基于漏波波导的X波段高功率微波天线

 基于漏波波导行波天线辐射理论,设计了一种X波段基于漏波波导的高功率微波（HPM）天线。采用微扰法和横向谐振法对天线的辐射特性进行分析,结合数值模拟优化给出了一种基于漏波波导的X波段HPM天线的设计方案。数值模拟表明:该天线在9.6 GHz时增益为26.2 dBi,口径效率大于70%,反射系数小于-20 dB。通过理论分析与数值模拟得到该天线的功率容量大于200 MW,在最大增益点上对ns量级短脉冲的远场响应波形不存在畸变,验证了该天线在HPM条件下使用的可行性。     

基于宽波束磁电偶极子天线的宽角扫描线性相控阵列

设计并加工了两款基于宽波束磁电偶极子天线单元的宽角扫描线性阵列.首先,通过加载磁偶极子的方法拓展了天线单元的3-dB波束宽度.然后,基于该宽波束天线单元设计了两款具有良好宽角扫描特性的一维阵列天线.实测结果表明,天线单元的E面方向图3-dB波束宽度在9GHz—12 GHz均大于107°,H面方向图3-dB波束宽度在7GHz—12 GHz均大于178°.E面阵列中心单元的有源驻波比在9GHz—13 GHz小于2,相对阻抗带宽为36.36%.H面阵列中心单元的有源驻波比在9.6GHz—12.6 GHz小于2.5,相对阻抗带宽为27.03%.E面阵列在9GHz—12 GHz可实现±70°的有效宽角扫描.H面阵列在9GHz—GHz可实现±90°的有效宽角扫描.与传统的扫描阵列相比,设计的阵列可实现有效宽带宽角扫描,在X波段相控阵雷达方面具有广阔的应用前景.     

X波段高功率容量Rotman透镜设计与仿真

介绍了Rotman透镜的工作原理,给出了透镜的设计方程。为适应天线在高功率水平下工作的需求,使用平板型设计,以提升功率容量,采用宽度渐变的方式改善了Rotman透镜的传输线分布方式。设计了一款工作在9.4 GHz、拥有9个输入端口和9个输出端口的高功率容量Rotman透镜天线。仿真结果表明,天线的扫描角度可以达到±22°,各方向增益大于16.5 dBi,效率约为60%,功率容量可达到0.9 GW。     

Planar Spoof Surface Plasmon Polariton Antenna by Using Transmissive Phase Gradient Metasurface

Spoof surface plasmon polariton (SSPP) antennas are of particular importance in communication and radar systems. Currently available SSPP radiation devices are limited to low performance with high side-lobes because it is extremely challenging to accurately control the wave vector of SSPP and the inherent momentum mismatch between the SSPP and spatial waves. Inspired by the optical principle of reversibility, high-performance radiation control of SSPP is proposed to be achieved with transmissive phase gradient metasurface (TPGM). The TPGM, placed a meticulously optimized distance above the SSPP propagation structure, can provide an additional opposite wave vector to match the momentum between the SSPP and spatial waves. When the propagating SSPP transmits on the TPGM, it can be decoupled into the free space accurately and flexibly. Numerical results coincide well with the measurements, indicating that the radiation control of SSPP achieves high-performance and low side-lobe within 9 to 10.5 GHz with the measured radiation efficiency higher than 50%. The measured maximum efficiency appears at 9.8 GHz for 69%. Thanks to the flexible and accurate manipulation of the dispersion relation of SSPP provided by TPGM, the findings may open an avenue in achieving larger angle scanning antenna.     

Metamaterial beam scanning leaky-wave antenna based on quarter mode substrate integrated waveguide structure

In this paper, we first propose a metamaterial structure by etching the same two interdigital fingers on the upper ground of quarter mode substrate integrated waveguide(QMSIW). The simulated results show that the proposed QMSIWbased metamaterial has a continuous phase constant changing from negative to positive values within its passband. A periodic leaky-wave antenna(LWA), which consists of 11 QMSIW-based metamaterial unit cells, is designed, fabricated,and measured. The measured results show that the fabricated antenna achieves a continuous beam scanning property from backward-43° to forward +32° over an operating frequencyrange of 8.9 GHz–11.8 GHz with return loss better than 10 d B.The measured antenna gain keeps consistent with the variation of less than 2 d B over the operating frequency range with a maximum gain of 12 d B. Besides, the measured and simulated results are in good agreement with each other, indicating the significance and effectiveness of this method.     

