Abstract: In a high-frequency transmission line that is used in a high-frequency band such as the microwave band or the millimeter wave band, at least one resistive film is disposed in a plane that is substantially perpendicular to an electric field of an operating transmission mode, and the resistive film attenuates, by dielectric loss, an unwanted mode having an electric field that is perpendicular to the electric field of the operating transmission mode.

Abstract: A line transition device which intervenes between a non radiative dielectric waveguide and a hollow waveguide for example, includes a dielectric waveguide having a dielectric strip held by a pair of conductors which face each other, and a waveguide, wherein a part of the dielectric strip of the dielectric waveguide is adjacent to or inserted in the hollow waveguide.

Abstract: An antenna device capable of increasing the speed of scanning as well as extending the scanning angular range of a beam to obtain a high gain. A radar module and a communication apparatus having enhanced detection capabilities obtainable by using the antenna device. In the antenna device, electromagnetic waves radiated from a primary radiator are transmitted to a plurality of openings, e.g., dielectric lenses and/or reflectors or optical transmitters. The dielectric openings are arranged on a fixed portion and the primary radiator is arranged on a moving portion. The moving portion is displaced relatively with respect to the fixed portion. This arrangement enables the selection of an opening used for receiving each of the electromagnetic waves from the primary radiator to change the direction of the beam.

Abstract: A phase shifter includes upper and lower conductive plates, and a dielectric strip sandwiched between the conductive plates, and a plurality of slots formed in the upper conductive plate, thereby forming a dielectric line. A rotator is positioned at either side of the dielectric strip so that the distance from the rotator to the dielectric strip varies as the rotator rotates. As the rotator rotates, the phase constant of the dielectric line progressively changes in the direction of electromagnetic propagation. The rotation of the rotator causes a change in feed phase with respect to the slots as the rotator rotates, thereby performing beam scanning.

Abstract: A sector antenna apparatus mounted on a vehicle has a casing, in which six horn antennas having apertures over an angular range of 180 degrees and extending radially are accommodated. The proximal ends of the horn antennas are connected to an antenna changeover switch. A portion of the horn antennas which emits beam radiation in the forward and backward direction and diagonal direction of the vehicle have large apertures, and a portion of the horn antennas which emits beam radiation to the right and left of the vehicle have a small aperture. Thus, the required antenna characteristics, such as angular resolution, beam width, antenna gain, are achievable in the required direction.

Abstract: In a high-frequency transmission line that is used in a high-frequency band such as the microwave band or the millimeter wave band, at least one resistive film is disposed in a plane that is substantially perpendicular to an electric field of an operating transmission mode, and the resistive film attenuates, by dielectric loss, an unwanted mode having an electric field that is perpendicular to the electric field of the operating transmission mode.

Abstract: A directional coupler includes two non-radiative dielectric lines, each formed by a dielectric strip between flat conductive surfaces placed substantially parallel to each other, such that the two non-radiative dielectric lines are close to each other. The main transmission mode of electromagnetic waves at the frequency used is an LSE mode, the electromagnetic waves being propagated in the non-radiative dielectric lines. Therefore, the insertion loss due to mode switching in the coupling portion of the primary line and the secondary line which form the directional coupler can be reduced, and leakage of the electromagnetic waves from the gap between the primary line and the secondary line of the directional coupler when they are separated from each other can be suppressed.

Abstract: A line transition device which intervenes between a non radiative dielectric waveguide and a hollow waveguide for example, includes a dielectric waveguide having a dielectric strip held by a pair of conductors which face each other, and a waveguide, wherein a part of the dielectric strip of the dielectric waveguide is adjacent to or inserted in the hollow waveguide.

Abstract: A phase shifter includes upper and lower conductive plates, and a dielectric strip sandwiched between the conductive plates, and a plurality of slots formed in the upper conductive plate, thereby forming a dielectric line. A rotator is positioned at either side of the dielectric strip so that the distance from the rotator to the dielectric strip varies as the rotator rotates. As the rotator rotates, the phase constant of the dielectric line progressively changes in the direction of electromagnetic propagation. The rotation of the rotator causes a change in feed phase with respect to the slots as the rotator rotates, thereby performing beam scanning.

