Griogair
Newbie level 3
Hi All,
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 out above.
I think it's related to the Q factor as I am getting v. high values (calculated on the back of a cigarette packet) of Qrad (9million) and negligible values for the rest (lossless substrate, gold metallisation, thin sub of 400um), hence resulting in very low overall Q.
Any thoughts are most welcome.
Thanks
Griogair
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 out above.
I think it's related to the Q factor as I am getting v. high values (calculated on the back of a cigarette packet) of Qrad (9million) and negligible values for the rest (lossless substrate, gold metallisation, thin sub of 400um), hence resulting in very low overall Q.
Any thoughts are most welcome.
Thanks
Griogair