An offset reflector antenna with low sidelobes

The corrugated conical horn is considered to be an ideal feed for low sidelobe reflector antennas because of its unique characteristics. Analysis is carried out to show that low flare horns are preferred over high flare horns to give rise to low sidelobe performance for a given offset reflector antenna system.     

Design and simulation of metamaterial-based hybrid-mode horn antennas

The design and analysis of novel hybrid-mode soft and hard horn antennas with a low index metamaterial wall liner are presented. Metamaterial horn antennas have the potential for considerably larger bandwidth than the current state-of-the-art horns. The optimal or required metamaterial dispersion curve for these horns is qualitatively similar to the Drude dispersion, which indicates that the metamaterial horns are realisable.     

Application of rectangular and elliptical dielcore feed horns toelliptical reflector antennas

The pattern characteristics of elliptical reflector antennas are investigated when they are fed by rectangular and elliptical horns partially filled with a dielectric. The bandwidth characteristics of these dielcore horns are superior to those of their corrugated horn counterparts. Representative reflector patterns are computed to properly demonstrate the utility of these feeds for reflector antennas with elliptical apertures. This reflector antenna exhibits high efficiency and low cross polarization, and may be suitable for radar and satellite antenna applications. The antenna configuration may become useful in relatively small antennas where more than 10% cross-polar bandwidth is required. The efficient dielcore horns may also be used as feeds for elliptical nonshaped dual-reflector antennas     

Broad-band elliptical beamshape horns with low cross polarization

Horn antennas with an elliptical beam and low cross polarization are discussed. A new class of elliptical-beamshape horns has been investigated. The horns are based on the dielectric core approach, using a dielectric core inside a smooth-walled horn. Horns with rectangular as well as elliptical cross sections have been studied. Experiments show that they have considerably larger cross-polar bandwidth than that obtained from corrugated horns with an elliptical beam. They are also potentially much cheaper to manufacture     

Design and optimization of corrugated feeds: X_HORN softwarepackage

Satellite telecommunication-antenna systems require high performance, in terms of extremely low cross polarization, low return loss, high power levels, and low levels of passive intermodulation, over a range of more than 30% of the frequency bandwidth. Among the available feeds that provide good performance, circular corrugated horns have long been among the most popular. This is because of their ease of manufacture, low cross polarization, and low return loss over a broad range of frequencies. To achieve optimum performance for these feed horns, an accurate design tool is needed. With this mind, a software package was developed for the analysis (Coccioli et al., 1997) and optimization (Coccioli et al., 1996) (based on the Davidon-Fletcher-Powell method, Fletcher and Powell, 1963) of corrugated horns. The current version of the code is suitable for circular corrugated horns, but future plans are to extend this to elliptical configurations, as well. The analysis approach employed (Coccioli et al., 1997) is based on a hybrid technique, which combines the generalized scattering matrix for modeling the interior region of the horn, with the combined electric- and magnetic-field integral equation (CFIE), to model the surface currents on the exterior perfectly conducting walls of the feed. The combined used of these modeling techniques provides a rigorous and efficient representation of the fields on their respective regions of application     

Compact multimode horn with low sidelobes for global Earth coverage

A new multimode corrugated horn is described for full-Earth coverage from a geostationary satellite. The horn has low sidelobes, low cross polarization, and is compact. We outline the design of this horn and compare its performance with other circular horn types, including conventional single and multimode-corrugated horns and dielectric loaded horns. A design was fabricated and measured results are described for return loss, radiation patterns, and axial ratio. These measurements demonstrate excellent agreement with computer predictions using mode-matching software     

准太赫兹波段角锥波纹喇叭天线的设计

波纹喇叭天线是20世纪70年代出现的用于微波天线的一种新型器件,它结构紧凑、加工方便、成本较低。不仅如此,它还是一种高效率的馈源,它的方向图具有低旁瓣、轴对称、交叉极化小等一系列优点,因而得到广泛的应用。文中介绍了准太赫兹角锥波纹喇叭天线的基本设计思想。设计了一种工作在140 GHz左右频段的E面波纹角锥喇叭天线。计算机模拟达到了相对于平壁角锥喇叭来说较小波瓣宽度,极低旁瓣电平,E,H面波瓣图趋同的效果。     

