User defined primitive / helix can work. Try making it using this youtube video.

https://www.youtube.com/watch?v=y_I97QRZ_Kw

In HFSS Antenna_Design_kit, find the Helix antenna in Normal mode.

so bad I don't have the design kit

You can download the antenn design kit package it is free. Try unzip the attached file 

Here you go. Hope it is helpful good luck!

Try to Update to the latest version of HFSS, they have a wizard where you input the parameters and it makes a 3D model of it for you.

Regads,

AO

Thank you guys

Helical Antenna Design at 1.35 Ghz using FDTD simulation

https://anilkrpandey.wordpress.com/2017/03/10/helix-helical-antennas-design/

U can use Line "Draw equation based curve" with this formula and sweep Circule along path...

X=a*cos(_t*2*pi)

Y=a*sin(_t*2*pi)

Z=_t

_t=0 to 1