An indirect bonding apparatus for orthodontic bonding procedures includes a tray having inner wall sections defining a channel for receiving the patient’s dental arch. The conductive member includes, at an inner edge thereof, multiple portions whose distances from the terminal are different. A sector antenna system comprising a number of linear array antennas, in which distance between the antenna sensors is determined in consideration of overlapping angle of beams to supply softer handoff is provided. A diffuser can be arranged in relation to the LEDs so that at least some light from the LEDs passes through the diffuser and is dispersed into the desired emission pattern.