Abstract: Provided is a reflector/scatterer arranged around a side lobe beam which is generated from a transmission antenna, in a radiation direction of the side lobe beam, for use in expanding a communication service coverage area.

Abstract: A radio frequency (RF) weak magnetic field detection sensor includes a ferromagnetic core, a pickup coil disposed to surround the ferromagnetic core, a substrate that includes an opening, a core pad connected to the ferromagnetic core and a coil pad connected to the pickup coil, and an insulating tube interposed between the ferromagnetic core and the pickup coil. The insulating tube includes a bobbin around which the pickup coil is wound, and a core hole formed to pass through the bobbin and configured to accommodate the ferromagnetic core.

Abstract: An apparatus and method for transmitting and receiving magnetic field signals in a magnetic field communication system are provided. The apparatus includes a controller configured to generate a communication signal, matching units that are configured to receive the communication signal and that respectively correspond to different matching frequencies, and loop antennas that are connected to the matching units, respectively, and that are configured to convert communication signals according to the different matching frequencies into magnetic transmission signals in the form of magnetic field energy and to transmit the magnetic transmission signals.

Abstract: A semiconductor light-emitting device having high optical extraction efficiency is provided. The semiconductor light-emitting device includes a substrate on which an n-type semiconductor layer, an active layer, and a p-type semiconductor layer are formed sequentially; an n electrode formed in an exposed part of the n-type semiconductor layer by removing parts of the n-type semiconductor layer, the active layer, and the p-type semiconductor layer; a current spreading layer formed on the p-type semiconductor layer; a p electrode formed on the current spreading layer; and a current blocking layer formed between the p-type semiconductor layer and the current spreading layer to include a region corresponding to the p electrode.