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.

Example slot antennas for electronic user device and related methods are disclosed herein. An example electronic user device including at least one of a lid or a base. The at least one of the lid or the base have a first surface and a second surface spaced apart from the second surface. The example electronic user device includes an antenna including a first aperture in the first surface and a second aperture in the second surface. The example user device includes a first cover at least partially disposed in the first aperture and a second cover at least partially disposed in the second aperture.

Example slot antennas for electronic user device and related methods are disclosed herein. An example electronic user device including at least one of a lid or a base. The at least one of the lid or the base have a first surface and a second surface spaced apart from the second surface. The example electronic user device includes an antenna including a first aperture in the first surface and a second aperture in the second surface. The example user device includes a first cover at least partially disposed in the first aperture and a second cover at least partially disposed in the second aperture.

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 method for upgrading a dual-band antenna assembly to a tri-band antenna assembly is provided. The dual-band antenna assembly includes a main reflector, and first and second antenna feeds arranged in a coaxial relationship and directed toward the main reflector. The first and second antenna feeds are for first and second frequency bands, respectively. The method includes positioning a third antenna feed through a medial opening in a center of the main reflector, with the third antenna feed directed towards the first and second antenna feeds. The third antenna feed is for a third frequency band. A subreflector is positioned between the main reflector and the first and second antenna feeds. The subreflector includes a frequency selective surface (FSS) material that is reflective for the third frequency band and transmissive for both the first and second frequency bands.

A method for upgrading a dual-band antenna assembly to a tri-band antenna assembly is provided. The dual-band antenna assembly includes a main reflector, and first and second antenna feeds arranged in a coaxial relationship and directed toward the main reflector. The first and second antenna feeds are for first and second frequency bands, respectively. The method includes positioning a third antenna feed through a medial opening in a center of the main reflector, with the third antenna feed directed towards the first and second antenna feeds. The third antenna feed is for a third frequency band. A subreflector is positioned between the main reflector and the first and second antenna feeds. The subreflector includes a frequency selective surface (FSS) material that is reflective for the third frequency band and transmissive for both the first and second frequency bands.

A wireless communication system, in which a redundancy bit is transmitted from a first communication device to a second communication device when the second communication device fails to decode the encoded bits, includes a processor. The processor selects communication patterns that respectively satisfy a requested quality, calculates, for each of the selected communication patterns, a transmission data length that indicates a length of the redundancy bit, calculates, for each of the selected communication patterns, a transmission latency between the first communication device and the second communication device based on the calculated transmission data length, and generates a retransmission parameter corresponding to a communication pattern with lowest transmission latency among the selected communication patterns. The first communication device transmits the redundancy bit according to the retransmission parameter, and the second communication device decodes the encoded bits by using the redundancy bit according to the retransmission parameter.

An antenna includes a first radiation part, a matching circuit, and a feed source, where the first radiation part includes a first radiator, a second radiator, and a capacitor structure. A first end of the first radiator is connected to the feed source using the matching circuit, the feed source is connected to a grounding part, a second end of the first radiator is connected to a first end of the second radiator using the capacitor structure, a second end of the second radiator is connected to the grounding part, the first radiation part is configured to generate a first resonance frequency, and a length of the second radiator is one-eighth of a wavelength corresponding to the first resonance frequency which helps to reduce an antenna length, and a volume of a mobile terminal.

An antenna includes a first radiation part, a matching circuit, and a feed source, where the first radiation part includes a first radiator, a second radiator, and a capacitor structure. A first end of the first radiator is connected to the feed source using the matching circuit, the feed source is connected to a grounding part, a second end of the first radiator is connected to a first end of the second radiator using the capacitor structure, a second end of the second radiator is connected to the grounding part, the first radiation part is configured to generate a first resonance frequency, and a length of the second radiator is one-eighth of a wavelength corresponding to the first resonance frequency which helps to reduce an antenna length, and a volume of a mobile terminal.