Ntt Docomo, Inc.

Tohoku University

Nippon Telegraph and Telephone Corporation

Tamami Maruyama

Yasuhiro Oda

Jiyun Shen

Tatsuo Furuno

Ngoc Hao Tran

Tomoyuki Ohya

Hidetoshi Kayama

Shinji Uebayashi

Kunio Sawaya

Qiang Chen

Qiaowei Yuan

Jianfeng Li

Kazuhiro Uehara

Keizo Cho

Kenichi Kagoshima

Long Li

Fumio Kira

Shiwei Qu

A disclosed dual antenna system includes a receiving antenna which includes a first surface orthogonal to an incident wave, the first surface being a first antenna aperture, and a transmitting antenna which includes a second surface parallel to a reflection direction which is a transmission direction, the second surface being a second antenna aperture. A portion of a structure of the transmitting antenna is shared by the receiving antenna.

Dual antenna system

A reflectarray reflects an incident wave in a desired direction, and the reflectarray includes a plurality of elements arranged in a first direction and in a second direction perpendicular to the first direction. The elements reflect the incident wave. A phase of a reflected wave by one element among the plurality of elements differs from a phase of the reflected wave by an element adjacent to the one element in the first direction by a predetermined value, and the phase of the reflected wave by the one element is equal to a phase of the reflected wave by an element adjacent to the one element in the second direction. Gap sizes between patches of a predetermined plural number of elements arranged in the first direction vary from a smallest value to a largest value. Here, an oblique TM incidence is utilized at a spurious resonance frequency.

Reflectarray

A method of designing a reflectarray including a substrate having a surface perpendicular to a predetermined axis, wherein elements are disposed on the substrate. The method obtains a reflection phase of the elements as a function of a design parameter such as element spacing, when a radio wave enters the arranged elements, and stores a relationship between the reflection phase and the design parameter in a memory. Here, the design parameter is equally set for the elements. The method repeatedly determines, for each of the elements, the design parameter of a specific element in accordance with the relationship. The function of the design parameter has a range of almost 360 degrees with respect to a range of the design parameter. The reflection phase is the continuous function of the element spacing such that two resonant points occur at which the reflection phase becomes zero.

Reflectarray and design method

A reflectarray having multiple elements arranged in an array, each element having a H-shaped patch provided in separation from a ground plate, the H-shaped patch formed by four outer vertices defined by two rectangular outer patches and four inner vertices defined by an inner patch. A length of the inner patch with respect to a first direction is determined to change the reflection phase of an electric field incoming in parallel to the first direction while keeping positions of the four outer vertices and sizes of the outer patches constant. The first direction is determined by positions of the four inner vertices, and a length of the H-shaped patch with respect to a second direction is determined to change the reflection phase of an electric field incoming in parallel to the second direction, wherein the second direction is determined by positions of the four outer vertices.

A reflectarray reflects an incident wave in a desired direction. The reflectarray includes a substrate including a surface which is perpendicular to a predetermined axis; and at least first and second element groups, wherein the first and second element groups are disposed on the substrate, and include elements that reflect a radio wave. The first element group and the second element group reflect the radio wave with corresponding reflection phases which are different from each other. The radio wave enters while forming an angle other than 0 degrees with respect to the predetermined axis. The elements included in the first element group reflect the radio wave with a first reflection phase, and the elements included in the second element group reflect the radio wave with a second reflection phase, wherein the second reflection phase is different from the first reflection phase.

A reflectarray reflects an incident wave in a desired direction. The reflectarray includes a substrate including a surface which is perpendicular to a predetermined axis, and elements disposed on the substrate. A specific element among the elements reflects the incident wave with a specific reflection phase among a plurality of reflection phases. Each of the elements has an element structure including, at least, a patch and a ground plate. Element spacing of first neighboring elements is different from element spacing of second neighboring elements, and a length of a gap between patches of the first neighboring elements is equal to a length of a gap between patches of the second neighboring elements.

A propagation path estimation method using an imaging method according to the invention includes a step of, in a case where a reflectarray which causes reflection and scattering in a different direction (&#x3b8;&#x2212;&#x3b7;)&#xb0; from a specular reflection direction &#x3b8;&#xb0; exists on a propagation path from a transmission point to a reception point RX of the radio wave, calculating a virtual reception point VRX by rotating the reception point RX about a rotation center point O, and estimating the propagation path by using the virtual reception point VRX.

Propagation path estimation method and program and apparatus using the same

A propagation path estimation method using an imaging method according to the invention includes a step of, in a case where a reflect array(structure) which causes reflection and scattering in a predetermined direction (&#x3b8;-&#x3b7;)&#xb0; different from a specular reflection direction &#x3b8;&#xb0; exists on a propagation path, rotating the reflect arrayby &#x3b7;/2&#xb0; about a rotation center O to set a virtual rotated reflect array(virtual structure), and estimating the propagation path by using the virtual rotated reflect array

A multi-beam reflectarray includes two or more element arrays including plural elements aligned along a predetermined direction. The multi-beam reflectarray is such that, in each of a first element group and a second element group included in at least one of the element arrays, a difference between phases of radio waves reflected by corresponding two elements is in proportion to a first product of a distance between the two elements and a value of a trigonometric function with respect to an angle of reflection by the two elements, and a distance between neighboring elements in the first element group is equal to a product of a rational number and a distance between neighboring elements in the second element group.

Multi-beam reflectarray

An apparatus having multiple mushroom structures is disclosed. Each of the multiple mushroom structures includes: a ground plate; a patch provided parallel to the ground plate with a separation of a distance to the ground plate, wherein a distance between a ground plate and a patch in a certain mushroom structure is different from a distance between a ground plate and a patch in a different mushroom structure.

Apparatus having mushroom structures

An apparatus having multiple mushroom structures is disclosed. Each of the multiple mushroom structures including: a ground plate; a first patch provided parallel to the ground plate with a separation of a distance to the ground plate; and a second patch provided parallel to the ground plate with a separation of another distance to the ground plate, which another distance being different from the distance from the first patch to the ground plate, wherein the second patch is a passive element which is capacitatively coupled with at least the first patch.

A reflectarray, including: a substrate; and a plurality of patches formed on each of areas into which a principal surface of the substrate is divided, wherein the plurality of patches are formed by including a gap.

An apparatus having multiple mushroom structures is disclosed. Each of the multiple mushroom structures includes: a ground plate; a first patch provided parallel to the ground plate with a separation of a distance to the ground plate; and a second patch provided parallel to the ground plate with a separation of another distance to the ground plate, which another distance being different from the distance from the first patch to the ground plate, wherein the second patch is a passive element which is capacitatively coupled with at least the first patch.

A relay apparatus is disclosed for relaying a signal from a transmitter to a receiver in a MIMO (Multiple Input Multiple Output) based communication system, comprising: a power difference determination unit configured to determine a difference of reception levels between a direct wave and a relayed wave based on positional relationship among the transmitter, the relay apparatus and the receiver, the direct wave traveling from the transmitter to the receiver without the relay apparatus, the relayed wave traveling from the transmitter to the receiver via the relay apparatus; a gain determination unit configured to determine an amplification gain of the relay apparatus to make the difference smaller; and a transmitting unit configured to amplify the signal from the transmitter at the determined amplification gain and transmit the amplified signal to the receiver.

Relay apparatus and relay method

A radio communication system according to the present invention includes a scatterer configured to reflect, refract, or transmit a radio wave radiated primarily from a transmission side apparatus to radiate the radio wave secondarily to a desired area and a metamaterial is used for the scatterer.

Growing community of inventors

Yokohama, Japan

Tamami Maruyama