Abstract: The present invention relates to a porous copper sulfide nano/micro hollow sphere and a method for preparing the same. The porous copper sulfide nano/micro hollow sphere of the present invention has plural through holes and a hollow structure so as to increase the reactive area thereof. In particular, the porous copper sulfide nano/micro hollow sphere can be applied in a solar cell to enhance a photoelectric effect.

Abstract: A high frequency SAW device and the substrate thereof are disclosed. The disclosed high frequency SAW device does not need to use the conventional and expensive sapphire substrate as its substrate. Besides, the disclosed substrate for a high-frequency SAW device can replace the conventional sapphire substrate in the use of the substrate for a high frequency SAW device. The disclosed high frequency SAW device comprises: a substrate; a first buffering layer forming on the surface of the substrate; a second buffering layer forming on the surface of the first buffering layer; a piezoelectric layer forming on the surface of the second buffering layer; an input transformation unit; and an output transformation unit, wherein the input transformation unit and the output transformation unit are formed in pairs on the surface of or beneath the piezoelectric layer.

Abstract: The present invention relates to a circularly polarized antenna and, more particularly, to a compact circularly polarized antenna for transmitting and receiving a circularly polarized signal. The circularly polarized antenna comprises a substrate having an upper surface and a lower surface; a signal distributor; an antenna for transmitting and receiving the circularly polarized signal; and a plurality of support units. The upper surface of the substrate comprises a plurality of slots. One end of each slot overlaps with the respective ends of the other slots at a central region. The lower surface of the substrate comprises a coupling unit being electrically connected with the signal distributor, and the center of the coupling unit corresponds to the central region.