please help me regarding HFSS simulations

help regarding HFSS

Hi,
I am learning HFSS by trying to simulate some structures, but I am very much confused about HFSS ports and HFSS designs like "driven modal" and "driven terminal". Can anybody explain to me what exactly is lumped port and wave port, what is the difference between them and where are they used? especially i did not understand the term "background" with reference to ports. Also please explain the difference between the driven modal and driven terminal. I shall be very thankful to you.

Awaiting your replies

Regards
Ankesh Garg,
IIT Kanpur,
INDIA

hi ankesh,

->antenna port is assigned as lumped when it reside inside your design while wave port is assigned when the port is outside

->driven terminal is assigned in the case of probe feeding,while line feeding is assigned as driven modal

don't u hav any guide n ur proj...as u r stdin n IITK

feel free to ask any query & click on helped me

Hi Nitin,
Thanks for your reply. Here are few more questions:
1. As far as I have learnt about the ports, wave port assumes an infinitely long waveguide of same cross section as of the port, so its characteristic impedance is now dependent on the shape of the port so how does it matter if the port is inside the design (inside the airbox surrounding the structure) or outside the design as was stated in your reply.
2. Secondly the soution type (modal or terminal) must not depend on the kind of feeding (for example eigen based solutions do not depend on the excitation and the general solution for an ordinary differential equation is a linear combination of its eigen solutions with a forcing term added to satisfy the excitation conditon) as was again stated in your reply.


Regards
-Ankesh

Driven modal find modal based S parameters. S matrix Solution expressed in terms of the reflected and incident power of the wave guide. generally used for TE, TM or hybrid modes.

Driven Terminal finds termianl based S parameters solution for multi conductor line ports. the s matrix will be expressed in terms of terminal voltage and currents.

Eigen mode calculates the eigen mode, resonance of a structure. the solver finds the resonant frequencies and fields at those frequencies.