Transmitter of tire condition monitoring apparatus and tire condition monitoring apparatus

摘要

A transmitter of a tire condition monitoring apparatus wirelessly transmits transmission data containing air pressure data of a tire. The wireless transmission of the transmission data is performed when a reception antennal in the transmitter receives a trigger signal transmitted by an initiator. The reception antenna is arranged relative to the tire such that the orientation of the directivity of the reception antenna is constant irrespective of a rotation angle of the tire. Therefore, the transmitter operates reliably irrespective of the rotation angle of the tire.