摘要:
A flat antenna device is constructed such that circular patches are provided on one surface of a dielectric film, a metallic grounding conductor film is fitted to one surface of a dielectric film, a dielectric member is sandwiched between the dielectric film and the dielectric film, and an extending mechanism is provided to the periphery of the device so as to maintain the dielectric film and the dielectric film in a fully extended state. A circular microstrip patch antenna is formed by the metallic grounding conductor film and each of the circular patches.
摘要:
In an antenna apparatus in which n dielectric layers with .epsilon..sub.r1 -.epsilon..sub.rn in dielectric constants are respectively stacked between a ground plate and a major radiating conductor, the thickness t.sub.1 -t.sub.n of the dielectric layers are determined so as to satisfy substantially the following equations:(t.sub.1 +t.sub.2 + . . . +t.sub.n)/(t.sub.1 /.epsilon..sub.r1 +t.sub.2 /.epsilon..sub.r2 + . . . +t.sub.n /.epsilon..sub.rn)=.epsilon..sub.reff, andt.sub.1 +t.sub.2 + . . . t.sub.n =t.sub.minwith respect to a dielectric constant .epsilon..sub.reff of the antenna defined for a desired beam width, and the minimum value t.sub.min of the dielectric layers capable of ensuring a desired operation band and low reflection losses in this dielectric constant .epsilon..sub.reff. Thus, the thinnest antenna structure which can ensure a desired radiation in directions of low elevation angles, and desired operation bands and low reflection losses can be made.
摘要:
Herein is revealed a helical antenna apparatus wherein the direction of beam radiation hardly changes even if the frequency in use changes. Two helical antennas which are wound with two conductive wires spirally, respectively, at equal intervals with a specified pitch .alpha. in the form of a cylinder are disposed along the length of the helical antennas so that the axes thereof substantially coincide with each other. By determining the lengths of the feeders of the respective helical antennas appropriately in order to set the phase of supplied power, it is possible to form the beam of signals radiated into space in the shape of conical beam having a directivity oriented obliquely upward. Additionally, it is possible to obtain the conical beam in which the direction of beam radiation does not change even if the frequency in use is changed.
摘要:
A composite antenna apparatus comprising a balun connected to an inner conductor at the upper end of a coaxial line 11, one end of a helical element formed by a pair of wire conductors is connected to the balun, the other end is wound symmetrically around the coaxial line using the the coaxial line as a center so as to face the balun and is connected to the outer conductor 13 at the lower end of the coaxial line. The provision of an outer conductor connecting terminal connected to the outer conductor and an inner conductor connecting terminal connected to the inner conductor at the lower end of the coaxial line, allows the formation, on the same axis, of a helical antenna fed by the coaxial line via the helical element and a monopole antenna formed by the outer conductor of the coaxial line. Thereby equivalent gain in the horizontal plane and a reduction in the occupied volume is achieved.
摘要:
A planar antenna apparatus adapted to excite a small radiating element by electromagnetic coupling is provided. The antenna apparatus has a triplate line including ground conductor plates formed on the upper and lower surfaces of a dielectric substrate and a feed line sandwiched by the ground conductor plates. A coupling hole is formed through one of the ground conductor plates, and a mechanism is provided near the coupling hole for electrically interconnecting the two ground conductor plates. A radiating section coupled to the feed line through the coupling hole has one end grounded to form a short patch antenna. The short patch antenna has a size substantially half the size of a patch antenna. Also, the connecting mechanism prevents unnecessary coupling.
摘要:
An antenna apparatus, a method of manufacturing the same, and a method of designing the same, are provided. A first dielectric layer, first dielectric film, second dielectric layer and second dielectric film are laminated on a flat metal plate in the mentioned order. A radiation element fed through a feeding line is arranged below another radiation element that is not fed through the feeding line. The feeding line forms, along its overall length, a microstrip line having the dielectric layer sandwiched by the feeding line and the flat conductive plate, resulting in no model change from the microstrip line to a triplate line or vice versa, with reduced feeding loss. The thickness of the dielectric layer is so set as to be sufficiently small compared with the used wavelength, to thereby suppress the radiation from discontinuities lying on the microstrip line constituted of the feeding line and flat conductive plate. This eliminates the need for a metal shield plate to prevent unnecessary radiation from the feeding line.
摘要:
A radio tag communication system, when a plurality of RW apparatuses are arranged in such a manner that communication areas of adjacent RW apparatuses overlap one another, makes the polarized waves of the adjacent RW apparatuses orthogonal to each other, and causes the tag to switch the polarization direction with the movement of the tag. This makes it possible to prevent signal interference even when the communication areas are expanded.
摘要:
A radio tag communication system, when a plurality of RW apparatuses are arranged in such a manner that communication areas of adjacent RW apparatuses overlap one another, makes the polarized waves of the adjacent RW apparatuses orthogonal to each other, and causes the tag to switch the polarization direction with the movement of the tag. This makes it possible to prevent signal interference even when the communication areas are expanded.
摘要:
A ground conductor constituting a bottom board and a loop antenna formed of a strip conductor formed separately from and around the ground conductor are provided on one face of a dielectric substrate, and a transmitter-receiver is connected to one end of the loop antenna serving as the power dispatching unit via a first matching circuit, and a second matching circuit is connected to the other end. A conductor formed of the strip conductor is provided on the dielectric substrate on the other face of the dielectric substrate so as to oppose the loop antenna with the intermediary of the dielectric substrate. A third matching circuit is connected to one end of the conductor and a fourth matching circuit is connected to the other end of the conductor. The loop antenna and the conductor are set to have a wavelength shorter than that of the frequency band to be used.
摘要:
A plurality of concentric circle array antennas each having a different radius are disposed on an identical plane, and a plurality of element antennas are arranged circumferentially in each of the concentric circle array antennas. The plurality of concentric circle array antennas are arranged at regular intervals d in most part thereof, and the concentric circle array antennas corresponding to a remaining part of the plurality of concentric circle array antennas are arranged at intervals d±0.4 to 0.6d. The radii of the part of plural concentric circles change by ±(0.4 to 0.6)d, so that it is possible to reduce a wide-angle side lobe.