Using WiFi antenna for UMTS / GSM ?

[espresso]

Hello. Can one use a WiFi 2.4GHz omni antenna (stick) for receiving primarily UMTS 2100 signal? That's frequency range between 1.9-2.2 GHz approximately. I have a 3G modem and I'd like to get a better reception but I only have WiFi antennas around. Are they much different from the ones advertised as UMTS antennas?
Thanks

 

[drkirkby]

Hello. Can one use a WiFi 2.4GHz omni antenna (stick) for receiving primarily UMTS 2100 signal? That's frequency range between 1.9-2.2 GHz approximately. I have a 3G modem and I'd like to get a better reception but I only have WiFi antennas around. Are they much different from the ones advertised as UMTS antennas?
Thanks

I think you will just have to check. My experience is that a lot of antennas sold for WiFi don't meet anywhere near the specifications claimed - they are just as likely to work better at 1.9 to 2.2 GHz than one designed to work at those frequencies. I suspect 99% of the antennas marketed for WiFi have never seen a network analyser or had their gain measured.

Dave

 

[espresso]

Hi. I have an option to order a cheap adapter (modem's CRC9 to SMA) and use an existing WiFi antenna or order an expensive UMTS antenna together with this adapter. That's why I needed this information. If I could get away with a standard WiFi antenna, that would be nice.

 

[DavidReina]

Hi espresso,

For typical antennas:
WiFi central Freq (fo) is 2.44GHz with a Bandwidth (BW) of 80MHz.... that gives a range from 2.4-2.8 GHz
UMTS fo is 1.955GHz with a BW of 140MHz... that gives a range from 1.885-2.025 GHz

if the antenna is well designed it will filter the UMTS signals... so, to answer your question, it is not recommendable to use it, nonetheless you can try and tell us how it went xD.

hope this helps .

 

[E Kafeman]

Are they much different from the ones advertised as UMTS antennas?

There are many types of antennas. A typical "wifi stick" contains two dipole antennas inside this stick and I do not recommend this antennas type as UMTS antenna.
If you want to replace an internal antenna with a better performing external antenna on a cheap budget, buy that CRC9 and solder a 40 mm long wire at center-pin.
That is probably the best you can do without any deeper knowledge and if it not gives expected result, you have learned this at a minor cost.
An alternative to buy a contact, is to open up the modem and solder this wire directly on PCB, if you have the right tools and knowledge.
An more advanced antenna with higher gain, such as a Yagi, can be bought on Ebay relative cheap, but at least for quality, you get what you pay for.

 

[espresso]

Ok, thank you guys. I will give it a shot with a WiFi antenna first and then try with a wire at the central pin. The only problem is that I wouldn't be able to say which solution works best as this is an auxiliary antenna for diversity. The modem is Huawei E182e and it has a main internal antenna from which it reads signal strength info. The additional antenna connector is used for receive diversity and only helps the stability of the link (doesn't influence reception strength reading).

 

[E Kafeman]

Not sure but it is maybe not enough to just connect an antenna to center pin at the router. There is probably a mechanical switch inside the router that sens when CRC9 is inserted.

 

[espresso]

It won't go directly to modem's pin. I will be using this adapter cable, so it will detect connection.