How to determine the radius for probe, coax, coax pin and the height for coax in HFSS

link makes sense for calculating dimensions of coax

good luck


http://www1.sphere.ne.jp/i-lab/ilab/tool/cx_line_e.htm

thanx man that was gud.....
hey can u guide me on a problem i have...

see i am making an H shaped microstrip antenna in hfss......

i made a substrate of given dimensions using box option......which material is prefferable for the substrate
1. rt duroid
2 vacumm?

for making the ground plane i made a rectangle at bottom and assignes perfectly dielectric to it.....similarly i made the patch using rectangle at the top using rectangle giving it perfectly electric boundary conditions to it


should i make these things of box type with some height for better results or its ok?


how much the coaxial dimensions affect the results of this structure?


i want to short the patch and ground....how should i do it/?

First ; you have to decide about bandwidth and resonance frequency. dielectric permittivity effect on bandwidth and frequency. (air small banwidth etc.)

second you have to draw H shaped patch over dielectric and also assign it perfect E,
Ground plane should be assigned perfect E with infinite or finite ground plane option, (Also you need a cut on it for coax probe)
Dielectric box doesnt need assignment of perfect etc.

third; dielectric box height effects banwidth and also resonance frequency. Similiar condition exist on coax measures too. Cos impedance changes with dimensions.

good luck[/b]