A method for wireless data transmission, in, for example, RFID systems, between a base station and a passive transponder, as well as a passive transponder is provided by inductive coupling, as well as a passive transponder. The magnets andor shunting pieces have a first position producing a weak magnetic field for asynchronous induction motor operation at startup and a second position producing a strong magnetic field for efficient synchronous operation. The termination beam is configured to electrically connect to and retain the conductor of the wire. A venturi is formed near an end of the hollow rotary shaft to apply vacuum to the hollow rotary shaft and the openings in the chuck surface. An IQ imbalance correction circuit corrects a quadrature error and an amplitude error between the first and second digital signals from the digital band-pass filter.