prba6629
Newbie level 1
Hi,
I am trying to simulate a coax connector in HFSS and trying to correlate simulation results with theoretical formulae. Currently, I have modeled a coax connector with a GOLD inner conductor and PTFE dielectric(epsilon = 2.1). I have setup ports at both ends of the coax with port impedances 50 and 80 ohms respectively.
As per theoretical results, velocity of signal in the coax = 3 x 10^8m/s / sqrt(epsilon)
= 207 mm/ns. Round trip time delay = 2 X Length of coax / velocity of signal in coax. For a coax of length 10mm, RTT delay = 96.6 ps.
Therefore, I am expecting all the reflected signal ( rho = 80-50/80+50 = 23%) to be seen at exactly 96.6 ps. But, from simulations, I am seeing all the reflected signal at close to 120 ps and not the expected 96.6 ps.
It would be a great help if you could point out the mistake either in my simulation setup or analytcial formulation? Thanks.
NOTE : I have attached my HFSS file for reference.
I am trying to simulate a coax connector in HFSS and trying to correlate simulation results with theoretical formulae. Currently, I have modeled a coax connector with a GOLD inner conductor and PTFE dielectric(epsilon = 2.1). I have setup ports at both ends of the coax with port impedances 50 and 80 ohms respectively.
As per theoretical results, velocity of signal in the coax = 3 x 10^8m/s / sqrt(epsilon)
= 207 mm/ns. Round trip time delay = 2 X Length of coax / velocity of signal in coax. For a coax of length 10mm, RTT delay = 96.6 ps.
Therefore, I am expecting all the reflected signal ( rho = 80-50/80+50 = 23%) to be seen at exactly 96.6 ps. But, from simulations, I am seeing all the reflected signal at close to 120 ps and not the expected 96.6 ps.
It would be a great help if you could point out the mistake either in my simulation setup or analytcial formulation? Thanks.
NOTE : I have attached my HFSS file for reference.