L 波段宽带缝隙耦合天线设计

本文采用变异hour glass 形状缝隙耦合馈电,并引入背腔结构,设计了一种适用于L 波段,具有良好波束前后 比特性的宽带缝隙耦合微带天线,并讨论了馈电网络参数和背腔结构对天线性能的影响。设计结果表明：该天线驻波 相对带宽≥50%,频带内辐射前后比均≥12dB。     

复杂波缝天线阵的工程计算方法

俄罗斯的天线设计师为其机载雷达设计的波缝阵天线被广泛用于各种先进战机。本文就其波缝阵天线的工程计算方法做一介绍。该方法在磁通势方程和以集中传导率形成的缝隙模型方程的基础上，获得了用于分析和综合复杂激励结构谐振波导缝阵的方程。该方程可以计算缝隙间各种相互影响，并且可以计算由1个缝隙至数千个缝隙组成的波导缝阵。     

一种小型化缝隙圆极化印刷天线

设计了一种小型化的方形缝隙圆极化（CP）平面印刷天线,该天线采用在方形缝隙的四个边上均加载尺寸相同的矩形缝隙,使其具有更低的谐振频率;在方形缝隙的任一个加载缝隙里插入与外围地相连的细金属带条以产生微扰,激励出一对相位差90°的差分正交简并模,从而辐射圆极化波。对天线模型进行了优化设计和实物加工,测试结果表明,缝隙加载后天线谐振频率降低了约10%,验证了该小型化措施的有效性;另外该天线在3%的带宽内轴比<3 dB,具有良好的圆极化特性。     

基于特征模理论的缝隙宽带天线设计

基于特征模理论,设计了一种新型微带缝隙宽带天线。该天线设计中,首先分析了三种不同天线结构的特征模态,得到初步的天线结构;然后依据该结构的特征电流分布,将天线馈源设置在多个模态的特征电流相似区域,激励出所需的目标模式,得到多模谐振,从而提高缝隙天线带宽。天线由一个长矩形缝隙和对称地镶嵌于其两侧的圆形缝隙构成,其馈源设置在矩形缝隙槽中的非对称位置上。测试表明,在S_(11)<-10 dB情况下,该天线的阻抗带宽为1.09～2.79 GHz,相对带宽为87.60%,天线辐射性能良好。该天线结构简单、拥有易于共形的窄缝等特点,在无线通信中有一定应用价值。     

基于宽带极化转换超表面的天线RCS缩减

针对天线隐身问题,设计了一款宽带极化转换超表面加载的缝隙阵列天线。超表面采用渐变L型枝节的设计方法,其极化转换比大于0.9的工作带宽为79.2%。为缩减一款2×2的H形缝隙阵列天线的雷达散射截面(Radar Cross Section,RCS),将超表面结构加载到该天线上方。对阵列天线及超表面天线分别进行了仿真和测试,超表面天线的辐射特性保持良好,同时其RCS对于垂直入射方向上的x和y极化波分别在13.4~30.5 GHz和13.1~30.7 GHz得到10.0 dB的缩减。     

基于PSO/FDTD的波导缝隙天线优化设计

设计了一种16阵元波导缝隙天线,其阵元在波导宽边中心线一侧排列。该设计采用泰勒分布进行阵列综合,利用粒子群优化算法(PSO)与时域有限差分法(FDTD)在不同偏置位置对谐振长度进行优化。由于该天线属于非谐振式波导缝隙阵,设计的关键是调整缝隙对宽边中心线的偏移。仿真结果表明天线指标与设计要求吻合,证明了设计方法的可行性。     

采用口径耦合馈电的5.8GHz天线的设计

文章根据不停车电子计费系统（ETC）的国家标准（GB/T 20851.1-2007）要求,设计出了一款采用圆形贴片的右旋圆极化微带贴片天线,并对其馈电结构进行了传输线等效模型的理论分析。该天线采用十字型缝隙口径耦合馈电方式,结构简单,可作为ETC系统的车载单元（OBU）天线使用。经实验证实,此种类型天线不但易于产生圆极化波,而且可以得到比较理想的阻抗带宽、圆极化带宽和增益等以满足设计要求。     

