What's the type of antenna shown in the uploaded pictures?
what's the type of antenna shown in the uploaded pictures?
they're two sides of an antenna pictures
anyone has some materials related to this antenna?
thank you
It's some kind of flat microwave antenna, look at the wire type. I supose it's for WIFI.
yup,of course it's a microwave antenna, but it's not used for WIFI. it's used for BTS to client in 3G communication network.
what i want to know is the name (something's like helix, dipole, patch etc ) of this antenna, coz i dont have any clues from where i have to start studying this antenna
I have something about flat antenas not only spiral!
http://esl.eng.ohio-state.edu/~csg/a...piral-antenna/
seem like a patch to me
there are two feedline in picture 1,but the second picture have three feed point .
i don't understand this.
yup, there are three feed points on this antenna, but it's only fed by two feedline.
on 2nd picture, two feed points in vertical position , are connected each other using a coax cable and only one of these two feed points is fed by one feedline and the middle feed point is fed by another feed line.
sorry guys, it's an old topic,but im still waiting for somes replies,ideas or reference materials related with this antenna.
perhaps...
it seems to me a 4 printed dipole the two vertical (jioned with one common feeding pont) provide a sum beam of (array of 2 elements), the second couple (horizontal dipoles) seems fed out of phase (180° ?) providing a difference beam (a deep null in the horizontal plane. If my assumptions are right also the polarizaion is orthogonal between these two couples of dipoles.
....
It only has two feeding probes, the third one is the ground reference. I would like to say that it is an antenna with two dipoles, which can give us better signal to noice ratio.
Hi Masadi & friends,
There are 4 dipoles made in microstrip in one of the sides of the board, fed by Marchand type baluns. The U-shaped strips on the other side of the board are coupled to the balanced lines that go from the central ground to the arms of the dipoles. The length of each arm of the dipole is aprox. 1/4 wavelenght, and the same is the length of the balanced lines.
Let’s number clockwise (from the top in the second picture) the dipoles as 1, 2, 3, 4. Dipoles 2 and 4 are fed in phase. There should be a bridge that connects dipoles 1 and 3 (it seems that it was removed), that are fed in phase as well.
I suppose that the two feeding points are fed with 90 degrees out of phase. In that way, we have a circular polarization antenna with maximum radiation in the axis normal to the board. The radiation on the plane of the board is weak because dipoles 1 and 3 are half wavelength apart in the direction of their maximum radiation (and dipoles 2 and 4 as well).
Probably there is a ground plane at 1/4 wavelenght (parallel to the board) that acts as a reflector in order to maximase radiation on one side of the axis and avoid radiation in the other side.
I hope that helps.
Best regards
Z
I second what zorro said.
At second glance after what he said, it did look indeed like dipoles with baluns etched on the other side of the substrate.
I wonder if it could be a dual-polarised element instead? I don't know much about circular-polarisation though.
BR,
Dave
Each dipole has two legs, while unipole has one leg. I agree that the back plane may be a balun.