Hi Anastasiia. Welcome to the forum. When this happens only at higher speeds it is usually an out-of-balance tire but you should feel it in the car too. Other potential causes are a broken tire belt, bent wheel, warped brake rotor, and worn inner cv joint housing.
The broken tire belt can often be felt at very low speeds and the steering wheel will move back and forth, but if it is just beginning to break, you might only feel it at higher speeds. The same is true for a bent wheel. While you'll feel it mostly at higher speeds, the steering wheel will wobble a little a low speeds. The brake rotor can warp two different ways. If there is a thickness variation at various places around its surface, that's what you will feel in the brake pedal when stopping. There can be no thickness variation but the entire rotor can be warped causing the brake caliper to slide back and forth once per wheel revolution. That can act on the steering linkage to tug it back and forth. That will be most noticeable at higher speeds. A worn inner cv joint housing is a hard-to-diagnose cause but the wobble it causes only occurs during acceleration and more so in the 5 - 35 mph range. The load on it causes the rollers to bind in the housing. That forces the shaft to push on the spindle and that tugs on the steering linkage.
Sunday, July 28th, 2013 AT 2:04 AM