- This topic has 11 replies, 1 voice, and was last updated 14 years, 6 months ago by Pix.
28th January 2008 at 05:38 #50642MazinGuest
in kathrein antennas we have 2 holes of the jumber cable goes in and it’s written + and – so which one is RX and TX/RX.28th January 2008 at 09:48 #50643RonaldGuest
I think + is the tx and – is the RX28th January 2008 at 10:56 #50644MazinGuest
how can we make sure plz28th January 2008 at 14:33 #50645pixGuest
+ means the branch with a +45° polarization
– is the -45° polarization.
It’s not mandatory to put the Tx/Rx on the +45° branch. It’s just a custom, but you can do as you want.31st January 2008 at 11:42 #50646AbdelGuest
The plus and minus has nothing to do with the TX and RX either, as pix told you it is +45 and -45, that means the – port the antenna you are is a cross polarization. Polarization is divided into horizantel, vertical and cross. Cross polarization antennas are much difficult and much expensive than Horizantel and vertical. It is the way it sends the signal, is it up and down(vertical) is it left and right(horizental). Cross polarization has a better sending and receiving of signal and is less vunerable to climate changes. If you see and antenna with one port it is either vertical or horizantel.
Abdel31st January 2008 at 19:42 #50647pixGuest
how many horizontal polarized antennas have you seen on the field ? it’s as rare as a smart manager 🙂 I’ve never seen this in any antenna vendor..1st February 2008 at 00:35 #50648diwaGuest
check the duplexer unit, there sould be mention the Tx cable and rx/tx cable.
So simple way it to go accordingly.
+45 is always used for main Tx and -45 is for deversity Rx n TX both.
is this clear to you now ??1st February 2008 at 07:00 #50649AbdelGuest
Hi Diwa and pix,
“how many horizontal polarized antennas have you seen on the field ? it’s as rare as a smart manager 🙂 I’ve never seen this in any antenna vendor..”
In the GSM field I have never seen a horizontal polarized antennas. When I was talking about antennas I was thinking of all types of antennas in Earth station, terrestrial transmission and wireless telephones which uses a horizontal polarized Yagi antennas. I just defined the word polarization.
Diwa, you remind me of one day some BTS installers argueing each other saying you connect the -45 to TX port and the +45 to the TX/RX. as Pix told this is just a custom you can reverse it if you wish. I think we can not say -45 is TX and +45 is TX/RX. am I right? please let me know if I am wrong.
Abdel1st February 2008 at 15:43 #50650PixGuest
Ok, I was curious about the H-pol antenna in GSM.
So to come back to the initial point : Yes, it’s just a convention : if you do the opposite (TX on -45) it will not change anything in terms of coverage or quality.
It’s not even possible to argue about this : it’s like holding a torchlight a certain way or another way. As long as you’re pointing it in the right direction, the light will go there. The positions of the hands around the torchlight will not change the path of the light 🙂2nd February 2008 at 16:13 #50651diwaGuest
technically, it make difference, if u mistaken here.
and connect wrong cables +45/-45, ur coverage will be effeccted
it should be proper as per RF planning
else drive test guys will cry on u.
Hor pol antenna r good fit in gsm.
Kathrian r most famous2nd February 2008 at 21:26 #50652TNSGuest
I’m disagree with the last opinion.
The signal polarizaion changes every time the signal reflects.
So the original polarization doesn’t matter for the the final orientation of the vector at MS point.
I think Pix and Abdel are right.
diwa, which model of Kathrain Horizontal Pol antenna has good fit in GSM?
TNS4th February 2008 at 12:17 #50653PixGuest
You’re wrong ! Be careful because your answer might mislead many people that are going to read it.