How is phase recovered from wireless signals?
Radar beam forming is performed by feeding an array of small aperture antennas at different phases of the RF carrier. The phase shifting can be accomplished by digital processing, lumped circuits, spacial positioning, or delay lines formed from various electrical lengths of transmission lines. Phase shifting is the basis of nearly every multi element antenna. Phase shifting is also generally reciprocal for receiving and transmitting on the same antenna.

So generally we are not interested in the exact phase of an RF signal but rather its relative phase to another path of the same signal. This extends beyond antennas to include selective fading, multipath distortions, standing waves and other topics.

QAM is a different beast. The QAM signal modulates a carrier frequency. So the phase of the carrier is not of interest for decoding.

Radio signals propagate due to the accelerating nature of the sinusoidal waveform and because they are composed of an electric and magnetic field at right angles to one another.