K波段低副瓣波导缝隙驻波阵设计

本文设计了一种 K 频段低副瓣波导缝隙驻波阵天线,给出了实现低副瓣的方法。设计副瓣电平为-27dB,缝隙幅度分布按-30dB 泰勒分布计算,结合高频仿真软件 Ansoft HFSS 对各缝隙归一化导纳进行计算,建立仿真模型并优化天线各参数。依据设计结果加工实物并测试其方向图及增益。测试结果表明,该天线在工作频带内波束宽度约 3°,副瓣电平小于-27dB,工作频带内增益大于 30.8dB,仿真结果与实测结果相符,设计满足指标要求。     

A multielement high power monopulse feed with low sidelobe and high aperture efficiency

A multielement high power monopulse feed was investigated for excitation of a phased array. This feed has the advantages of high antenna efficiency, effective independent sidelobe control for the sum and difference patterns, and high power handling capability. A 32-element device has been designed which yields theoretical sidelobe levels less than -31 dB for both the sum and difference patterns over the 2800 to 3200 MHz frequency band. The aperture efficiency is 69.5 percent which includes 0.1 dB spillover loss and 1.40 dB tapering loss. The difference slope efficiency defined as the actual slope gain over the maximum possible value is 50 percent at midband. An experimental feed was constructed to verify the predicted performance characteristics. Measured data on both the radiation patterns and the antenna gain agreed very Well with the analytical results. The measured sidelobe level is below -30 dB for all sum and difference beams over the 2800 to 3200 MHz. In addition, this feed can be designed for low power intensity at the feed aperture so that very high power operation can be attained.     

一种具有双缝隙结构的双频宽带MIMO天线

设计一种双频宽带多输入多输出(MIMO)天线。天线采用微带线耦合馈电,在天线的表面开有圆环形缝隙,把宽缝隙和窄缝隙结合到一起,因此在辐射体上同时存在2种缝隙结构;天线采用双面结构,带宽范围为1.7~2.33 GHz和3.2~3.9 GHz,2个频带的带宽分别为630 MHz和700 MHz,可用于移动通信的DCS(1 710~1 880 MHz)、PCS(1 850~1 990 MHz)、UMTS(1 920~2 170 MHz)以及WIMAX(3.3~3.6 GHz)。天线在低频段的最大增益为3.6 dB,在高频段的最大增益为5.1 dB,隔离度在-20 dB以下,符合MIMO天线的设计需求。     

超高频RFID小型化读写器天线设计

提出了一款应用于超高频段(Ultra High Frequency,UHF)(912 ~935 MHz)的射频识别(RFID)读写器圆极化单层结构微带天线,基板采用FR4 板材达到价格低廉、辐射贴片采用开槽的结构实现小型化、接地板采用开槽结构提高天线的增益,该天线实现了小型化设计,满足了天线的设计要求。利用三维电磁仿真软件对天线模型进行了分析,仿真与测试结果吻合良好。天线测试结果表明:回波损耗小于-10 dB 的阻抗带宽为25 Hz(910 ~ 935 MHz),轴比(AR)小于3 dB的带宽为21 MHz(914 ~935 MHz);在UHF 频段内,读写器天线的最大增益为-1.2 dB,所以本天线能满足我国射频识别读写器的应用要求,具有良好的应用前景。     

Transreflector antenna design for millimeter-wave wireless links

A transreflector antenna is compact, like a Cassegrain reflector antenna, but it has the high efficiency and low sidelobe levels of a prime-focus reflector. We describe in detail how to design a transreflector antenna and its components, including the transreflector, the polarization twist-reflector, and the feed horn. As validation of our design methods, we have developed a 9.5-in transreflector antenna with a focal length of 3.2 in. We can operate the antenna at the Ka or V band, depending on whether we use a Ka- or V-band feed horn and twist-reflector. In both bands, the measured efficiency of the antenna exceeds 50%, the peak sidelobe level is below -17 dB, and the principal-plane cross-polarization rejection exceeds 33 dB. The input return loss is greater than 12.5 dB across each band of operation.     

