The CustomMicrophoneElement object creates a custom microphone element.
To compute the response of the microphone element for specified directions:
H = phased.CustomMicrophoneElement creates a custom microphone system object, H, that models a custom microphone element.
H = phased.CustomMicrophoneElement(Name,Value) creates a custom microphone object, H, with each specified property set to the specified value. You can specify additional name-value pair arguments in any order as (Name1,Value1,...,NameN,ValueN).
Operating frequency vector
Specify the frequencies in hertz where the frequency responses of element are measured as a vector. The elements of the vector must be increasing. The microphone element has no response outside the specified frequency range.
Default: [0 1e20]
Specify the frequency responses in decibels measured at the frequencies defined in the FrequencyVector property as a row vector. The length of the vector must equal the length of the frequency vector specified in the FrequencyVector property.
Default: [0 0]
Polar pattern measuring frequencies
Specify the measuring frequencies in hertz of the polar patterns as a row vector of length M. The measuring frequencies must be within the frequency range specified in the FrequencyVector property.
Polar pattern measuring angles
Specify the measuring angles in degrees of the polar patterns as a row vector of length N. The angles are measured from the central pickup axis of the microphone, and must be between –180 and 180, inclusive.
Specify the polar patterns of the microphone element as an M-by-N matrix. M is the number of measuring frequencies specified in the PolarPatternFrequencies property. N is the number of measuring angles specified in the PolarPatternAngles property. Each row of the matrix represents the magnitude of the polar pattern (in decibels) measured at the corresponding frequency specified in the PolarPatternFrequencies property and corresponding angles specified in the PolarPatternAngles property. The pattern is assumed to be measured in the azimuth plane where the elevation angle is 0 and where the central pickup axis is assumed to be 0 degrees azimuth and 0 degrees elevation. The polar pattern is assumed to be symmetric around the central axis and therefore the microphone's response pattern in 3-D space can be constructed from the polar pattern.
Default: An omnidirectional pattern with 0 dB response everywhere
|clone||Create omnidirectional microphone object with same property values|
|directivity||Directivity of custom microphone element|
|getNumInputs||Number of expected inputs to step method|
|getNumOutputs||Number of outputs from step method|
|isLocked||Locked status for input attributes and nontunable properties|
|plotResponse||Plot response pattern of microphone|
|release||Allow property value and input characteristics changes|
|step||Output response of microphone|
Create a custom Cardioid microphone, and calculate that microphone's response at response at 500, 1500, and 2000 Hz in the directions [0;0] and [40;50].
h = phased.CustomMicrophoneElement; h.PolarPatternFrequencies = [500 1000]; h.PolarPattern = mag2db([... 0.5+0.5*cosd(h.PolarPatternAngles);... 0.6+0.4*cosd(h.PolarPatternAngles)]); resp = step(h,[500 1500 2000],[0 0;40 50]'); plotResponse(h,500,'RespCut','Az','Format','Polar');
The total response of a custom microphone element is a combination of its frequency response and spatial response. phased.CustomMicrophoneElement calculates both responses using nearest neighbor interpolation and then multiplies them to form the total response. When the PolarPatternFrequencies property 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.