Urgent!Please help!feed of print meander line antenna

I have been simulated printed meander line antenna, according to the attached file.
But I do not understand the paper. It only shows the top side of the antenna. What is the back side of the antenna?
I simulated using figure 1. I can make it resonate at around 2.5 GHz, but the return loss is about -4db too high.
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Ａｌｓｏ，　ｔｈｅｒｅ　ｉｓ　ａ　ｈｏｌｌｏｗ　ａｒｒｏｗ　ａｎｄ　ｄｏｔｔｅｄ　ｌｉｎｅ　ｉｎ　ｆ ｉｇｕｒｅ　１．　Ｗｈａｔ　ｄｏｅｓ　ｔｈｅｍ　ｓｔａｎｄ　ｆｏｒ？　Ｈｏｗ　ｃａｎ　Ｉ　ｆｅｅｄ　 ｔｈｅ　ａｎｔｅｎｎａ？
Ｔｈａｎｋｓ　ａ　ｍｉｌｌｉｏｎ！

The other side is a whole sheet of metal covering the whole substrate (the ground)

it is a microstrip fed antenna and the other side must be the metalic gound plane I think

Thank you flashking! I simulated now as you said. The return loss at 2.4GHz is now around -10dB still too low. The paper said it should be -39dB. And my radiation pattern did not seem right. I attached my hfss file here.
Please! Could anyone help me to see where I was wrong? Thanks a million!

I viewed the figure fast

a small notice, I didn't see integration line for the lumped port

also you can try the waveguide port instead

finally, did you simulate with a lossy or a lossless FR4 Substrate ?