URA Sum and Difference Monopulse

Sum-and-difference monopulse for URA

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Libraries:
Phased Array System Toolbox / Direction of Arrival

Description

The URA Sum-and-Difference Monopulse block estimates the direction of arrival of a narrowband signal on a uniform rectangular array (URA) based on an initial guess using a sum-and-difference monopulse algorithm. The block obtains the difference steering vector by phase-reversing the latter half of the sum steering vector.

Ports

Input

X — Input signal

length-N row vector

Input signal, specified as a length-N row vector whose number of columns corresponds to number of channels.

Data Types: single | double
Complex Number Support: Yes

Steer — Steering angle

2-by-1 real-valued vector

Steering angle, specified as a real-valued 2-by-1 vector in the form [AzimuthAngle ElevationAngle]. The steering angle serves as initial guess of the direction arrival direction. A typical initial guess is the current steering angle. Azimuth angles must be between –180 and 180 degrees. Elevation angles must be between –90 and 90 degrees. Angles are measured in the local coordinate system of the array. For details regarding the local coordinate system of the URA, type phased.URA.coordinateSystemInfo Units are in degrees.

Example: [-45 20]

Data Types: single | double

Output

Ang — Incoming direction

2-by-1 real-valued vector

Estimate of incoming direction, returned as a 2-by-1 vector in the form [AzimuthAngle; ElevationAngle]. Azimuth angles are between –180 and 180. Elevation angles are between –90 and 90. Angles are measured in the local coordinate system of the array. Units are in degrees.

Data Types: single | double

Parameters

To edit block parameters interactively, use the Property Inspector. From the Simulink^® Toolstrip, on the Simulation tab, in the Prepare gallery, select Property Inspector.

Signal propagation speed (m/s) — Signal propagation speed

physconst("LightSpeed") (default) | real-valued positive scalar

Signal propagation speed, specified as a real-valued positive scalar. The default value of the speed of light is the value returned by physconst("LightSpeed"). Units are in meters per second.

Example: 3e8

Data Types: double

Operating frequency (Hz) — System operating frequency

3e8 (default) | positive real scalar

System operating frequency, specified as a positive scalar. Units are in Hz.

Data Types: single | double

Number of bits in phase shifters — Number of phase shift quantization bits

0 (default) | nonnegative integer

The number of bits used to quantize the phase shift component of beamformer or steering vector weights. Specify the number of bits as a non-negative integer. A value of zero indicates that no quantization is performed.

Simulate using — Block simulation method

Interpreted Execution (default) | Code Generation

Block simulation, specified as Interpreted Execution or Code Generation. If you want your block to use the MATLAB^® interpreter, choose Interpreted Execution. If you want your block to run as compiled code, choose Code Generation. Compiled code requires time to compile but usually runs faster.

Interpreted execution is useful when you are developing and tuning a model. The block runs the underlying System object™ in MATLAB. You can change and execute your model quickly. When you are satisfied with your results, you can then run the block using Code Generation. Long simulations run faster with generated code than in interpreted execution. You can run repeated executions without recompiling, but if you change any block parameters, then the block automatically recompiles before execution.

This table shows how the Simulate using parameter affects the overall simulation behavior.

When the Simulink model is in Accelerator mode, the block mode specified using Simulate using overrides the simulation mode.

Acceleration Modes

Block Simulation	Simulation Behavior
	Normal	Accelerator	Rapid Accelerator
Interpreted Execution	The block executes using the MATLAB interpreter.	The block executes using the MATLAB interpreter.	Creates a standalone executable from the model.
Code Generation	The block is compiled.	All blocks in the model are compiled.

For more information, see Choosing a Simulation Mode (Simulink).

Programmatic Use

Block Parameter: SimulateUsing

Type: enum

Values: Interpreted Execution, Code Generation

Default: Interpreted Execution

Array Parameters

Specify sensor array as — Method to specify array

Array (no subarrays) (default) | MATLAB expression

Method to specify URA array, specified as Array (no subarrays) or MATLAB expression.