0.22 THz折叠波导行波管设计

在一支0.22 THz折叠波导行波管样管的模拟设计和实验研究基础上,对该样管进行了优化设计。对慢波损耗特性、慢波结构的尺寸冗余度进行了研究,对结构加工进行了进一步的考虑,对样管的实验研究进行了详细讨论并论述了新慢波结构的设计。采用HFSS软件结合大信号理论计算进行模拟,结果表明,折叠波导行波管的输出功率不低于100 mW,带宽不低于5 GHz。     

基于电磁带隙结构的微带天线小型化设计

提出了一种确定电磁带隙结构慢波波长的分析方法,利用电磁带隙结构支持慢波传播的特性,设计了一种小型化微带天线。以"*"型电磁带隙结构作为接地板,增大了天线的相对电长度。天线工作于2 GHz,相对带宽为2.57%,最大增益为5.45 dB,相比于传统天线,该天线的尺寸减小了40%,带宽有了一定的提高。最后,进行了天线的实物制作和测试,天线的实测结果和仿真结果吻合良好。     

一种宽带缝隙耦合微带天线

采用"hour glass"形状缝隙设计了一种新型宽带缝隙耦合微带天线,分析了缝隙参数对天线输入阻抗的影响.该天线使用了多层聚四氟乙烯介质,不仅对贴片单元进行了保护,而且增加了天线的机械强度.同时,由于其结构简单,因此便于阵列集成.研究结果表明,该天线相对带宽超过30%(VSWR<2.0),E面和H面交叉极化分别低于-40 dB和-35 dB.     

Dual circularly polarized radial line slot antennas

A radial line slot antenna (RLSA) is a circularly polarized high efficiency planar array. Two types of RLSAs, a single-layered and a double-layered one, have been released commercially for 12 GHz band DBS reception. The former adopts nonuniform slots excited by a radially outward traveling wave, while the latter has uniform ones excited by an inward traveling wave. The paper merges the two into a novel, dual circularly polarized RLSA. Minimum antenna gain of 33.5 dBi in a DBS bandwidth of 500 MHz is measured for a 0.55 m diameter antenna     

The development of radial line slot array antenna for direct broadcast satellite reception

Microwave antennas are extensively used in communications systems such as satellite, television and high-speed data transmission due to their wide and absolute bandwidth. Among the variety of microwave antennas, satellite communication commonly adopts an antenna of parabolic dish type, despite some drawbacks. In a primary fed design, there is considerable aperture blockage. An offset parabolic antenna design, which then eliminates the blockage, is susceptible to physical damage as its feed is significantly exposed from the body of reflector. The radial line slot array (RLSA) type antenna is thus designed to cope with the problems encountered in parabolic antennas. RLSA is a planar antenna suitable for direct broadcast satellite (DBS) reception, with advantages including high radiation efficiency (high gain), low profile, low cost and feed rear-mounted. The prototype development started with the selection of the cavity's dielectric material and construction of the feeding structure of coaxial-to-waveguide transition. Within the frequency band of interest, between 10.95 and 11.7?GHz, results, is showed a lower than ?10?dB of return loss. A DBS receiver test-bed had been developed to test the constructed antenna prototypes and it revealed that the prototype has the capability of receiving TV programs from DBS.     

A reflection cancelling slot set in a linearly polarized radialline slot antenna

A radial line slot antenna (RLSA) is a high-gain and high-efficiency planar antenna. A linearly polarized RLSA (LP-RLSA) is attractive for applications of various subscriber radio systems. However, the slot arrangement for linear polarization gives rise to serious reflection from slots, which disturbs the normal antenna operation. A new LP-RLSA slot design is presented where reflection canceling slots are added to the conventional ones; four slots form one slot set as a unit radiator of linear polarization. The experiments confirm the design: the antenna return-loss is improved from -2 to -10 dB. Antenna efficiencies of 48 and 54% are measured for 400 and 600-mmφ antennas, respectively. This is the first report of the normal operation of LP-RLSAs     