Fabrication and performance of MMW and SMMW platelet horn arrays

Future spaceborne millimeter and sub-millimeter wave sensing systems will require the sensitivity and resolution only achievable with large focal plane array receiving systems. A technique has been developed for the low cost fabrication of large arrays of millimeter and sub-millimeter wave corrugated feed horns. These arrayed horns exhibit high efficiency and symmetrical receiving patterns and are compatible with integrated receivers. W-band test results of a 3×3 array are presented.     

A novel horn radiator with high aperture efficiency and low cross-polarization and applications in arrays and multibeam reflector antennas

A step horn structure is presented that yields about 90% aperture efficiency with low cross-polar radiation. It is found that for obtaining high aperture efficiency, the horn aperture should consist of only the TE/sub z/ type of modes in appropriate amplitudes and phases. The desired TE/sub z/ modes are produced using multiple steps in the horn walls. The distances between the steps are critical to suppress the undesired TM/sub z/ modes. Radiation characteristics of high efficiency circular and square horns are presented and potential applications of such high efficiency horns are discussed.     

基于SIW的多波束CTS阵列天线设计

文中设计了一款基于基片集成波导(SIW)的毫米波高增益多波束连续横向枝节(CTS)阵列天线,它通过切换馈电端口实现多波束功能。该天线整体结构简单,采用印刷电路板工艺实现。天线主要包含馈电喇叭、平面波转换结构以及辐射结构三个部分,由三层基板构成。馈源为基于SIW的馈电喇叭,并在口径处添加匹配结构以提高其辐射性能;平面波转换结构由SIW抛物面和渐变耦合槽组成,可将馈电喇叭辐射出的柱面波转换为幅度服从泰勒分布的平面波进而为CTS阵列馈电,因此天线具有低副瓣的特性;辐射结构为1×8的CTS阵列,通过优化缝隙宽度以保证每个单元辐射出相等的能量。天线工作在30 GHz,通过切换馈电端口可在±20°范围内实现波束切换,天线测试结果与仿真结果吻合,验证了设计的合理性。     

Full-Wave Analysis of Monopulse Dielectric Lens Antennas at W-band

Lens antenna is a good substitute for the Cassegrain antenna at millimeter-wave frequencies, especially at W-band. On one hand, the antenna design, which is bulky and heavy at low frequencies, becomes compact and light-weighted at W-band. On the other hand, without the blockage caused by the sub-reflector and the feed horns which are unavoidable in a Cassegrain antenna, the lens antennas show better radiation characteristics. In this paper, several lens antennas fed by metal horns are analyzed using a full-wave method-finite element method based on the weak form of the Helmholtz equation (WF-FEM). Numerical results show that the lens antennas presented have low side lobe level (SLL), and good sum and difference performances.     

A dielectric hybrid mode antenna feed: A simple alternative to the corrugated horn

A hybrid-mode horn antenna has been analyzed theoretically and experimentally. It consists of a conical metal horn with a dielectric core inside, separated from the metal wall by another dielectric layer with lower permittivity than for the core material. It is characterized by a very simple design and excellent electrical performance. The horn can support the balanced hybrid HE11-mode, and exhibits low cross polarization and low sidelobes over a wide frequency range. Compared to corrugated horns, the new horn has a simpler design, is easier to analyze, and has the potential of similar cross-polar bandwidth as for corrugated horns with ring-loaded corrugations. Drawbacks are the effects of dielectric losses. Thus the new horn represents an attractive alternative to the corrugated horn antenna.     