一种空气同轴馈电的X波段低副瓣阵列天线

设计了一种应用于雷达系统中的低成本低副瓣阵列天线, 该天线阵包含256个辐射单元, 由四个64单元的子阵组成, 采用波导合成网络进行功率合成.天线单元采用空气同轴馈电的角锥喇叭, 空气同轴馈线内外导体呈方型结构, 其终端为短路馈电方式, 实现了内导体的自支撑设计和较低的传输损耗, 并依据综合幅度分布采用若干数量的不等功分器进行低副瓣设计.测试结果表明, 小于2的驻波带宽为0.5 GHz, 相对带宽为7.5%.另外, 中心频率的增益为30 dB, 增益大于29.5 dB的带宽为0.2 GHz, E面和H面的旁瓣电平为28.5 dB和29 dB.     

Dual polarised multibeam antenna

A dual polarised four-beam antenna array for the 1850-1990 MHz frequency band is presented. The polarisations are ±45° to vertical. The antenna has eight inputs corresponding to two orthogonal polarisations and four beams. The return loss and cross-polar isolation for a single Butler beam exceeds 15 and 22 dB, respectively. The radiation pattern is similar to an ideal Butler pattern and the cross-polarisation level is <-21 dB in the beams     

A novel lightweight dual-frequency dual-polarized sixteen-element stacked patch microstrip array antenna for soil-moisture and sea-surface-salinity missions

The main motivation for this paper is to discuss the development of a novel compact and light-weight dual-frequency, dual linearly polarized, high-efficiency, stacked-patch microstrip-array antenna for use in standalone aircraft-based remote sensing applications. Results from simulation, fabrication, and testing of a sixteen-element stacked-patch array antenna, optimized for an L-band frequency of operation, are presented. The design center frequencies were 1.26 GHz and 1.413 GHz with 10 MHz and 25 MHz bandwidths in each band, respectively. Due to the large number of design parameters and demanding design requirements of beam-efficiency, sidelobe levels, and polarization characteristics, particle-swarm optimization (PSO) and finite-difference time-domain (FDTD) simulations were used for synthesis and analysis. Cancellation techniques, based on symmetry, were applied to the antenna ports, with a custom-built feed network to reduce cross polarization. Simulations and measurement results from a spherical near-field test facility confirmed excellent performance of the array configuration, with a beam efficiency of greater than 90%, isolation better than -35 dB, and cross polarization in the main beam of the array better than -40 dB. From the sixteen-element array simulations and experimental verifications, one of the objectives of the present study is to suggest the possibility of using customized dual-frequency, dual-polarized arrays as potential feeds for reflectors to replace the traditionally used conical horns for future soil-moisture and sea-salinity missions     

一种波导窄边裂缝天线缝隙倾角的改进方法

为减小波导窄边裂缝天线缝隙间互耦对天线性能的影响, 实现低副瓣的设计, 提出了一种倾角波动分布的设计方法.天线电流分布选用泰勒分布, 利用HFSS软件确定缝隙倾角初值, 在此基础上得到波动分布的倾斜角度, 并通过遗传算法对缝隙倾角进行优化.使用Matlab与HFSS软件联合仿真, 省略了建模、设置参数等大量操作, 提高了设计效率.基于此, 设计了一款长度为1.2 m的X波段波导窄边裂缝天线, 仿真发现副瓣电平比传统设计方法低2.17 dB, 加工了天线实物并进行了测试, 天线实测增益和副瓣电平分别为20.9 dBi和-28.7 dB, 验证了方法的有效性.     

基于波导缝隙阵列的新型太赫兹频率扫描天线

为缩短太赫兹系统成像时间,该文提出将频率扫描天线应用于太赫兹成像系统中,并设计了一种基于波导缝隙阵列的太赫兹频率扫描天线。该文采用泰勒综合法降低副瓣电平,通过软件仿真结合功率传输法设计最优的缝隙分布。太赫兹波导缝隙阵列天线具有加工简单、成本低的优势,通过太赫兹准光测试系统对天线性能进行测试,实测天线扫描角度可达40°,增益约为15 dB,副瓣电平抑制优于–20 dB。测试结果表明太赫兹波导缝隙天线具有扫描角度大和副瓣低的优良特性,在太赫兹成像和目标探测等领域有巨大的应用价值。      