Data Types: char | string

Array size — Size of URA array

[2,2] (default) | positive integer | 1-by-2 vector of positive integers

Size of a URA array, specified as a positive integer or 1-by-2 vector of positive integers.

• If Array size is a 1-by-2 vector, the vector has the form [NumberOfArrayRows,NumberOfArrayColumns].

• If Array size is an integer, 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 the leftmost array column, and continued to the next columns from left to right. In this figure, the Array size value of [3,2] creates an array having three rows and two columns.

Dependencies

To enable this parameter, set Geometry to URA.

Element spacing — Spacing between URA array elements

[0.5,0.5] for URA arrays (default) | positive scalar for URA arrays | 2-element vector of positive values for URA arrays

Spacing between adjacent array elements:

• URA — specify the spacing as a positive scalar or a 1-by-2 vector of positive values. If Element spacing (m) is a scalar, the row and column spacings are equal. If Element spacing (m) is a vector, the vector has the form [SpacingBetweenArrayRows,SpacingBetweenArrayColumns].

Dependencies

To enable this parameter, set Geometry to URA.

Array normal direction — Array normal direction

x for URA arrays or z for UCA arrays (default) | y

Array normal direction, specified as x, y, or z.

Elements of planar arrays lie in a plane orthogonal to the selected array normal direction. Element boresight directions point along the array normal direction.

Array Normal Parameter Value	Element Positions and Boresight Directions
x	Array elements lie in the yz-plane. All element boresight vectors point along the x-axis.
y	Array elements lie in the zx-plane. All element boresight vectors point along the y-axis.
z	Array elements lie in the xy-plane. All element boresight vectors point along the z-axis.

Dependencies

To enable this parameter, set Geometry to URA or UCA.

Taper — Array element tapers

1 (default) | complex scalar | complex-valued row vector

Specify element tapering as a complex-valued scalar or a complex-valued 1-by-N row vector. In this vector, N represents the number of elements in the array.

Also known as element weights, tapers multiply the array element responses. Tapers modify both amplitude and phase of the response to reduce side lobes or steer the main response axis.

If Taper is a scalar, the same weight is applied to each element. If Taper is a vector, a weight from the vector is applied to the corresponding sensor element. The number of weights must match the number of elements of the array.

Data Types: double

Expression — Matlab expression

character vector | string

MATLAB expression for creating an array, specified as a character vector or string.

Example: phased.URA(Size=[15,10])

Data Types: char | string

Sensor Array Tab: Element Parameters

Element Parameters

Element type — Array element types

Isotropic Antenna (default) | Cardioid Antenna | Cosine Antenna | Custom Antenna | Gaussian Antenna | Sinc Antenna | Omni Microphone | Custom Microphone

Antenna or microphone type, specified as one of the following:

• Isotropic Antenna

• Cardioid Antenna

• Cosine Antenna

• Custom Antenna

• Gaussian Antenna

• Sinc Antenna

• Omni Microphone

• Custom Microphone

Operating frequency range (Hz) — Operating frequency range of the antenna or microphone element

[0,1e20] (default) | real-valued 1-by-2 row vector

Specify the operating frequency range of the antenna or microphone element as a 1-by-2 row vector in the form [LowerBound,UpperBound]. The element has no response outside this frequency range. Frequency units are in Hz.

Dependencies

To enable this parameter, set the Element type parameter to one of these types:

• Isotropic Antenna

• Cardioid Antenna

• Cosine Antenna

• Omni Microphone

• Gaussian Antenna

• Sinc Antenna

• Omni Microphone

Baffle the back of the element — Set back response of an Isotropic Antenna element or an Omni Microphone element to zero

off (default) | on

Select this check box to baffle the back response of the element. When back baffled, the responses at all azimuth angles beyond ±90° from broadside are set to zero. The broadside direction is defined as 0° azimuth angle and 0° elevation angle.

Dependencies

To enable this check box, set Element type to Isotropic Antenna or Omni Microphone.

Null axis direction — Null axis direction

-x (default) | +x | +y | -y | +z | -z

Dependencies

To enable this parameter, set Element type to Cardioid Antenna.

