A radiofrequency antenna device includes a carrier, an antenna structure, a high-frequency blocking unit, and a proximity sensor (P-sensor), which are disposed on the carrier. The antenna structure includes a supporting frame disposed on the carrier, a first coupling segment disposed on the supporting frame, a second coupling segment disposed on the carrier, an insulating adhesive layer connected between the first and the second coupling segments, a radiating body disposed on the supporting frame and connected to the first coupling segment, and a feeding conductor disposed on the supporting frame. The feeding conductor is configured to transmit a signal to the radiating body. The high-frequency blocking unit is electrically connected to the first coupling segment. The P-sensor is electrically connected to the high-frequency blocking unit, and the P-sensor is electrically connected to the first coupling segment and the radiating body through the high-frequency blocking unit.