JPH10135733A - Shared antenna device and portable radio unit using the antenna device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antenna that can be used in common to both satellite communication and terrestrial communication by performing parallel feeding to a circular polarized antenna and serial feeding to a linear polarized antenna respectively and preparing a capacitive element between every antenna and feeding point to control the flow of a high frequency current. SOLUTION: In regard to a polarized antenna 11, two lead wires (a) are wound round a cylindrical supporter 12 180 degrees and both wires (a) are electrically connected to each other at their crossing part 13. When both wires (s) are also electrically connected together at a winding end terminal 14 and then excited via a gamma matching element (b), the complex resonance is generated at a desired frequency to secure the function of the antenna 11. A linear polarized antenna 21 is electrically connected to a common feeding point 1 via a 2nd capacitive element 3 for addition of the antenna 21 with no influence caused to the working of the antenna 11. Then the transmitting power is supplied to the point 1 from a radio circuit part contained in a main body via a coaxial line 31.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the field of communications, and more particularly to an antenna device for portable wireless communication mainly using satellites and portable wireless communication via a wireless base station installed on the ground, and a portable device using the same. It relates to a wireless device.

[0002]

2. Description of the Related Art In recent years, various companies have proposed a concept of a mobile phone using a satellite, and the frequency band is 1.6 GHz from a terrestrial mobile phone to a satellite, and from a satellite to a terrestrial mobile phone. Is assigned to the 2.4 GHz band. In the 1.6 GHz band, it is also assigned as a frequency band used for bidirectional communication from the ground to the satellite and from the satellite to the ground.
Furthermore, for terrestrial communication, 800 MHz band, 1.5
GHz band, 1.9 GHz band and the like are allocated. As a common antenna for satellite communication and terrestrial communication, the present applicant has proposed a method of feeding power at the upper end of a two-wire helical antenna using a coaxial cable and a conductor (Japanese Patent Application No. 8-2697).
7).

[0003]

SUMMARY OF THE INVENTION The present invention provides an antenna which can be used for both satellite communication and terrestrial communication, and realizes a portable radio (portable telephone) which can perform both satellite communication and terrestrial communication using the antenna. The task is to

[0004]

According to the present invention, the above-mentioned objects are achieved by the means as set forth in the appended claims. That is, parallel feeding is performed to a four-wire helical antenna (circularly polarized antenna) or the like, and serial feeding is performed to a linear antenna antenna or a single-wire helical antenna (linearly polarized antenna) so that the two antennas do not affect each other. For this purpose, a capacitive element such as a capacitor is provided between the antenna and the feeding point to control the flow of the high-frequency current. Antennas are arranged so that their axes are arranged substantially coaxially to avoid mutual interference and maintain good directivity. Also,
When the circularly polarized antenna is operated in the 1.6 GHz band and the linear antenna is operated in the 800 to 900 MHz band, especially in the case of the linear antenna, a good half-wavelength vertical The characteristics as a dipole antenna (FIG. 2) are shown.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to solve the above-mentioned problems, an embodiment of the present invention provides a feed point for supplying a high-frequency current below the axis of a circularly polarized antenna (four-wire helical antenna) via a capacitive element. Add a linearly polarized antenna (linear antenna or single-wire helical antenna). With this configuration, the circularly polarized antenna and the linearly polarized antenna can be fed by one feeder (coaxial line). Therefore, the antenna can be mounted on a mobile phone and provided with a plurality of wireless communication networks without mechanical switching operation. Can be accessed.

The common antenna according to the present invention mainly includes a feed point 1 common to a circularly polarized antenna (four-wire helical antenna) 11, a linearly polarized antenna (single-wire helical antenna) 21,
It comprises a first capacitive element 2 and a second capacitive element 3. The linearly polarized antenna 21 may be a linear antenna.

First, the circularly polarized antenna 11 has two conductors a.
Are wound around the cylindrical support 12 while being rotated by 180 degrees. At the crossing portion 13 at the upper end, the conductors a facing each other while being separated by a DC by an insulator (not shown) are connected to each other. Connected. Next, there is a winding end 14 at the lower end of the support 12 and two conductors a
Are electrically coupled at a winding end 14. The two conductors a at the intersection 13 at the upper end are separated from each other by the insulator, so that their lengths are slightly different substantially. This means
It means that it resonates at two frequencies. Further, by exciting through the gamma matching element b, double resonance occurs at a desired frequency, and the antenna operates as a circularly polarized antenna.