Exponent of cosine pattern — Exponents of azimuth and elevation cosine patterns

[1.5 1.5] (default) | nonnegative scalar | real-valued 1-by-2 matrix of nonnegative values

Specify the exponents of the cosine pattern as a nonnegative scalar or a real-valued 1-by-2 matrix of nonnegative values. When Exponent of cosine pattern is a 1-by-2 vector, the first element is the exponent in the azimuth direction and the second element is the exponent in the elevation direction. When you set this parameter to a scalar, both the azimuth direction and elevation direction cosine patterns are raised to the same power.

Dependencies

To enable this parameter, set Element type to Cosine Antenna.

Operating frequencies — Operating frequency range of microphone elements

[0,1e20] (default) | real-valued row vector

Specify the frequencies at which to microphone frequency responses as a 1-by-L row vector of increasing real values. The microphone element has no response outside the frequency range specified by the minimum and maximum elements of this vector. Frequency units are in Hz.

Dependencies

To enable this parameter, set Element type to Custom Microphone. Use Frequency responses (dB) to set the responses at these frequencies.

Frequency responses — Custom microphone frequency response

[0,0] (default) | real-valued row vector

Frequency responses of custom microphone for the frequencies defined by the Operating frequencies parameter. The dimensions of Frequency responses must match the dimensions of the vector specified by the Operating frequencies parameter.

Dependencies

To enable this parameter, set Element type to Custom Microphone.

Coordinate system of custom antenna pattern — Coordinate system of custom antenna pattern

az-el (default) | phi-theta

Coordinate system of custom antenna pattern, specified az-el or phi-theta. When you specify az-el, use the Azimuth angles (deg) and Elevations angles (deg) parameters to specify the coordinates of the pattern points. When you specify phi-theta, use the Phi angles (deg) and Theta angles (deg) parameters to specify the coordinates of the pattern points.

Dependencies

To enable this parameter, set Element type to Custom Antenna.

Azimuth angles (deg) — Azimuth angles of antenna radiation pattern

[-180:180] (default) | real-valued row vector

Specify the azimuth angles at which to calculate the antenna radiation pattern as a 1-by-P row vector. P must be greater than 2. Azimuth angles must lie between –180° and 180°, inclusive, and be in strictly increasing order.

Dependencies

To enable this parameter, set the Element type parameter to Custom Antenna and the Coordinate system of custom antenna pattern parameter to az-el.

Elevation angles (deg) — Elevation angles of antenna radiation pattern

[-90:90] (default) | real-valued row vector

Specify the elevation angles at which to compute the radiation pattern as a 1-by-Q vector. Q must be greater than 2. Angle units are in degrees. Elevation angles must lie between –90° and 90°, inclusive, and be in strictly increasing order.

Dependencies

To enable this parameter, set the Element type parameter to Custom Antenna and the Coordinate system of custom antenna pattern parameter to az-el.

Phi Angles (deg) — Phi angle coordinates of custom antenna radiation pattern

0:360 | real-valued 1-by-P row vector

Phi angles of points at which to specify the antenna radiation pattern, specify as a real-valued 1-by-P row vector. P must be greater than 2. Angle units are in degrees. Phi angles must lie between 0° and 360° and be in strictly increasing order.

Dependencies

To enable this parameter, set the Element type parameter to Custom Antenna and the Coordinate system of custom antenna pattern parameter to phi-theta.

Theta Angles (deg) — Theta angle coordinates of custom antenna radiation pattern

0:180 | real-valued 1-by-Q row vector

Theta angles of points at which to specify the antenna radiation pattern, specify as a real-valued 1-by-Q row vector. Q must be greater than 2. Angle units are in degrees. Theta angles must lie between 0° and 360° and be in strictly increasing order.

Dependencies

To enable this parameter, set the Element type parameter to Custom Antenna and the Coordinate system of custom antenna pattern parameter to phi-theta.

Magnitude pattern (dB) — Magnitude of combined antenna radiation pattern

zeros(181,361) (default) | real-valued Q-by-P matrix | real-valued Q-by-P-by-L array

Magnitude of the combined antenna radiation pattern, specified as a Q-by-P matrix or a Q-by-P-by-L array.

