基于液晶聚合物的双陷波可穿戴天线的设计

基于超薄液晶聚合物柔性材料,设计了一种满足无线体域网(WBAN)需求的双陷波UWB可穿戴天线。该天线由椭圆形贴片、锥形三叉戟共面馈线和梯形地板组成。通过分别在辐射贴片上蚀刻椭圆开口谐振环和在共面馈线上蚀刻n形槽以实现双陷波特性。该天线采用共面波导的馈电方式,具有良好的共面性,易于与载体共形。经网络矢量分析仪测试结果表明,该天线在3. 1~10. 6 GHz的超宽带频段内回波损耗小于-10 d B的同时,在4. 88~6. 15 GHz和7. 55~8. 51 GHz内拥有双陷波特性,可抑制WiMAX和ITU 8 GHz频段对系统产生的干扰。与以往的可穿戴天线相比,该天线厚度仅为0. 1 mm,且柔性可弯曲。此外,对天线在弯曲情况下进行测试,天线特性基本保持不变。     

一种小型宽带双极化5G基站天线

设计了一种适用于2G/3G/4G/5G移动通信的小型宽带±45°双极化基站天线。该天线由2对偶极子辐射片、2条微带馈线和1块反射板组成,辐射臂和微带馈线采用双面印刷工艺印刷在0.8 mm厚的FR4板,并固定放置于开有圆形槽的反射板上。对天线实物进行加工测试,测试结果表明,端口1工作频段为1.82～3.60 GHz,端口2工作频段为1.64～3.41 GHz;工作频段内,反射系数小于-10 dB,端口隔离度优于18 dB;交叉极化比在视轴方向大于17 dB,±60°方向大于15 dB;半功率波束65°左右,前后比优于18 dB,测试和仿真结果较吻合。所设计天线带宽宽,尺寸小,且制作工艺简单,成本低廉,适合批量生产,应用于5G移动通信基站中。     

新型强耦合宽带双圆极化阵列天线

空间飞行器由于受到动力和负载的限制, 需要尽可能使搭载的天线轻质小型化.文中提出了一种新型强耦合双圆极化轻质天线.天线单元采用H型缝隙耦合和增加寄生贴片方法, 提高了天线带宽.同时, 通过在辐射贴片、寄生贴片上开圆形槽, 以及金属反射板栅格化的处理, 明显地减轻了天线的质量.采用这种新型天线单元, 设计了8单元的宽带双圆极化阵列天线.仿真结果表明:该阵列天线的中心频率为433 MHz, 左旋和右旋圆极化的相对轴比(Axial Ratio, AR)带宽(AR < 3 dB)分别达到了24.4%和23.2%, 有效实现了小型轻质化宽频带双圆极化阵列天线.     

螺旋天线的快速分析及宽带化设计

研究了一种快速计算螺旋天线电特性的新方法,并结合遗传算法对天线进行了宽带、小型化设计。采用直线段对法向模螺旋天线进行划分,应用合成基函数及合成检验函数的矩量法对阻抗矩阵进行了降阶处理,节省了求解矩阵方程所需的时间和存储量。结合遗传算法对加载法向模螺旋天线上的加载集总元件的值、加载位置以及匹配网络参数进行一体化优化设计,并采用Sherman-Morrison-Woodbury公式快速求解加载后的矩阵方程,提高了优化设计的效率。最后,成功设计了一副工作在100～1000MHz的宽带小型化螺旋天线。     

一种应用于三频GPS的宽频带单馈电天线设计

为了实现全球定位系统（global positioning system,GPS）天线小型化并提高其性能,提出了一种新型的三频段GPS宽频带单馈电背腔天线,可在1176.45 MHz（L5）、1227.60 MHz（L2）和1575.42 MHz（L1）三个GPS频段下工作。通过在一端馈送交叉型行波天线并在另一端添加负载,来实现提出天线的右旋圆极化（right-hand circular polarization,RHCP）,且配有弯折线散热器。天线尺寸仅为120×120×29 mm3。仿真和实际测量结果显示,提出的单馈电天线无需使用复杂的馈电网络或双馈结构便可提供宽阻抗带宽（VSWR<2）、低轴比（AR）（<2 dB）和高RHCP增益（>4 dBic）。     

一种宽频带微带天线的设计

介绍了宽频带渐变式微带缝隙天线的工作原理、设计参数及其对电性能的影响，设计了一种结构简单的天线形式，给出了该天线工作于S、C频段的结构尺寸以及VSWR、辐射方向图的仿真和测试数据曲线，两者之间有很好的一致性，并对影响天线性能的关键参数进行了误差计算。结果表明：在加工精度可达到的范围内，对天线性能的影响不大。该天线可应用于宽频带单极化、双极化阵列天线单元或反射面天线馈源。     

