System object: phased.CustomMicrophoneElement
Output response of microphone
RESP = step(H,FREQ,ANG)
Starting in R2016b, 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,
y = step(obj,x) and
y = obj(x) perform equivalent operations.
The object performs an initialization the first time the object 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
release method to unlock the object.
Frequencies in hertz.
Directions in degrees.
Response of microphone.
Construct a custom cardioid microphone with an operating frequency of 500 Hz. Find the microphone response in the directions: (0,0) degrees azimuth and elevation and (40,50) degrees azimuth and elevation.
sCustMic = phased.CustomMicrophoneElement; sCustMic.PolarPatternFrequencies = [500 1000]; sCustMic.PolarPattern = mag2db([... 0.5+0.5*cosd(sCustMic.PolarPatternAngles);... 0.6+0.4*cosd(sCustMic.PolarPatternAngles)]); fc = 700; ang = [0 0; 40 50]'; resp = step(sCustMic,fc,ang)
resp = 2×1 1.0000 0.7424
The total response of a custom microphone element is a combination
of its frequency response and spatial response.
both responses using nearest neighbor interpolation and then multiplies
them to form the total response. When the
value is nonscalar, the object specifies multiple polar patterns.
In this case, the interpolation uses the polar pattern that is measured
closest to the specified frequency.