RESP = step(H,FREQ,ANG)
Note: H specifies the System object™ on which to run this step method.
The object performs an initialization the first time the step method is executed. This initialization locks nontunable properties 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 call the release method to unlock the object.
Operating frequencies of array in hertz. FREQ is a row vector of length L. Typical values are within the range specified by a property of H.Element. That property is named FrequencyRange or FrequencyVector, depending on the type of element in the array. The element has zero response at frequencies outside that range.
Directions in degrees. ANG can be either a 2-by-M matrix or a row vector of length M.
If ANG is a 2-by-M matrix, each column of the matrix specifies the direction in the form [azimuth; elevation]. The azimuth angle must be between –180 and 180 degrees, inclusive. The elevation angle must be between –90 and 90 degrees, inclusive.
If ANG is a row vector of length M, each element specifies a direction's azimuth angle. In this case, the corresponding elevation angle is assumed to be 0.
Voltage responses of the phased array. The output depends on whether the array supports polarization or not.
Create a 4-element ULA and find the response of each element at the boresight. Plot the array response at 1 GHz for azimuth angles between –180 and 180 degrees.
ha = phased.ULA('NumElements',4); fc = 1e9; ang = [0;0]; resp = step(ha,fc,ang); c = physconst('LightSpeed'); plotResponse(ha,fc,c)
Find and plot the response of an array of 10 microphones. In this example, the Element property matches the acoustic frequency range of a microphone.
hmic = phased.OmnidirectionalMicrophoneElement(... 'FrequencyRange',[20 20e3]); Nele = 10; hula = phased.ULA('NumElements',Nele,... 'ElementSpacing',3e-3,... 'Element',hmic); fc = 100; ang = [0; 0]; resp = step(hula,fc,ang); c = 340; plotResponse(hula,fc,c,'RespCut','Az','Format','Polar');