uc pbg ebg

Hi, everyone. I do have a question about the electromagnetic bandgap (EBG) structure and patch antenna interaction. I saw some paper that the EBG or AMC can improve the patch antenna performance, but forcus on increasing main lobe gain, damping surface current and reduce side lode.

My question is that whether the EBG can be used to reduce the patch antenna sizes or increase the band width? And recommendation and reference will be greatly appreciated.

BTW: are there any tutorial about using HFSS or IE3D to simulate the EBG structure? Thanks in advanced.

I personally am not aware of EBGs reducing the size of the p@ch antennas. For wire antennas above ground plane, they can reduce the size because they will be able to reduce the the distance of the antenna from λ/4 to being very close to the ground plane. For p@ch antennas though, due to multiple periods being used, EBGs infact increase the antenna size. You should look at the more interesting metamaterials for size reduction.

-svarun

PBG or EBG exists when the periodicity is at the order of wavelength (please correct me if I am wrong), just imagine how big your structure should be in order to get band gap. It can not contribute anything into antenna miniaturization.

Regards,

Hi, svarun and asdfaaa, thanks for your reply.

But the EBG such as Meshroom structure or UC-PBG structure, the unit cell is much smaller than the wavelength. Do you think that will make the antenna miniaturization possible?

By the way, if the EBG/PBG cannot contribute to the antenna miniaturization, what other functions make it popular in research area right now, besides decreasing the mutual coupling in array.

Hi winglj,

I agree with your statement. UC-PBG structures require far less periodicity than traditional ones. The key to their operation is creation of distributed L and C components which at their resonant frequency of

produce surface wave attenuation and in-phase reflection. They are shown to be equivalent to 2-D metamaterials. In this case, you can look at ground plane sizes of the order of

. However, note that the EBG pattern wil not affect your p@ch size.

-svarun

I would like to see any published result about EBG structure which is size of the order of wavelength in free space. I agee with you that the key design consideration is the creation of distributed L and C, where C is primarily contributed from the capcitance between parallel plates, inductance is contributed inductance of the metal sheet or the inductance got from the inductor similar struture. Consider with the each cell size limitation of one-tenth of wavelength in free space, how much L and C you can get.
While for microstrip antenna design, the ground size can be controlled within the limit of one guided wavelength.
Will EBG contribute anything to antenna miniaturization?

Regards,