Where To Find This Example
AWR Version 14
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This example was renamed since the previous version. Please see Previous Example Page for the version 13 page.
Bondwires and Finite Dielectrics
This example demonstrates Analyst EM extraction and simulation of finite dielectrics and bondwires.
Simulating this project is time-consuming. This example, with the datasets included, is available at: http://kb.awr.com/display/Examples/Bond_Wires_and_Finite_Dielectrics.
This example shows how to model a bond wire connection from one board into another. The dielectric properties and substrate heights are different on each board. The 50 Ohm microstrip line on each board is connected using a bond wire. The boards share a common ground. We study a situation in which there is a small (air) gap between the boards and a situation when there is no such gap present.
Finite Dielectric Setup
In order to accurately model the finite dielectric and bondwires, the EXTRACT blocks in each schematic will need to be enabled prior to simulation to initiate Analyst simulation.
The finite dielectrics are defined in the STACKUP element in Global Definitions. In the Dielectric tab, Air is defined as an infinite dielectric layer. The finite dielectrics are introduced by appropriate material definition under Material Defs tab. In this example, they are Diel_1 and Diel_2. Then those dielectric materials are assigned to traces in the Materials tab. In this example, the dielectric traces are PCB1 and PCB2. The negative heights of dielectrics are set such that the two PCBs extrude downwards. Then those traces are mapped to Drawing Layers on the EM Layer Mapping tab. With this setup, one PCB occupies EM layer 3 while the other occupies EM layers 2&3. Shapes drawn on PCB1 or PCB2 now represents finite dielectrics.
For extraction, the finite dielectric shapes are drawn in the schematic layout. Then those shapes are enabled for extraction in the Layout tab of the Shape Properties window.
For 3D EM Extraction, three additional steps are necessary:
The Z position for 3D EM elements, such as BWIRES must be defined for proper placement. In this example the element parameters of the BWIRES are set relative to the bottom ground. So it must be placed on the bottom of the enclosure (Z=0). The Z position is set by selecting the element in schematic layout, Right Click > Shape Properties > Layout tab.
The Boundary is added by drawing a shape in schematic layout, and then selecting the shape and choosing Draw > Create Simulation Boundary. Set boundary conditions on the Boundary shape, and then enable it for extraction in the same manner the finite dielectrics were enabled.
Circuit versus EM results can be compared by toggling ON/OFF Extract blocks. All results agree reasonably well.
Schematic - Bondwire_circuit_model_Gap
EM Structure 3D - Gap_EM_Extract_Doc
EM Structure 3D - No_Gap_EM_Extract_Doc
Graph - Sparameters