Gain improvement of planar-printed broadband end-fire antenna

A broadband high-gain planar-printed end-fire antenna is presented for microwave imaging application. The proposed antenna consists of a conventional Vivaldi antenna (CVA) with slot edges (SEs) and a planar phase compensation lens (PCL). Taking into account the actual phase error along E-plane direction at antenna aperture, a more precise and detailed analysis for the printed antenna with PCL is carried out. The PCL with specific layout of rectangular patches is utilised to enhance antenna gain especially at high frequencies, while the SE technique is employed to further improve directivity at low frequencies. The final design combining PCL and SE develops an expected high-flat-gain Vivaldi antenna over the entire operating range. The CVA and the proposed antenna are fabricated and measured. The measured results agree with the simulated ones well. The proposed antenna provides a high gain of 10–11.7 dBi in the range, which corresponds to a gain increase of 0.9–3.2 dBi compared to the CVA.     

A miniaturized broadband bow-tie antenna with improved cross-polarization performance

In this paper, a modified broadband bow-tie antenna with low cross-polarization level and miniaturization is presented. The cross-polarization in both E- and H-planes are suppressed by defecting the antenna flares using rectangular slots. The proposed modified antenna demonstrated a cross-polarization improvement over $\pm 120°$ around the boresight from 2 to 5 GHz. In addition, an overall 23.5% of miniaturization compared to conventional bow-tie antenna is achieved. A tapered feed transition between microstrip-to-parallel stripline is designed to match 50 ohm SMA connector to the antenna flares. A prototype of the modified antenna is fabricated on RO4003 substrate ($\epsilon$_r = 3.38, tan $\delta$ = 0.0027, h = 0.813 mm), and its performance is experimentally studied. The antenna’s characteristics including return loss, gain and radiation pattern are measured, along with the time domain characteristics, and showed reasonable agreement with the simulated results.     

A novel broadband circularly polarised monopole antenna

A novel broadband circularly polarised (CP) monopole antenna is designed and implemented in this article. The antenna consists of a radiating patch that is composed of an annular-ring linked by a square ring over the corner and a modified ground plane. The broadband property is achieved based on a novel monopole structure that is connected by two perturbed loops, so the CP wave is generated due to the perturbation. Besides, by cutting a rectangular slit and embedding a vertical stub on the ground plane, the impedance and axial-ratio (AR) bandwidths can be greatly enhanced. The measured results reveal that the proposed monopole antenna has an impedance bandwidth of 4.575 GHz from 2.3 to 6.85 GHz, reaching the particularly broad bandwidth of 99.5%. Furthermore, a wide 3-dB AR bandwidth of 34.6% (1.53 GHz, 3.65–5.18 GHz) centred at 4.42 GHz is achieved. The radiation characteristics of the designed antenna are also presented.     

一种新型圆极化法向模反转螺旋天线

针对于传统圆极化法向模螺旋天线输入阻抗低、增益小等问题,设计了一种新型反转结构的螺旋天线。该天线采用了反转结构,即在电流反向点处使螺旋物理结构反向,实现天线辐射能力增强,提高天线在工作频率处的辐射电阻,增大阻抗带宽和增益。研究结果显示,一次反转螺旋天线仿真增益达2.45 dBi;两次反转螺旋天线加上巴伦后仿真增益达2.72 dBi,仿真阻抗带宽为2.9%,相应测试结果分别为2.5 dBi和2.8%。需要指出的是,随着反转次数的增多,天线的辐射电阻和增益可以进一步提高,因此可根据不同的设计需求选择不同反转次数。另外,采用3D打印技术加工螺旋,可以有效降低天线加工难度。     

Optimized matching liquid with wide-slot antenna for microwave breast imaging

In this paper, we introduce an optimized matching liquid together with a wide-slot ultra-wideband antenna to be used in a breast microwave imaging system. The slot antenna is small with 13 mm × 14 mm × 0.625 mm dimensions so that many of them can be placed around a breast. The matching liquid is needed to effectively couple the microwave signal into breast tissues. Exhibiting a suitable permittivity and moderate loss, the matching liquid is a mixture of 83% sunflower oil with 17% distilled water. We build a phantom in order to investigate the penetration of microwave signal into the breast tissues. Experimental measurements and simulation results indicate that this matching liquid provides, nearly, the maximum scattering power from inside of breast tissues in interval [2.5, 7 GHz] that is an appropriate frequency range for breast imaging.     

