Help me to design the antenna E-shaped

dear all....
my name Evyta, and now i try yo design the Antenna Wideband E-shape for my Mid term assignment in college.
And Now I have a problem when making an Antenna Wideband E-shaped that operating in 1800 MHz-2400 MHz with VSWR 1.3 using HFSS.
i tried by my self to simulated by HFSS, but actually there is something wrong with my design. And unfortunately, I don't know what is wrong.
If you don't mind, please help me to solve my problem by checking my design and tell me, which part that I should fix to get the specification above.
i try to attach the HFSS that i design and also the paper that becomes the reference of my project.

best regards

evyta angelya

Hi
Your design doesn't match with the paper design and you are trying to feed in the middle part of 'E', but in the paper the feed is at Yo and Xo. You have also elevated the 'E' patch by 15 mm, why? it should be on substrate. I think you have to redesign enter model again and try.
Best of Luck
Lakshminarayana.

dear Lakshminarayana.
thanks for reply.

actually I don't know how to find the feed accurately. I mean, The Paper didn't mention how to get the Yo and Xo. so I try to feed my antenna by trial and error. if you don't mind will you tell me how to get the value of Xo and Yo.

I also elevated the "E" patch 15 mm, because I read some article to get widebandwidth we can increasing Bandwidth by thicker of substrate. so I think maybe making a "gap" between substrate and patch could expand the bandwidth.
is it wrong?
will you tell me the "right step" making this antenna. So i can redesign my antenna and get the specification that require.
I'm sorry if my Q looks silly.
I'm just beginner on making Antenna.
This Antenna is my assignment from my year project in college.

thanks Lakshminarayana
Best regards

Hi
In page 401 it is mentioned. Its true that we get more bandwidth by increasing 'h' of substrate, but in your design patch is not touch the substrate.
First you go through the paper correctly and make a notes of design parameters and then model in hfss, you will get the result.
Regards
Lakshminarayana

Don't have hfss, so can't see what you are doing. But Y0 is chosen in the middle of the patch. You then vary X0 and the sizes of the "tongue" (mostly Ls) to get both a 50 ohm match and the broadest bandwidth. I think if you move Y0 from the middle of the patch, you would get dual polarizations!

This design does work, as I have built some. But you do not really get a broad-bandwith so much as you get a "double humped" or "double tuned" shape in return loss. Right in the middle of the band, the return loss will get worse. You can only broaden the bandwidth wide enough until your reach your worst case return loss at midband.

Rich

dear Lakshminarayana and Biff44

thank you for reply and your explanation.
I wanna ask you more, how to find the Variable on the paper (Ls, Ws, Lt, and Lt), I meant the equation to get the value of the Variable.
Or we can get the value by doing trial and error?

I have found the reference giving information about it from the text book ''compact and broadband microstrip antenna" by Kin Lu Wong on page 242

on the text book, they tell that the length of LS is between (0.7- 0.85)L
and the Value of Ws ≤ 0.27 W.
and my Question
is it right to use the equation, I mean is it My antenna have similiarity with the antenna on that Text book?
Cause it seems as same as mine.
And how about the Lt and Wt?
Because on the Text book, He didn't mention the variable of it.

thank you for your attention
Best regard
evyta

If you have HFSS and it seems to be analyzing the circuit well, I would set a number of variables as fixed, and vary one, like X0 for 2 or 3 values, and then draw a graphs of Re Zin vs X0. Then I would pick the point that said 50 ohms, and reanalyze on HFSS for that one. It is hard to optimize anything using HFSS, since it takes a long time to get a each solution.