便携设备中带陷蝶形UWB天线的设计

提出了一种应用于便携设备中具有带陷特性的平面蝶形UWB天线.该天线采用蝶形贴片作为辐射单元,并由渐变线作为阻抗变换器与50 Ω馈线进行匹配.通过在辐射面上挖C形槽实现带陷功能,并给出仿真和实测结果.该天线的工作频带覆盖3.1～10.6 GHz,并有效避免了5.15～5.825 GHz的无线局域网(WLAN)频段,适于便...     

Bow-tie slot antenna fed by CPW

A bow-tie slot antenna fed by CPW is introduced. It is designed to work in the Ku-band around 15.5 GHz. The proposed antenna is analysed both theoretically and experimentally. The presented results include the return loss and the radiation patterns. Two different geometries of the bow-tie antenna are presented and compared. The proposed antenna has several advantages such as a very large bandwidth, good control of its input impedance, and ease of fabrication. The proposed antenna has a dipole like radiation pattern which makes it suitable for mobile communication systems designed to work in the Ku-band     

一种工作于UHF频段的宽频带互补天线设计

本文应用互补天线的原理,通过采用蝶形平面天线作为电偶极子,采用垂直壁与接地面作为等效磁偶极子,设计了一种新颖的蝶形宽频带天线.该天线实现了62%的相对带宽(1.52-2.89GHz,S11<-10dB),在工作频段内具有稳定的波瓣图,优于-30dB的交叉极化和超过18dB的前后比.     

Genetic algorithm based inversion of neural networks applied to optimised design of UWB planar antennas

An inversion of artificial neural networks using a genetic algorithm is presented for a novel concept of optimisation applied to UWB planar antennas of bow-tie type with respect to specified values of antenna performance in the frequency range 3.1-10.6 GHz. This efficient concept is shown to achieve significant reduction in computing time for optimisation. The multidimensional inversion is characterised by a simple composite fitness or target function that includes antenna parameters as a function of signal frequency or/and angle dependence. Good impedance matching and gain performance is achieved over the whole frequency range by adequately modifying the radiating contour profile of the conventional triangular bow-tie antenna.     

Far-infrared embedding impedance measurements

A technique which allows the measurement of detector embedding impedance has been developed. By using a bismuth microbolometer as a variable resistance load the impedance of one element in a bow-tie antenna array operating at 94GHz was inferred. The technique is frequency insensitive, and could be used throughout the far-infrared.     

Measurement of integrated tuning elements for SIS mixes with a Fourier transform spectrometer

Planar lithographed quasioptical mixers can profit from the use of integrated tuning elements to improve the coupling between the antenna and the SIS mixer junctions. We have used a Fourier transform spectrometer with an Hg-arc lamp source as an RF sweeper to measure the frequency response of such integrated tuning elements. The SIS junction connected to the tuning element served as the direct detector for the spectrometer. This relatively quick, easy experiment can give enough information over a broad range of millimeter and submillimeter wavelengths to test both design concepts and success in fabrication. One type of tuning element, an inductive wire connected in parallel with a series array of 5 SIS junctions across the terminals of a bow-tie antenna, shows a resonant response peak at 100 GHz with a 30% bandwidth. This result is in excellent agreement with theoretical calculations based on a simple L-C circuit. It also agrees very well with the RF frequency dependence of the mixer gain measured using the same structure. The other type of tuning element, an open-circuited stub connected in parallel with a single SIS junction across the terminals of a bow-tie antenna, exhibits multiple resonances at 110, 220, and 336 GHz, with bandwidths of 9–15 GHz. This result is in good agreement with theoretical calculations based on an open-circuited stub with small loss and small dispersion. The position and the bandwidth of the resonance at 110 GHz also agrees with the RF frequency dependence of the mixer gain measured using similar structures.     

小型化宽带蝶形微带天线的设计与仿真

传统形式上的微带贴片天线虽具有体积小、重量轻的特点,但窄带特性却制约了其工程应用的范围。在对曲边蝶形天线结构和特性理论分析的基础上,使用Ansoft公司的HFSS三维电磁场软件对其进行建模仿真,最终优化得出了在0.8～3.0GHz宽频带范围内都具有良好的辐射特性,且在工作带宽内VSWR<1.5的曲边蝶形微带天线,在小型化的基础上实现了微带天线的宽频带特性。     

