xdc_focus_times for 2D array transducer in Field2

Hi,

I'm trying to simulate time delays for each element in a 2D array transducer using field2 program.

I only managed to use the xdc_focus_times function to add delays for 1D array and not 2D.

Is there any way to do it for 2D transducer created with xdc_2d_array() ?

thank you in advance.

Answer 1

[karthik kumar k]

To set delays for a 2D transducer array in Field II, calculate the delays for each element and use xdc_focus() to apply the focus. Here's how:Steps:

1. Create the 2D Array:

Nx = 16; Ny = 16; % Number of elements
width = 0.5e-3; height = 0.5e-3; % Element dimensions
kerf_x = 0.1e-3; kerf_y = 0.1e-3; % Spacing
focus = [0, 0, 0.04]; % Focus point
Th = xdc_2d_array(Nx, Ny, width, height, kerf_x, kerf_y, focus);

2. Calculate Delays:

c = 1540; % Speed of sound (m/s)
[elem_x, elem_y] = ndgrid(...
    linspace(-Nx/2, Nx/2-1, Nx) * (width + kerf_x), ...
    linspace(-Ny/2, Ny/2-1, Ny) * (height + kerf_y));
element_positions = [elem_x(:), elem_y(:), zeros(numel(elem_x), 1)];
delays = sqrt(sum((element_positions - focus).^2, 2)) / c;

3. Assign Delays:

xdc_focus(Th, 0, delays);