System object: phased.IsotropicProjector
Voltage response of isotropic projector
resp = step(projector,freq,ang)
Instead of using the
step method to perform
the operation defined by the System
object™, you can call the object
with arguments, as if it were a function. For example,
= step(obj,x) and
y = obj(x) perform
The object performs an initialization the first time the object is executed. This
initialization locks nontunable properties (MATLAB)
and input specifications, such as dimensions, complexity, and data type of the input data.
If you change a nontunable property or an input specification, the System
object issues an error. To change nontunable properties or inputs, you must first
release method to unlock the object.
freq— Voltage response frequencies
Voltage response frequencies of projector, specified as a positive real scalar or a real-valued 1-by-L vector of positive values. Units are in Hz.
ang— Direction of arriving signals
Direction of arriving signals, specified as a real-valued 1-by-M row
vector or 2-by-M matrix. When
a 2-by-M matrix, each column of the matrix specifies
the direction in the form
The azimuth angle must lie between –180° and 180°,
inclusive. The elevation angle must lie between –90° and
ang is a 1-by-M row
vector, each element specifies the azimuth angle of the arriving signal.
In this case, the corresponding elevation angle is assumed to be zero.
Examine the response and patterns of an isotropic projector operating between 1 kHz and 10 kHz.
Set the projector parameters and obtain the voltage response at five different elevation angles: -30°, -15°, 0°, 15° and 30°. All elevation angles at 0° azimuth angle. The voltage response is computed at 2 kHz.
projector = phased.IsotropicProjector('FrequencyRange',[1,10]*1e3); fc = 2e3; resp = projector(fc,[0,0,0,0,0;-30,-15,0,15,30]);
Draw a 3-D plot of the voltage response.
pattern(projector,fc,[-180:180],[-90:90],'CoordinateSystem','polar', ... 'Type','power')
Examine the response and patterns of an isotropic projector at three different frequencies. The projector operates between 1 kHz and 10 kHz. Specify the voltage response as a vector.
Set up the projector parameters, and obtain the voltage response at 45° azimuth and 30° elevation. Compute the responses at signal frequencies of 2, 5, and 7 kHz.
projector = phased.IsotropicProjector('FrequencyRange',[1 10]*1e3, ... 'VoltageResponse',[90 95 100 95 90]); fc = [2e3 5e3 7e3]; resp = projector(fc,[45;30]); resp
resp = 1×3 0.0426 0.0903 0.0708
Next, draw a 2-D plot of the voltage response as a function of azimuth
pattern(projector,fc,[-180:180],0,'CoordinateSystem','rectangular', ... 'Type','power')
The total response of a projector is a combination of its frequency
response and spatial response.
both responses using nearest neighbor interpolation, and then multiplies
the responses to form the total response.