Beam steerable square loop antenna over hybrid high impedance surface

A novel hybrid high impedance surface is presented and a beam steerable four feed square loop antenna is built on this structure. At a test frequency of 4.7 GHz, the proposed hybrid high impedance surface based square loop antenna is 4.69 mm high and has an impedance bandwidth of 650 MHz and directivity of 8.7 dBi. Compared with the earlier reported steerable square loop antenna the new antenna s performance equates to a thickness reduction of 61, bandwidth enhancement of 150 , a directivity improvement of 2 dBi, a co-polar sidelobe reduction of 11 dB, and a cross-polarisation sidelobe reduction of 5 dB.     

DESIGN OF A SHAPED BEAM BASE STATION ANTENNA USING GENETIC ALGORITHM

Genetic algorithm is used to optimize a base station antenna in order to achieve ashaped beam in a frequency band. During the optimization process5 different antenna models havebeen evaluated using the Method of Moment (MoM). As a result of this optimization, a shapedbeam antenna with suppressed sidelobe smaller than-18dB, backlobe smaller than-30dB and     

基于HPSO的波束扫描反射阵天线设计

提出一种基于混合粒子群算法(HPSO)的低旁瓣波束扫描反射阵天线设计方法。在该方法中,首先利用天线实际方向图和渐变的理想方向图构建了加权的适应度函数。然后通过优化口径面相位分布搜索适应度函数的最小值,最终达到降低旁瓣的目的。同时,设计并制作了一副中心频率为12GHz 的圆极化波束扫描反射阵天线。实测结果与仿真结果较为吻合,天线在56°扫描范围内,旁瓣电平均小于-15dB,且带宽达到11. 67%。     

用遗传算法综合波束赋形基站天线

本文利用遗传算法对不等间距阵列天线进行优化,实现了一种赋形波束基站天线。天线模型用矩量法分析,并采用遗传算法综合天线方向图.在优化过程中通过合适的目标函数,保证了天线较好的频段特性,并压制干扰区副瓣、填充服务区零值、控制后瓣。优化后天线在整个工作频段上实际性能为:上副瓣小于－18.32dB,填充零点大于－14.71dB,前后比小于－26dB.与以前的方法相比,本文的结果更接近实际情况,并且该方法可应用于较复杂的天线.本文中的结果对工程和理论研究都有重要意义.     

Conformal four-beam antenna arrays with reduced sidelobes

Investigations on sidelobe reduction in multibeam conformal antenna arrays are presented. The recently presented concept of sidelobe reduction in planar multibeam antenna arrays in conjunction with the phase compensation technique has been applied for the design of reduced sidelobe multibeam conformal antenna arrays. Six- and eight-element antenna arrays fed by modified Butler matrices have been investigated and minimum radii have been found for which the sidelobe level is comparable to the respective planar multibeam arrays. A novel fully integrated six-element four-beam antenna array has been successfully designed in which sidelobes equal -14 dB for all four beams have been achieved.     

Equivalent circuit model-based design and analysis of microstrip line fed electrically small patch antenna for sub-6 GHz 5G applications

In this paper, an equivalent circuit model-based electrically small patch antenna is designed for sub-6 GHz 5G application (3.5 GHz) using 50-Ω microstrip line feed. The overall size of the proposed antenna is 0.33λ₀ × 0.4λ₀ × 0.019λ₀ (28 × 34 × 1.6 mm³) at 3.50 GHz frequency. The proposed antenna has a tilted Y-shape slot, two rectangular shape slots, and two rectangular shape notches in the radiating patch. The proposed antenna is resonating from 3.21 to 3.74 GHz covering the entire sub-6 GHz 5G band (3.3–3.8 GHz). The impedance bandwidth (simulated) of the proposed antenna has been obtained 530 MHz resonating at 3.50 GHz frequency. The good return loss of −23.62 dB is also obtained at 3.50 GHz resonant frequency. The simulation results and geometry of the proposed antenna are validated with equivalent circuit model and experimental measurement of prototype antenna using vector network analyzer (VNA) and anechoic chamber. In the whole operating frequency range, the measured findings show reasonable agreement with the simulated ones. The measured impedance bandwidth of the proposed antenna has been obtained 480 MHz (3.21–3.69 GHz) resonating at 3.48 GHz frequency with a return loss of −21.61 dB, while the theoretical impedance bandwidth of the proposed antenna has been obtained 720 MHz (3.18–3.90 GHz) resonating at 3.58 GHz frequency with a return loss of −21.5 dB. The peak gain of 3.39 (simulated) and 3.2 dB (measured) is obtained at 3.50 GHz frequency. Moreover, the antenna shows 97% (simulated) and 95% (measured) efficiency at 3.50 GHz frequency.     

