JPH10290115A - Shared antenna and portable radio equipment using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify and miniaturize the holding mechanism of antenna by composing a shared antenna of 1st antenna, which performs circularly polarizing operation while helically winding a lead wire around the side face of cylinder made of dielectrics, and a 2nd linear antenna which is held on the almost center axis of 1st antenna by dielectrics filled in the cylinder, so as to operate linearly polarization. SOLUTION: The 1st antenna can consist of a one-wire helical antenna by winding a lead wire 2 around a dielectric cylinder 1 and can thin the diameter of cylinder by winding the lead wire around the cylindrical dielectric with high dielectric constant. The 2nd antenna is a monopole antenna 3 and one part of monopole antenna passes the almost center of dielectric cylinder 1 consisting of the 1st antenna. By filling the inside of dielectric cylinder 1 with dielectrics such as silicon rubbers, the 2nd antenna can be simply and easily held. Thus, the shared antenna is miniaturized by excluding the interference of electromagnetic fields between the 1st and 2nd antennas.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna effective for both satellite communication and terrestrial communication and a portable radio using the same, and more particularly, to features of miniaturization and holding of a radiating element.

[0002]

2. Description of the Related Art Currently, 800 MHz band, 1.5 GHz band, and 1.9 GHz band linearly polarized waves are used in mobile communications such as mobile phones. In recent years, various companies have proposed a concept of a mobile phone using a satellite, and the 1.6 GHz band and the 2.4 GHz band have been assigned to these frequency bands. As an antenna, for example, a common antenna has been proposed in which a helical antenna is formed by winding a conductive wire and a coaxial wire on a dielectric cylinder, and a vertical dipole antenna is provided inside the cylinder.

FIG. 4 shows an example of such a conventionally known common antenna. In a helical antenna for circularly polarized wave operation at a first frequency for satellite communication, a conductive wire 32 and a coaxial wire 33 are spirally wound around a side surface of a dielectric cylinder 31, respectively.
Is connected to the inner conductor 33a of the coaxial cable 33 at the tip of the dielectric cylinder 31 and the other end of the conductor 32 is connected to the outer conductor 33c of the coaxial cable 33 at the lower end of the dielectric cylinder 31. Symbol 33
b is an insulator of the coaxial line 33. Also, inside the dielectric cylinder 31, a different second terrestrial wave communication
A dipole antenna 35 that performs linear polarization operation at the frequency shown in FIG. Since the second antenna is arranged substantially on the central axis of the first antenna, there is almost no electromagnetic interference, and therefore the first antenna and the second antenna can be fed independently.

[0004]

However, the above-mentioned conventional common antenna in which a dipole antenna is provided inside the helical antenna has a small degree of freedom in design, and the mechanism for holding the internal antenna is complicated, so that the whole becomes large.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to simultaneously simplify and reduce the size of a holding mechanism for a shared antenna. It is another object of the present invention to make it possible to be mounted on a portable wireless device such as a mobile phone.

[0006]

According to the present invention, the above-mentioned objects are achieved by the means as set forth in the appended claims.

That is, the present invention provides a first antenna which circularly operates by circularly wrapping a conducting wire around a side surface of a cylinder made of a dielectric, and a dielectric filled in the cylinder. And a linear second antenna that is linearly polarized and held substantially on the central axis of the antenna. Further, this antenna configuration is provided at the upper end of the housing of the portable wireless device.

According to the present invention, there is provided a ceramic antenna having a hole on a substantially central axis, the first antenna having a spiral circular polarization operation on the side surface, and the linear antenna having a linear polarization operation in the hole. The second antenna is characterized by being formed by metallization. Further, the ceramic body is provided at the upper end of the housing of the portable wireless device.

[0009]

FIG. 1 shows an embodiment of the present invention. First, the operation of the first antenna will be described. First
Is a one-wire helical antenna formed by winding a conducting wire 2 around a dielectric cylinder 1. In the helical antenna, at a desired frequency (first frequency f1),
When the pitch angle is 10 to 15 degrees and the helix circumference is about one wavelength, circular polarization occurs in the axial mode. By winding a conductive wire around a cylindrical dielectric having a high dielectric constant, the diameter of the cylinder can be reduced. The dielectric cylinder 1 is made of ceramics, and this helical antenna can be made by metallization. In order to construct a circularly polarized antenna, it is not limited to a cylindrical dielectric, but may be a cylindrical dielectric such as a conical dielectric.

