155 lines
4.8 KiB
OpenSCAD
155 lines
4.8 KiB
OpenSCAD
include <idt.scad>
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include <bond_pad.scad>
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// creates the input and output idts
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// [TODO] clean this
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module bi_directional_idt(
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c,
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f,
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n_fingers,
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distance = 100,
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finger_length = 50,
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gap = 0,
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thickness = 0,
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impedance = 50,
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// bond pad prams
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has_bond_pads = false,
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bond_pad_leg_length = 0.00005,
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bond_pad_leg_width = 0.00001875,
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bond_pad_size = 0.000075,
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bond_pad_angle = 45,
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bond_pad_bond_pad_shape = "square",
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// id number prams
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id_number = 0,
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has_id = false,
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id_scale = [1, 1, 1],
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id_translate = [0, 0, 0],
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id_rot = [0, 0, 0],
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// extra
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post_scale = 1,
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echo_stats = false,
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center = false
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) {
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lambda = c/f * post_scale;
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// dont worry about these magic fractions
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length_of_input = n_fingers*lambda+1.74*lambda;
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should_be_centered = center ? 1 : 0;
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center_offset_y = length_of_input + distance * lambda/2;
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center_offset_x = finger_length*lambda/2 + gap/2 + thickness;
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translate([-center_offset_x * should_be_centered, -center_offset_y * should_be_centered, 0]) {
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if (has_id) {
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color([255/255, 0/255, 255/255])
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translate([finger_length*lambda/2, has_bond_pads ? -(bond_pad_leg_length * post_scale * cos(bond_pad_angle)) : -lambda*finger_length/2, 0])
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translate(id_translate)
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rotate(id_rot)
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scale(id_scale)
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text(str(id_number), size=id_text_size, halign="center");
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}
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// echo(str("lambda_scale = ", post_scale));
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delay_line(lambda, n_fingers, finger_length, gap, thickness);
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color([0/255, 255/255, 128/255]) {
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translate([0, distance*lambda+length_of_input, 0]) {
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delay_line(lambda, n_fingers, finger_length, gap, thickness);
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}
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}
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// near ori
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rotate([0, 0, -90]) {
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if (has_bond_pads) {
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color([255/255, 255/255, 255/255]) {
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bond_pad(
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leg_length_tweak = lambda/4,
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leg_width=c/f/4,
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leg_length=length(
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[0,0,0],
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[bond_pad_leg_length, bond_pad_leg_length, 0]
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),
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leg_angle = -bond_pad_angle,
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size = bond_pad_size,
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post_scale=scale_unit
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);
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}
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}
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}
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// near side
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translate([lambda*finger_length+gap+thickness*2+lambda, 0, 0]) {
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rotate([0, 0, -90]) {
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if (has_bond_pads) {
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bond_pad(
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leg_length_tweak = lambda/5,
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leg_width=c/f/4,
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leg_length=length(
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[0,0,0],
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[bond_pad_leg_length, bond_pad_leg_length, 0]
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),
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leg_angle = bond_pad_angle,
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size = bond_pad_size,
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post_scale=scale_unit
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);
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}
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}
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}
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// far side
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translate([0, length_of_input+distance*lambda+length_of_input, 0]) {
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rotate([0, 0, 90]) {
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if (has_bond_pads) {
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bond_pad(
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leg_length_tweak = lambda/5,
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leg_width=c/f/4,
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leg_length=length(
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[0,0,0],
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[bond_pad_leg_length, bond_pad_leg_length, 0]
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),
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leg_angle = bond_pad_angle,
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size = bond_pad_size,
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post_scale=scale_unit
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);
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}
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}
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// furthest side
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translate([lambda*finger_length+gap+thickness*2+lambda, 0, 0]) {
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rotate([0, 0, 90]) {
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if (has_bond_pads) {
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bond_pad(
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leg_length_tweak = lambda/4,
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leg_width=c/f/4,
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leg_length=length(
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[0,0,0],
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[bond_pad_leg_length, bond_pad_leg_length, 0]
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),
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leg_angle = -bond_pad_angle,
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size = bond_pad_size,
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post_scale=scale_unit
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);
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}
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}
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}
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}
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}
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if (echo_stats) {
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echo("===== DELAY LINE IDT INFO ===== ");
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echo(str("lambda = ", lambda));
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echo(str("min feature size lambda/4 = ", lambda/4));
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echo(str("impedance = ", impedance));
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echo(str("total capacitance = ", 1/(2*PI*f*impedance)));
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echo("===== DELAY LINE IDT INFO ===== ");
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}
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}
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