The design of the most powerful antenna for a 3g modem - how to assemble?

Question

Antenna

I understand that the phrase - "the most powerful" is formulated too trite, but still.)
Here is a 3g modem, for a number of reasons, sometimes, and in my case - always, the connection leaves much to be desired. 3g is, but here's the ping ... does not allow you to play online games. I tried all existing ways to improve the signal, except for installing external antennas.
And here I came across a huge variety of designs of home-made antennas, ranging from complex in execution and quite large, and ending with outrageously primitive, "mini" antennas from a DVD disc)
After everything I saw and read, I was puzzled by the question: is there in nature, more precisely, in the scientific world, such an antenna that, with its technical capabilities and characteristics, would be the most and ideally suited for a 3g modem, or one can say in another way: how realistic is it? amplify the modem signal with external antennas?
That, in fact, is all. I would be crazy happy if they helped me with the search here, or maybe even someone has design drawings for such an antenna)

Answer 1

See 3 variants:
1. Self-made antenna from a beer can or pan (not a joke).
2. Buying an external antenna ( an example of a list ), on eBay, of course, you can find cheaper.
3. Purchase of a GSM repeater.