Do not attempt to connect to the modem any amplifiers. Power output of any wireless equipment, including standard 4G (WiMax), is limited by law. In addition, the amplifier can create out-of-band radiation at the harmonics, which is also a violation.
Radio waves at frequencies used for data transmission in the network Yota, are objects that can conduct current. In the house, whose walls are concrete, it makes sense to bring the laptop along with the modem to the window. Even if it does not go in the direction of the base station, the signal level may increase. You can just walk around with a laptop in the room - due to the presence of interference maxima and minima points with a high signal level can be anywhere.
Move the laptop to search for places of confident reception is not always convenient, but if the computer is stationary, even more so. Will solve the problem the extension to include the modem from the USB port to a distance of 2.5 meters. It needs to be USB 2.0, otherwise reduce the data transfer rate. Move the modem slowly because update of information about the quality of reception is delayed.
To focus the ultra high frequency radio waves, you can use a parabolic mirror, similar to those used in the satellite antennas. The best results provide the reflectors from such receptors. The modem is placed in the focus of the mirror instead of the Converter. You can use a surrogate reflectors in the form of conventional metal cans, including painted. To place the modem outside the room is impossible, because it is not sealed. To place the entire structure will have within the room. The antenna should be directed to the nearest base station of the network Yota. If you don't know where she is, pick the best direction empirically.