antenna-theory.com

[trent393]

Hello all... I have an issue which is totally my fault and I am hoping to fix it... I took my phone apart in order to fix it speaker because it had a buzzing/no sound issue... When I took it apart I tore the GSM/WCMDA antenna sort of in half... It is not a wire, it is a flat piece of black flexible plastic and you can see all the interior lines running through it... My question is am I able to cut another piece of copper with the same exact shape... I feel very confident I could get fairly close to precision on replicating the shape but was curious if it had to be computer precise??? Also if the gauges of copper have to be identical or if i was able to use something slightly thicker (due to availability)... My issue is I bought this phone from china since I needed a dual simcard phone and most US companies do not sell... Well I have not been able to locate replacement antenna and was curious if I am crazy or if yall think I might be able to rig it up... I am able to connect a wire to it and it works halfway... Halfway meaning one sim card will work but not the other...It is a dual sim dual standby phone... 3G: WCDMA 850MHz, WCDMA 2100MHz
2G: GSM 1900MHz, GSM 1800MHz, GSM 900MHz, GSM 850MHz

[Schubert]

The thickness of the copper doesn't matter. If you didn't screw up the feed (there is usually a coaxial connector to the main board) then you can replace the copper you tore off and it will likely function just fine

[trent393]

Does the layout have to be pretty precise of how it is cut... I had watched a couple of videos on here and it seemed like the way certain paths were laid out made a difference on functionality... I think I can get relatively close (with a tolerance of 1/64th of an inch)... Only reason I ask is because one of the SIM cards was working with great reception if i simply touched a copper wire to the connection... The other SIM card would not pick up any signal

[Schubert]

If you don't have a network analyzer, there is no way to reliably tell how critical it is.

From my experience (and I've done antennas on a lot of phones), it isn't critical to the mm level (i.e. that will not change your results by an amount that will affect your results from an end users perspective)

If it isn't connecting for some reason, there are a million other reasons besides the antenna on why that is. Get it approximately right, and forget about it

[trent393]

I actually cut a piece that is relatively close and it works... But I also discovered that there was a setting in my phone that had got changed also and it works just as good by touching a wire to the dang connection... The whole time I thought it was the antenna having to be perfect when its just a simple setting