Next, the operation of the second antenna will be described. This antenna is a monopole antenna 3 and has a second
At the frequency f2 (≠ f1). Part of the monopole antenna passes through substantially the center of the dielectric cylinder 1 constituting the first antenna. By filling the inside of the dielectric cylinder 1 with a dielectric such as silicone rubber,
Antenna can be held. The dielectric to be filled may fill the entire inside of the dielectric cylinder 1 or may be filled to such an extent that the second antenna can be partially held. Alternatively, a hole may be formed in the center axis of the ceramic cylinder as the dielectric cylinder 1, and a monopole antenna portion inside the helical antenna may be formed by metallizing the hole.

With the above arrangement, electromagnetic interference between the first antenna and the second antenna can be eliminated in principle, so that power can be supplied to each antenna independently. The electrical length of the first antenna that generates circularly polarized waves is reduced by winding or metallizing the surface of the dielectric. This makes it possible to reduce the diameter of the dielectric. The electrical length of the second antenna covered with the dielectric is also reduced. When the second antenna is a linear antenna, it can be easily held by the dielectric.

FIG. 2 shows another embodiment. FIG. 2A shows a state in which the second antenna is constituted by a rod antenna and the tip is housed inside a dielectric. In this case, all the helical antennas can be formed by metallizing the above-mentioned ceramic body (dielectric cylinder 1), while the rod antenna can be formed by metalizing the inside of the helical antenna to a ceramic body. Can be freely pulled out and stored from the hole formed in the ceramic body. FIG. 2B shows a case where the second antenna is used at a relatively high frequency (PHS or the like), and the second antenna (monopole antenna) is operated at a length halfway through the dielectric cylinder 1. is there.
In this case, the helical antenna and the monopole antenna can all be formed by metallizing a ceramic body.
2C and 2D show a case where a capacitive element 8 is added for impedance matching.

FIG. 3 shows an example in which the common antenna 12 configured as described above is mounted on the upper part of the portable radio device 11.
Since the gain and axial ratio of the circularly polarized antenna are affected by the size and shape of the reflective conductor, it is needless to say that various circularly polarized parameters need to be determined according to the target satellite communication system.

[0014]

Since the present invention is configured as described above, the size of the entire common antenna can be reduced, and the built-in second antenna can be easily held. Further, according to the present invention, a small portable wireless device having a dual mode function of satellite communication and terrestrial communication can be realized.

[Brief description of the drawings]

FIG. 1 is a diagram of a shared antenna illustrating an embodiment of the present invention.

FIG. 2 illustrates another embodiment of the present invention.
(A) is a diagram illustrating a state in which the second antenna is housed in a dielectric body with the second antenna being a telescopic rod antenna, and (b) is a case where the second antenna is completed inside the dielectric body. FIGS. 3C and 3D are diagrams in which a capacitive element is partially provided.

FIG. 3 is a diagram in which the shared antenna of the present invention is mounted on a portable wireless device.

FIG. 4 is a diagram of a conventionally known shared antenna.

[Explanation of symbols]

1: Dielectric cylinder (ceramic body) 2: Conductor wire 3: Monopole antenna (rod antenna, etc.) 4: Feeding wire 5: First feeding point 6: Second feeding point 7: Reflective conductor 8: Capacitive element 11 : Portable wireless device 12: Shared antenna 13: Display unit 14: Receiver unit 15: Operation unit 16: Transmitter unit 31: Dielectric cylinder 32: Conductive wire 33: Coaxial wire which becomes a radiating element 33 a:
Inner conductor of coaxial line 33b: Insulator of coaxial line 33c:
Outer conductor of coaxial line 34: Feeding point 35: Dipole antenna

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁶ Identification code FI H01Q 21/30 H01Q 21/30 (72) Inventor Hideto Ohita 2-1-1 Kagahara, Tsuzuki-ku, Yokohama-shi, Kanagawa Prefecture Kyocera Yokohama Office Co., Ltd.

Claims (4)

[Claims] 1. A first antenna that operates in a circularly polarized wave by spirally winding a conducting wire around a side surface of a cylinder made of a dielectric, and a substantially center of the first antenna by a dielectric filled in the cylinder. A shared antenna comprising: a linear second antenna that is linearly operated and held on an axis. 2. A spirally polarized first antenna which operates on a side surface of a ceramic body having a hole substantially on the center axis, and a linear second antenna which operates linearly on said hole. A shared antenna, wherein each antenna is metallized. 3. A first antenna that operates in a circularly polarized wave by spirally winding a conducting wire around a side surface of a cylinder made of a dielectric, and a substantially center of the first antenna by a dielectric filled in the cylinder. A portable wireless device comprising: a linear second antenna that is linearly polarized and held on an axis; 4. A first antenna having a spiral circular polarization operation on a side surface of a ceramic body having a hole substantially on a central axis, and a second linear antenna having a linear polarization operation in said hole. A portable wireless device comprising: a ceramic body having an antenna formed by metallization;