www.gusucode.com > phased 案例源码 matlab代码程序 > phased/DirectivityCustomMicrophoneElementExample.m

    %% Directivity of Custom Microphone Element
% Compute the directivity of a custom microphone element. Create a custom
% cardioid microphone, and plot the microphone's response at
% 700 Hz for elevations between -90 and +90 degrees.
%%
% Define the pattern for the custom microphone element. The System object's
% |PolarPatternAngles| property has default value of |[-180:180]| degrees.

% Copyright 2015 The MathWorks, Inc.


myAnt = phased.CustomMicrophoneElement;
myAnt.PolarPatternFrequencies = [500 1000];
myAnt.PolarPattern = mag2db([...
    0.5+0.5*cosd(myAnt.PolarPatternAngles);...
    0.6+0.4*cosd(myAnt.PolarPatternAngles)]);

%%
% Calculate the directivity as a function of elevation at zero degrees
% azimuth.
elev = [-90:5:90];
azm = zeros(size(elev));
ang = [azm;elev];
freq = 700;
d = directivity(myAnt,freq,ang);
plot(elev,d)
xlabel('Elevation (deg)')
ylabel('Directivity (dBi)')
%%
% The directivity is maximum at $0^{\circ}$ elevation.