Abstract: There is provided a dual-band antenna having small size and low height which has a characteristic of not affecting a bandwidth of signal waves of a low band in its miniaturized state. In a dual-band antenna 11, a first radiating conductive plate 13 is arranged to oppose a surface of a grounding conductor 12 in an approximately parallel manner, being excited at a first frequency. A feeding conductive plate 14 extends approximately orthogonally from an outer edge of the first radiating conductive plate 13 and is connected to a feeding circuit A second radiating conductive plate 15 is stood downward the first radiating conductive plate 13, whose lower end is connected to the feeding conductive plate 14. The second radiating conductive plate 15 is excited at a second frequency.

Abstract: In an antenna system, a short-circuiting conductive plate and a power-supply conductive plate are bent at the center region of a metal plate so as to be perpendicular to the planar surface of the metal plate. The remaining metal plate excluding the short-circuiting conductive plate and the power-supply conductive plate constitutes the emission conductive plate. The antenna system is mounted on a ground plane and the emission conductive plate is disposed parallel to the ground plane. The bottom end of the short-circuiting conductive plate is soldered to the ground plane and the bottom end of the power-supply conductive plate is connected to a power-supply circuit.

Abstract: The antenna-integrated module contains a circuit board 1 on which a high frequency circuit is provided, a cover 2 that is composed of a metal plate and is mounted to the circuit board 1 so as to cover almost the entire surface of the circuit board 1, and a dedicated shield case 3 that is composed of a metal plate and is mounted to the circuit board 1 so as to cover a specific region on the circuit board 1. The high frequency circuit comprises a wiring pattern 4 and a ground pattern 5, and electronic parts 6, and the dedicated shield case 3 covers a portion of the high frequency circuit. Leg pieces 2b and 2c of the cover 2 are connected to the wiring pattern 4 and the ground pattern 5, In the cover 2, an upper plate 2a corresponding to a radiation conductor portion functions as both an inverted F-type antenna and a shield case.

Abstract: There are provided a dielectric substrate that erects from a ground surface, and a radiation conductor that is provided on a surface of the dielectric substrate so as to extend in the vertical direction. The bottom end of the radiation conductor is connected to a feeder line. The radiation conductor has a bottom portion and a top portion that is distant from the ground surface and is wider than the bottom portion. Increasing the capacitance by making wide the top portion (capacitive region), having a large voltage variation, of the radiation conductor in this manner lowers the resonance frequency. Therefore, a height dimension of the radiation conductor for attaining resonance at a desired frequency can be made much smaller than in conventional monopole antennas.

Abstract: A first ground-plane portion, on which an antenna element is disposed, is arranged above a second ground-plane portion with a predetermined distance therebetween. The first ground-plane portion operates as a parasitic antenna. The antenna element includes a dielectric substrate, a patch electrode provided on the top surface of the dielectric substrate, a ground electrode provided on substantially the entire bottom surface of the dielectric substrate, and current-feed pins that extend through the dielectric substrate and that are connected to the patch electrode. The first ground plane is defined by a conductor layer, which is provided on the top surface of a circuit board. The size of the ground-plane portion and the height of a support are appropriately set so that the first ground-plane portion is excited at a frequency that is substantially equal to a frequency at which the patch electrode is excited when current is fed.

Abstract: A patch antenna apparatus includes an antenna element and a metal frame, which are disposed on a ground plane. The antenna element has a dielectric substrate, which has a patch electrode on the top surface and has a ground electrode on the bottom surface. The patch electrode is connected to current-feed pins. The metal frame is positioned so as to surround the peripheral surface of the dielectric substrate. The height dimension of the metal frame is set to be slightly larger than the thickness dimension of the dielectric substrate. Electromagnetic radiation radiated from the antenna element is reflected upon reaching the metal frame. Thus, the metal frame causes interference with the electromagnetic radiation such that the traveling direction of the electromagnetic radiation is redirected closer to the lateral direction.

