k-Wave User Forum » Topic: Multiple transducers with different frequencies

k-Wave User Forum » Topic: Multiple transducers with different frequencies http://www.k-wave.org/forum/topic/multiple-transducers-with-different-frequencies Support for the k-Wave MATLAB toolbox en-US Wed, 13 May 2026 09:02:50 +0000 http://bbpress.org/?v=1.0.2 <![CDATA[Search]]> q http://www.k-wave.org/forum/search.php Bradley Treeby on "Multiple transducers with different frequencies" http://www.k-wave.org/forum/topic/multiple-transducers-with-different-frequencies#post-7453 Fri, 01 May 2020 08:21:43 +0000 Bradley Treeby 7453@http://www.k-wave.org/forum/ Hi knaftchi, It looks like you have a single source term in <code>source.p</code>. If you want to use different source terms for different grid points (the points that are set to 1 in <code>source.p_mask</code>) you need to define <code>source.p</code> as a matrix indexed as <code>(source_index, time_index)</code>. The indexing follows MATLAB's column-wise matrix indexing. There are some more details in the manual if you need them. Brad. knaftchi on "Multiple transducers with different frequencies" http://www.k-wave.org/forum/topic/multiple-transducers-with-different-frequencies#post-7426 Mon, 20 Apr 2020 19:29:14 +0000 knaftchi 7426@http://www.k-wave.org/forum/ Hi, I am trying to set up two transducers with two different frequencies. The code runs, but the problem is I am not able to set independent frequencies for each transducer. For instance, if I want freq1 for the first transducer and freq2 for the second transducer, it runs both transducers at freq1+freq2! Could you please help me figure out where I am making a mistake? Thanks!! '% ========================================================================= % SIMULATION % ========================================================================= n = 2; % use this parameter to modulate the number % of grid points. % create the computational grid Nx = n * 216; % number of grid points in the x (row) direction Ny = n * 216; % number of grid points in the y (column) direction dx = 160e-3/Nx; % grid point spacing in the x direction [m] dy = dx; % grid point spacing in the y direction [m] kgrid = kWaveGrid(Nx, dx, Ny, dy); % define the properties of the propagation medium medium.sound_speed = 1500 * ones(Nx, Ny); % [m/s] medium.alpha_coeff = 0.75; % [dB/(MHz^y cm)] medium.alpha_power = 1.5; medium.density = 1000 * ones(Nx, Ny); %[kg/m^3] % create the time array kgrid.makeTime(medium.sound_speed); % define the first curved transducer element arc_pos_1 = [Nx/2 - 1, 1]; % [grid points] radius_1 = n * 108; % [grid points] diameter_1 = n * 81 + 1; % [grid points] focus_pos_1 = [Nx/2, Ny/2]; % [grid points] source_1.p_mask = makeArc([Nx, Ny], arc_pos_1, radius_1, diameter_1, focus_pos_1); source_freq_1 = 1.0e6; % [Hz] source_mag_1 = 0.5; % [Pa] source_1.p = source_mag_1 * sin(2 * pi * source_freq_1 * kgrid.t_array); % filter the source to remove high frequencies not supported by the grid source_1.p = filterTimeSeries(kgrid, medium, source_1.p); % define the second curved transducer element arc_pos_2 = [1, Ny/2]; % [grid points] radius_2 = n * 108; % [grid points] diameter_2 = n * 81 + 1; % [grid points] focus_pos_2 = [Nx/2, Ny/2]; % [grid points] source_2.p_mask = makeArc([Nx, Ny], arc_pos_2, radius_2, diameter_2, focus_pos_2); source_freq_2 = 0.5e6; % [Hz] source_mag_2 = 0.50; % [Pa] source_2.p = source_mag_2 * sin(2 * pi * source_freq_2 * kgrid.t_array); % filter the source to remove high frequencies not supported by the grid source_2.p = filterTimeSeries(kgrid, medium, source_2.p); % combine the two sources source.p = source_1.p + source_2.p; % filter the final source source.p = filterTimeSeries(kgrid, medium, source.p); % create a display mask to display the transducer source.p_mask = source_1.p_mask + source_2.p_mask; % create a sensor mask covering the entire computational domain using the % opposing corners of a rectangle sensor.mask = [1, 1, Nx, Ny].'; % set the record mode capture the final wave-field and the statistics at % each sensor point sensor.record = {'p', 'p_max', 'u'}; % assign the input options input_args = {'DisplayMask', source.p_mask, 'PMLInside', false, 'PlotPML', false}; % run the simulation sensor_data = kspaceFirstOrder2D(kgrid, medium, source, sensor, input_args{:});'