Chapter 5: Excitations 14. 0 Release
Chapter 1.5: Excitations Introduction
Introduction to ANSYS HFSS
to ANSYS HFSS
Excitations • Ports – Ports are a unique type of boundary condition that allows energy to flow into and out of a structure. You can assign a port to any 2D object or 3D object face. Before the full three-dimensional electromagnetic field inside a structure can be calculated, it is necessary to determine the excitation field pattern at each port. HFSS uses an arbitrary port solver to calculate the natural field patterns or modes that can exist inside a transmission structure with the same cross section as the port. The resulting 2D field patterns serve as boundary conditions for the full three-dimensional problem.
• By default HFSS assumes assumes that all all structures structures are completely completely encased encased in a conductive conductive shield shield with no energy energy propagating through it. You apply Wave Ports to the structure to indicate the area were the energy enters and exits the conductive shield. • As an alter alternat native ive to usin using g Wave Ports, Ports, you can can apply apply Lumped Ports to a structure instead. Lumped Ports are useful for modeling internal ports within a structure. – Network Parameters
• HFSS uses uses the incident and reflected reflected energy energy at the port to compute compute Generalized Generalized S-Parameters S-Parameters – Generalized S-parameters normalize the S-parameters by the port’s (transmission line’s) characteristic impedance
• Y and Z parameters parameters are are then derived from these these generalize generalized d S-parameter S-parameters s • Port are the the only excitations excitations that that can be used used to compute compute Network Network Parameters Parameters (S, Y and Z Parameters) Parameters)
ANSYS, Inc. Proprietary 5-2 ©Proprietary 2012 ANSYS, ANSYS, Inc. © 2009 ANSYS, Inc. All rights reserved. reserved.
February 1, 2012
Release 14.0 February 23, 2009
Inventory #002593
Excitations • Ports – Ports are a unique type of boundary condition that allows energy to flow into and out of a structure. You can assign a port to any 2D object or 3D object face. Before the full three-dimensional electromagnetic field inside a structure can be calculated, it is necessary to determine the excitation field pattern at each port. HFSS uses an arbitrary port solver to calculate the natural field patterns or modes that can exist inside a transmission structure with the same cross section as the port. The resulting 2D field patterns serve as boundary conditions for the full three-dimensional problem.
• By default HFSS assumes assumes that all all structures structures are completely completely encased encased in a conductive conductive shield shield with no energy energy propagating through it. You apply Wave Ports to the structure to indicate the area were the energy enters and exits the conductive shield. • As an alter alternat native ive to usin using g Wave Ports, Ports, you can can apply apply Lumped Ports to a structure instead. Lumped Ports are useful for modeling internal ports within a structure. – Network Parameters
• HFSS uses uses the incident and reflected reflected energy energy at the port to compute compute Generalized Generalized S-Parameters S-Parameters – Generalized S-parameters normalize the S-parameters by the port’s (transmission line’s) characteristic impedance
• Y and Z parameters parameters are are then derived from these these generalize generalized d S-parameter S-parameters s • Port are the the only excitations excitations that that can be used used to compute compute Network Network Parameters Parameters (S, Y and Z Parameters) Parameters)
ANSYS, Inc. Proprietary 5-2 ©Proprietary 2012 ANSYS, ANSYS, Inc. © 2009 ANSYS, Inc. All rights reserved. reserved.
February 1, 2012
Release 14.0 February 23, 2009
Inventory #002593
Setting Solution Type • Solution type selection general rule, rule, one could choose choose the solution solution type based on on the type type of transmission transmission line that is being analyzed analyzed – As a general – Driven Modal
• Hollow Hollow wavegui waveguides des (metall (metallic ic rectangu rectangular, lar, circula circular…et r…etc) c) • Any proble problem m where where a symmetry symmetry boundar boundary y conditio condition n is applied applied – Driven Terminal
• Microstr Microstrip, ip, strip stripline line,, coax, coax, coplana coplanarr wavegu waveguide ide
ANSYS, Inc. Proprietary 5-3 ©Proprietary 2012 ANSYS, ANSYS, Inc. © 2009 ANSYS, Inc. All rights reserved. reserved.
February 1, 2012
Release 14.0 February 23, 2009
Inventory #002593
