Electronics and Telecommunications Research Institute

University of Florida Research Foundation Inc

Hae Yong Yang

Dae Heon Lee

Seahee Hwangbo

Woong Hee Kim

Dong Hoon Shin

Jinchun Wang

Yong-Kyu Yoon

Yong Kyu Yoon

Sang Han Lee

Chun Sug Kim

Inho Hwang

Eungki Park

Kyung Hoon Lee

Various examples are provided that are related to fractal-based reactive impedance surfaces. These surfaces allow for miniaturization of antennas. In one example, a fractal rectangular reactive impedance surface (FR-RIS) includes a plurality of fractal rectangular (FR) patches having an outer edge defined by a fractal rectangular pattern that is repeated along each side of inner FR patches of the plurality of FR patches. The fractal rectangular pattern of a FR patch matches with the fractal rectangular pattern of an adjacent FR patch. An antenna can include a planar antenna disposed over the FR-RIS.

Fractal-rectangular reactive impedance surface for antenna miniaturization

Various examples are provided for point symmetric complementary meander line (PSC-ML) slots, which can be used for mutual coupling reduction. In one example, an antenna array includes first and second patch antenna elements disposed on a first side of a substrate, the first and second patch antenna elements separated by a gap. The antenna array can include point symmetric complementary meander line (PSC-ML) slots formed in a ground plane disposed on a second side of the substrate. The PSC-ML slots can include a pair of ML slots aligned with the gap between the first and second patch antenna elements. In another example, a method includes forming first and second antenna elements on a first side of a substrate and forming PSC-ML slots in a ground plane disposed on a second side of the substrate that are aligned with a gap between the first and second antenna elements.

Point symmetric complementary meander line slots for mutual coupling reduction

An anti-jamming apparatus and method for a compact array antenna are provided. The anti-jamming apparatus for a compact array antenna includes a Global Navigation Satellite System (GNSS) array antenna unit including a plurality of GNSS antennas for receiving GNSS signals transmitted from a satellite. A first beam-forming unit includes a plurality of combination units for receiving respective signals received by the plurality of GNSS antennas as a first reference signal and first auxiliary signals and combining the first reference signal with the first auxiliary signals, thus forming different beams. A second beam-forming unit receives signals of the different beams, and combining the signals of the different beams, thus forming an anti-jamming beam in which an invisible area is minimized.

Anti-jamming apparatus and method for compact array antenna

A method and apparatus for measuring the synthetic reception pattern of an adaptive array antenna, which are divided into a hardware apparatus and a measurement method. The hardware apparatus includes a wavefront simulator, a GNSS simulator, an external controller, a signal measurement unit, and a GNSS receiver. The measurement method using the hardware apparatus includes setting a direction of arrival of jamming and calculating a weight vector, fixing weight vectors at the calculated weight vector and collecting outputs of an array antenna system for all test signals, and displaying the collected data on a grid of a 2D plane. In accordance with the present invention, a weight vector calculated under a specific jamming situation is maintained for all test signals, so that the synthetic reception pattern of the array antenna system can be measured.

Method and apparatus for measuring synthetic reception pattern of adaptive array antenna

An ultra-wideband tapered slot antenna that is capable of providing spatial independent band-stop characteristics which are irrelevant to the radiation direction of the antenna in a dual-stop band. The antenna includes an ultra-wideband tapered slot antenna includes a radiating unit formed on a first surface of a substrate and configured to radiate radio signals. A feeding unit is formed on a second surface of the substrate and is configured to provide the radio signals to the radiating unit. Separate stubs are formed to be spaced apart from the feeding unit around the feeding unit and are configured to reject frequencies in a first stop band from the radio signals radiated from the radiating unit. A slot is formed in a stub formed at a first end of the feeding unit and is configured to reject frequencies in a second stop band from the radio signals.

Ultra-wideband tapered slot antenna

Provided are a method and apparatus for partially encrypting speech packets, more specifically, a method and apparatus for selecting partial encryption sets used for a partial encryption technique in which compressed speech packets are partially encrypted to obtain the same effect as a full encryption technique. The method includes the steps of: (a) compressing respective speech files stored in a large-capacity speech database into the speech packets using a speech codec; (b) measuring single-bit loss distortion and sequential-bit loss distortion of the speech packets compressed in step (a); (c) generating standards for selecting partial encryption sets based on the measurement results of the single-bit loss distortion and sequential-bit loss distortion; (d) selecting the partial encryption sets according to the generated standards; and (e) encrypting the speech packets using the selected partial encryption sets. In this method, distortion sensitivity caused by loss of a speech packet can be exactly measured in various embodiments so that partial encryption sets can be efficiently and securely selected based on the measurement result. As a result, by reducing the amount of encryption operation, encryption services can be applied in various wireless communication environments.

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Daejeon, South Korea

Hae Yong Yang