Abstract: An antenna structure includes a radiation conductor made of a metal plate that is supported by legs provided upright on a surface of a dielectric substrate and is spaced apart from the surface. The radiation conductor is circularly shaped such that the contour of the radiation conductor conforms to the outer periphery of the dielectric substrate and such that the radiation conductor includes an open portion. One of the legs functions as a feeding terminal and the other functions as a grounding terminal, whereby the radiation conductor operates as a dipole antenna. The radiation conductor has slots for adjusting impedance. Impedance can be adjusted by changing the length of the slots.

Abstract: An antenna structure includes a radiation conductor made of a metal plate that is supported by legs provided upright on a surface of a dielectric substrate and is spaced apart from the surface. The radiation conductor is circularly shaped such that the contour of the radiation conductor conforms to the outer periphery of the dielectric substrate and such that the radiation conductor includes an open portion. One of the legs functions as a feeding terminal and the other functions as a grounding terminal, whereby the radiation conductor operates as a dipole antenna. The radiation conductor has slots for adjusting impedance. Impedance can be adjusted by changing the length of the slots.

Abstract: First and second radiating conductors are concentrically formed on a top surface of a dielectric substrate, and a grounding conductor is formed on a bottom surface of the dielectric substrate. A feeding pin is connected to a power feeding point of the first radiating conductor. Shorting pins are connected to an inner circumferential portion of the second radiating conductor to be shorted by the grounding conductor. An interval between the radiating conductors allows the first and second radiating conductors to be electromagnetically coupled with each other. When the first radiating conductor is excited at a frequency fH by direct feeding from the feeding pin, the second radiating conductor is fed by the coupling, so that it is excited at a frequency fL lower than the frequency fH.

Abstract: A patch antenna contains a dielectric substrate, a radiating electrode formed almost entirely on a top surface of the dielectric substrate, a grounding electrode having four notched portions and provided on a bottom surface of the dielectric substrate, and a feeding pin passing through the dielectric substrate and being connected to a feeding point of the radiating electrode. Degeneracy breaking elements are disposed on the radiating electrode. The notched portions are formed at positions close to approximately middle portions of four sides of the dielectric substrate, and the grounding electrode is formed almost entirely on the bottom surface of the dielectric substrate, except for areas corresponding to the respective notched portions. The grounding electrode is not formed larger than the radiating electrode.

Abstract: A combined antenna combining a circularly polarized wave antenna and a vertically polarized wave antenna is provided. A flat plate antenna for ground waves is fixed on a printed board, and a two-point feeding type patch antenna is placed and fixed on a metallic flat plate of the plate antenna. The plate antenna has one feed terminal and six uniformly spaced ground terminals. The patch antenna has two feed pins at equidistant positions from the center of the patch electrode along radial lines that form a right angle. Each of feed pins is connected to a 90-degree phase difference circuit using an opening of the plate antenna. The relative position between the flat plate and the patch electrode is the same along the peripheral direction. All of the feed terminals, the ground terminals and the feed pins have a predetermined positional relationship relative to one another.

Abstract: A combined antenna combining a circularly polarized wave antenna and a vertically polarized wave antenna is provided. A flat plate antenna for ground waves is fixed on a printed board, and a two-point feeding type patch antenna is placed and fixed on a metallic flat plate of the plate antenna. The plate antenna has one feed terminal and six uniformly spaced ground terminals. The patch antenna has two feed pins at equidistant positions from the center of the patch electrode along radial lines that form a right angle. Each of feed pins is connected to a 90-degree phase difference circuit using an opening of the plate antenna. The relative position between the flat plate and the patch electrode is the same along the peripheral direction. All of the feed terminals, the ground terminals and the feed pins have a predetermined positional relationship relative to one another.

Abstract: In a circularly polarized wave antenna, a dielectric member, which is formed of a dielectric material, such as ceramic, is formed in a quadrilateral columnar shape. A through-hole formed in a quadrilateral shape when viewed from above is provided at the center of the dielectric member. Radiation conductors having the same configuration are formed according to, for example, a printing technique, and are disposed on the corresponding four side surfaces of the dielectric member while being tilted at 45°. In the circularly polarized wave antenna, the dielectric member is fixed on a printed circuit board, and the bottom portions of the radiation conductors are soldered to the corresponding portions of the printed circuit board. With this configuration, mutually in-phase power is supplied to the four radiation conductors.

Abstract: In a circularly polarized wave antenna, a dielectric member, which is formed of a dielectric material, such as ceramic, is formed in a quadrilateral columnar shape. A through-hole formed in a quadrilateral shape when viewed from above is provided at the center of the dielectric member. Radiation conductors having the same configuration are formed according to, for example, a printing technique, and are disposed on the corresponding four side surfaces of the dielectric member while being tilted at 45°. In the circularly polarized wave antenna, the dielectric member is fixed on a printed circuit board, and the bottom portions of the radiation conductors are soldered to the corresponding portions of the printed circuit board. With this configuration, mutually in-phase power is supplied to the four radiation conductors.