讨论了脊形接地板高度(脊高)和基片长度对天线性能的影响,并对影响规律进行仿真对比.最后通过HFSS软件对其远近场仿真,仿真结果验证了基于微带天线设计原理设计的平面天线具有结构设计灵活,宽频带,实用性强等优点.     

口面天线无塔校相方法

单脉冲跟踪体制下测控设备需要进行校相,传统校相依赖于标校塔.针对这个局限性开展了无塔校相方法研究.从和差双通道角度跟踪原理出发,介绍了无塔校相研究的最新进展,总结了三种无塔校相方法以及各种方法的应用条件.试验证明了这些方法的可行性,并且有些方法已进入工程应用阶段.     

天线阵列编码合成孔径成像

合成孔径雷达(SAR)方位理论分辨率为天线长度的二分之一,使得SAR高分辨率、远距离成像对天线的要求相互矛盾。该文提出了对天线阵列编码的合成孔径成像方法,通过将长天线分解为子阵、发射不同的信号进行阵列编码、协同工作,提高空间能量利用率,实现子阵小天线的高分辨率以及全阵列长天线的高增益,从而解决了高分辨率与远距离成像难以同时兼顾的问题。在介绍阵列编码基本概念的基础上,给出了阵列编码雷达成像模型及处理流程,对系统的分辨率、信噪比、脉冲重复频率(PRF)及距离方位模糊等性能进行了理论分析与探讨。在飞行测试实验中,用4个子阵获取了方位分辨率优于0.1 m、幅宽超过8 km的连续条带图像,打破了传统SAR采用聚束模式实现高分辨率时只能小范围成像的制约,新方法为解决传统SAR的原理限制问题提供了有效的途径。同时,通过阵列编码扩展了信号维度,为雷达系统能力的增强提供了技术基础。理论分析及实验结果验证了该文天线阵列编码方法的显著优势及工程实现的可行性。     

用太阳源测量UHF频段50 m天线增益及误差分析

简述了利用太阳源测量天线增益的基本公式,讨论了各种修正因子的计算方法.当50 m天线工作于611 MHz时,测量的天线增益为47.754 dBi,天线效率为58.25%,且测量的天线增益同理论增益吻合很好.最后,对增益测量误差进行了分析,其均方根误差小于或等于±0.29 dB.     

Comparison of Antenna Measurement Facilities With the DTU-ESA 12 GHz Validation Standard Antenna Within the EU Antenna Centre of Excellence

The primary objective of many antenna measurement facilities is to provide a specified high accuracy of the measured data. The validation of an antenna measurement facility is the process of proving that such a specified accuracy can be achieved. Since this constitutes a very challenging task, antenna measurement accuracy has been the subject of much research over many years and a range of useful measures have been introduced. Facility comparisons, together with antenna standards, error budgets, facility accreditations, and measurement procedure standards, constitute an effective measure towards facility validations. This paper documents the results of a comparison between 8 European antenna measurement facilities with a specially designed reference antenna, the DTU-ESA 12 GHz Validation Standard Antenna (VAST-12). The electrical and mechanical properties of the VAST-12 antenna are presented and its three different coordinate systems are defined. The primary objective of the comparison is to obtain experience and results that can serve to develop standards for validation of antenna measurement facilities. The paper focuses on the comparison of the radiation pattern and presents not only the measurement data obtained at the facilities, but also investigates several procedures for comparing these data. This includes various definitions of pattern difference and statistical measures as well as a reference pattern. The comparison took place in 2004–2005 as part of the European Union network of excellence called ACE—Antenna Centre of Excellence.      

带罩天线的口径积分-表面积分分析技术的改进

研究了带罩天线电磁辐射特性分析的口径积分-表面积分法,在罩外表面电磁流积分过程中,引入Gordon公式将罩面单元上的均匀相位分布修正为更贴近实际的线性分布,通过具体算例对改进方法的有效性进行了验证,计算结果表明,改进方法显著提高了带罩天线辐射方向图的计算效率和精度。     

一种高频电大尺寸天线测试的新方法

文章提出一种简单可行的高频电大尺寸天线辐射测量新方法.该方法基于天线形面光学精密测量,将形面分为多个区域,每个区域带入实际光学测试采样点数据,采用电磁场数值计算得到天线的辐射方向图.光学测试系统提供了足够高的测试精度可以满足微波、毫米波甚至太赫兹等频段天线的测试要求.该方法还可以解决超大型可展开天线测试以及模拟星载环境实验条件下天线辐射测试难题.     

