Abstract: A wireless signal transmitter is disclosed as including a sensor for detecting signals signifying heart beat of an individual, rotation of a wheel of a bicycle or rotation of a pedal of a bicycle, and two antennae for wirelessly transmitting the signals detected by the sensor, in which the two antennae are non-parallel to each other. A method of transmitting signals wirelessly is also disclosed as including steps of (a) providing a sensor for detecting signals signifying heart beat of an individual, rotation of a wheel of a bicycle or rotation of a pedal of a bicycle; (b) providing two antennae for wirelessly transmitting the signals detected by the sensor; and (c) transmitting the signals wirelessly via the two antennae; in which the two antennae are non-parallel to each other.