Newbie level 6
I want to design a UHF antenna for a RFID doorway reader with circular polarization of at least 30 deg. My approach was printing a yagi-uda antenna on a PCB with a coaxial port. However, it had less directivity. So an array of two yagi antennae were used and in order to get circular polarization another array was fixed in 90 deg orthogonal to the previous array. Now the pencil beam is too narrow. I need someone who can give some assistance with this. I use CST Microstripes for the design. A pic is attached as well.