Abstract: A base station antenna device containing a transmission and reception module is provided, which includes at least one antenna element configured to transmit and receive RF signals; the transmission and reception module configured to be connected to the antenna element and to form transmission and reception paths for the RF signals; a digital control module configured to digitally control the RF signals transmitted and received by the antenna element by transmitting digital control signals to the transmission and reception module; and a power supply configured to supply operating power to the transmission and reception module and the digital control module.

Abstract: A capacitive coupled extendable antenna for portable radio communication devices with improved operating characteristics is disclosed. The extendable antenna includes a quarter-wavelength helical antenna, a quarter-wavelength whip antenna movable between the extended position and the retracted position through the helical antenna, and an electrically conductive sleeve acting as the feed point of the antenna. The helical antenna is electrically insulated from the sleeve so that the helical antenna is capacitively coupled to the sleeve. The whip antenna is enclosed within an insulating tube, which is disposed within a guide for longitudinal movement therethrough. The whip antenna is disposed in electrically insulated relation to the sleeve in the retracted position and electrically connected to the sleeve in the extended position via a stopper.

Abstract: A antenna system of the present invention comprises a radiator for radiating a radio frequency, which is converted from electric power, and which has a impedance matching unit and a power divider; a first reflector for reflecting and filtering the radio frequency; and at least one second reflector for filtering the radio frequency radiated in the sideward direction of the antenna system, which is vertically attached to the first reflector, and is able to be moved in a horizontal direction.

Abstract: An capacitive coupled extendable antenna for cordless telephones and for portable cellular telephones is disclosed. The antenna is operated, in its extended state, as the equivalent of a half-wave dipole antenna due to capacity capacitive coupling between the quarter-wave helical antenna element and the quarter-wave whip antenna element and compensates, in its retracted state, the deficient capacity component of the helical antenna element owing to capacity capacitive coupling between the metal sleeve and the helical antenna element. The antenna also improves the efficiency of the whip antenna element as well as the efficiency of the helical antenna element by coupling the metal sleeve to a tube under the condition that the whip antenna element is fully inserted into the tube.