一种宽角扫描紧耦合阵列天线单元设计

提出一种新型紧耦合偶极子阵列天线单元,并结合等效电路对天线参数进行分析与优化。引入频率选择表面置于天线口径上方,取代传统的电介质板,用以改善宽角扫描时阻抗变换。巴伦采用微带线到共面平行双线过渡结构,实现平衡馈电及阻抗变换。仿真结果表明,该阵列能够实现3倍频(2~6 GHz) E面80°、H面45°的波束扫描,且在扫描范围内有源驻波比均小于3。仿真得到的阵列法向交叉极化隔离度保持在25 dB,由于阻性FSS的损耗,天线增益有所下降。该天线结构简单紧凑,易于加工制作,实现了紧耦合阵列的小型化。     

Mechanically scanned leaky-wave antenna based on a topological one-way waveguide

We propose a uniform backfire-to-endfire leaky-wave antenna (LWA) based on a topological one-way waveguide under external bias magnetic field. We systematically analyze the dispersion, showing that the proposed structure supports leaky mode arisen from total internal reflection. By means of tuning frequency or magnetic field, we obtain fixed-bias frequency and fixed-frequency bias LWA with continuous beam scanning from backward, broadside to forward direction. More importantly, we, for the first time, demonstrate that this proposed LWA shows mechanical tunability, allowing us to manipulate the radiation direction from backward, broadside to forward direction by mechanically tuning the air layer thickness. The simulated results show that our system exhibits super low 3dB beam width, high radiation efficiency as well as high antenna gain. Being provided such multiple controlled (especially mechanically) beam scanning manners, the present LWA paves an advanced approach for continuous beam scanning, holding a great potential for applications in modern communication and radar system.     

高功率无移相器自旋转波束扫描天线设计

设计了一种无移相器结构的平板高功率天线,通过辐射层自旋转方式改变口径场相位分布,从而实现空间波束扫描,满足轻质、低剖面集成要求,辐射增益36 dB,波束扫描范围-30°至+30°,GW级功率容量,满足Ku波段工作的系统指标与能力要求。对天线进行了实物加工与测试,测试结果说明该天线具有良好的波束扫描特性和较高的口径辐射效率。无需加载移相馈电网络便可改变波束指向,具有伺服简单,结构紧凑,平面化、低剖面、轻质等优点,可广泛应用于机载、车载、舰载等高功率微波系统的表面共形发射。     

X波段超宽角扫描相控阵天线设计

为了实现X波段超宽角扫描,提出一种新型的紧耦合阵列天线单元设计,并结合等效电路分析优化天线参数。采用集成式Marchand巴伦馈电,可以实现偶极子与巴伦共基板印刷,进而减小天线的重量与成本。阵列口径上方加载垂直寄生覆层及水平单层电介质板,两者共同作用以改善宽角扫描时阻抗变换。仿真结果表明该天线可实现X波段（8～12 GHz）E面80°、H面70°的扫描角,且有源驻波比小于3。该天线结构简单紧凑,易于加工制作。     

伸缩式全金属反射阵列扫描天线

提出了一种伸缩式全金属反射单元,在此基础上设计了一个可用于高功率微波领域的全金属反射阵列波束扫描天线。通过反射单元的上下独立滑动,阵列中每个阵元所接收电磁波的传输路径可改变,从而实现了相控波束扫描。由电磁仿真可知,设计的反射单元能够在10～13 GHz的频带范围内实现0～360°的线性相位调节,且可在15°～40°偏馈条件下相位调节时保持高功率容量。由该型单元组成的中心工作频率为10 GHz的伸缩式全金属反射阵列扫描天线具备90°锥角范围内的二维波束扫描能力,功率容量可达5 GW/m2。同时,在波束扫描过程中,天线增益变化小于3 dB,副瓣电平低于?13 dB,最大口径效率为54.59%。     

X波段高功率宽频带双螺旋反射阵列天线的设计

为了提升高功率微波辐射天线的带宽,提出并设计了一种X波段高功率圆极化反射阵列天线,该天线采用喇叭天线作为馈源,阵列天线单元由可旋转金属双螺旋线构成,通过旋转螺旋线可以实现360°的相位补偿,同时反射损耗极小。设计了15×15矩形栅格螺旋反射阵列天线,全波仿真结果表明：该口径为315 mm的阵列天线在中心频点9.3 GHz下,增益为28 dB,轴比为0.53 dB,口径效率为52.6%;在8.5~10.9 GHz的频带范围内增益大于26.8 dB,轴比小于1.14 dB,1 dB增益带宽和40%以上口径效率带宽均大于21%;在真空中所能承受的最大功率约为207 MW。     

