Abstract: A directional coupler includes: a first waffle-iron ridge waveguide extending from one end to other end; a second waffle-iron ridge waveguide extending from one end to the other end; a first bypass waveguide connecting a first site of the first waffle-iron ridge waveguide and a first site of the second waffle-iron ridge waveguide; and a second bypass waveguide connecting a second site of the first waffle-iron ridge waveguide and a second site of the second waffle-iron ridge waveguide.

Abstract: A mounting substrate includes a circuit board and a coupler. The circuit board has a mounting surface on which a microwave integrated circuit element is to be mounted, the microwave integrated circuit element having a plurality of terminals including first and second antenna I/O terminals. The coupler connects the first and second antenna I/O terminals to a waveguide device. The coupler includes: a first electrical conductor portion to be connected to the first antenna I/O terminal; a second electrical conductor portion to be connected to the second antenna I/O terminal; and an elongated gap in which an end face of the first electrical conductor portion and an end face of the second electrical conductor portion oppose each other. The elongated gap has a narrow portion at which the distance between the end face of the first electrical conductor portion and the end face of the second electrical conductor portion is locally decreased.

Abstract: A waveguide device includes a first electrically conductive member having a first electrically conductive surface; a second electrically conductive member having a second electrically conductive surface which opposes the first electrically conductive surface; and a ridge-shaped waveguide member on the second electrically conductive member. The second electrically conductive member has a throughhole which splits the waveguide member into first and second ridges. The first and second ridges each have an electrically conductive end face, the end faces opposing each other via the throughhole. The opposing end faces and the throughhole together define a hollow waveguide. The hollow waveguide is connected to a first waveguide extending between the waveguide face of the first ridge and the first electrically conductive surface, and to a second waveguide extending between the waveguide face of the second ridge and the first electrically conductive surface.

Abstract: An antenna array includes: an electrically conductive member having an electrically conductive surface in which a plurality of slots are open; a plurality of electrically-conductive ridge pairs on the electrically conductive surface, each pair protruding from edges of the central portion of a corresponding one of the plurality of slots. As viewed along a direction that the central portion of each slot extends, at least a portion of the first gap between the first ridge pair and at least a portion of the second gap between the second ridge pair overlap each other, with no other intervening electrically-conductive member therebetween; or at least a portion of the first ridge pair and at least a portion of the second ridge pair overlap each other, with no other intervening electrically-conductive member therebetween.

Abstract: An antenna array according to an embodiment includes a conductive member having a first and second slots adjacent to each other. The conductive surface on a front side of the conductive member is shaped so as to define a first and second horns respectively communicating with the first and second slots. The respective E planes of slots are on the same plane, or on a plurality of planes which are substantially parallel to each other. In an E-plane cross section of the first horn, a length from one of two intersections between the E plane and an edge of the first slot to one of two intersections between the E plane and an edge of the aperture plane of the first horn is longer than a length from the other intersection between the E plane and the edge of the first slot to the other intersection between the E plane and the edge of the aperture plane of the first horn, the lengths extending along an inner wall surface of the first horn.

Abstract: A slot antenna includes: a first electrically conductive member having a first electrically conductive surface; a second electrically conductive member having a second electrically conductive surface opposing the first electrically conductive surface; a waveguide member between the first electrically conductive member and the second electrically conductive member, the waveguide member having an electrically conductive waveguide face of a stripe shape opposing the first electrically conductive surface, the waveguide member extending in a first direction along the first electrically conductive surface; and an artificial magnetic conductor extending on both sides of the waveguide member, between the first electrically conductive member and the second electrically conductive member. The first electrically conductive member has one or more slots. At least one of the slot or slots is a complex slot having a pair of vertical portions and a lateral portion that interconnects the pair of vertical portions.

Abstract: A method of producing a horn antenna array includes: a step of providing a first die and a second die; a step of assembling the first die and the second die, filling an internal space surrounded by the first die and the second die with a fluid material, and solidifying the fluid material; and a step of, after the material has solidified, separating the first die and the second die. In a portion corresponding to each horn antenna element, the first die has a pair of protrusions and a groove between the pair of protrusions, and the second die has a protrusion. In a state where the first die and the second die are assembled, a gap exists between a tip end of each protrusion of the second die and a bottom face of each groove.

