I am trying to design a CP patch
antenna at 24 GHz. The antenna is to be fed by CPW
and is EM coupled into the patch on the other side.
The substrate that I am using has a high permitivity
value of 12.9. I am using HFSS and would consider
myself an experienced user so I am confident the
of the values of axial ratio I am getting (which
is at best about 10dB)
I have tried chopping
the corners, alternating the angle of the feed,
alternating the type of feed (cap or inductive),
putting slots in the patch but all to no avail.
Is there something fundamental I am missing that
means I can't generate CP with the parameters set