Need a help to simulate a reflector for monopole antenna T_T

Hi guy!
Now, I am simulating a monopole antenna. I simulated a circular patch antenna successfully . However, my teacher asked me to change it's radiation pattern from omni direction to one direction.
My friend advised me that I can use a reflector to put behind my antenna. The reflector will help my antenna can radiate one direction better.
Unfortunately, I cannot search any reflector model with information about dimensions , material and characteristics.
Thus, can u help me? give me some advices and reference document related to reflector.
I have to finish my project in next 2 days.
Thanks so much
I am going to die

Re: Need a help to simulate a reflector for monopole antenna

yes, u can place reflector but it will narrow down your bandwidth.
With respect to the size of groundplane, antenna gain and beamwidth varies.
Usually the distance between edge of the radiator and ground plane should be greater than λ/4.

plz,u can tell me more detail. I really do not understand what the picture is.

Re: Need a help to simulate a reflector for monopole antenna

Top circular green colour indicates the circular radiator patch and Brown colour indicates reflector.
the distance between edge of the radiator and edge of the ground plane (reflector) should be more than λ/4.
Attached here is the side view of the general circular patch antenna.

this is my antenna, so can I use your reflector model?

Added after 1 minutes:

thX

Re: Need a help to simulate a reflector for monopole antenna

Your post was a bit ambiguous as to whether the antenna you are supposed to use is the monopole or the patch.

If it is the monopole, instead of a reflector, you could try placing some additional monopoles (non-excited) with varying heights to either side of your main monopole to create a yagi-uda type antenna. This will probably not give you as high gain as an well-designed reflector, but it should be much easier to design.

John

Re: Need a help to simulate a reflector for monopole antenna

con_ga said:

this is my antenna, so can I use your reflector model?

Added after 1 minutes:

Click to expand...

yes, you can use that type of ground plane.
also refer to the below figure
These are basic antennas you can refer in any antenna books for further details.

Hi, balaguru thavamani.
My antenna is UWB antenna. I am wondering if I use your model, I can have impedance matching entire band (3.1->10.6GHz). Plz, reply me through my email and tell me more detail. Because I do not know how to apply your advice in my antenna
Thank u so so much
mtn11901@yahoo.com

Added after 3 minutes:

to John: I like your idea. today I try simulating it, but the result is not good. Furthermore, I have no impedance matching over entire band(3.1->10.6GHz). My teacher says that it is not suitable for manufacturing , because how can I hold 3 separate antennas together?

Re: Need a help to simulate a reflector for monopole antenna

Well, from the picture you posted it seems like you are using a patch antenna instead of monopoles, so I'm not sure if my comment is appropriate.

However, I do not understand why your teacher says there are manufacturing difficulties with using parasitic wires. Yagi-Uda type antennas are/were one of the most popular types of antennas in existence. Where I live, there is one on top of almost every single house and building around, so I think there are no big manufacturing problems. As for getting a good result, these type of antennas are covered in numerous antenna books, so you can easily find some design suggestions for improving your results.

John

to John, oh,no I use it as a UWB monopole antenna.
yagi is not difficult to manufacture, but if I use 3 monopole antennas,maybe it so difficult


Added after 4 minutes:

I simulated this antenna and have a good impedance matching over entire band.
So,if I add 2 copies of this antenna in 2 sides with the distance of 0.15*wavelength, I can have a model of Yagi uda. is it right?

Re: Need a help to simulate a reflector for monopole antenna

I guess I am still a little confused about what you are trying to do. Maybe you need to define exactly what kind of pattern you want. Just saying not omni-directional is very vague. What I had in mind was monopoles perpindicular to a ground plane (no dielectric). The driven monopole would be fed through the ground plane by a coax and the parasitics would be soldered directly to the ground plane. In this case, the beam would concentrate in the plane containing the ground plane but more in one direction.

I do not know if you can make a yagi-type antenna with the circular patches. The first problem I see is that the patch is radiating in the direction perpindicular to the ground plane. So when you place patches side-by-side, the radiation will concentrate in the same direction (assuming you are not trying to tilt the beam). I suppose anything is possible though and I haven't thought about it long enough to say that it isn't.

Re: Need a help to simulate a reflector for monopole antenna

Hi con_ga,

The figure that you have posted is an UWB monopole antenna.
If You use reflector for this circular patch UWB becomes narrow band.
But Gain of your antenna will increased in that particular narrow band since radaitions are directed in one direction when compared to earlier design.

Better go through
Modern Antenna design by Milligan
Compact and Broad Band Microstrip Antenna design by Kin Lu Wong.
Microstrip Antenna design Handbook by Ramesh Garg
Regards,
Balaguru.