Abstract: An inverted-F metal plate antenna is composed of a radiating conductor plate disposed opposing and substantially in parallel with a ground conductor surface, a power-feeding conductor plate extending substantially perpendicularly from an outer edge of the radiating conductor plate, and shorted conductor plates extending substantially perpendicularly from two points on outer edges of the radiating conductor plate and connected to the ground conductor surface. When a predetermined high-frequency electric power is supplied to the radiating conductor plate via the power-feeding conductor plate, a first resonance mode with a relatively long resonant length, in which one of the shorted conductor plate works as a shorted stub, and a second resonance mode with a relatively short resonant length, in which the other shorted conductor plate works as a shorted stub, are generated, causing excitation of the radiating conductor plate.

Abstract: An antenna device includes a meandering radiating conductor plate composed of a metal ribbon having a predetermined width that is folded a plurality of times so as to meander, a capacitive conductor plate disposed substantially parallel to a ground conductor and connected to the top end of the meandering radiating conductor plate, a connection conductor plate for electrically shorting the capacitive conductor plate to the ground conductor, and a straight radiating conductor plate extending upwardly in a vertical direction and being connected to the bottom end of the meandering radiating conductor plate. The antenna device operates as a dual-band antenna where the meandering radiating conductor plate resonates by feeding first high-frequency power and the straight radiating conductor plate resonates by feeding second high-frequency power that has a higher frequency than that of the first high-frequency power.

Abstract: An antenna includes a dielectric substrate disposed on a ground conductor and first and second radiating conductors containing meandering lines that are symmetrically disposed on a surface of the dielectric substrate and whose lower ends are connected at a junction. A third radiating conductor is disposed between the first radiating conductor and the second radiating conductor and extends in a straight line along the symmetry axis of both the radiating conductors. A capacitive conductor is disposed on the dielectric substrate and is substantially parallel to the ground conductor. The upper ends of the first, second and third radiating conductors are connected to the capacitive conductor. Power of a frequency supplied to the junction causes the first and second radiating conductors to resonate while power of a higher frequency causes the third radiating conductor to resonate.

Abstract: A radiating conductor having first and second meandering portions and capacitive conductor portions is provided on a surface of a dielectric substrate perpendicularly provided on a grounding conductor plate. The first meandering portion and one of the capacitive conductor portions are locally opposed to each other to form a capacitive coupling portion. The first meandering portion receives high-frequency power through its bottom end. The second meandering portion is formed to have a smaller pitch than the first meandering portion, and continues to the upper end of the first meandering portion. One capacitive conductor portion formed on a front surface continues to the upper end of the second meandering portion, while the other capacitive conductor portion is formed on a back surface and connected with the former capacitive conductor portion via through holes.

Abstract: A dual-band antenna is described that includes a grounded conductor over a support base; a first radiating conductor plate that is disposed substantially parallel to the grounded conductor; a feeding conductor strip that extends downward from the first radiating conductor plate; a connecting conductor strip for short-circuiting the first radiating conductor plate to the grounded conductor; a second radiating conductor plate that stands vertically to the grounded conductor below the first radiating conductor plate; and a bridge for linking the lower end of the second radiating conductor plate to the lower end of the feeding conductor strip.

Abstract: A converter for satellite communication reception which reduces signal losses and has a simplified assembling work is disclosed. In operation, orthogonal bipolarized signals transmitted from a satellite are branched into two propagation paths within a waveguide. A horizontally polarized wave is caused to proceed in a first propagation path, while a vertically polarized wave is caused to proceed in a second propagation path. A pair of probes supported by a circuit substrate and fitted to a case have tips that extend into two waveguides to receive the respective signals. By integrating the waveguide and the case by fastening, the first propagation path and the first waveguide are positioned to communicate with each other, as are the second propagation path and the second waveguide.

Abstract: A dipole antenna (linearly-polarized antenna) is housed in a lower casing and a patch antenna (circularly-polarized antenna) is housed in an upper casing. The upright position of the upper casing, which is supported above the upper casing, can be changed. Thus, the effect of polarization diversity can be expected in addition to the effect of spatial diversity, so that the susceptibility to multipath influence is reduced. Also, an appropriate adjustment of the direction of the patch antenna allows the patch antenna to perform signal transmission to and/or reception from above and/or below which cannot be performed by the dipole antenna.

