bisgaard
Newbie level 1
Hi
I am trying to simulate a helical (helix) antenna at 1GHz in HFSS. I have started with a "Ansoft Antenna Design Kit" generated helical. This generated antenna is driven by a waveport through a coax and has a very resonable returnloss graph and an impendace of about 140ohm at the center frequency. However, I would like to change from a waveport to a lumped port but this is proving difficult.
I thought I could simply feed the helix with a small vertical lumped port at 140ohm from the ground sheet to the bottom of the helix (similar to how it is done in the tutorials of a monopol over a ground plane).
The gain of the antenna is the same with the waveport and the lumped port.
However, the return loss (and ofcourse vswr) looks rather weird
I would have thought that the result should be similar for the two types of ports. Is it not possible to drive a helix from a lumped port and if so: How do I do it ?
Regards
I am trying to simulate a helical (helix) antenna at 1GHz in HFSS. I have started with a "Ansoft Antenna Design Kit" generated helical. This generated antenna is driven by a waveport through a coax and has a very resonable returnloss graph and an impendace of about 140ohm at the center frequency. However, I would like to change from a waveport to a lumped port but this is proving difficult.
I thought I could simply feed the helix with a small vertical lumped port at 140ohm from the ground sheet to the bottom of the helix (similar to how it is done in the tutorials of a monopol over a ground plane).
The gain of the antenna is the same with the waveport and the lumped port.
However, the return loss (and ofcourse vswr) looks rather weird
I would have thought that the result should be similar for the two types of ports. Is it not possible to drive a helix from a lumped port and if so: How do I do it ?
Regards