viaSingleEnded

Create single ended via in PCB stack

Since R2023a

Description

Use the viaSingleEnded object to create a single-ended via model within a printed circuit board (PCB) stack.

A vertical interconnect access (via) is an essential part of a multilayer PCB. You can use vias to create an electrical connection between the different layers in a PCB. You can construct vias by placing copper pads on each layer of the PCB and drilling a hole through the pads, using a non-conductive material in the inner layer of the via and a conductive plating on the outer layer.

A via consists of:

1. Barrel — Conductive tube filling the drilled hole

2. Pad — Connects each end of the barrel to a component, plane, or trace

3. Antipad — Clearance hole between the barrel and metal layer

In a multilayer PCB, vias reduce the length over which you need to route a trace to complete its connection. Smaller the via, the better the performance of the circuit.

Note

In this release, viaSingleEnded only supports behavioral model analysis of s-parameters. For more information, see Behavioral Models.

Creation

Syntax

via = viaSingleEnded

via = viaSingleEnded(number of dilectric layers)

via = viaSingleEnded(Name=Value)

Description

via = viaSingleEnded creates a single-ended via with default properties. This via has one dielectric layer, two ground layers, one signal via, and one ground return via.

via = viaSingleEnded(number of dilectric layers) returns a single-ended via based on the number of dielectric layers.

via = viaSingleEnded(Name=Value) sets Properties using one or more name-value arguments. For example, viaSingleEnded(ViaDiameter=0.0065) creates a single-ended via with a diameter of 0.0065 meters. Properties not specified retain their default values

Properties

SignalViaDiameter — Diameter of signal via(s) barrel

2.5000e-04 (default) | scalar | vector

Diameter of the signal via(s) barrel in meters, specified as a scalar or a vector. if this is a vector, the size is equal to the number of signal vias.

Example: via = viaSingleEnded(SignalViaDiameter=0.0045)

Data Types: double

SignalViaLocations — Location of signal via(s)

[0 0 1 3] (default) | N-by-4 matrix

Location of the signal via(s) in Cartesian coordinates, specified as a N-by-4 matrix, where N is the number of signal vias. The first and the second column corresponds to the X and Y coordinates of the via in meters, respectively. The third and the fourth columns corresponds to layer where the via starts and stops, respectively.

Note

All vias start at layer 1. This object only supports through vias.

Example: via = viaSingleEnded(SignalViaLocations=[0.5 0.25 1 5])

Data Types: double

GroundReturnViaDiameter — Diameter of ground return via(s)

2.5000e-04 (default) | scalar | vector

Diameter of the ground return via(s) in meters, specified as a scalar or a vector. If this property is a vector, the size of the vector is equal to the number of ground return vias.

Example: via = viaSingleEnded(GroundReturnViaDiameter=0.0045)

Data Types: double

GroundReturnViaLocations — Location(s) of ground return via(s)

[1e-3 1e-3 1 3] (default) | scalar | M-by-4 matrix

Location(s) of the ground return via(s) in Cartesian coordinates, specified as an M-by-4 matrix, where M represents the number of ground return vias in the PCB stack. The first and the second column corresponds to the X and Y coordinates, respectively, of the via in meters. The third and the fourth columns corresponds to layer where the via starts and stops, respectively.

Note

All vias start at layer 1. This object only supports through vias.

Example: via = viaSingleEnded(GroundReturnViaLocations=[1 1 1 5])

Data Types: double

GroundLayer — Position of ground layers in PCB stack

[1 3] (default) | positive integer vector

Position of the ground layers in the PCB stack, specified as a positive integer vector. The start and stop layers should be among the ground layers.

Example: via = viaSingleEnded(GroundLayer=[1 4 6])

Data Types: double

SignalViaAntipad — Shape of signal via antipad

antenna.circle shape object (default)

Shape of the signal via antipad, specified as an antenna shape object. For this release, the shape is limited to circle.

Example: obj = viaSingleEnded('SignalViaLocations',[0 0 1 3;3e-3 -3e-3 1 3]); obj.SignalViaAntipad = [antenna.Circle('Radius',6e-4) antenna.Circle('Radius',8e-4)];

Substrate — Type of dielectric material

'FR4' (default) | dielectric object

Type of dielectric material used as a substrate, specified as a dielectric object. The thickness of the default dielectric material FR4 is 0.000127 m. The object supports a heterogeneous substrate, but if you position the substrate in the region between consecutive conducting planes.

Example: obj = viaSingleEnded(2);d = dielectric("FR4", "Teflon");d.Thickness = [1e-4 1e-4];obj.Substrate = d;

Data Types: string | char

Object Functions

criticalwavelength	Number of wavelengths between signal via and ground return vias
gapratedistance	Gap rate distance metric
layout	Plot all metal layers and board shape
shapes	Extract all metal layer shapes of PCB component
show	Display PCB component structure or PCB shape
sparameters	Calculate S-parameters for RF PCB objects

Examples

Single-Ended Via with Default Properties

Create a single-ended via with default properties.

via = viaSingleEnded

via = 
  viaSingleEnded with properties:

          SignalViaLocations: [0 0 1 3]
           SignalViaDiameter: 2.5000e-04
    GroundReturnViaLocations: [1.0000e-03 1.0000e-03 1 3]
     GroundReturnViaDiameter: 2.5000e-04
                 GroundLayer: [1 3]
            SignalViaAntipad: [1x1 antenna.Circle]
                   Substrate: [1x1 dielectric]

View the via.

show(via)

Single-Ended Vias with Ground Return Via

Create a single-ended via.

via = viaSingleEnded;

Create signal via locations and the ground return via locations.

via.SignalViaLocations = [1,2,1,7];
via.GroundLayer = [1 7];
via.GroundReturnViaLocations = [1.0015,2.001,1,7;1.0015,1.999,1,7; ...
           0.999,1.999,1,7;1,2.0015,1,7;0.999,2.001,1,7;1.0001,1.9987,1,7];
via.Substrate = dielectric("Name","FR4","EpsilonR",4.8,...
               "LossTangent",0.026,"Thickness",1.27e-4,"Frequency",1e8);

View the via.

show(via)    

References

[1] Steinberger, Telian, Tsuk, Iyer and Yanamadala, “Proper Ground Via Placement for 40+ Gbps Signaling”, DesignCon 2022, April 2022.

[2] Ramo, Whinnery and Van Duzer, Fields and Waves in Communications Electronics, third edition, section 9.3, John Wiley and Sons Inc., copyright 1994

Version History

Introduced in R2023a