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gregorianOffset

Create offset Gregorian antenna

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    Description

    ThegregorianOffsetobject creates a offset Gregorian antenna. The offset Gregorian antenna is a parabolic antenna. It consists of feed antenna mounted off-axis to concave sub reflector and concave main reflector. The asymmetric arrangement of reflectors provides less blockage for waves redirected from main reflector. The advantage of these antennas is high gain, to reduce side-lobes and to improve cross polarization. The offset Gregorian antennas are used in satellite communication ground antennas, radar systems, and, radio telescopes, etc.

    偏移Gregorian天线几何形状，默认辐射模式和阻抗图。

    Creation

    Syntax

    蚂蚁= gregorianOffset
    Ant = GregorianOffset（名称，值）

    Description

    example

    蚂蚁= gregorianOffsetcreates a conical horn fed offset Gregorian antenna with dimensions for a resonant frequency of 17.76 GHz.

    example

    蚂蚁= GregorianOffset（名称，值）setsProperties使用一个或多个名称值对。例如，ANT = GregorianOffset（'focallength，0.04）creates an offset Gregorian antenna with the focal length of main reflector set to 40 mm.

    Properties

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    Antenna type used as exciter, specified as an antenna or an array object.

    Example:“激励者”,dipole

    Example:ant.exciter =偶极子

    Example:蚂蚁.Exciter = rectangularArray('invertedF')

    半径of the main and sub reflector, specified as a two-element vector with each element unit in meters. The first element specifies the radius of the main reflector, and the second element specifies the radius of the sub reflector.

    Example:'半径',[0.4 0.2]

    Example:蚂蚁.Radius = [0.4 0.2]

    Data Types:double

    Focal length of the main reflector, specified as a positive scalar integer in meters.

    Example:“焦点”，0.0850

    Example:蚂蚁.FocalLength = 0.0850

    Data Types:double

    The distance between the main reflector and x=0 along X-axis, specified as a positive scalar integer in meters.

    Example:'MainReflectorOffset',0.8

    Example:蚂蚁.MainReflectorOffset = 0.8

    Data Types:double

    主反射器的底部边缘与沿X轴的底部边缘之间的间距，该间距被指定为米的正标性整数。

    Example:'DualReflectorSpacing',0.8

    Example:蚂蚁.DualReflectorSpacing = 0.8

    Data Types:double

    Angle between the main reflector and the sub reflector co-ordinate systems, specified as a positive scalar integer in degrees.

    Example:'InterAxialAngle',8

    Example:蚂蚁.InterAxialAngle = 8

    Data Types:double

    Tilt angle of the reflectors, specified as a two-element vector with each element unit in degrees. The first element specifies the tilt of the main reflector, and the second element specifies the tilt of the sub reflector.

    Note

    You can use propertyBasisReflectorTiltto obtain initial value of tilt angles of reflectors with respect to reflector dimensions.

    Example:“ Reflectortilt”，[60 20]

    Example:蚂蚁.ReflectorTilt = [60 20]

    Data Types:double

    Tilt angle of the antenna, specified as a scalar or vector with each element unit in degrees. For more information, seeRotate Antennas and Arrays.

    Example:'Tilt',90

    Example:蚂蚁.Tilt = 90

    Example:'Tilt',[90 90],'TiltAxis',[0 1 0;0 1 1]tilts the antenna at 90 degrees about the two axes defined by the vectors.

    Data Types:double

    Tilt axis of the antenna, specified as:

    • Three-element vector of Cartesian coordinates in meters. In this case, each coordinate in the vector starts at the origin and lies along the specified points on the X-, Y-, and Z-axes.

    • Two points in space, each specified as three-element vectors of Cartesian coordinates. In this case, the antenna rotates around the line joining the two points in space.

    • A string input describing simple rotations around one of the principal axes, 'X', 'Y', or 'Z'.

    For more information, seeRotate Antennas and Arrays.

    Example:'tiltaxis'，[0 1 0]

    Example:'TiltAxis',[0 0 0;0 1 0]

    Example:蚂蚁.TiltAxis = 'Z'

    Lumped elements added to the antenna feed, specified as a块状object handle. You can add a load anywhere on the surface of the antenna. By default, the load is at the feed. For more information, see块状.

