I’m trying to design a wide band aperture coupled stacked circular p@tch antenna (Circular p@tches not circularly polarized) for 10 GHz but so far I’m only getting a dual resonance response as shown in the attached file. I tried to optimize: the upper and lower patch (radius, substrate permittivity, substrate thickness), aperture length and stub length. Basically I tried all possible ways but still cannot get wide bandwidth although many papers say it can be done. Any suggestions please?
Well, one obvious comment: 14 GHz is the 2nd harmonic of 7, so you may be just seeing a fundamental and harmonic response. If so, try just concentrating on moving the 7.4 GHz response to a higher frequency--ignoring the 2nd harmonic. I would think shorter radius and length. But I am not an antenna guy!
Thank u Piff44,
The design i'm doing is supposed to give me two resonant frequencies as i'm using stacked patches with different radiuses. The problem is that i cannot bring the two resonant frequencies closer to give me wider response although i tried all the optimisation methods i mensioned.
from these two resonance frequency, 7GHz and 14GHz, I suspect that they came from the same p@tch. That means one of your p@tch does not resonant at all, just functioning like capacitive loading to the resonant p@tch. I have no idea about your two p@tches stack up, if they are stacked up in logitudinal direction, have you tried to control the slot openning?
each response is from a different patch as
i get about 7 GHz when i do the simulation with the upper patch only(bigger radius)
i get about 14 GHz when i do the simulation with the lower patch only(smaller radius)
i tried changing the slot length. Pozar and other did manage to get a wider BW but i still don't. ANy more suggestions please
Regards,
Hassan
Please find attached a view of the stacked circular patches,
u will find the following layers starting from bottom:
1- air layer
2- feed line layer (h=2mm, εr=6)
3- air gap
4- patch layer (h=1.588mm, εr=2.2)
5- air layer for radiation
Pls check the attached Fig, Did I correctly understand the stack up?
If I am right, I dont think this slot will properly excite the ustrip patches because the air gap can not properly confine the EM wave and form any kind of resonant mode.