High gain and circularly polarized substrate integrated waveguide cavity antenna array based on metasurface

Two substrate integrated waveguide (SIW) cavity antenna arrays based on metasurface are proposed in this paper. By rotating the metasurface element, circularly polarized and high gain antennas are achieved respectively. Firstly, multi-mode resonance theory is employed to broaden the bandwidth of the slot antenna. And then, an SIW cavity composed of 4×4 cornercut elements is added on the top of the slot antenna to achieve the circular polarization and improve the front-to-back ratio. Thirdly, the metasurface elements are sequentially rotated and a high gain antenna with 2-dBi enhancement on average in the operation band is obtained. Based on the two antenna units, two 2×2 antenna arrays are designed. The circularly polarized and high gain antenna arrays are both fabricated to verify the correctness. Furthermore, the novel wideband phase shifter is employed in the circularly polarized antenna to obtain an operating bandwidth of 38% (4.05 GHz-5.95 GHz) and AR bandwidth of 24.9% (4.4 GHz-5.65 GHz). The bandwidth of the high gain antenna can reach 42.7% (3.95 GHz-6.1 GHz) and with the gain enhancement of 2 dBi compared with that of the circularly polarized antenna. The gain remains steady in most of operating band within a variation of 1 dBi. It is remarkable that the rotating of the metasurface element has a great influence on the antenna performance, which provides a new explication for the multi-function antenna design.     

高功率微波行波阵列纵向宽角扫描特性

利用机械调节波导宽边尺寸可变化波导波长,从而实现变频波束扫描相同的效果,针对窄边辐射波导行波阵的波束扫描特性进行了分析,以实现宽角波束扫描为目标,着重分析了不同辐射缝隙间距下变化宽边所能得到的最大波束扫描范围。设计了通过变化宽边尺寸实现宽角扫描的X波段窄边辐射波导缝隙阵,设计波束扫描范围指向波导馈入端,避开阵列法向辐射(此方向辐射效率较低),实现了29°的连续波束扫描范围,在波束扫描范畴内增益下降小于3 dB,辐射效率大于62%;设计缝隙宽度3 mm, 波导长度约1 m(缝隙数40),单根波导缝隙天线可实现高功率微波功率容量70 MW。     

Compact ellipse shaped patch with ground slotted broadband monopole patch antenna for head imaging applications

This paper represents an ellipse-shaped patch with a ground slotted broadband patch antenna for microwave head imaging systems. The proposed antenna constructs with a simple ellipse shaped square patch and modified slotted plane. The proposed design is very simple to fabricate and is enclosed in a microwave imaging system. The slotted patch, and the partial ground plane improves the antenna's efficiency, operating frequency range, and gain. The size of the proposed antenna is 70 × 60 × 1.5 mm³ with the electrical dimension being 0.277λ × 0.238λ × 0.006λ at a lower frequency of 1.19 GHz and connected to a 50Ω microstrip feeding line. This antenna is printed onto a low-cost FR-4 substrate whose relative permittivity is 4.4, and whose thickness is 1.5 mm. CST and HFSS software have been used for simulation and thereafter successful completion of the measurements and the fabrication. The comprehensive simulation exhibits that this design provides a bandwidth of 2.37 GHz (1.19 – 3.56 GHz) and 100% of the fractional bandwidths (% BW) with the reflection coefficient of <-10 dB. This antenna on FR-4 can produce an average gain of around 3.63 dBi with 5.95 dBi peak gain at whole operation frequencies. The prototype has a peak radiation efficiency of approximately 97% across the active frequency spectrum with 93% of average. The antenna does have an improved fidelity-factor (> 90 %) with a shorter group-delay. Several design modifications have been performed to get perfect, effective, and suitable results for microwave imaging applications. A 3D-realist Hugo head model is fitted with a single antenna and a 9-antenna array component to verify the performance of both the single antenna, and the configured array antenna. The antenna penetrates the brain human tissues satisfactorily. Across the operational range, the specific absorption rate (SAR) attains a limit of <1 W/kg. The analysis of both numeric and experimental evidence clearly indicates that the suggested antenna is ideal for microwave head-imaging implementations.     