一种基于AFSS的可重构天线设计

针对5G智能天线双频工作,提出一种基于有源频率选择表面（active frequency selective surface, AFSS）的可重构天线,该天线由蝶形频率可重构馈源和八棱柱形AFSS构成,馈源采用的是共面波导方式馈电的蝶形单极子. AFSS由对称弯钩状缝隙的周期结构构成,通过PIN二极管进行加载,使得AFSS能够在3.4～3.6 GHz和4.8～5.0 GHz两个5G频段互为反射模式和透射模式. 利用AFSS对馈源天线激励的电磁波进行空间调控,可实现两个频段的全向和定向波束的切换,也可实现水平面波束扫描. 根据仿真设计的天线模型进行设计加工和实际测试,结果表明:该天线的工作频段可以覆盖以上两个频段,低频定向波束增益为7.6 dBi,高频定向波束增益为8.6 dBi;并且能实现高/低频双波段切换、全向/定向波束切换和水平面内360°波束扫描功能. 该天线具有波束切换灵活、功耗低、造价低等特点,在新一代无线通信系统中具有一定的应用价值.     

Modeling of a quasi-optical Josephson oscillator

The authors have developed a computer model of a Josephson tunnel junction embedded in a general circuit with frequency-dependent impedance using the harmonic balance method. This model has been applied to the analysis of a two-dimensional Josephson junction array with integrated coupling structures, called a quasi-optical Josephson oscillator. Simulations are done for a junction with dipole, slotline, and bow-tie antennas. The results show that the junction with a bow-tie antenna gives the best performance, and the output power from an array of 4000 junctions can reach 25.7 μW at a frequency as high as 1091 GHz for niobium junctions deposited on a 0.207-mm-thick quartz substrate     

Bow-tie antennas on a dielectric half-space: Theory and experiment

A new formulation is discussed for the rigorous calculation of the radiation pattern of a bow-tie antenna of finite length and infinitesimal thickness, placed on a lossless dielectric substrate. The analysis is based on a representation of the current density on the metal surface of the antenna as a sum of an imposed (quasistatic) term and a set of current modes with unknown amplitudes. Free-space fields that are expressed in terms of continuous spectra of symmetrized plane waves are matched to the current modes using the method of moments. The resulting set of equations are solved for the unknown current amplitudes. The calculations show that for increasing bow length the antenna impedance spirals rapidly to a value predicted by transmission line theory. The theory also shows that theE-plane pattern of a two wavelength,60degbow-tie antenna is dominated by low-loss current modes propagating at the dielectric wavenumber. As the bow tie narrows, the loss of the modes increases, and the dominant wavenumber tends to the quasistatic value. Pattern measurements made at 94 GHz are shown to agree well with theoretical predictions. Measurements for a long-wire antenna, a linear array of bow-tie elements, and a log-periodic antenna are also presented.     

CPW馈电缝隙耦合蝶形毫米波贴片天线

该文研究了一种工作在Ka波段共面波导(CPW)馈电缝隙耦合的蝶形贴片天线。耦合缝隙位于接地板上,而不需要额外的缝隙耦合层,使天线更易与电路相集成。耦合缝隙的存在改变了接地板上原有表面电流的分布,使电流沿着缝隙边缘流动,因此馈线与辐射源的电磁耦合效率得到提高。用有限元分析软件(Ansoft HFSS)对衬底厚度、贴片角度、耦合缝隙大小等参数变化时的天线性能进行了仿真。比较并分析了S11,增益等天线性能参数的变化规律,并在带宽最优的条件下给出了一组参数值,此时天线的工作频率为35.5GHz,带宽为1.22GHz,增益为6.38dB。     

模拟分析具有表面等离子体效应的纳米光学天线及其阵列

基于时域有限差分方法,模拟分析了位于介质材料上的杆形和蝴蝶结形两种金纳米天线及杆形天线阵列.结果表明天线近场光斑直径约可以达到波长的1/11,蝴蝶结形天线的光斑强度可以比入射光场增强91倍.杆形天线阵列仍可以实现这种增强效应.蝴蝶结形天线中光场增强最高可以达到28000倍,而且局域化的光场町以耦合到天线臂上的纳米颗粒.     

A Wideband Slotted Bow-Tie Antenna With Reconfigurable CPW-to-Slotline Transition for Pattern Diversity

We propose a slotted bow-tie antenna with pattern reconfigurability. The antenna consists of a coplanar waveguide (CPW) input, a pair of reconfigurable CPW-to-slotline transitions, a pair of Vivaldi-shaped radiating tapered slots, and four PIN diodes for reconfigurability. With suitable arrangement of the bias network, the proposed antenna demonstrates reconfigurable radiation patterns in the frequency range from 3.5 to 6.5 GHz in three states: a broadside radiation with fairly omnidirectional pattern and two end-fire radiations whose main beams are directed to exactly opposite directions. The proposed antenna is investigated comprehensively with the help of the radiation patterns in the two principal cuts and also the antenna gain responses versus frequencies. The simulation and measurement results reveal fairly good agreement and hence sustain the reconfigurability of the proposed design.     

