Recommend directional antennae for 3 / o2

sennah

Hi

I'm looking for a directional antennae to use on 3's mobile broadband network so I'm hoping some posters here could recommend one or clear up some questions I have

The area I'll be using it in has both Three 3G and 4G networks and also old o2 3G signals available. I don't exactly know which mast might be the best to latch onto yet so do I have to look for certain band or frequency support with the antennae to cover the 3 different signals?

As for the connector, it'll be connecting to a Huawei dongle which I think are CRC9 connectors. I know I can get adaptors to change from one connector to another so I'm not too worried if a given antennae doesn't have the correct connector


Thanks

editorsean

Where I live, I get a Meteor 3G signal that my phone intermittently latches on to when I'm outside the house. With the SIM in a Huawei wingle (MiFi that depends on USB power), I get no signal. I have tried two antennas so far, so I'll base my experience trying them at home. I don't get Three 4G (let alone 3G) in my area, so unable to test any with 4G yet.

I initially bought a cheapy 3G/4G antenna, the diamond shaped one (with a white plus) sold by numerous sellers on Amazon and eBay with a heavily exaggerated "35dBi" rated gain. After various positioning attempts of the antenna, the wingle finally got connected to 3G and intermittently switched between showing no bars and 1 bar. It only worked carefully positioned in one of the windows upstairs.

For my second antenna, I bought a LOG antenna that covers 780MHz to 2.6GHz with a 11dBi gain rating. The seller I bought it from no longer stocks it, but there are similar others on Amazon, eBay, etc. that look like a white cropped triangle that mounts on a pole, which can be aimed. So far I've just tried it in the upstairs window mounted on a camera tripod and the wingle is showing 4 bars (out of 5). The best speed test I got was 6.5Mbps down and 0.8Mbps up. If I connect one of the leads from the cheapy antenna to the wingle's second antenna port (RX diversity on 3G), the download speed goes up to 9.5Mbps. 10Mbps was the maximum speed I got.

When I'm in the town where I have clear line of sight with the transmitter, I get roughly 10Mbps down and 3.1Mbps up on the speed test with my phone on Meteor 3G, so I probably would get a much better uplink speed with the LOG antenna if I place it on the outside gable or with a larger higher gain LOG antenna.

I'm not sure how a Yagi or a dish antenna would perform as I haven't tried either and most I've found were over €100. For 4G, you will need two antennas for MiMo, one aimed with horizontal polarity and the other with vertical polarity. From what I've heard, one antenna will work to try out, limited to half the bandwidth. For 3G, a second antenna is recommended for RX diversity to improve the download speed, assuming the modem supports 3G RX diversity with its second antenna port.

sennah

Thanks editorsean. That's one hell of a comprehensive response so I've a bit of reading to do tonight I guess!

I've never heard of an LOG antenna before but I'm familiar with the form-factors you mentioned. A quick google here states the following

"Log-periodic antennas are designed to work across a wide range of frequencies; Yagi-Uda is optimised for one frequency. Yagi-Uda will give higher gain at its optimal frequency; log-periodic will have lower gain across a wide range of frequencies. So the answer depends on the bandwidth and gain you require"


So I suppose I could get a directional LOG antenna to try with first and when I find the most appropriate signal to latch onto, I could perhaps upgrade to a Yagi for that frequency if it might offer better gain. Very interesting points too about 4G requiring two antenna in opposite polarity and I wasn't aware that some of the Huawei dongles actually offered dual antenna connectors

I'll have a browse of some online sellers tonight and see what I can come up with. I'll try to keep it simple to start so perhaps I'll stick to working with 3G for now

editorsean

The near-flat gain across the spectrum with a LOG antenna was indeed the main reason I wanted to try a LOG antenna to start with. :cool:

With a wide-band Yagi, the rated gain is generally near the upper end of the band and slopes down towards the lower end the band. A Yagi covering a narrow frequency range will have considerably higher gain than the equivalent size wide band Yagi. This is why most Yagi UHF TV antennas cover a narrow frequency range, such as group A covering 470-606MHz, Group B covering 582-734MHz, etc. as a wide band Yagi with the equivalent gain would be huge in comparison and may perform worse than a much smaller Band A Yagi towards the lower UHF TV frequencies.

As far as I'm aware of, 3G only operates on 2100MHz in Ireland. Three uses both 800MHz (LTE band 20) and 1800MHz (LTE band 3) for 4G, so if you later decide to upgrade to Yagi antennas for 4G, you will need to find out what frequency Three is using in your area. Hopefully the LOG antenna will be sufficient.

A few Smartphones such as certain Samsung models are able to show the frequency in use such as with the LTE Discovery app. Some Smartphones don't support the 800MHz LTE band 20, so this may be another way to check if you know someone with an affected phone. For example, the OnePlus One doesn't support 800MHz, so if it shows 'LTE' on Three, then you know Three is using 1800MHz there.

editorsean

editorsean wrote: »

As far as I'm aware of, 3G only operates on 2100MHz in Ireland. Three uses both 800MHz (LTE band 20) and 1800MHz (LTE band 3) for 4G, so if you later decide to upgrade to Yagi antennas for 4G, you will need to find out what frequency Three is using in your area. Hopefully the LOG antenna will be sufficient.

I hope I'm not bringing confusion here, but I read several contributions on other threads to say that the 900MHz band was operative and was by far the best in rural areas.

editorsean

That indeed does make it more complicated to pick the right Yagi for 3G reception. I had a quick check and going by Wikipedia, Three uses both 900MHz and 2100MHz for 3G, which I didn't know. So a phone (or dongle) that is capable of showing the 3G frequency in use would be required to pick the right Yagi or narrow band antenna.