Abstract: A circularly-polarized-wave patch antenna includes a main body having a patch electrode provided with two feeding points and a circuit for generating a phase difference of 90° between signals supplied to the feeding points. A Wilkinson distribution circuit is provided between the 90°-phase-difference generating circuit and a coaxial cable (feeder line) so as to improve a reflection characteristic. The patch antenna includes two feeding points, and thus a favorable axial ratio characteristic can be obtained in a wide band. Also, a favorable reflection characteristic can be obtained in a wide band because of the Wilkinson distribution circuit. Accordingly, the patch antenna can be used in a wider frequency band.

Abstract: A direction of a power feed patch relative to a rod-shaped antenna is set so that a short axis thereof substantially orthogonally crosses a plane containing an intersection between the short axis and a long axis of the power feed patch of a patch antenna and an axis of the rod-shaped antenna. As a plane of polarization of a linearly polarized electromagnetic wave radiated from the rod-shaped antenna is thereby caused to substantially coincide with a direction of the long axis of the power feed patch and to substantially orthogonally cross a direction of the short axis, even if a powerful wave of a higher frequency than a desired frequency to be received by the patch antenna and difficult to be removed by a band pass filter of a low-noise amplifier circuit is radiated from the rod-shaped antenna, field components of the high frequency electromagnetic wave in the direction of the short axis will become virtually zero.

Abstract: In an ultrawide-band linear-circular polarization converter, in a noncircular waveguide which has negative-phase characteristics in which a phase gradually decreases in accordance with an increase in a frequency over an ultrawide-band frequency range, a dielectric structure which has positive-phase characteristics, in which a phase gradually increases in accordance with an increase in a frequency, having a complementary relationship with the negative-phase characteristics in the ultrawide-band frequency range is provided.

Abstract: A radiation section of a dielectric feeder protrudes from an opening of a waveguide to improve the efficiency of receiving radio signals. An opening is provided at one end of the waveguide. A dielectric feeder held within the waveguide has a radiation section protruding from the opening. An annular wall having a bottom surrounds the opening of the waveguide. The depth of the annular wall is about ¼ of the wavelength of radio waves, and the width of a bottom surface of the annular wall is about ⅙ to {fraction (1/10)} of the wavelength of the radio waves. Consequently, the phases of a surface current that flows from the opening toward the bottom surface of the annular wall and a surface current which flows from the bottom surface of the annular wall toward the open end are substantially out of phase. As a result, the side lobes of the received radio signals are greatly reduced, and the gain of the main lobe is increased, improving the reception of radio waves transmitted from a satellite.

Abstract: A primary radiator includes a waveguide holding a dielectric feeder on which a radiation part, an impedance-conversion part, and a phase-conversion part are integrally formed. The radiator part widens from the aperture of the waveguide, and the phase-conversion part intersects a probe at an angle of substantially 45 degrees. Also, on the impedance-conversion part, a pair of curved surfaces are formed converging in the direction from the radiator part to the phase-conversion part, the impedance-conversion part has a cross-sectional shape which includes an approximately quadratic curve, and the thickness of the dielectric feeder converges such that the thickness gradually decreases in the direction from the radiator part to the phase-conversion part.

Abstract: In an ultrawide-band linear-circular polarization converter, in a noncircular waveguide which has negative-phase characteristics in which a phase gradually decreases in accordance with an increase in a frequency over an ultrawide-band frequency range, a dielectric structure which has positive-phase characteristics, in which a phase gradually increases in accordance with an increase in a frequency, having a complementary relationship with the negative-phase characteristics in the ultrawide-band frequency range is provided.

Abstract: There are provided a dielectric substrate that erects from a ground surface, and a radiation conductor that is provided on a surface of the dielectric substrate so as to extend in the vertical direction. The bottom end of the radiation conductor is connected to a feeder line. The radiation conductor has a bottom portion and a top portion that is distant from the ground surface and is wider than the bottom portion. Increasing the capacitance by making wide the top portion (capacitive region), having a large voltage variation, of the radiation conductor in this manner lowers the resonance frequency. Therefore, a height dimension of the radiation conductor for attaining resonance at a desired frequency can be made much smaller than in conventional monopole antennas.