The present invention relates to a base station antenna comprising: a reflective plate; at least one first band radiation element positioned on the upper surface of the reflective plate, including a first power feed unit, and having a first wavelength (λ.sub.H); and at least one second band radiation element positioned on the upper surface of the reflective plate, including a second power feed unit, and having a second wavelength (λ.sub.L), wherein the first power feed unit is connected to a power feed line on the lower surface of the reflective plate, and the power feed line is shorted with the reflective plate at a short point spaced apart at a preset interval from the first band radiation element.

The present invention relates to a base station antenna comprising: a reflective plate; at least one first band radiation element positioned on the upper surface of the reflective plate, including a first power feed unit, and having a first wavelength (λ.sub.H); and at least one second band radiation element positioned on the upper surface of the reflective plate, including a second power feed unit, and having a second wavelength (λ.sub.L), wherein the first power feed unit is connected to a power feed line on the lower surface of the reflective plate, and the power feed line is shorted with the reflective plate at a short point spaced apart at a preset interval from the first band radiation element.

Antenna systems are described which provide means of mitigating the undesirable transmission line effect(s) by using fractal metamaterials in close proximity to an antenna, with both the antenna and fractal metamaterials being positioned a conductive surface, which may be inside or adjacent to a cavity. The fractal metamaterial can include an array of close spaced (e.g., less than 1/10 wavelength separation) resonant structures of a fractal shape, resonant at or near the intended frequency of use of the antenna. The fractal metamaterial can reverse the phase of the reflected wave so that the metal cavity no longer produces an out of phase current induced by the antenna. Without the cavity being out of phase to the antenna, the transmission line effect is mitigated substantially and the antenna performance can accordingly be enhanced. Further embodiments omit a cavity and locate a fractal metamaterial and antenna(s) adjacent to an underlying conductive surface.

A communication system is described where multiple communication networks are simultaneously accessible from a plurality of fixed and/or mobile communication devices. A Master and Slave hierarchy is implemented among the communication devices to improve communication properties on one or multiple networks. A network system controller is implemented to select the network with optimal communication characteristics for subsets of communication devices as well as assigning Master status to a communication device within these subsets.

A system and methods for RF (Radio Frequency) penetration imaging of one or more objects in a medium, the system including a generation and reception subsystem configured to generate and receive a plurality of RF signals, an RF antenna array including a plurality of antennas, the antennas being configured to transmit the RF signals towards the medium and receive a plurality of RF signals reflected from the medium, a data acquisition subsystem configured to receive and store the reflected RF signals, and a processor configured to estimate the distance between the surface of the target medium and the antenna array, the delay between the transmitted signals and the plurality of signals reflected from the object using a dedicated frequency sub-band of the received signals, the location of the antennas at each transmitting time, and determine whether there is an object within the medium.

A system and methods for RF (Radio Frequency) penetration imaging of one or more objects in a medium, the system including a generation and reception subsystem configured to generate and receive a plurality of RF signals, an RF antenna array including a plurality of antennas, the antennas being configured to transmit the RF signals towards the medium and receive a plurality of RF signals reflected from the medium, a data acquisition subsystem configured to receive and store the reflected RF signals, and a processor configured to estimate the distance between the surface of the target medium and the antenna array, the delay between the transmitted signals and the plurality of signals reflected from the object using a dedicated frequency sub-band of the received signals, the location of the antennas at each transmitting time, and determine whether there is an object within the medium.

A multilayer body with a functional layer which includes an antenna element as well as with an optical security element which includes at least one electrically conductive partial region which is galvanically connected to the antenna element. A security document with such a multilayer body, as well as a method for the authentication thereof.

A multilayer body with a functional layer which includes an antenna element as well as with an optical security element which includes at least one electrically conductive partial region which is galvanically connected to the antenna element. A security document with such a multilayer body, as well as a method for the authentication thereof.

The antenna module comprises a communication circuit for processing a radio signal; a shield member covering the communication circuit; a conductive strip electrically connected with the communication circuit; a dielectric integrated with the shield member and the conductive strip; and an antenna formed on an outer surface of the dielectric and electrically connected with the conductive strip.

An antenna-unit (110) for at least dual-FDD bands includes a first combiner (100) splitting its input (101) into at least two outputs (102, 103). Each output (102, 103) operates in at least two narrow-bands from two different FDD systems, and is respectively connected to a second and third combiners (200, 300). The second and third combiners (200, 300) are respectively connected with a first RF circuit (800, 900) enabling separation of two different FDD channels in an inverted Transmitter/Receiver fashion. An antenna system (700) based on the antenna unit (110) includes a set of columns of dual-polarized radiating elements (500) arranged on a reflector (702), and the first RF circuit (800,900) is connected with a second RF circuit (10) of the Base Station processing, SDR is set along with the RF circuit (10) to enable 3D beamforming features as well as independent system link control for optimization purpose.