Abstract: A method for manufacturing metal nano particles having a hollow structure is provided. First, a suitable reducing agent is added into a first metal salt solution, and first metal ions are reduced to form first metal nano particles. Next, after the reducing agent is decomposed, a second metal salt solution with a higher reduction potential than that of the first metal is added. Then, the first metal particles are oxidized to form first metal ions when the second metal ions are reduced on the surface of the first metal by electrochemical oxidation reduction reaction, and thus, second metal nano particles having a hollow structure and a larger surface area are obtained. The method is simple and the metal nano particles with uniform particle size are obtained by this method.

Abstract: A dual-band dual-antenna structure is provided. The dual-band dual-antenna structure comprises a substrate, a first antenna and a second antenna. The substrate comprises a first signal transport layer and a second signal transport layer, wherein the second signal transport layer is not coplanar with the first signal transport layer. The first antenna is disposed on the first signal transport layer and comprises a first U-shaped radiation element and a first polygon radiation element. The first polygon radiation element is disposed in an opening of the first U-shaped radiation element. The second antenna is disposed on the second signal transport layer but does not overlap under the first antenna. The second antenna comprises a second U-shaped radiation element and a second polygon radiation element. The second polygon radiation element is disposed in an opening of the second U-shaped radiation element.

Abstract: A dual-band dual-antenna structure is provided. The dual-band dual-antenna structure comprises a substrate, a first antenna and a second antenna. The substrate comprises a first signal transport layer and a second signal transport layer, wherein the second signal transport layer is not coplanar with the first signal transport layer. The first antenna is disposed on the first signal transport layer and comprises a first U-shaped radiation element and a first polygon radiation element. The first polygon radiation element is disposed in an opening of the first U-shaped radiation element. The second antenna is disposed on the second signal transport layer but does not overlap under the first antenna. The second antenna comprises a second U-shaped radiation element and a second polygon radiation element. The second polygon radiation element is disposed in an opening of the second U-shaped radiation element.

Abstract: A method for manufacturing metal nano particles having a hollow structure is provided. First, a suitable reducing agent is added into a first metal salt solution, and first metal ions are reduced to form first metal nano particles. Next, after the reducing agent is decomposed, a second metal salt solution with a higher reduction potential than that of the first metal is added. Then, the first metal particles are oxidized to form first metal ions when the second metal ions are reduced on the surface of the first metal by electrochemical oxidation reduction reaction, and thus, second metal nano particles having a hollow structure and a larger surface area are obtained. The method is simple and the metal nano particles with uniform particle size are obtained by this method.