In order to add a linearly polarized antenna (single line helical antenna) 21 without significantly affecting the operation of the circularly polarized antenna 11, the common feeding point 1 is connected to the The polarization antenna 21 is electrically connected. The linearly polarized antenna 21 has a linear conductor c wound around a cylindrical support 22. Here, circularly polarized antenna 1
1, the operating frequency band is 1.6 GHz band (satellite communication frequency band), and the linearly polarized antenna 21 is 800 MHz to 900 M
Λ / 4 (1/4) in the Hz band (terrestrial mobile phone frequency band)
Wavelength) antenna, the linearly polarized antenna 21 cooperates with the circularly polarized antenna 11 to substantially form one λ / 2 antenna.
Acts as a (half wavelength) vertical dipole antenna. That is, it has a function as a λ / 2 vertical dipole antenna (FIG. 2).

Further, since the linearly polarized antenna 21 is disposed on the side opposite to the radiation direction of the circularly polarized antenna 11, it is possible to suppress the disturbance of the circularly polarized radiation pattern.

A central conductor 34 of the coaxial line 31 is connected to the common feeding point 1. Power supply to the circularly polarized antenna 11 is as follows.
This is performed from the feeding point 1 to the gamma matching element b via the first capacitive element 2. The conductor a is connected to the outer conductor 33 of the coaxial cable 31 by the coupling wire 4. Power is supplied to the linearly polarized antenna 21 from the power supply point 1 via the second capacitive element 3.

The above-mentioned antenna is mounted on the main body of the portable telephone, and a feeding point 1 is connected through a coaxial line 31 from a radio circuit section in the main body.
Is supplied with transmission power.

[0012]

EXAMPLE In order to confirm the operation experimentally, a radiation pattern was measured with an antenna conforming to the configuration of FIG. 1 (FIG. 3).

Circularly polarized antenna (4-wire helical antenna)
11 is a glass cylinder having a diameter of 15 mm and a length of 55 mm and a width of 2
mm copper wire is wound. The linearly polarized antenna (single-wire helical antenna) 21 has a diameter of 7 mm and a length of 17
A conductive wire having a diameter of 0.3 mm was made to make 5 turns on a resin cylinder of 5 mm. A ceramic capacitor (second capacitive element 3) of several pF was provided between the common feeding point 1 and the linearly polarized antenna 21.

[0014]

As described above, according to the present invention, a small shared antenna that can be used for both satellite communication and terrestrial communication can be realized, and a small portable radio that can be used for both satellite communication and terrestrial communication can be realized. realizable. Power can be simultaneously supplied to a shared antenna operating at different polarizations and different frequencies, interference between the antennas can be suppressed, and mechanical switching is not performed, so that the reliability of the antenna unit and the radio unit is improved.

[Brief description of the drawings]

FIG. 1 is an antenna configuration diagram according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a half-wavelength dipole antenna.

FIG. 3 is a measurement example of a radiation pattern in a satellite communication frequency and a terrestrial mobile phone frequency band in FIG.

[Explanation of symbols]

 1: Common feeding point 2: First capacitive element 3: Second capacitive element 4: Coupling line 11: Circularly polarized antenna (4-wire helical antenna) 12: Support body 13: Intersection 14: End of winding End 21: linearly polarized antenna (single-wire helical antenna) 22: support a: conducting wire b: gamma matching element c: linear conductor 31: coaxial line 32: coaxial dielectric 33: coaxial external conductor 34: coaxial Center conductor of wire

Claims (4)

[Claims] 1. A first antenna is fed in parallel with high frequency power, a second antenna is fed in series with high frequency power, the first antenna performs circularly polarized wave operation at a first frequency, and Are antennas that perform linear polarization operation at a second frequency, and the two antennas have a common feed point, and a portable wireless device using the same. 2. The antenna according to claim 1, wherein the first antenna is a four-wire helical antenna, the second antenna is a linear antenna or a single-wire helical antenna, and the axes of the two antennas are arranged substantially coaxially. A shared antenna device according to claim 1, and a portable wireless device using the same. 3. The shared antenna device according to claim 1, wherein the first antenna and the second antenna are each supplied with electric power via a capacitive element, and a portable wireless device using the same. 4. The shared antenna device according to claim 1, wherein said first antenna operates in a 1.6 GHz band, and said second antenna operates in a 800 to 900 MHz band. Portable radio.