Problem： Ringing VSWR for spiral antenna in CST MWS

Hi,

I'm trying to validate an Archimedean spiral antenna with inner radius of 3mm, outer radius of 10mm, 8 turns with 16 segments/turn to operate between 0 to 4GHz in free space, using CST MWS (please refer to attachment 'a').

I used a discrete port (with an impedance set at 188.5 ohm due to self-complementary structure) with an open (add space) boundary condition for all dimensions.

What concerns me is that the VSWR gives a ringing effect at these region. Is it acceptable to have this kind of result?, because in the paper that I refer to have a straight line instead (please refer to attachment '1' and '2').

Please help me.. Thank you!

It seems that your port is not properly connected as ringing occurs due to mismatch at the port. Try waveport instead.

Abdul mueed, thank you for the suggestion. i've already overcome the problem by properly feed the antenna. Thanks again

suraya can u upload the new file here?

申明：网友回复良莠不齐，仅供参考。如需专业解答，请学习易迪拓培训专家讲授的CST视频培训教程。