W波段双极化单脉冲天线设计

为了探测目标的极化特性,研制了工作在W波段的双极化单脉冲卡塞格伦天线.天线由主反射面、副反射面、馈源喇叭、正交模耦合器及和差器组成.天线主反射面口径为137 mm,馈源为五喇叭形式,正交模耦合器采用渐变波导匹配方案,和差器通过平面型定向耦合结构实现.通过将馈源喇叭、正交模耦合器及和差器集成设计,减小了连接损耗,压缩了天线纵向尺寸.测试结果表明,天线驻波带宽约3. 7 GHz,极化隔离度优于35 dB,和波束增益大于37. 9 dBi,副瓣电平优于-15 dB,差波束零深优于-25 dB.天线在W波段实现了较好地双极化单脉冲性能.     

Broadband sub-6 GHz flower-shaped MIMO antenna with high isolation using theory of characteristic mode analysis (TCMA) for 5G NR bands and WLAN applications

A small size neutralization line integrated flower-shaped MIMO antenna is designed and analyzed for sub-6 GHz type 5G NR frequency bands like n79 (4400–5000 MHz), n78 (3300–3800 MHz), n77 (3300–4200 MHz), and WLAN (5150–5825 MHz) applications. The novel approach of theory of characteristic mode analysis (TCMA) is introduced to provide physical insight of the designed structure and its characteristics behavior. Due to the suggested modifications in the geometry, the isolation among the patches is greatly increased. The overall miniaturized dimension of the MIMO antenna is 25 × 40 mm². The edge-edge spacing among the elements is 0.0233λ. The prototype antenna is fabricated and measured that shows good agreement compared with simulated results. The designed MIMO antenna without the presence of decoupling structure offers an isolation of 28 dB, gain of 3.6 dBi, and radiation efficiency of 69.7% at the resonant frequency. The proposed MIMO antenna covers a broad range of frequency band from 3.296 to 5.962 GHz with −10 dB impedance bandwidth of 2666 MHz and maintains a good isolation of greater than 50 dB for the entire operating band. The tested radiation efficiency and gain are 85.3% and 6.22 dBi at 3.5 GHz. Moreover, the diversity parameters of the neutralization line integrated MIMO antenna, that is, channel capacity loss (CCL) isolation, mean effective gain (MEG), total active reflection coefficient (TARC) diversity gain (DG), and envelope correlation coefficient (ECC), are analyzed and discussed in this article.     

频率方向图复合可重构寄生单极子天线阵列

提出了一种能应用于无线通讯系统的新型介质支撑开关寄生阵列天线.基于八木天线原理,天线可以实现频率及方向图的复合可重构.所引入的开关用来切换不同状态的工作频率并实现方向图的扫描.地支结构用来改善天线的阻抗匹配并展宽频带.测量结果表明:天线阵列可以在保证回波损耗小于-10 dB的情况下完全覆盖1710～1880 MHz、1...     

Compact broadband stacked implantable antenna for biotelemetry with medical devices

A compact stacked implantable antenna for biotelemetry in medical implant communication services band (MICS band: 402-405 MHz) is proposed. Using a stacked planar inverted-F antenna (PIFA) structure can enhance bandwidth and reduce the effect of frequency shift in human tissue giving complex and highly variable characteristics. The antenna looks like one dime (US currency) and has a 7.5 mm radius, 1.9 mm thickness, operating frequency at 402 MHz and a bandwidth of 50 MHz at return loss of 10 dB. A miniature, broadband stacked implantable antenna for biotelemetry with medical devices is provided