Abstract: A non-radiative hybrid dielectric line transition permits a line transformation between two different types of non-radiative dielectric lines to be performed in a limited space. In addition, a non-radiative dielectric line component, an antenna apparatus, and a wireless apparatus include the above line transition. In this structure, a dielectric strip is disposed between a lower conductive plate and an upper conductive plate to form each of a hyper NRD waveguide (HNRD) and a normal NRD waveguide (NNRD). Between the two waveguides, grooves whose depths gradually become shallow from the HNRD to the NNRD are formed for receiving a third non-radiative dielectric line for performing a line transformation.

Abstract: A line transition device which intervenes between a non radiative dielectric waveguide and a hollow waveguide for example, includes a dielectric waveguide having a dielectric strip held by a pair of conductors which face each other, and a waveguide, wherein a part of the dielectric strip of the dielectric waveguide is adjacent to or inserted in the hollow waveguide.

Abstract: An antenna device capable of increasing the speed of scanning as well as extending the scanning angular range of a beam to obtain a high gain. A radar module and a communication apparatus having enhanced detection capabilities obtainable by using the antenna device. In the antenna device, electromagnetic waves radiated from a primary radiator are transmitted to a plurality of openings, e.g., dielectric lenses and/or reflectors or optical transmitters. The dielectric openings are arranged on a fixed portion and the primary radiator is arranged on a moving portion. The moving portion is displaced relatively with respect to the fixed portion. This arrangement enables the selection of an opening used for receiving each of the electromagnetic waves from the primary radiator to change the direction of the beam.

Abstract: A directional coupler includes two non-radiative dielectric lines, each formed by a dielectric strip between flat conductive surfaces placed substantially parallel to each other, such that the two non-radiative dielectric lines are close to each other. The main transmission mode of electromagnetic waves at the frequency used is an LSE mode, the electromagnetic waves being propagated in the non-radiative dielectric lines. Therefore, the insertion loss due to mode switching in the coupling portion of the primary line and the secondary line which form the directional coupler can be reduced, and leakage of the electromagnetic waves from the gap between the primary line and the secondary line of the directional coupler when they are separated from each other can be suppressed.

Abstract: A non-radiative hybrid dielectric line transition permits a line transformation between two different types of non-radiative dielectric lines to be performed in a limited space. In addition, a non-radiative dielectric line component, an antenna apparatus, and a wireless apparatus include the above line transition. In this structure, a dielectric strip is disposed between a lower conductive plate and an upper conductive plate to form each of a hyper NRD waveguide (HNRD) and a normal NRD waveguide (NNRD). Between the two waveguides, grooves whose depths gradually become shallow from the HNRD to the NNRD are formed for receiving a third non-radiative dielectric line for performing a line transformation.

Abstract: An antenna apparatus includes two substantially parallel conductor plates, a dielectric strip held between the two conductors, an aperture formed on the upper conductor plate above the dielectric strip, and a matching section for matching impedance between the dielectric strip and the aperture. The matching section is integrated with the dielectric strip below the aperture, thus continuously connecting the matching section to the dielectric strip.

Abstract: An antenna apparatus includes two substantially parallel conductor plates, a dielectric strip held between the two conductors, an aperture formed on the upper conductor plate above the dielectric strip, and a matching section for matching impedance between the dielectric strip and the aperture. The matching section is integrated with the dielectric strip below the aperture, thus continuously connecting the matching section to the dielectric strip.

Abstract: In a directional coupler comprising two separated dielectric guides, reflection and loss in the separation position (separated faces) is reduced. Furthermore, the beam of an antenna device comprising a primary emitter and a dielectric lens can be tilted quickly even by a low-torque motor. A moving portion and a fixed portion each comprise dielectric guides, and in addition, grooves are provided in opposing end faces of conductive plates thereof, at a distance from the electrode faces of the dielectric guides of approximately an integral multiple of half the wavelength of the transmitted waves. Furthermore, the dielectric guide of the directional coupler portion is a normal NRD guide, and the dielectric guide of another portion is a hyper NRD guide.