Hello Azita,

the attached documents will help you on your investigation about planar slot antenna

B.Regards

@chaouki

thank you dear. but i need a planar antenna with these properties

1: doesn,t have a stack structure

2:has widrband properties( about 7-12)

3:has complete groun plane under its structures. 

because of these conditions, i think a slot antenna or bow tie antenna can be good. but many of them are stack or dont have a complete ground plane . i read the book of compact and broadband ms antenna before. but  most of them dont have a good wideband properties or use pin, short wall or stack structured, that aren,t appropriate for me. 

thank you

I advice printed yagi-uda antenna. I think it can meet your requirement.

Hi Azita

Check the attached paper to get an idea

@chaouki

thank you dear. is it broadside or endfire antenna?? do you think i can change or scale it to reach an uwb  from 7 to 12ghz??

i check some yagi yuda antennas and i think they aren't complete ground plane.

thanl you

Hello Azita,

It is scalable in frequency. This kind of printed yagi antenna has a complete ground plane, and it has endfire radiation pattern.

Regards

Please find a paper about a cavity backed wide-slot antenna attached to this message. This antenna will simply scale to your frequency band though you might have to change the substrate thickness. You'll notice that the cavity extends along way from the back of the slot so I'm not sure if this will fulfil your requirements. It is hard to achieve a low-profile wide band antenna of this form due to the resonant nature of the backing cavity. While it is easy to produce such an antenna for a single frequency. it is a lot harder.

The antenna in the paper works on the principle of an absorbing cavity. where the back radiation is attenuated. It might be possible, with the right absorber, to significantly reduce the size of the cavity to something that suits you.  

Article A Comparison of a Wide-Slot and a Stacked Patch Antenna for ...

@David

thank you dear Gibbins.

your paper  has very good results.Congratulations to you. thank you to your suggestion.  i consider this paper too. 

best regard

You say nothing about antenna's dimensions in the directions transversal to the direction of radiation. Another important parameter is the desired radiation pattern.

The answer may depend on the features mentioned.