    Example:“负载”，块状, wherelumpedelementis the load added to the antenna feed.

    Example:蚂蚁.Load = lumpedElement('Impedance',75)

    Solver for antenna analysis, specified as the comma-separated pair consisting of“ solverType”和'妈妈'或者'PO'(Physical Optics) or'MoM'（时刻方法）或'FMM'(Fast Multipole Method).

    Example:“ solverType”,'MOM'

    Data Types:char

    Object Functions

    show Display antenna or array structure; display shape as filled patch
    solver Access FMM solver for electromagnetic analysis
    axialRatio Axial ratio of antenna
    beamwidth Beamwidth of antenna
    charge Charge distribution on metal or dielectric antenna or array surface
    current Current distribution on metal or dielectric antenna or array surface
    设计 设计原型天线或阵列，以共振围绕指定频率
    EHfields Electric and magnetic fields of antennas; Embedded electric and magnetic fields of antenna element in arrays
    impedance Input impedance of antenna; scan impedance of array
    网 Mesh properties of metal or dielectric antenna or array structure
    网config Change mesh mode of antenna structure
    optimize Optimize antenna or array using SADEA optimizer
    pattern Radiation pattern and phase of antenna or array; Embedded pattern of antenna element in array
    patternAzimuth 天线或阵列的方位角图案
    模式增长 Elevation pattern of antenna or array
    rcs Calculate and plot radar cross section (RCS) of platform, antenna, or array
    returnloss Return loss of antenna; scan return loss of array
    sparameters 计算天线和天线阵列对象的S参数
    vswr 天线的电压站立波比

    Examples

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    打开实时脚本

    Create a offset gregorian dual reflector antenna with default properties.

    蚂蚁= gregorianOffset
    蚂蚁= gregorianOffset with properties: Exciter: [1x1 hornConical] Radius: [0.3000 0.0600] FocalLength: 0.2450 MainReflectorOffset: 0.2600 InterAxialAngle: 15 DualReflectorSpacing: 0.0450 ReflectorTilt: [55.9000 31.6000] Tilt: 0 TiltAxis: [1 0 0] Load: [1x1 lumpedElement] SolverType: 'MoM-PO'

    View the antenna using theshowfunction.

    show(ant);

    图包含一个轴对象。带有标题Gregorianoffset天线元件的轴对象包含7个类型贴片的对象。这些对象代表pec，feed。

    Plot the radiation pattern of offset gregorian dual reflector antenna at a frequency of 17 GHz.

    pattern(ant,17e9);

    Figure contains an axes object and other objects of type uicontrol. The axes object contains 7 objects of type patch, surface.

    打开实时脚本

    Create a circular array of rectangular spiral antennas.

    e =螺旋角；arr =圆形array（'Element',e,'半径',0.02);

    创建一个圆形阵列喂养的偏置Gregorian天线。

    ant = GregorianOffset（“激励者”,arr)
    蚂蚁= gregorianOffset with properties: Exciter: [1x1 circularArray] Radius: [0.3000 0.0600] FocalLength: 0.2450 MainReflectorOffset: 0.2600 InterAxialAngle: 15 DualReflectorSpacing: 0.0450 ReflectorTilt: [55.9000 31.6000] Tilt: 0 TiltAxis: [1 0 0] Load: [1x1 lumpedElement] SolverType: 'MoM-PO'
    show(ant)

    图包含一个轴对象。The axes object with title gregorianOffset antenna element contains 17 objects of type patch, surface. These objects represent PEC, feed.

    More About

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    参考

    [1] Granet, C. “Designing Classical Offset Cassegrain or Gregorian Dual-Reflector Antennas from Combinations of Prescribed Geometric Parameters.”IEEE Antennas and Propagation Magazine44, no. 3 (June 2002): 114–123.

    See Also

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    Topics

    Introduced in R2021a

    天线工具箱文档

    金宝app

    Hybrid Beamforming for Massive MIMO Phased Array Systems

    Hybrid Beamforming for Massive MIMO Phased Array Systems

    Download the white paper