Hello
Happy New Year , I wish the best for all of us and our kind planet Earth in 2021
OK, I designed an microstrip patch antenna on CST and now i want to use EBG structure to enhance its parameters but when i place the antenna on EBG structure everything get ruined! should i use different boundary? like periodic boundary or what?!!! and i used a spacer like foam in between my antenna and EBG structure. but i don't get a good result like in the paper i use as reference.
so I look forward to your help!
thank you all.
Hi Maryam Darabi ,
PBG structures are normally used for wideband applications, band suppression applications, and other antenna performance enhancement. PBG structures have been used lately for surface wave suppression which, decreases the back radiation, increases the gain, and improves other antenna performance parameters.
The introduction of air holes decreases the overall effective permittivity of the antenna. Therefore, you can not expect identical results as of a uniform substrate. The resonance conditions of the antenna will be dictated by the air hole dimensions and their periodicity.
It will be wise to design and optimize the antenna with the PBG structure throughout. Keep the dimensions of the patch and the PBG as variables. Utilize the automatic optimization (Google it) option provided by CST. It will make your work easier. Following articles and their references may prove helpful:
Article Effect of photonic crystal and frequency selective surface i...
Article High-gain and ultrawide-band graphene patch antenna with pho...
Article Analysis of photonic crystal and multi-frequency terahertz m...
Best Wishes!
Hi,
The EBG structure is printed on ground plane below the antenna as reflector or surrounding the antenna or above the antenna as Superstate?
In general, you should design the antenna without ebg and optimized it to find a good return loss.
After that, you save the antenna dimension and add inside it the ebg structure.
Mr Mohamed Aymen El Cafsi the antenna is suppose to place above the EBG structure. i want to know boundary's or other specification in CST that i should use to get the real and correct answer. thank you
Hello Maryam Darabi
According to your answer, the EBG structure act as reflector which is called an artificial magnetic ground.
Firstly, you need to design the EBG unit cell using periodic structure by exciting the unit cell by plane wave. so, you need to specify x and y as periodic boundary and -z where the ground plane of EBG structure as a perfect conductor (Et=0) and z direction as open by adding a distance between the excitation and unit cell.
I advice you to use the distance as variable and change its value to see its effect in return loss.
After that, you should to look the phase of return loss which should around 0° with an acceptable amplitude of s11 (between 0.6 and 0.9 in linear value)
After obtaining this result, you design antenna and put the ebg structure under the antenna and try to adjust the distance between them (as i remember, the distance is bewteen lambda0/8 and lambda0/16.
hello Mr Mohamed Aymen El Cafsi thank you for your explanation. sure it will really help me. i'm gonna work on it.
I advice you to use the distance as variable and change its value to see its effect in return loss.
After that, you should to look the phase of return loss which should around 0° with an acceptable amplitude of s11 (between 0.6 and 0.9 in linear value)
After obtaining this result, you design antenna and put the ebg structure under the antenna and try to adjust the distance between them (as i remember, the distance is bewteen lambda0/8 and lambda0/16.
Atul Varshney thank you, but I did what Mr Mohamed Aymen El Cafsi told me and it worked and i got my results. thanks to Mohamed Aymen El Cafsi and all of you for helping me.
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