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step

System object: phased.OmnidirectionalMicrophoneElement
Namespace: phased

Output response of microphone

Syntax

RESP = step(H,FREQ,ANG)

Description

Note

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.

RESP = step(H,FREQ,ANG) returns the microphone’s magnitude response, RESP, at frequencies specified in FREQ and directions specified in ANG.

Note

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 call the release method to unlock the object.

Input Arguments

H

Microphone object.

FREQ

Frequencies in hertz. FREQ is a row vector of length L.

ANG

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.

Output Arguments

RESP

Response of microphone. RESP is an M-by-L matrix that contains the responses of the microphone element at the M angles specified in ANG and the L frequencies specified in FREQ.

Examples

expand all

Create an omnidirectional microphone. Find the microphone response at 200, 300, and 400 Hz for the incident angle 0° azimuth and 0° elevation. Then, plot the azimuth response of the microphone at three frequencies.

microphone = phased.OmnidirectionalMicrophoneElement;
microphone.FrequencyRange=[20 2e3];
fc = [200 300 400];
ang = [0;0];
resp = microphone(fc,ang);

Plot the response pattern. The response patterns for at all three frequencies are the same.

pattern(microphone,fc,-180:180,0,'CoordinateSystem','polar','Type','power');