Abstract: A waveguide device includes: a first electrically conductive member having a first electrically conductive surface and a second electrically conductive surface opposite thereto; a second electrically conductive member having a third electrically conductive surface and a fourth electrically conductive surface opposite thereto, the third electrically conductive surface opposing the second electrically conductive surface; a waveguide member on the third electrically conductive surface; and a plurality of electrically-conductive rods on the third electrically conductive surface.

Abstract: A waveguide device module includes: a waveguide device and a circuit board having an electrically-conductive line pattern. A conductor face of an electrically conductive member of the waveguide device defines a waveguide between itself and the line pattern. A line pattern on the circuit board includes a stem pattern and a first and second branch patterns branching out from the stem pattern. The waveguide includes a main waveguide, a first branch waveguide between the first branch pattern and the conductor face, and a second branch waveguide between the second branch pattern and the conductor face. A difference between a variation in phase of the first electromagnetic wave while propagating through the first branch waveguide and a variation in phase of the second electromagnetic wave while propagating through the second branch waveguide is within ±90 degrees of an odd multiple of 180 degrees.

Abstract: A waveguide device according to an embodiment includes an electrically conductive member having an electrically conductive surface, a waveguide member extending so as to face along the electrically conductive surface, and stretches of artificial magnetic conductor on both sides of the waveguide member. The waveguide member includes a first portion extending in one direction, and at least two branches extending in mutually different directions from one end of the first portion, the at least two branches including a second portion and a third portion. The second portion has a recess in a side face that connects to one side face of the first portion, the recess reaching the waveguide face.

Abstract: A waveguide device for use in propagating an electromagnetic wave of a band having a shortest wavelength ?m in free space includes: a first electrically conductive member having an electrically conductive surface and a first throughhole; a second electrically conductive member including a plurality of electrically conductive rods each having a leading end opposing the electrically conductive surface, the second electrically conductive member having a second throughhole which overlaps the first throughhole as viewed along an axial direction of the first throughhole; and an electrically-conductive waveguiding wall at least partially surrounding a space between the first throughhole and the second throughhole and being surrounded by the plurality of electrically conductive rods, the waveguiding wall allowing the electromagnetic wave to propagate between the first throughhole and the second throughhole. The height of the waveguiding wall is less than ?m/2.

Abstract: A horn antenna array includes at least two horn antenna elements arranged along a first direction. Each of the at least two horn antenna elements includes a base having a slot extending along a second direction which intersects the first direction, and a horn communicating with the slot, the horn having a pair of electrically-conductive first inner walls intersecting the first direction and a pair of electrically-conductive second inner walls intersecting the second direction. The pair of second inner walls include a pair of opposing protrusions. When radiating an electromagnetic wave, the pair of protrusions create two radiation sources on the inside of the pair of first inner walls.

Abstract: An electromagnetic wave transmission device includes a transmission line module and a hollow waveguide module. The transmission line module includes: a plurality of electrically conductive members stacked with interspaces therebetween, the plurality of electrically conductive members including three or more electrically conductive members; and a plurality of artificial magnetic conductors each located between two adjacent electrically conductive members among the plurality of electrically conductive members. Among the plurality of electrically conductive members, at least one electrically conductive member located between two endmost electrically conductive members is shaped as a plate having at least one slit. The at least one slit extends to an edge of the at least one electrically conductive member. The hollow waveguide module includes at least one hollow waveguide having an aperture plane which is opposed via a gap to an open end of the at least one slit at the edge.

Abstract: A transmission line device includes: a plurality of electrically conductive members stacked with interspaces therebetween, the plurality of electrically conductive members including three or more electrically conductive members; and a plurality of artificial magnetic conductors each located between two adjacent electrically conductive members among the plurality of electrically conductive members. Among the plurality of electrically conductive members, at least one electrically conductive member located between two endmost electrically conductive members is shaped as a plate having at least one slit. At least a portion of the plurality of artificial magnetic conductors is located around the at least one slit to suppress leakage of an electromagnetic wave propagating along the at least one slit.