新型顶部加载单极天线

提出了一种新型顶部加U型负载的单极天线结构,给出了设计思想和结构模型,该天线采用同轴馈电,辐射轴向笔状波束且线极化特性良好的波,在理论分析的基础上具体对其进行了仿真,并依照仿真的尺寸结果,加工实物进行了实验研究。仿真结果表明:该天线实现了同轴馈电单极天线的轴向辐射,当工作频率在4.0 GHz时,天线轴向增益为8.33 dBi,轴向轴比为-69.64 dB,反射系数为0.034;在3.83~4.5 GHz的频率范围内反射系数小于0.1。实验结果表明:该天线在中心频率时测量增益为8.116 dBi,驻波比为1.098,并且在3.75~4.50 GHz的范围内驻波比都小于1.2,可以看出仿真结果与实验结果基本一致,互相进行了验证。     

高增益宽带圆极化Vivaldi天线阵的设计

提出了一种由新型Vivaldi天线单元构成的22十字交叉圆极化天线阵。Vivaldi天线单元采用边缘渐变对拓的锯齿结构,提高了天线在4.7～7.0 GHz频带内的增益,其反射系数低于-10 dB的带宽为2.4～11.0 GHz,具有超宽带线极化特性。圆极化天线阵测量结果显示,在4.5～7.0 GHz频带范围内,其轴比均低于3 dB,且整个频带范围内增益达11～13 dBi。     

高增益宽带圆极化Vivaldi天线阵的设计

提出了一种由新型Vivaldi天线单元构成的22十字交叉圆极化天线阵。Vivaldi天线单元采用边缘渐变对拓的锯齿结构,提高了天线在4.7～7.0 GHz频带内的增益,其反射系数低于-10 dB的带宽为2.4～11.0 GHz,具有超宽带线极化特性。圆极化天线阵测量结果显示,在4.5～7.0 GHz频带范围内,其轴比均低于3 dB,且整个频带范围内增益达11～13 dBi。     

基于矩形波导缝隙馈电的阵列天线设计

提出一种具有高功率容量的直线阵列天线,该天线阵基于矩形波导缝隙馈电,馈电耦合结构采用新型的弧形耦合缝隙,利用小螺旋天线作为辐射单元,通过旋转螺旋线内导体来调整各个辐射单元相位,从而实现一维波束扫描。采用等效传输法进行理论设计,数值模拟结果表明,该长度为3200 mm的单元天线在中心频率8.40 GHz上可获得的增益为27.50 dB,主瓣轴比为0.51 dB。功率容量约90 MW,辐射效率为97.10%,反射低于-24 dB,波束扫描范围±38°。     

L波段小型化同轴扩张型天线设计

为了减小常规L波段高功率微波测量接收天线的结构尺寸及增益,设计了一种基于轴向缝隙馈电的小型化同轴扩张型天线。通过理论分析和数值模拟,选择了较优的结构尺寸,得到天线的增益及方向图特性：在1.3~1.6 GHz范围内,增益从-2.0 dBi变化至0.8 dBi;天线最大辐射方向在物理结构轴向。基于矢量网络分析仪E8362B的天线特性测量结果与数值计算结果基本一致：工作频率从1.3~1.6 GHz变化时,增益从-2.3 dBi变化至1.2 dBi;E面方向图主瓣宽度大于60,轴向轴比大于35 dB,结果表明设计的天线能够满足L波段高功率微波测量天线低增益小型化要求。     

一种辐射零点可控的紧凑型滤波贴片天线

提出了一种辐射零点可控的紧凑型滤波贴片天线。该滤波天线以基本的微带贴片天线为原型,主要由一个简单的金属辐射贴片和两个对称的分割形槽组成。两个分割形槽蚀刻在金属贴片上,使得高/低频段分别产生两个宽边辐射零点,从而引入滤波选频功能。该结构未引入额外滤波电路和其他寄生单元,节省了空间尺寸,结构更加紧凑;两个辐射零点独立可控,提高了设计的灵活度。且在实现滤波选频功能的同时,对天线增益的影响很小。利用HFSS仿真软件优化滤波天线结构,制作了一个实物模型并进行了测试。测试结果与仿真结果基本一致。测试结果表明,提出的滤波天线工作在2.40 GHz,两个独立可控的辐射零点分别位于1.96 GHz和2.66 GHz,平均实际增益约为7.0 dBi,带外抑制水平超过39 dB。