Filed II 绘制超声 3D/2D 点扩散函数

点扩散函数可以较好地描述超声对成像目标分辨能力，利用 filed II 仿真工具实现点扩算函数 PSF 的 3D 和 2D 绘制。

定义换能器基本参数

f0=5e6; % Transducer center frequency [Hz]
fs=100e6; % Sampling frequency [Hz]
c=1540; % Speed of sound [m/s]
width=0.15/1000; % Width of element
element_height=10/1000; % Height of element [m]
kerf=0.05/1000; % Kerf [m]
focus=[0 0 60]/1000; % Fixed focal point [m]
N_elements=64; % Number of physical elements

设置发射接收换能器

aperture = xdc_linear_array (N_elements, width, element_height, kerf, 1, 1, focus);
excitation=sin(2*pi*f0*(0:1/(fs):3/f0));
excitation=excitation.*hanning(max(size(excitation)))';
xdc_excitation (aperture, excitation);
xdc_impulse (aperture, excitation);

计算点扩散函数PSF

对比增加变迹函数后的PSF

# 设置汉宁窗变迹
xdc_apodization (aperture, 0, hanning(N_elements)');