探地雷达超宽带背腔蝶形天线设计与实现

设计实现了一种中心频率为400 MHz的吸波材料填充式背腔蝶形天线,并将此天线应用于超宽带探地雷达系统,组装完成了一套400 MHz无线控制探地雷达系统样机。背腔式设计的探地雷达收发天线可以克服传统蝶形天线在H面全向辐射所带来的缺点,从而提高雷达系统的信噪比及收发天线之间的隔离度。对背腔蝶形天线的设计进行了规律性研究,总结了吸波材料填充式背腔蝶形天线系统在工程化实现时的设计经验。实际路测数据验证了所设计背腔天线在此套探地雷达系统中性能表现稳定良好。     

Coplanar waveguide-fed uniplanar bow-tie antenna

The design of coplanar waveguide (CPW)-fed bow-tie antenna for the 2.4-GHz ISM band is described. A coplanar waveguide-to-coplanar strips (CPW-to-CPS) balun is used to obtain the balanced feed line for the printed bow-tie. An analysis method based on the mixed potential integral equation method is used to characterize the input characteristics of the bow-tie antenna. The numerical results obtained are in good agreement with the experimental data. Through experiments with bow-tie antennas of various extended angles, the bow-tie antenna with a 90° extended angle exhibits the widest bandwidth in the desired frequency band which has a bandwidth of 17% for a VSWR <1.5:1     

Millimeter wave monolithic schottky diode imaging arrays

Planar Schottky diodes are integrated with bow-tie antennas to form a one-dimensional array. The energy is focused onto the antennas through a silicon lens placed on the back of the gallium-arsenide substrate. A polystyrene cap on the silicon lens reduces the reflection loss. A self-aligning process with proton isolation has been developed to make the planar Schottky diodes with a 1.1-THz zero-bias cutoff frequency. The antenna coupling efficiency and imaging properties of the system are studied by video detection measurements at 94 GHz. As a heterodyne receiver, a double-sideband mixer conversion loss of 11.2 dB and noise temperature of 3770°K have been achieved at a local oscillator frequency of 91 GHz. Of this loss, 6.2 dB is attributed to the optical system and the antenna.     

一种低剖面紧耦合超宽带天线设计

设计一种新型紧耦合天线阵列(TCA).该阵列单元采用平面蝶形偶极子,利用单元之间的耦合效应以达到展宽天线频带的效果.通过在天线阵列与导体接地板之间加载阻性频率选择表面(RFSS)来抑制导体接地板对天线造成的短路点,进一步增加阻抗匹配带宽.本文设计寄生层以代替传统的介质板宽角匹配层,大大降低天线的剖面高度及质量,改善阵列...     

Analysis and design of broadside-coupled striplines-fed bow-tieantennas

The design of a bow-tie antenna fed by broadside-coupled striplines (BCS) for the 2.4-GHz ISM band is described. The two fins of the bow tie are, respectively, on the two sides of the substrate. The feeding balanced lines adopted are the BCS. A quarter-wave transformer is used to transform the microstrip line input to the BCS feed. An analysis method based on the mixed-potential integral equation method is used to characterize the input characteristics of the bow-tie antenna. The numerical results obtained are in good agreement with the experimental data. Through experiments with bow-tie antennas of various extended angles, the bow-tie antenna with a 90° extended angle exhibits the widest bandwidth in the desired frequency band, which has a bandwidth of 19% for a VSWR<1.5:1     

一种基于新型组合加载方式的大频差三频段蝶形天线

将分形技术和槽加载技术相结合,文中提出了一种基于新型组合加载方式的大频差三频段蝶形天线,其加载方式为开口圆环缝隙和寄生分形多三角形结构(TSFPE)的组合加载。新型天线可同时工作于X/ Ku/ Ka 三个频段,其中,蝶形天线两三角形臂控制X 频段,加载于三角形臂上的开口圆环缝隙和位于蝶形天线三角形臂顶点位置附近的TSFPE 分别控制Ku 和Ka 频段。新型组合加载方式充分合理地利用了天线各部分的空间,减小了各频段之间的互相影响,确保了每个频段的性能。验证了新型组合加载方式的可行性,丰富了多频天线的结构形式和种类。     

Slot-loaded bow-tie microstrip antenna for dual-frequency operation

By loading a pair of narrow slots close to the radiating edges of a bow-tie microstrip antenna, dual-frequency operation can be obtained using a single probe feed. Various frequency ratios, within the range 2.0-3.0, of the two operating frequencies can be obtained by varying the flare angle of the bow-tie patch. Details of the antenna design and experimental results are presented and discussed