Air-spring with heigth sensor having a non-contact power supply

Air-spring with a distance sensor comprising: a signal receiving unit, an electromagnetic wave transmitting unit, and a magnetic signal transmitting unit; wherein the signal transmitting unit is adapted to transmit to the signal receiving unit a sensed distance between the signal receiving unit and the magnetic signal transmitting unit, wherein the magnetic signal transmitting unit further comprises an electromagnetic wave receiving unit and an electromagnetic wave-to-electric power converter, and wherein the electromagnetic wave receiving unit receives electromagnetic waves transmitted from the electromagnetic wave transmitting unit to operate the magnetic signal transmitting unit.