Engee documentation

EngeePhased.URA

Uniform rectangular antenna array (URA).

Library

EngeePhased

Description

System object EngeePhased.URA simulates a rectangular antenna array (URA) formed from identical isotropic elements of a phased array. The elements of a rectangular antenna array are arranged in the yz plane in the form of a rectangular array.

To calculate the grid response for the specified directions, follow these steps:

  1. Create the EngeePhased.URA object and set its properties.

  2. Call the object with arguments as if it were a function.

Syntax

Creation

The constructor of a system object can be called in the following ways:

  • object = EngeePhased.URA creates a uniform rectangular antenna array (URA) formed from identical isotropic phased array elements with default property values. The elements of a rectangular antenna array are arranged in the yz plane in the form of a rectangular array. The viewing direction of the antenna array (boresight) is directed along the positive axis x.

    Example:

    array = EngeePhased.URA
  • object = EngeePhased.URA(Name=Value) creates a uniform rectangular antenna array (URA) with each specified Name property set to the specified Value. You can specify additional arguments as a name-value pair in any order (Name1=Value1,…​,NameN=ValueN).

    Example:

    array = EngeePhased.URA(Taper=[2 0.2 1])
  • object = EngeePhased.URA(SZ,D,Name=Value) creates a uniform rectangular antenna array (URA) with the Size property set to SZ, and for the ElementSpacing property , the value D, and other specified Name properties set to the specified Value.

    Example:

    array = EngeePhased.URA(SZ,D,Lattice="Triangular")

SZ and D they are arguments for values only. When specifying a value-only argument, all preceding value-only arguments must be specified. The arguments of the Name-Value pair can be specified in any order.

Using

  • RESP = object(FREQ,ANG) returns the responses of the rectangular antenna array elements, the argument RESP, at the operating frequencies specified in the argument FREQ, and the directions specified in the arguments ANG.

When an object is executed for the first time, it is initialized. This initialization captures non-configurable properties and input characteristics such as size, complexity, and type of input data. If you change the non-configurable property or input specification, the system object EngeePhased.URA returns an error. To change non-configurable properties or input data, you must first call the method release! to unlock the object.

Features

Element — element of the phased array antenna

+ EngeePhased.AbstractAntennaElement

Details

An element of the antenna array.

Example: EngeePhased.CosineAntennaElement

Size — the dimension of the rectangular antenna array

+ [2 2] (default) | positive scalar | vector of positive values 1 by 2

Details

The dimension of a rectangular antenna array, defined as a vector of 1 by 2 integers or a single integer.

  • If Size is a 1 by 2 vector, then the vector has the form [NumberOfRows, NumberOfColumns].

  • If Size is a scalar, then the rectangular antenna array has the same number of elements in each row and each column. For URA, the antenna array elements are indexed from top to bottom in a column and then in the following columns from left to right. In this picture, a rectangular antenna array Size with the value [3,2] it has three rows and two columns.

so ura

Example: [3,2]

Data types: Float64

ElementSpacing — the distance between the elements

+ [0.5 0.5] (default) | positive scalar | vector of positive values 1 by 2

Details

The distance between the elements, defined as a positive scalar or a vector of positive values of 1 by 2.

  • If ElementSpacing is a 1 by 2 vector, it has the form [SpacingBetweenRows,SpacingBetweenColumns].

  • If ElementSpacing is a scalar, then the distances between rows and columns are equal.

The units of measurement are m.

Example: [0.3, 0.5]

Data types: Float64

Lattice — type of lattice

+ Rectangular (by default) | Triangular

Details

The grid type of the element is set as Rectangular or Triangular.

  • If the Lattice parameter is set to Rectangular all URA elements are aligned both in the direction of the rows and in the direction of the columns.

  • If the Lattice parameter is set to Triangular, the elements in the even rows are shifted towards the positive direction of the row axis. The offset is half the distance between the elements in the row.

Data types: Float32

ArrayNormal — the direction of the antenna array normal

+ x (default) | y | z

Details

The normal direction of a rectangular antenna array, set as one of x, y or z.

The elements of the URA lie in a plane orthogonal to the selected direction of the normal of the rectangular antenna array. The viewing directions of the elements are directed along the direction of the antenna array normal.

x The elements of the rectangular antenna array lie in the yz-plane. All the normal vectors of the elements are directed along the x axis. This value is used by default.

y

The elements of the rectangular antenna array lie in the zx plane. The normal vectors of all elements are directed along the y axis.

z

The elements of the rectangular antenna array lie on the xy plane. The normal vectors of all elements are directed along the z axis.

Taper — cones of elements

+ 1 (default) | the complex scalar | a complex vector of lines 1 by MN | the complex matrix M by N

Details

Cones of elements defined as a complex scalar, a complex vector 1 by MN, or a complex matrix M by N.

Cones are applied to each antenna element of the antenna array. Cones are often referred to as element weights. M is the number of elements along the z axis, and N is the number of elements along the y axis. M and N correspond to the values [NumberofRows,NumberOfColumns] in the SIze property.

  • If Taper is a scalar, then the same value is applied to all elements.

  • If the value of Taper is a vector or a matrix, the values of the cone are applied to the corresponding elements. Cones are used to change the amplitude and phase of the received data.

Example: [0.4 1 0.4]

Data types: Float64

Entrance

FREQ — the operating frequency of the antenna element

+ a positive real vector of 1 on L lines

Details

The operating frequency of the antenna element, set as a positive real vector of 1 per L lines.

The units of measurement are Hz.

Data types: Float64

ANG — azimuth and elevation angles of the response directions

+ a real vector of lines 1 by M | the real matrix is 2 by M

Details

Azimuthal and elevation angles of the response directions, given as a real vector of lines 1 by M or a real matrix 2 by M, where M is the number of angular directions.

The units of measurement are degrees.

The azimuthal angle should be in the range from -180° to 180° inclusive. The elevation angle should be in the range from -90° to 90° inclusive.

If ANG – vector 1 by M, each element sets the azimuth angle of the direction. In this case, the corresponding elevation angle is assumed to be zero.

If ANG – a 2-by-M matrix, each column of the matrix defines a direction in the form of [azimuth; altitude].

The azimuthal angle is the angle between the x–axis and the projection of the direction vector onto the xy plane. This angle is positive when measured from the x-axis towards the y-axis. The elevation angle is the angle between the direction vector and the xy plane. This angle is positive when measured in the direction of the z axis.

Data types: Float64

Output

RESP — antenna array radiation pattern

+ the complex matrix of N by M

Details

The voltage response of the antenna element of a rectangular antenna array, returned as a complex matrix N by M. In this matrix, N is the number of angles specified in ANG, and M is the number of frequencies specified in FREQ.

Data types: Float64

Methods

Common to all system objects

step!

Running the system object operation algorithm

release!

Permission to change the value of a system object property

reset!

Resetting the internal states of a system object

  1. Brookner, E., ed. "Radar Technology". Lexington, MA: LexBook, 1996.

  2. Brookner, E., ed. "Practical Phased Array Antenna Systems". Boston: Artech House, 1991.

  3. Mailloux, R. J. "Phased Array Theory and Technology", Proceedings of the IEEE, Vol., 70, Number 3s, pp. 246–291.

  4. Mott, H. "Antennas for Radar and Communications", A Polarimetric Approach. New York: John Wiley & Sons, 1992.

  5. Van Trees, H. "Optimum Array Processing". New York: Wiley-Interscience, 2002.