Abstract: According to an embodiment of the present disclosure, provided is a radiation element structure arranged on a reflective plate, comprising: a radiation unit including a dielectric portion made from plastic material and first to fourth radiation arms arranged in a four-sided symmetrical structure on one surface of the dielectric portion; and a plurality of balun units, including a balun body connecting the reflective plate and the radiation unit, a feed line disposed on the upper surface of the balun body to feed the radiation unit, and a ground disposed on the lower surface of the balun body.

Abstract: Disclosed herein is an untact DC electric-field sensor having improved sensitivity. The untact DC electric-field sensor has a circuit composed of a variable capacitor and an RF generator and improves sensitivity through resonance of the circuit by connecting an inductor to the sensor.

Abstract: A wireless communication device is disclosed. According to at least one embodiment of the present disclosure, a wireless communication device is provided, comprising a first antenna housing, a mounting space formed in at least part of the first antenna housing, and a plurality of first antenna elements disposed in the first antenna housing and configured to transmit and receive a first signal.