一种宽频带双极化印刷偶极子基站天线

设计并优化了一款适用于LTE天线系统的基站天线振子单元。在印刷偶极子天线以及微带巴伦的基础上,通过等效电路模型进行分析,设计出该天线的多级阻抗匹配巴伦。采用寄生贴片、领结型设计等技术,有效地拓展了天线频带带宽,实现了±45°双极化。仿真结果表明,天线的VSWR≤1.5和回波损耗大于15 d B的带宽达到了54.5%,可以覆盖GSM1800,CDMA2000,WCDMA,TD-SCDMA和LTE系统。在此频带范围内,该天线的驻波特性、方向性、增益和隔离度等指标均满足LTE多模式系统的指标。同时该天线也易于制作,适用于LTE多模式基站天线系统。     

新型带扇形馈源的宽带缝隙天线

介绍了一种新型的采用扇形微带馈源的宽带缝隙天线,给出了反射损失曲线和辐射方向图。该天线采用稍高的相对介电常数（εr=4．3）和薄基片（h=1．1mm）,获得了约106％的阻抗带宽（S11≤-10dB）,频率范围是1．65GHz～5．38GHz。采用电磁仿真软件Ansoft HFSS8．0^TM对几个天线尺寸的影响进行了仿真与讨论,并与文献[6]的结果相比较,验证了设计的有效性,同时也证明了结果的可靠性。     

一种新型超短波宽带天线

介绍了一种新型的超短波宽带双鞭天线.根据经验确立了天线的结构,利用三维电磁场仿真软件HFSS对该天线进行了理论分析,并根据实测天线的输入阻抗,设计出合适的匹配网络.理论计算值与实验测试结果较好地吻合,结果表明该双鞭天线的阻抗带宽,增益,方向图都达到设计要求.     

Study on a novel ellipsoidal helical antenna

A novel ellipsoidal helical antenna is proposed and studied in this letter. As a special instance, the hemispherical helical antennas are analyzed firstly, which indicates that the characteristics of a two-arm unit are better than that of a single-arm unit. Based on this, the ellipsoidal helical antenna, formed by changing the axial direction＇s dimension of the two-arm hemispherical helical antenna, is analyzed by the moment method with curved basic and testing function. The effects to VSWR （Voltage Standing Wave Ratio）, gain, polarization and patterns by the axial direction＇s dimensions are investigated. The study results provide dependable gist to the choice of antenna format according to the practical requirements.     

新型舰载超短波宽带平面天线

设计出一种新型舰载超短波宽带天线,该天线采用平面非对称偶极子形式,上辐射面为椭圆拟合结构,下辐射面为指数渐变梯形结构。采用时域有限差分法（FDTD）计算了天线的输入阻抗和辐射方向图。在13.3∶1的频带内,天线的电压驻波比小于2.9,水平面方向图失真度小于3.8 dB,而天线高度仅为0.326 λ_max.理论值与实验结果进行了比较,两者吻合较好     

Analysis of L-shaped slot cut broadband rectangular microstrip antenna

Broadband microstrip antenna (MSA) is realised by cutting the slot at an appropriate position inside the patch. The bandwidth (BW) of the rectangular MSA (RMSA) has been increased by cutting an L-shaped slot inside the patch and it gives a BW of more than 550?MHz (>25%). The reported antenna has a peak gain of 9?dBi which reduces to less than 4?dBi towards the higher frequencies of BW. In this article, an analysis to study the broadband response of the L-shaped slot-cut RMSA is presented. Through the analysis, it was observed that the slot does not introduce any mode but modifies the orthogonal and higher-order TM₁₁ and TM₂₀ mode resonance frequencies of the patch and along with the TM₀₁ mode realises broader BW. Since TM₁₁ mode is dominant towards the higher frequencies of the BW, the cross-polarisation levels increases, which reduces the antenna gain to less than 4?dBi.     

一种UHFRFID系统宽带标签天线的设计

基于微带天线结构,设计了一款适用于整个UHF RFID系统的新型宽带标签天线。在H型贴片上开H槽,形成了两个相近的谐振点,调整H槽的位置和大小,使两个谐振点靠近耦合,从而拓展了天线带宽。通过改变贴片底部矩形槽深度和微带线长度调整天线的输入阻抗。使用软件HFSS14.0进行仿真分析。结果表明,该天线具有很好的宽频特性(766～989 MHz,回波损耗S11<10 dB),在超高频段(840～960 MHz)内具有良好的阻抗匹配特性。     

HF high power electronically tunable helical resonator filter

A novel design of a high power electronically tunable helical resonator filter suitable for applications in HF radio communication is proposed. The helical resonator is loaded in the middle of the helix and the tuning element is set outside the cavity. Theoretical analysis and experimental verification are demonstrated.     

（英）一种基于透镜天线的宽带太赫兹准光检波器

设计了一种能够工作在140~325 GHz频带的宽带准光检波器,由一颗高阻硅透镜和单片集成检波芯片组成.设计并加工出双缝天线,在天线馈电端集成了肖特基二极管,该紧凑结构使其能够接收空间中的太赫兹辐射并转换为基带信号.为增强片上天线的方向性,利用MLFMM算法进行了扩展半球硅透镜的设计和优化,实现了良好的辐射特性.通过测试,天线在220 GHz和324 GHz处的辐射增益分别为26 dB和28 dB.在140~325 GHz,检波器测试得到的响应率可达到1 000~4 000 V/W,对应的等效噪声功率(NEP)估算为0.68~273 pW/Hz.