Abstract: A waveguide device includes a first electrically conductive member having a first electrically conductive surface; a second electrically conductive member having a second electrically conductive surface which opposes the first electrically conductive surface; and a ridge-shaped waveguide member on the second electrically conductive member. The second electrically conductive member has a throughhole which splits the waveguide member into first and second ridges. The first and second ridges each have an electrically conductive end face, the end faces opposing each other via the throughhole. The opposing end faces and the throughhole together define a hollow waveguide. The hollow waveguide is connected to a first waveguide extending between the waveguide face of the first ridge and the first electrically conductive surface, and to a second waveguide extending between the waveguide face of the second ridge and the first electrically conductive surface.

Abstract: A waveguide device includes: a first conductive member having a first conductive surface; a first waveguide member having a first waveguide face opposing the first conductive surface; a plurality of first conductive rods on both sides of the first waveguide member; a second conductive member having a second conductive surface; a second waveguide member having a second waveguide face opposing the second conductive surface; and a plurality of second conductive rods on both sides of the second waveguide member. A first waveguide gap exists between the first waveguide face and the first conductive surface. A second waveguide gap exists between the second waveguide face and the second conductive surface. One end of the first waveguide gap is connected to the second waveguide gap, and at a connecting portion therebetween, the first waveguide face extends in a direction that intersects a plane which is parallel to the second conductive surface.

Abstract: A multicopter includes: motors to respectively rotate three or more rotors; and a radar system to transmit and receive a signal wave and detect a target by using the signal wave. An object detection apparatus in the radar system transmits and receives a signal wave to perform a target detecting process. An antenna element is in a position to receive the transmission wave reflected off a rotor (a rotor-originated reflected wave). The signal wave received at the antenna element is inclusive of a target-originated reflected wave reflected off a target and a rotor-originated reflected wave. The apparatus determines whether or not a frequency band satisfying a predefined condition for identifying a frequency peak is contained in a frequency spectrum of the signal wave as received by the antenna element, and determines a peak of a frequency band satisfying the predefined condition to be a frequency of the target-originated reflected wave.

Abstract: A function varying a wavelength in a waveguide including a ridge-shaped conductor and columnar conductors in a parallel flat structure is added to reduce a size of a phase shifter in which input and output ports are fixed. Thus, a phased array antenna including a plurality of phase shifters is reduced in size. A plurality of convex shapes or concave shapes are provided on a conductor plate on a side not including a ridge-shaped conductor and columnar conductors. A mechanism that moves the conductor plate in a direction crossing a direction in which the ridge-shaped conductor extends is applied. After the convex shapes or the concave shapes are changed by a fixed number between phase shifters adjacent to each other, conductor plates are respectively configured by single members. A mechanism that relatively moves the conductor plates in the direction crossing the direction in which the ridge-shaped conductor extends of the phase shifter is applied.

Abstract: A waveguide device includes: a circuit board having a microstrip line thereon; a microwave IC connected to one end of the microstrip line; a first waffle-iron ridge waveguide; a second waffle-iron ridge waveguide; a first hollow waveguide which is at one end connected to another end of the microstrip line, and at another end connected to a first site of the first waffle-iron ridge waveguide; and a second hollow waveguide which is at one end connected to a second site of the first waffle-iron ridge waveguide, and at another end connected to a first site of the second waffle-iron ridge waveguide.

Abstract: A waveguide device includes: an electrically conductive member having an electrically conductive surface; a waveguide member having an electrically-conductive waveguide face of a stripe shape opposing the electrically conductive surface, the waveguide member extending along the electrically conductive surface; and an artificial magnetic conductor extending on both sides of the waveguide member. The waveguide member has a bend at which the direction that the waveguide member extends changes. A waveguide which is defined by the electrically conductive surface, the waveguide face, and the artificial magnetic conductor includes a gap enlargement where a gap between the electrically conductive surface and the waveguide face is locally increased. In a perspective view along a direction perpendicular to the electrically conductive surface, at least a portion of the bend has an overlap with the gap enlargement.