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James Manns 2024-2-6

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/2079016-follow-up-to-previous-question

编辑： Matt J 2024-2-6

How do I display the calculations for each below?

clc
clear all
f=446000
f = 446000
Gf=10^-4*(sin(pi*(f-10^6)*10^-4)/(pi*(f-10^6)*10^-4))
Gf = -5.4645e-07
% calculate half-power beamwidth
function Bw = half_power_bw(f, Gf)
% Find the index of the maximum value in the magnitude spectrum
[~,imax] = max(abs(Gf));
% Find the indices of the half-power points
i_half_lower = find(abs(Gf) < abs(Gf(imax))/sqrt(2), 1, 'first');
i_half_upper = find(abs(Gf) < abs(Gf(imax))/sqrt(2), 1, 'last');
% Calculate the half-power bandwidth 
Bw = f(i_half_upper) - f(i_half_lower);
end
% null-to-null beamwidth
function Bw = null_to_null_bw(f, Gf)
% Find the first and last nulls of the magnitude spectrum
nulls = find(abs(Gf) == 0);
i_null_lower = nulls(1);
i_null_upper = nulls(end);
% Calculate the null-to-null bandwidth
Bw = f(i_null_upper) - f(i_null_lower);
end
% 99% of power beamwidth
function Bw = power_bw(f, Gf, power_fraction)
% Calculate the total power
total_power = trapz(f, abs(Gf).^2);
% Find the index where the cumulative power reaches the desired fraction
power_integral = cumtrapz(f, abs(Gf).^2);
i_power = find(power_integral >= total_power*power_fraction, 1, 'first');
% Calculate the bandwidth at the desired power fraction
Bw = f(i_power);
end
% Bandwidth beyond which the attenuation is 35 dB.
function Bw = attenuation_bw(f, Gf, attenuation_dB)
% Convert attenuation from dB to linear scale
attenuation_linear = 10^(-attenuation_dB/20);
% Find the index where the magnitude spectrum falls below the attenuation level
i_attenuation = find(abs(Gf) < abs(max(Gf))*attenuation_linear, 1, 'first');
% Calculate the bandwidth beyond the attenuation level
Bw = f(i_attenuation);
end

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Matt J 2024-2-6

编辑：Matt J 2024-2-6

Do we need to know what your previous question was? Some people weren't there.

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Answer 1

Matt J 2024-2-6

0
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此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/2079016-follow-up-to-previous-question#answer_1403986

编辑：Matt J 2024-2-6

在 MATLAB Online 中打开

Just call the function, and omit a semicolon to see what its output is. However, your functions will not give nontrivial results unless f and Gf are vectors of the same size,

f=rand(1,10);
Gf=rand(1,10);
output = half_power_bw(f, Gf)
output = 0.0527
% calculate half-power beamwidth
function Bw = half_power_bw(f, Gf)
% Find the index of the maximum value in the magnitude spectrum
[~,imax] = max(abs(Gf));
% Find the indices of the half-power points
i_half_lower = find(abs(Gf) < abs(Gf(imax))/sqrt(2), 1, 'first');
i_half_upper = find(abs(Gf) < abs(Gf(imax))/sqrt(2), 1, 'last');
% Calculate the half-power bandwidth 
Bw = f(i_half_upper) - f(i_half_lower);
end