Experimental investigations into a linearly polarized radial slotantenna for DBS TV in Australia

A hybrid theoretical/experimental approach to the design of radial line slot array (RLSA) antennas for receiving direct broadcast satellite (DBS) TV programs in Australia is presented. Using this approach, 0.4-m and 0.6-m diameter linearly polarized Ku-band prototype antennas were constructed and experimentally investigated. The 0.6-m prototype incorporates reflection cancelling slots, which allow it to overcome the inherent poor return loss performance in linearly polarized RLSA antennas. Measurements show high-radiation efficiency for this form of radial slot antenna and its suitability for the DBS TV application     

供Ku波段卫星电视接收的径向线缝隙天线

本文对供Ku波段卫星电视接收使用的径向线缝隙天线的结构,口面场分布,耦合因子和效率等问题给予简要地介绍和分析;并指出,它是一种具有十分广阔市场的理想的DBS电视平面接收天线。     

A slot design for uniform aperture field distribution insingle-layered radial line slot antennas

A single-layered radial line slot antenna (RLSA) is proposed for a direct broadcast from a satellite (DBS) subscriber antenna. It utilizes a radially outward-traveling wave and the aperture field is intolerably tapered if the uniform slots are used. Two novel techniques are applied. First, the slot design for uniform aperture field distribution is introduced. Second, the radial line is terminated by a matching spiral, in place of a dummy load. It suppresses reflection and radiates all the residual power in circular polarization. For a model antenna of 600-mm diameter, the efficiency of 65% is observed     

Linearly polarized radial-line slot-array antennas with improvedreturn-loss performance

The standard linearly polarized radial-line slot-array (RLSA) antenna exhibits poor return loss as seen by its coaxial feed. This paper describes techniques that improve the poor return-loss performance of this antenna, by using two interchangeable methods: i) reflection-canceling slots on the front and back surface of the antenna, and ii) beam squinting. A series of 550 mm diameter linearly polarized Ku-band prototype antennas were constructed to experimentally investigate the efficiency of each of these methods. In order to cut experimental costs, initial radiation-pattern modeling was performed theoretically, and then prototypes were developed using inexpensive aluminum foil. Measurements of the developed prototypes indicated that both the reflection-canceling and beam-squinting methods provided a substantial improvement in return loss over the desired frequency band     

Broadband circularly polarised high efficiency active antenna

A broadband circularly polarised (CP) high efficiency active antenna is presented, where the antenna is integrated directly with a high efficiency class-E power amplifier (PA). The printed antenna is employed not only as a broadband CP radiator but also as a harmonics-termination load network for the class-E PA. Measured results demonstrate broadband CP radiation and high efficiency.     

Slot coupling in a radial line slot antenna for 12-GHz bandsatellite TV reception

Coupling between slots and slow-wave waveguides in a radial line slot antenna (RLSA) is discussed. Field analysis of the waveguide with a surface impedance wall revealed a considerable change in the propagation constant due to coupling. Experiments were performed to confirm these results and to obtain the surface impedance for actual slots. The change in the propagation constant caused the antenna efficiency to exhibit its maxima at two separated frequencies. An efficiency of 60% and 50% was measured at 11.6 and 12.4 GHz, respectively, which confirms a theoretical prediction. This effect suggests the possibility of broadband planar antennas     

Low-cost monopulse radial line slot antenna

The authors propose the design of one radial line slot antenna with two simultaneous beams, one broadside beam and one conical beam. The antenna is a radial line slot antenna (RLSA), with the slots placed on the upper plate in concentric rings. The radiating element is a slot pair, designed for getting left hand circular polarization. The antenna has been designed to work in the range of 13.4 GHz and 14 GHz. Both beams are obtained independently through very simple excitation circuits, realized with microstrip technology. These feeding networks include a Butler Matrix Network. Comparing both radiation patterns, amplitude and phase, theta and phi angles of arrival direction can be obtained. This monopulse performance can be used to orientate the pencil beam for satellite communication antennas. Measurements for a first prototype are presented to validate the design.