PCBReader

Import and update Gerber files

Since R2020b

Description

Use the PCBReader object to create a printed circuit board (PCB) reader to import Gerber files and to facilitate the creation of an antenna model. A Gerber file is a set of manufacturing files used to describe a PCB antenna. A Gerber file uses an ASCII vector format to describe 2-D binary images.

Creation

You can create a PCBReader object using the following methods:

• gerberRead — Create a PCBReader object with the specified Gerber and drill files.

• The PCBReader function described here.

Syntax

B = PCBReader(S)

B = PCBReader(Name,Value)

Description

B = PCBReader(S) creates a PCBReader object that imports multilayer PCB antenna design files described in the stackUp object.

Note

• To translate the center of an imported symmetrical or asymmetrical polygon to [0,0] please use the following MATLAB^® functions, boundingbox and centroid. See examples.

• The PCBReader object reads RS-274X Gerber files. It does not support RS-274D Gerber files.

B = PCBReader(Name,Value) sets Properties using name-value pairs. For example, B = PCBReader('StackUp',S,'Drillfile','ant.txt') imports the layer and drill files into the PCBReader. You can specify multiple name-value pairs. Enclose each property name in quotes. Properties not specified retain their default values.

Input Arguments

S — PCB stackup definition

stackUp object

PCB stackup definition, specified as a stackUp object. For more information, see stackUp.

Example: S = stackUp; B = PCBReader(S)

Example: B = PCBReader('StackUp',S)

Properties

StackUp — PCB stackup definition

stackUp object

PCB stackup definition, specified as a stackUp object.

Example: S = stackUp; B.StackUp = S;

Example: B = PCBReader('StackUp',S)

DrillFile — Name of Excellon drill file

[ ] (default) | character vector | string scalar

Name of Excellon drill file, specified as a character vector or string scalar. You can specify either a DRL or a TXT file.

Example: B.DrillFile = 'ant.drl'

NumPointsOnCurves — Discretization points on curved segments

50 (default) | positive scalar

Discretization points on curved segments, specified as a positive scalar.

Example: B.NumPointsOnCurves = 80

Object Functions

shapes

Extract and modify metal layers from PCBReader object

Examples

Import Gerber Files Using PCB Stackup Definition

Create a default PCB stackup definition object.

S = stackUp;

Set the thickness of the dielectric Air in layer 1 and layer 5 of the stackUp object to 0.1 mm.

S.Layer1.Thickness = 0.1e-3;
S.Layer5.Thickness = 0.1e-3;

Import a top layer Gerber file to layer 2.

S.Layer2 = 'antenna_design_file.gtl';

Import a bottom layer Gerber file to layer 4.

S.Layer4 = 'antenna_design_file.gbl';

Create a PCBReader object, B, using the stackUp object, S.

B = PCBReader('StackUp',S);

Update and Analyze Imported Gerber File

Create a default PCB stackup definition object.

s = stackUp;

Import a top layer Gerber file to layer 2.

s.Layer2 = 'patchMicrostripCircular_design_file.gtl';

Create a PCBReader object using the stackUp object.

p = PCBReader('StackUp',s);

To update the Gerber file, convert the PCBReader object to a pcbStack object.

p3 = pcbStack(p);

View the pcbStack object.

figure
show(p3)

Update the feed diameter.

p3.FeedDiameter = 0.005;

View the updated pcbStack object.

figure
show(p3)

Plot the current distribution on the antenna at 2.4 GHz.

figure
current(p3,2.4e9)

Extract Metal from Two-Layer Design PCBReader Object

Create a PCBReader object.

B = PCBReader;

Import a two-layer design.

st = B.StackUp;
st.Layer2 = 'UWBVivaldi.gtl';
st.Layer4 = 'UWBVivaldi.gbl';
B.StackUp = st;

Extract shapes from the metal layers.

S = shapes(B);

View the top-layer Gerber file.

figure
show(S(1))

View the bottom-layer Gerber file.

figure
show(S(2))

Translate Center of Imported Symmetrical Polygon to [0,0]

This example will show how to translate the symmetrical polygon imported from the Gerber file to the respective co-ordinates.

Create a PCB stackup and import rectangular patch on it.

S = stackUp;
S.Layer2 = 'PatchRectangular.gtl';
S.Layer3 = dielectric('Teflon');

Use a PCB Reader to read the polygon shape from the stackup.

p1 = PCBReader ('StackUp',S);
figure; show(p1.shapes);

Translate the shape with center (0,0) using the centriod function from MATLAB.

s = p1.shapes

s = 
  Polygon with properties:

        Name: 'mypolygon'
    Vertices: [4x3 double]

polygon = s;
[x,y] = centroid(polygon);
translate(polygon,[-x, -y, 0]);

Translate Center of Imported Asymmetrical Polygon to [0,0]

This example shows how to translate the asymmetrical polygon imported from the Gerber file to the respective co-ordinates.

Create a PCB stackup and import rectangular patch on it.

S = stackUp;
S.Layer2 = 'RightAngleBend.gtl';
S.Layer3 = dielectric('Teflon');

Use a PCB Reader to read the polygon shape from the stackup.

p1 = PCBReader ('StackUp',S);
figure; show(p1.shapes);

Translate the shape's bottom left corner to (0,0). Use the boundingbox function from MATLAB to convert the shape to polyshape and find the upper and lower bounds of the shape.

s = p1.shapes

s = 
  Polygon with properties:

        Name: 'mypolygon'
    Vertices: [6x3 double]

ver = s.Vertices(:,1:2);
polygon = polyshape(ver);
[xlim, ylim] = boundingbox(polygon);
translate(s,[-xlim(1), -ylim(1), 0]);

Version History

Introduced in R2020b