Abstract:
A metal structure, a unit structure, and a method for forming the metal structure are provided to reduce a surface current on a metal structure of an electronic product by using an electromagnetic band gap. A metal structure for preventing electrostatic discharge includes an electromagnetic band gap(100), a metal structure(110), an opening part(120), and a unit structure(130). The opening part is formed a front surface of the metal structure. The electromagnetic band gap suppresses a current generated by the electrostatic discharge. The electromagnetic band gap is formed by an arrangement of the unit structure. The unit structure has a triangle or a rectangular shape. The electromagnetic band gap is formed by using a metal patch and a dielectric. The dielectric is formed between the electromagnetic band gap and a metal plate. The dielectric supports the electromagnetic band gap.
Abstract:
Provided are a method for preparing an aqueous urethane binder, and a paint composition for electromagnetic interference shielding containing the binder prepared by the method which is low in surface resistance, is excellent in adhesive strength and is environmentally friendly. The method comprises the steps of adding water to a prepolymer water dispersion; and controlling the content of a volatile organic compound to 5 g/L or less by vacuum distillation, to prepare an aqueous urethane binder. Preferably the prepolymer water dispersion is prepared by adding 20-25 parts by weight of polyoxypropylene glycol, 0.6-1.4 parts by weight of polyoxypropylene glycerin, 5-10 parts by weight of 2,4-toluene diisocyanate, 2.0-3.5 parts by weight of DMPA, 7.5-9.0 parts by weight of NMP, 1.0-3.0 triethylamine, 2.0-3.5 parts by weight of dibutyl tin dilaurate and water based on the weight of a urethane binder. The paint composition comprises 15-35 wt% of the aqueous urethane binder; 35-45 wt% of a silver powder; 0.01-0.09 wt% of a dispersant; 0.02-0.1 wt% of an antisettling agent; and 20-40 wt% of water.
Abstract:
PURPOSE: A handphone having lowered absorption rate is provided to effectively reduce the emittance of electromagnetic wave toward a head of a user without spoiling the beauty or causing troublesome to the user by mounting an antenna within a case with a structure obtaining high antenna gain. CONSTITUTION: Various electronic elements are arranged on at least one circuit board mounted within a case(11) so that the elements can perform various functions including the transmission and receive of electric wave. An antenna(17) helps the transmission or receive through the electronic elements arranged on the circuit board. In this structure, the antenna(17) is disposed within the case(11). In addition, an electromagnetic wave absorber(16) is disposed between the circuit board and the antenna(17) so as to correspond to a portion of the antenna.
Abstract:
PURPOSE: A mobile phone for reducing an electronic wave absorption rate by installing an antenna therein with a space reducing structure is provided to remove or reduce a harmful electronic wave absorbed into a human body from a mobile phone body and an antenna for a user's stable and reliable use by positioning an electronic wave absorbing unit between a circuit board of the mobile phone and the antenna. CONSTITUTION: An electronic absorbing unit(16) is mounted between an antenna(17) and an internal circuit(19). The electronic absorbing unit(16) absorbs an electronic wave reflected from a rotor contact of a circuit board to reduce an influence to a resonation of the antenna(17). Thus, the antenna(17) maintains its inherent characteristics at the internal side likewise at the outer side, thereby faithfully performing its role. The electronic absorbing unit(16) absorbs even an electronic wave directing to a human body after being generated from the front side of the mobile phone(10), as well as the electronic wave generated from the antenna(17). An outer face of the bottom portion of the electronic wave absorbing unit(16) is attached on the circuit board, and side walls formed at both sides of the bottom portion have a long hole shape protruded from the surface of the circuit board. A section of the electronic wave absorbing unit(16) makes an angular U-shape. That is, the bottom portion and the side walls make 90° with each other. The antenna(17) is installed in the hole shape electronic wave absorbing unit(16). The entrance of the electronic wave absorbing unit(16) is preferably 90° to 180° centering around the antenna(17) installed in the electronic wave absorbing unit(16).
Abstract:
PURPOSE: A mobile phone for reducing an electronic wave absorption rate by installing an antenna therein with a space reducing structure is provided to remove or reduce a harmful electronic wave absorbed into a human body from a mobile phone body and an antenna for a user's stable and reliable use by positioning an electronic wave absorbing unit between a circuit board of the mobile phone and the antenna. CONSTITUTION: An electronic absorbing unit(16) is mounted between an antenna(17) and an internal circuit(19). The electronic absorbing unit(16) absorbs an electronic wave reflected from a rotor contact of a circuit board to reduce an influence to a resonation of the antenna(17). Thus, the antenna(17) maintains its inherent characteristics at the internal side likewise at the outer side, thereby faithfully performing its role. The electronic absorbing unit(16) absorbs even an electronic wave directing to a human body after being generated from the front side of the mobile phone(10), as well as the electronic wave generated from the antenna(17). The electronic wave absorbing unit(16) includes two walls(16A,16B) that meet at 90°and form angular L-shape. The first wall(16A) is attached on the circuit board, and the second wall(16B) is protruded from the surface of the circuit board at one side of the first wall(16A) and extended to the inner face of the rear wall of the case(11). The other side of the first wall(16A) contacts the right wall of the case(11) when viewed from the front side. The antenna(17) is disposed inside the square space formed by the electronic wave absorbing unit(16) and the right rear walls of the case(10).
Abstract:
PURPOSE: A broad band antenna system for a terminal is provided to have a shorter electric length than 1/4 wave length, and be mountable on an inside as well as reducing electromagnetic wave effect. CONSTITUTION: A reflecting plate(101) is installed on a rear surface of a terminal, controls radiated patterns of an electromagnetic wave generated on an element(109), reduces the radiant electromagnetic wave in a head direction, in other words, at a front surface of the terminal, and thus decreases an electromagnetic wave absorption index. An element support(110) is fixed with a non-conductive material or a conductive material to prevent a damage on the element during the terminal is carried. In a case that the element support(110) is manufactured of the non-conductive material, resonance is determined according to size of a cap-shaped conductor(108) and the element(109), such that resonance frequency is adjusted according to the size. In case of the element support(110) is manufactured of the conductive material, the resonance frequency is controllable by varying a position where the element support(110) is mounted besides the size of the cap type conductor(108) and the element(109).