Antennes embarquées à réflecteurs multisources

Three telecommunication satellite antennas, developed under the research and development programme of the European Space Agency, ESA, are described. The first one, operating around 1.6 GHz, is to equip advanced mobile communications satellites. It includes an 8 m unfurlable reflector and a system of multiple feeds. The influence of facets in the mesh reflector surface on the radiation patterns is discussed. The second one, for European coverage in the 10.7 to 11.7 GHz band, includes a 1.1 m offset reflector fed by 23 horns backed by a numerically machined waveguide distribution network. Performances of the antenna, with emphasis on the distribution network, are discussed. The third antenna, operating at 19 GHz, generates 0.25° low sidelobe spot beams to cover major European traffic centers. Its 4 m offset Cassegrain reflector is fed by a system of about a hundred horns. Each beam originates from a cluster of seven horns, some clusters, corresponding to closely adjacent beams, partially overlap. The design and performances of the antenna and its components are discussed in the paper.     

纵槽波纹喇叭的模式算法

纵槽波纹喇叭是一种结构紧凑、加工方便、成本较低、具有良好辐射性能、易于实现双频共用的馈源。给出了一种计算纵槽波纹喇叭辐射性能的方法。运用模式匹配理论计算喇叭的内场、谱域方法计算喇叭的口面反射得出口面场,然后由口面积分法得出其辐射特性。计算结果与测试结果的比较说明该方法是一种概念清晰、简单实用的方法。     

Investigation of a 90° corrugated horn

Wide-angle corrugated horns have found important practical applications as feeds for front-fed reflector antennas when low levels of crosspolarisation are required. A theoretical study has been carried out on the 90° corrugated horn for a structure possessing an 'arbitrary, but finite, number of corrugations. Computed and measured results are shown to be in good agreement for a horn possessing three annular slots.     

Scales for rectangular horns

The scales presented are useful both for design of optimum horns for a given gain, and for finding the gains of rectangular horns from the dimensions. This article further illustrates the relationships among various parameters of rectangular horns. Although the design method started with a waveguide width-to-height ratio of 2:1, the method produces suitable designs for other waveguide ratios.     

Gain of corrugated conical horns

The absolute gain of a corrugated horn which is designed as a 100-GHz gain standard for the Crawford Hill 7-Meter offset reflector has been calculated and measured. The measured gain is determined from "three horn" transmission measurements. The other two horns are a TRG Model W869 corrugated horn and a dual mode horn. Correction factors were computed from the near field power transmission formula. The measured gain of the gain standard is30.8 pm 0.16 dB. Comparison between measured and calculated gains indicate very low ohmic loss in a corrugated horn. The condition of maximum gain for a given length has been found to be a half wavelength phase deviation in the horn aperture. Calculated gain data as well as near field correction factors for two identical corrugated conical horns are given here as reference information.     

海洋二号微波定标辐射计天线子系统

海洋二号微波定标辐射计HY-2Calibration Radiometer(HY-2 CR)采用了高增益、低副瓣、高波束效率低损耗的天线子系统.三个频率共用一个偏馈抛物面,天线频率分别为18.7 GHz、23.8 GHz和37 GHz.采用双隔膜正交模耦合器实现双极化信号提取,利用紧凑型圆锥波纹喇叭进一步降低天线结构尺寸和质量.测试结果显示天线完全达到了设计要求.     

指向性控制和恒指向性号筒综述

介绍了指向性因数和指向性指数的定义、计算式。按历史次序讨论了多格号筒、径向号筒、CE号筒、曼塔莱号筒的指向性特性。还简要讨论了号筒内的失真,以及一个恒指向性号筒的实例,给出了实测的水平和垂直的极坐标响应、波束宽度,及指向性因数和指向性指数与频率的关系。最后,简单介绍了磁液在压缩驱动器中的应用。     

Antenna Performance of a Directly Dug Corrugated Feedhorn for the 150-GHz Band

We have developed a 150 GHz band corrugated feed horn. These corrugated feed horns have been established by a new machining method, which involves digging corrugations through a metal material. We were able to realize E plane and H plane symmetry, low side lobe level, and low cross-polarization level. Measured co-polarization beam patterns above ??35 dB were consistent with the simulated patterns within a designed frequency range. The peak levels of cross-polarization beam patterns were less than ??30 dB. And, the performances were uniform in several horns. In the present paper, we describe the corrugated horn produced by this methods.