Abstract: A built-in antenna system for indoor wireless communications includes an AP antenna, all of the surfaces of which, except for an emitting surface, are installed behind wall surfaces in a wall of a building, and includes an access point (AP) (or an RF unit) connected to the AP antenna. Alternatively, the antenna system includes an antenna structure that is installed to pass through a selected wall of a building and an AP (or RF unit) connected to the antenna structure, the antenna structure having a sliding structure that can be adjusted according to the thickness of the wall. The shift of a frequency band caused by the wall may be avoided, and high-quality wireless communications is achieved regardless of the location of a wireless communication terminal in the building. Further, it is possible to increase the intensity of an electric field at the position of the terminal.

Abstract: An isotropic antenna system includes a first antenna for transmitting/receiving electric waves when a cover member installed to be capable of being open or closed with respect to a main body is open, a second antenna for transmitting/receiving electric waves when the cover member is closed, and a switching portion for selectively switching at least one of the first and second antennas to a predetermined RF circuit module according to the opening or closing of the cover member.

Abstract: An isotropic antenna system includes a first antenna for transmitting/receiving electric waves when a cover member installed to be capable of being open or closed with respect to a main body is open, a second antenna for transmitting/receiving electric waves when the cover member is closed, and a switch for selectively switching at least one of the first and second antennas to a predetermined RF circuit module according to the opening or closing of the cover member.

Abstract: An isotropic antenna system includes a first antenna for transmitting/receiving electric waves when a cover member installed to be capable of being open or closed with respect to a main body is open, a second antenna for transmitting/receiving electric waves when the cover member is closed, and a switch for selectively switching at least one of the first and second antennas to a predetermined RF circuit module according to the opening or closing of the cover member.

Abstract: A small planar antenna combined with a printed circuit board (PCB). The planar antenna includes: a dielectric layer with a predetermined thickness; first and second ground layers formed on top and bottom surfaces of the dielectric layer, respectively, corresponding to each other; and a first antenna unit which extends from a side of each of the respective first and the second ground layers, for radiating a first polarized wave with the application of current. A second antenna unit extends from a side of each of the respective first and second ground layers, for radiating a second polarized wave orthogonal to the first polarized wave with the application of current. A feeding stripline is installed between the first and second antenna units, in the dielectric layer, for applying the current to the first and second antenna units, wherein the first and second polarized waves can be separately radiated.

Abstract: A micro-strip patch antenna for a radiotelephone transceiver includes a dielectric ceramic module for transmission and reception having a first ground plate, just one dielectric ceramic part for synchronizing frequencies, a conductive patch on the dielectric ceramic part for transmitting and receiving electromagnetic waves, transmission and reception power supply terminals projecting from different sides of the conductive patch. The antenna also has printed circuit board having a base, a second ground plate on the base to contact the first, and strip lines formed on the base so as to be adjacent but spaced from to the ground plates. The strip lines take care of impedance matching, and antenna provides for the use of a single channel power supply without modification.