Engee documentation

EngeePhased.UCA

Uniform circular antenna array.

Library

EngeePhased

Description

System object EngeePhased.UCA simulates a uniform circular lattice (UCA). The UCA is formed from identical antenna element elements evenly spaced around the circumference.

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

  1. Define and configure a uniform circular array. See Syntax.

  2. Call the method step! to calculate the response according to the properties EngeePhased.UCA.

Syntax

Creation

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

  • object = EngeePhased.UCA creates a uniform circular array (UCA) consisting of five identical isotropic antenna elements, EngeePhased.IsotropicAntennaElement with default property values*. The elements are evenly distributed around a circle with a radius of 0.5 m.

    Example:

    sUCA = EngeePhased.UCA
  • object = EngeePhased(Name=Value) creates a uniform circular grid (UCA) 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:

    sUCA = EngeePhased.UCA(NumElements=3, Radius=7.5)
  • object = EngeePhased(N,R) creates creates a uniform circular grid (UCA) with the value N for the numElements property and the value R for the Radius property. This syntax creates a uniform circular array consisting of isotropic antenna elements., EngeePhased.IsotropicAntennaElement.

    Example:

    sUCA = EngeePhased.UCA(N,R)
  • object = EngeePhased(N,R,Name=Value) creates a uniform circular grid (UCA) with the value N for the numElements property and the value R for the Radius property, and other specified Name properties set to the specified Value.

    Example:

    sUCA = EngeePhased.UCA(N, R, ArrayNormal="x")

Features

Element — element of the phased array antenna

+ EngeePhased.AbstractAntennaElement

Details

An element of the antenna array.

Example: EngeePhased.CosineAntennaElement

numElements — the number of grid elements

+ 5 (default) | an integer greater than one

Details

The number of grid elements specified as an integer greater than one.

Example: 4

Radius — the radius of the array

+ 0.5 (default) | positive scalar

Details

The radius of the lattice, defined as a positive scalar.

The units of measurement are m.

Example: 2.5

ArrayNormal — direction of the lattice normal

+ z (default) | x | y

Details

The direction of the lattice normal, set as one of the directions x, y or z.

The UCA elements lie in a plane orthogonal to the direction of the array normal. The height vectors of the elements lie in the same plane and are directed radially outward from the origin.

Value of the ArrayNormal property Item positions

x

The elements of the array lie in the yz-plane. A pair of orthogonal vectors forming the plane of the element lie in the yz plane and point outward from the center of the array.

y

The elements of the array lie in the zx plane. A pair of orthogonal vectors forming the plane of the element lie in the zx plane and point outward from the center of the array.

z

The elements of the array lie on the xy plane. A pair of orthogonal vectors forming the plane of the element lie in the xy plane and point outward from the center of the array.

Example: x

Taper — taper elements

+ 1 (default) | the complex scalar | a complex vector of 1 by N rows | a complex vector of N-by-1 columns

Details

The narrowing or weighting of elements, defined as a complex scalar, a 1-by-N row vector, or an N-by-1 column vector.

The value N is the number of array elements. Cones, also known as weights, are applied to each element of the antenna element array and change the amplitude and phase of the received data.

If Taper If it is a scalar, then the same cone value applies to all elements.

If Taper – vector, each cone value is applied to the corresponding element of the antenna element.

Example: [1 2 3 2 1]

Methods

Common to all system objects

step!

Run the system object operation algorithm

release!

Allow changing the value of a system object property

reset!

Resetting the internal states of a system object

Additional Info

Algorithms

The UCA is formed from N identical sensor elements evenly spaced around a circle of radius R. The circle lies in the xy-plane of the local coordinate system, the origin of which lies in the center of the circle.

The positions of the elements are determined relative to the local coordinate system of the array.

The circular array lies in the xy-plane of the coordinate system. The normal to the UCA plane lies along the positive axis z. The elements are oriented so that their main response directions (normals) are directed radially outward in the xy plane.

so uca

If the number of array elements is odd, the middle element lies on the x axis.

If the number of elements is even, then the midpoint between the two middle elements lies on the x axis.

For an array of N elements, the azimuthal position angle is The element is defined as follows:

where

The azimuthal angle is defined as the angle in the xy plane from the x axis to the y axis.

The elevation angle is defined as the angle from the xy plane to the z axis. The angular distance between any two adjacent elements is 360/N degrees. The azimuthal angles are given in degrees. The elevation angles for all elements of the array are zero.

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

  2. Van Trees, H. "Optimum Array Processing". New York: Wiley-Interscience, 2002, pp. 274–304.