Port Impedance for Small Structures

Hi,

I am simulating a CPW in HFSS whose dimensions are: width = 50 um, gap = 30um, and substrate height = 430 um. Using the suggested port sizing from Ansoft ( Height = 4h, Width = 3(2g +w) ) gives me a port impedance of ~8 ohms. The only way I currently know of increasing port impedance is to increase the port size. I am worried this will lead to inaccurate results. Is there any way I can increase the port impedance without creating a relatively large port?

Thanks for you help!

hi
what u design frequency?

Thanks for the reply ferdows! I am trying to make the structure resonate at 2GHz.

hi Firkin
pls read this paper it may be help u a little but i dont have confidence that u can use for U structure because hiss and CST have problem with small antenna design

A 60-GHz Millimeter-Wave CPW-Fed Yagi Antenna
Fabricated by Using 0.18-μm CMOS Technology
by Shun-Sheng Hsu, Student Member, IEEE, Kuo-Chih Wei, Student Member, IEEE,
Cheng-Ying Hsu, Member, IEEE, and Huey Ru-Chuang, Member, IEEE
IEEE ELECTRON DEVICE LETTERS, VOL. 29, NO. 6, JUNE 2008

Thanks again ferdows, I will definitely check out the paper. I am not designing an antenna, I just want my meandering CPW structure to resonate with a high Q.

hi
did u seen how them in that paper that i said u design the port in hfss? but i think not difference between antenna and other microwave element and hfss has problem with small structure in lower frequency like 0.1λ