• When the Coordinate system of custom antenna pattern parameter is set to az-el, Q equals the length of the vector specified by the Elevation angles (deg) parameter and P equals the length of the vector specified by the Azimuth angles (deg) parameter.

• When the Coordinate system of custom antenna pattern parameter is set to phi-theta, Q equals the length of the vector specified by the Theta Angles (deg) parameter and P equals the length of the vector specified by the Phi Angles (deg) parameter.

The quantity L equals the length of the Operating frequency vector (Hz).

• If this parameter is a Q-by-P matrix, the same pattern is applied to all frequencies specified in the Operating frequency vector (Hz) parameter.

• If the value is a Q-by-P-by-L array, each Q-by-P page of the array specifies a pattern for the corresponding frequency specified in the Operating frequency vector (Hz) parameter.

Dependencies

To enable this parameter, set Element type to Custom Antenna.

Phase pattern (deg) — Custom antenna radiation phase pattern

zeros(181,361) (default) | real-valued Q-by-P matrix | real-valued Q-by-P-by-L array

Phase of the combined antenna radiation pattern, specified as a Q-by-P matrix or a Q-by-P-by-L array.

• When the Coordinate system of custom antenna pattern parameter is set to az-el, Q equals the length of the vector specified by the Elevation angles (deg) parameter and P equals the length of the vector specified by the Azimuth angles (deg) parameter.

• When the Coordinate system of custom antenna pattern parameter is set to phi-theta, Q equals the length of the vector specified by the Theta Angles (deg) parameter and P equals the length of the vector specified by the Phi Angles (deg) parameter.

The quantity L equals the length of the Operating frequency vector (Hz).

• If this parameter is a Q-by-P matrix, the same pattern is applied to all frequencies specified in the Operating frequency vector (Hz) parameter.

• If the value is a Q-by-P-by-L array, each Q-by-P page of the array specifies a pattern for the corresponding frequency specified in the Operating frequency vector (Hz) parameter.

Dependencies

To enable this parameter, set Element type to Custom Antenna.

Match element normal to array normal — Match element normal to array normal

on (default) | off

Align directions of the element normals to the direction of the array normal.

Dependencies

This parameter is enabled when Element type is set to Custom Antenna.

Beamwidth of antenna pattern (deg) — Pattern beamwidth

[10,10] (default) | 1-by-2 real-valued vector

Beamwidth of antenna pattern, specified as a 1-by-2 real-valued vector.

Dependencies

This parameter is enabled when Element type is set to Gaussian Antenna.

Polar pattern measuring frequencies — Polar pattern microphone measuring frequencies

1e3 (default) | real scalar | real-valued 1-by-L row vector

Polar pattern microphone measuring frequencies, specified as a real scalar, or a real-valued, 1-by-L vector. The measuring frequencies must lie within the frequency range specified by the Operating frequencies vector.

Dependencies

To enable this parameter, set Element type set to Custom Microphone.

Polar pattern measuring angles — Polar pattern measuring angles

[-180:180] (default) | real-valued 1-by-P row vector

Specify the polar pattern measuring angles, as a 1-by-P vector. The angles are measured from the central pickup axis of the microphone and must lie between –180° and 180°, inclusive.

Dependencies

To enable this parameter, set Element type to Custom Microphone.

Polar pattern (dB) — Custom microphone polar response

zeros(1,361) (default) | real-valued L-by-P matrix

Specify the magnitude of the custom microphone element polar patterns as an L-by-P matrix. L is the number of frequencies specified in Polar pattern measuring frequencies. P is the number of angles specified in Polar pattern measuring angles. Each row of the matrix represents the magnitude of the polar pattern measured at the corresponding frequency specified in Polar pattern measuring frequencies and all angles specified in Polar pattern measuring angles. The pattern is measured in the azimuth plane. In the azimuth plane, the elevation angle is 0° and the central pickup axis is 0° azimuth and 0° elevation. The polar pattern is symmetric around the central axis. You can construct the microphone response pattern in 3-D space from the polar pattern.

Dependencies

To enable this parameter, set Element type to Custom Microphone.

Version History

Introduced in R2014b