Uniform rectangular array
The URA object constructs a uniform rectangular array (URA).
To compute the response for each element in the array for specified directions:
H = phased.URA creates a uniform rectangular array System object™, H. The object models a URA formed with identical sensor elements. Array elements are distributed in the yz-plane in a rectangular lattice. The array look direction (boresight) is along the positive x-axis.
H = phased.URA(Name,Value) creates the object, H, with each specified property Name set to the specified Value. You can specify additional name-value pair arguments in any order as (Name1,Value1,...,NameN,ValueN).
H = phased.URA(SZ,D,Name,Value) creates a URA object, H, with the Size property set to SZ, the ElementSpacing property set to D and other specified property Names set to the specified Values. SZ and D are value-only arguments. To specify a value-only argument, you must also specify all preceding value-only arguments. You can specify name-value pair arguments in any order.
Phased array toolbox system object
Element specified as a Phased Array System Toolbox object. This object can be an antenna or microphone element.
Default: An isotropic antenna element that operates between 300 MHz and 1 GHz
Size of array
A 1-by-2 integer vector or a single integer containing the size of the array. If Size is a 1-by-2 vector, the vector has the form [NumberOfRows, NumberOfColumns]. If Size is a scalar, the array has the same number of elements in each row and column. For a URA, array elements are indexed from top to bottom along a column and continuing to the next columns from left to right. In this illustration, a 'Size' value of [3,2] array has three rows and two columns.
Default: [2 2]
A 1-by-2 vector or a scalar containing the element spacing of the array, expressed in meters. If ElementSpacing is a 1-by-2 vector, it is in the form of [SpacingBetweenRows,SpacingBetweenColumns]. See Spacing Between Columns and Spacing Between Rows. If ElementSpacing is a scalar, both spacings are the same.
Default: [0.5 0.5]
Specify the element lattice as one of 'Rectangular' | 'Triangular'. When you set the Lattice property to 'Rectangular', all elements in the URA are aligned in both row and column directions. When you set the Lattice property to 'Triangular', the elements in even rows are shifted toward the positive row axis direction by a distance of half the element spacing along the row.
Element taper specified as a scalar or M-by-N complex-valued matrix. Tapers are applied to each element in the sensor array. Tapers 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 y-axis. M and N correspond to the values of [NumberofRows, NumberOfColumns] in the Size property. If Taper is a scalar, identical weights are applied to each element. If the value of Taper is a matrix, a taper value is applied to the corresponding element.
|clone||Create URA object with same property values|
|collectPlaneWave||Simulate received plane waves|
|directivity||Directivity of uniform rectangular array|
|getElementPosition||Positions of array elements|
|getNumElements||Number of elements in array|
|getNumInputs||Number of expected inputs to step method|
|getNumOutputs||Number of outputs from step method|
|getTaper||Array element tapers|
|isLocked||Locked status for input attributes and nontunable properties|
|plotGratingLobeDiagram||Plot grating lobe diagram of array|
|plotResponse||Plot response pattern of array|
|release||Allow property value and input characteristics|
|step||Output responses of array elements|
|viewArray||View array geometry|
The spacing between columns is the distance between adjacent elements in the same row.
The spacing between rows is the distance along the column axis direction between adjacent rows.
This example shows how to construct a 3-by-2 rectangular lattice URA. Find the response of each element at boresight. Assume the operating frequency is 1 GHz.
ha = phased.URA('Size',[3 2]); fc = 1e9; ang = [0;0]; resp = step(ha,fc,ang); disp(resp)
1 1 1 1 1 1
Plot the azimuth response of the array.
c = physconst('LightSpeed'); plotResponse(ha,fc,c,'RespCut','Az','Format','Polar');
This example shows how to find and plot the positions of the elements of a 5-row-by-6-column URA with a triangular lattice and a URA with a rectangular lattice. The element spacing is 0.5 meters for both lattices.
Create the arrays.
h_tri = phased.URA('Size',[5 6],'Lattice','Triangular'); h_rec = phased.URA('Size',[5 6],'Lattice','Rectangular');
Get the element y,z positions for each array. All the x coordinates are zero.
pos_tri = getElementPosition(h_tri); pos_rec = getElementPosition(h_rec); pos_yz_tri = pos_tri(2:3,:); pos_yz_rec = pos_rec(2:3,:);
Plot the element positions in the yz-plane.
figure; gcf.Position = [100 100 300 400]; subplot(2,1,1); plot(pos_yz_tri(1,:), pos_yz_tri(2,:), '.') axis([-1.5 1.5 -2 2]) xlabel('y'); ylabel('z') title('Triangular Lattice') subplot(2,1,2); plot(pos_yz_rec(1,:), pos_yz_rec(2,:), '.') axis([-1.5 1.5 -2 2]) xlabel('y'); ylabel('z') title('Rectangular Lattice')
Construct a 5-by-2 element URA with a Taylor window taper along each column. The tapers form a 5-by-2 matrix.
taper = taylorwin(5); ha = phased.URA([5,2],'Taper',[taper,taper]); w = getTaper(ha)
w = 0.5181 1.2029 1.5581 1.2029 0.5181 0.5181 1.2029 1.5581 1.2029 0.5181
 Brookner, E., ed. Radar Technology. Lexington, MA: LexBook, 1996.
 Brookner, E., ed. Practical Phased Array Antenna Systems. Boston: Artech House, 1991.
 Mailloux, R. J. "Phased Array Theory and Technology," Proceedings of the IEEE, Vol., 70, Number 3s, pp. 246–291.
 Mott, H. Antennas for Radar and Communications, A Polarimetric Approach. New York: John Wiley & Sons, 1992.
 Van Trees, H. Optimum Array Processing. New York: Wiley-Interscience, 2002.