High Altitude Platform mm-Wave Aperture Antenna Steering Solutions

This paper compares the performance and complexity of two methods of steering an array of aperture antennas on a high altitude platform for the provision of broadband fixed wireless access using cellular type frequency reuse. The first method is to steer all antennas individually to maintain the boresight at the required cell centre. The paper also presents a second method of compensating for aperture antenna pointing error due to lateral and vertical displacement of the platform from the nominal station using only four actuators plus a gimbal that can correct for roll, pitch and yaw of the platform. Results for signal strength, CIR and handovers are given for both scenarios and conclusions drawn.Myles Capstick received his B.Sc and Ph.D degrees in Electronics from the University of Wales, Bangor, in 1987 and 1991, respectively. His current position is as a Senior Lecturer at the University of York and he has also been a Lecturer at the University of Wales in Bangor and at York. His research interests are centred in RF, microwave and mm-wave circuits and systems. More specifically, mm-wave and microwave filters, diplexers and planar array antennas and the design and modelling of broadband, multiband and compact antennas for MIMO communication. He has particular expertise in the area of EMC for RF and microwave circuits and systems, research that extends into the design of the dosimetry equipment for human exposure to EM fields used in human volunteer trials within the UK’s Human Health and Mobile Telecommunications Research programme. He has been an invited speaker at several conferences and seminars in the fields of mobile communications and EMC. He is a member of the IEE.David Grace received his M.Eng degree in Electronic Systems Engineering D.Phil degree from the University of York, UK in 1993 and 1999, respectively. His D.Phil thesis dealt with ‘Distributed Dynamic Channel Assignment for the Wireless Environment’. Since 1994 he has been a member of the Communications Research Group at York, where he is now a Research Fellow. He has worked on a variety of research contracts including several from the former Defence Evaluation and Research Agency. Current research interests include radio resource management for broadband communications, particularly from high-altitude platform and terrestrial ad hoc networks. He is now Principal Scientific Officer for CAPANINA a major European Framework 6 project that is developing broadband communications from high-altitude platforms. He has been an invited speaker at several conferences and industrial locations in the fields of HAP systems. He is also a nominated Researcher in the European NEWCOM Network of Excellence, and a Director of SkyLARC Technologies Ltd, a York based company, specialising in broadband communications from aerial platforms. He is a member of IEE and IEEE.     

一种电磁耦合馈电宽带宽角扫描微带天线阵列

文中提出一种可实现宽频带大角度波束扫描的低剖面相控阵微带贴片天线。为实现宽带特性,该阵列天线采用了缝隙电磁耦合馈电和双层贴片的设计。由于介质基板的堆叠,微带贴片阵列在高频大角度扫描时往往会受到表面波的影响,从而引发高次模谐振并带来扫描盲区。针对这一现象,通过对堆叠的介质基板开槽抑制表面波传播,从而改善高频的阻抗匹配特性。此外,还在贴片两侧加载寄生条带以优化低频阻抗匹配,拓展带宽并保持低剖面外形。该天线剖面高度仅4. 6 mm,约为高频波长的0. 19 倍,可满足许多低剖面载体平台的应用需求。仿真结果显示,该天线在±45°扫描和±60°扫描时可分别实现57. 9%(有源驻波比≤2. 25)和44. 4%(有源驻波比≤2. 75)的相对带宽。基于该设计加工了一款8×8 阵列样机。阵列样机的驻波及方向图测试结果与8×8 阵列的全波仿真结果吻合良好,有效验证了该微带贴片天线阵列的宽带和宽角扫描特性。     

一种缝隙耦合二元贴片天线的设计

设计并制作了一种移动载体上安装的方位面宽波束的二元微带天线阵,采用了缝隙耦合馈电的形式展宽带宽。为了提高增益而采用微带二元阵。通过调节贴片宽度、地板宽度,实现方位面的宽波束。并对其特性进行了仿真和测试。测试结果与仿真结果达到了较好的一致性,证明了设计方法的有效性。     

多天线组合孔径散射机理及隐身技术

多天线组合孔径是机载综合天线孔径的一种常见形式,散射机理复杂,隐身设计的难度较大,其散射分析与RCS减缩措施对实际工程应用有较大的意义.对多天线组合孔径的典型散射机理(包括镜面反射、两面角散射、腔体散射及棱边绕射等)作了简要分析,在此基础上提出了相应的隐身(RCS减缩)措施,并通过仿真及试验进行了验证.     

基于方向图乘积的阵列天线口径反演

介绍了一种利用近场测量系统进行阵列天线口径反演的新方法。该方法将近场测量系统采集的近场数据变换到平面波谱（PWS）,在平面波谱上进行天线单元因子补偿后运用口径场反演算法,重构出被测阵列天线口径面上各天线单元馈电端口的幅相分布。随后使用计算机模拟的方法在理想近场数据上加入单元通道误差,将乘积反演方法与传统插值反演方法在模拟结果上进行对比,随后分析了单元不一致给反演结果带来的影响,证明了该方法具有较高的反演精度,有效提高了阵列天线口径校正的效率。     

基于合成孔径阵列的雷达辐射源被动定位技术研究

本文引入被动合成孔径天线阵列新概念,将不同时间位于不同飞行位置的同一接收机视为合成孔径天线阵元,充分利用小型飞行器的空间运动特性及雷达脉冲信号的周期旋转特性,给出雷达辐射源信号虚拟到达时间差精确估计方法,并给出基于虚拟到达时间差的雷达辐射源被动定位方程构建方法及闭式求解算法,以实现雷达辐射源的快速可靠定位.计算机仿真验证了所提算法性能,并证明本文算法针对搜索警戒雷达等脉冲规律稳定的雷达辐射源具有较高的定位实用价值.     

A Low-Power Low-Cost Fully-Integrated 60-GHz Transceiver System With OOK Modulation and On-Board Antenna Assembly

A fully-integrated 60-GHz transceiver system with on-board antenna assembly is presented. Incorporating on-off keying (OOK) and low-cost antenna designs, this prototype demonstrates a low-power solution for multi-Gb/s wireless communication. The enhanced OOK modulator/demodulator obviates baseband and interface circuitry, revealing a compact solution. Two antenna structures, folded dipole and patch array, are employed to fully examine the performance. Designed and fabricated in 90-nm CMOS technology, the transmitter and the receiver consume 183 and 103 mW and occupy 0.43 and 0.68 ${hbox {mm}}^{2}$, respectively. With 4 $times$ 3 patch antenna array, the transceiver achieves error-free operation $({hbox{BER}}<10^{-12})$ for $2^{31}-1$ PRBS of 1 Gb/s over a distance of 60 cm.