stackUp

R2026b

Create PCB stackup definition

Description

Use the stackUp object to create a printed circuit board (PCB) stackup definition to import Gerber files. A Gerber file is a set of manufacturing files used to describe a PCB antenna. A Gerber file uses an ASCII vector format for 2-D binary images.

Creation

Syntax

s = stackUp

s = stackUp(NumMetalLayers=Value)

Description

s = stackUp creates a PCB stackUp object with a default of 2 metal layers and at least 5 total layers arranged as dielectric–metal–dielectric–metal–dielectric. Metal layers (layers 2 and 4) accept Gerber files, while dielectric layers (layers 1, 3, and 5) accept dielectric objects.

s = stackUp(NumMetalLayers=Value) creates a PCB stackUp object with the number of metal layers specified by Value. The stackUp object arranges layers in an alternating dielectric–metal pattern, starting and ending with dielectric layers. Odd-indexed layers are dielectric, and even-indexed layers are metal. The total number of layers is computed as 2 × NumMetalLayers + 1, with a minimum of five layers. Unused metal layers remain empty.

Properties

NumMetalLayers — Number of metal layers

2 (default) | integer scalar

Number of metal layers in the PCB stackup, specified as a positive integer.

Example: 4

Data Types: double

NumLayers — Number of layers in stackup

Read-only: 5 (default) | positive scalar

This property is read-only.

Number of layers in the stackup, returned as a positive scalar.

Layer1 — First layer in stackup

dielectric("Air") (default) | dielectric object

First layer in the stackup definition object, specified as a dielectric object.

Example: s = stackUp; d = dielectric("RO4725JXR"); s.Layer1 = d;

Layer2 — Second layer in stackup

character vector | string scalar

Second layer in the stackup definition object, specified as a character vector or string naming a Gerber file. The file must be saved with a .gtl, .gbl, or .gbr extension.

Example: s = stackUp; s.Layer2 = "antenna_design_file.gtl";

Note

You must import the Gerber file to the MATLAB^® workspace before setting this property.

Layer3 — Third layer in stackup

dielectric("FR4") (default) | dielectric object

Third layer in the stackup definition object, specified as a dielectric object.

Example: s = stackUp; d = dielectric("RO4725JXR"); s.Layer3 = d;

Layer4 — Fourth layer in stackup

character vector | string scalar

Fourth layer in the stackup definition object, specified as a character vector or string naming a Gerber file. The file must be saved with a .gtl, .gbl, or .gbr extension.

Example: s = stackUp; s.Layer4 = "antenna_design_file.gbl";

Note

You must import the Gerber file to the MATLAB workspace before setting this property.

Layer5 — Fifth layer in stackup

dielectric("Air") (default) | dielectric object

Fifth layer in the stackup definition object, specified as a dielectric object.

Example: s = stackUp; d = dielectric("RO4725JXR"); s.Layer5 = d;

Examples

Create PC Board Stackup Definition

Create a default PCB stackup definition object.

s = stackUp;

Create a dielectric object with Air as the dielectric material and with a thickness of 0.1 mm.

d1 = dielectric("Air");
d1.Thickness = 0.1e-3;

Create another dielectric object with RO4725JXR as the dielectric material.

d3 = dielectric("RO4725JXR");

Assign the dielectrics to the first and third layers.

s.Layer1 = d1;
s.Layer3 = d3;

Input Gerber files to the second and fourth layers.

s.Layer2 = "antenna_design_file.gtl";
s.Layer4 = "antenna_design_file.gbl";

Display the stackup definition object.

s

s = 
  stackUp with properties:

    NumMetalLayers: 2
         NumLayers: 5
            Layer1: [1×1 dielectric]
            Layer2: "antenna_design_file.gtl"
            Layer3: [1×1 dielectric]
            Layer4: "antenna_design_file.gbl"
            Layer5: [1×1 dielectric]

Create PCB Antenna with Three Metal Layers

Create a stackUp object with three metal layers. Assign Gerber files to the metal layers.

s = stackUp(NumMetalLayers=3);
s.Layer2='TopLayer.gtl';
s.Layer4='InnerCopperLayer.g2l';
s.Layer6='BottomLayer.gbl'

s = 
  stackUp with properties:

    NumMetalLayers: 3
         NumLayers: 7
            Layer1: [1×1 dielectric]
            Layer2: 'TopLayer.gtl'
            Layer3: [1×1 dielectric]
            Layer4: 'InnerCopperLayer.g2l'
            Layer5: [1×1 dielectric]
            Layer6: 'BottomLayer.gbl'
            Layer7: [1×1 dielectric]

Use the PCBReader object to import the PCB layout defined in the stackUp object. Specify the drill file and layer connectivity.

p = PCBReader(StackUp=s);
p.DrillLayerPairs = [1,3];
p.DrillFile = {'drillFile.txt'};

Convert the design into a PCB antenna using the pcbStack object. Define the feed properties.

pcbAnt = pcbStack(p);
pcbAnt.FeedDiameter = 0.5e-3;
pcbAnt.FeedLocations = [-5e-3 5e-3 2]

pcbAnt = 
  pcbStack with properties:

              Name: 'TopLayer'
          Revision: 'v1.0'
        BoardShape: [1×1 antenna.Rectangle]
    BoardThickness: 0.0121
            Layers: {[1×1 dielectric]  [1×1 antenna.Polygon]  [1×1 dielectric]  [1×1 antenna.Polygon]  [1×1 dielectric]  [1×1 antenna.Polygon]  [1×1 dielectric]}
        FeedFormat: 'FeedLocations'
     FeedLocations: [-0.0050 0.0050 2]
      FeedDiameter: 5.0000e-04
      ViaLocations: [-0.0060 0.0071 2 6]
       ViaDiameter: 1.0000e-03
      FeedViaModel: 'square'
       FeedVoltage: 1
         FeedPhase: 0
         Conductor: [1×1 metal]
              Tilt: 0
          TiltAxis: [1 0 0]
              Load: [1×1 lumpedElement]
        SolverType: 'MoM'

Visualize the PCB antenna.

figure
show(pcbAnt)
title("PCB Antenna")

Version History

Introduced in R2020b

R2026b: Specify number of metal layers

You can now specify the number of metal layers in the PCB stackup using the new NumMetalLayers property.