JPH08250926A - Antenna system and portable radio equipment - Google Patents

Abstract

PURPOSE: To facilitate mass-production of a 2nd antenna easier than that of a conventional helical antenna and to reduce the manufacturing cost by adopting a dielectric resonator antenna for the 2nd antenna. CONSTITUTION: A feeding pin 35p is formed coaxially to a lock conductor 35 and the feeding pin 35p is inserted along the shaft of a cylindrical dielectric resonator 41 to couple the lock conductor 35 and the dielectric resonator 41 electromagnetically and mechanically and to form a dielectric antenna system (2nd antenna) 40. Furthermore, a synthetic resin layer 42 is fixed to the lock conductor 35 to coat the dielectric resonator 41. Furthermore, the dielectric antenna system 40 and a linear conductor 31 of a whip antenna system 30 are electrically isolated by a spacer 34 made of an insulator. The dielectric resonator 41 of a simple shape as above is manufactured by forming with the use of a metallic die and mass-production of the resonators 41 is easier than that of helical antennas.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna device and a portable radio device.

[0002]

2. Description of the Related Art Recently, in the field of mobile communication, due to factors such as an improvement in call quality and an increase in line capacity, the frequency used has become tight and a frequency band exceeding 1 GHz has come to be used.

Conventionally, in such a high frequency band,
As an antenna for a portable wireless device, a fixed monopole antenna, a helical antenna, a movable type storable whip antenna, or the like is used.

It is generally known that these antennas have a high radiation efficiency when the electric length thereof is in the vicinity of λ / 4 (1/4 wavelength).

[0005]

By the way, a composite antenna in which a helical antenna is coupled to the tip of a movable whip antenna which can be housed in the housing of a radio is also known as an antenna for a portable radio. ing.

In this composite antenna, when the whip antenna is housed in the housing, the helical antenna is fed, and the ground (ground) of the circuit board and the shield case are grounded to operate as a helical antenna. The whip antenna operates when the whip antenna is pulled out from the housing.

Operating frequency band f in the stored state and the pulled out state
a is the same, and the antenna gain becomes good by pulling out the whip antenna. In addition, from the viewpoint of portability, the structure is such that it operates even when the antenna is housed.

In this case, the resonance frequency fo = 1.9 GHz
In the above case, and when the electrical length λ / 4 (λ is the wavelength) is adopted, the antenna shape is as follows: the length of the whip antenna Lw = 40 mm, the winding diameter of the helical antenna Dh = 4 mm, the number of turns of the helical antenna Nh = 3. 5 turns The pitch of the helical antenna becomes Ph = 5 mm.

However, in the conventional composite antenna as described above, the helical antenna is generally formed by a coil. However, in view of the performance of the winding machine, the number of turns of the coil and the accuracy of the pitch can be maintained. Difficult and also
There is a problem that the work efficiency is low with handmade products, the mass productivity is poor, and the cost is high in any case.

In view of the above point, an object of the present invention is to provide a composite antenna device and a portable radio device which can be easily mass-produced and are relatively low in cost.

[0011]

In order to solve the above-mentioned problems, an antenna device according to the present invention is arranged with a second antenna arranged in the axial direction of a first antenna made of a linear conductor. In the antenna device provided with the power feeding means for selectively feeding power to the respective feeding points of the first and second antennas, the second antenna is constituted by a dielectric resonator antenna.

In the portable radio apparatus according to the present invention, the second antenna is arranged so as to be aligned in the axial direction of the first antenna made of a linear conductor, and the first and second antennas are fed with power. A portable wireless device including a composite antenna having a point, and a power feeding unit that selectively feeds power to a power feeding point of the first and second antennas when the first antenna is hiddenly housed in a housing. In the second aspect, the second antenna is constituted by a dielectric resonator antenna.

[0013]

According to this structure, the second dielectric resonator
And the feeding point of the first conductor of the linear conductor are selectively fed in correspondence with the two states in which the first antenna is hidden in the housing, and each of them has a predetermined frequency. Radio waves are emitted or received.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a composite antenna device and a portable radio device according to the present invention will be described below with reference to FIGS.

1 and 2 show the overall construction of an embodiment of the present invention, and FIG. 3 shows the construction of the essential parts thereof.

In FIGS. 1 and 2, reference numeral 10 denotes a main body of a portable wireless device, and a circuit board (printed wiring board) on which a required circuit such as a transmission circuit is mounted inside a housing 11 made of synthetic resin. 21 is stored.

An opening 12 for inserting the antenna is formed in the upper end portion of the housing 11, and a metal fitting 13 for mounting the antenna is fixed to the opening 12 by, for example, press fitting.

On the inner surface of the metal fitting 13, as shown in the drawing,
A thread groove is engraved, and the outer surface of the metal fitting 13 is connected to a matching circuit 23 on the board 21 via a power supply spring 22 attached to the circuit board 21. This matching circuit 23
A transmission circuit (and a reception circuit), which is represented by a signal source 24, is connected to.

A whip antenna system 30 mainly comprises a linear conductor 31 having a circular cross section.
1 is covered with a suitable insulating layer 32 over substantially its entire length.

One end 31a of the conductor 31 is exposed without being covered by the insulating layer 32, and the cylindrical first supporting and locking conductor 33 is fitted to this end 31a. The support conductor 33 has a length enough to cover one end of the insulating layer 32.

At the other end 31b of the conductor 31, a spacer 34 made of an insulating material having the same diameter as that of the conductor 31 is axially aligned, and the spacer 34 is also covered with an insulating layer 32. Then, to cover the spacer 34,
The cylindrical second supporting and locking conductor 35 is coupled.

Small diameter portions 33a, 3 of both locking conductors 33, 35
5a is formed to have the same diameter, and one of the small diameter portions 33a and 35a is inserted inside the support conductor 36 so as to come into contact with the support spring 37 inside the cylindrical antenna support conductor 36. The locking conductors 33 and 35 are coupled to the ends 31a and 31b of the linear conductor 31, respectively. And the supporting conductor 3
The support conductor 36 and the mounting bracket 13 are formed by the screw groove formed on the outer surface of 6 and the screw groove on the inner surface of the mounting bracket 13.
And are combined.

As a result, the whip antenna system 30 becomes
As shown in FIG. 1, the linear conductor 31 is housed inside the housing 12, and the large-diameter portion 35b of the second locking conductor 35 is in contact with the support conductor 36. As shown, the linear conductor 31 is drawn out of the housing 12,
The large diameter portion 33b of the locking conductor 33 can occupy the position in which the large diameter portion 33b of the locking conductor 33 comes into contact with the support conductor 36 in the pulled-out state.

At the storage position, the antenna support conductor 36, the support spring 37, and the fitting 13 are used to
The second locking conductor 35 is connected to the power feeding spring 22. Further, at the pulled-out position, the first locking conductor 33 is connected to the power supply spring 22 along the same path as described above.

The above-mentioned structure is similar to the conventional composite antenna in which the helical antenna (not shown) is fixed to the large diameter portion 35b of the second locking conductor 35 on the side opposite to the small diameter portion 35a. is there.

In this embodiment, the large diameter portion 3 of the locking conductor 35 is used.
The power supply pin 35p is formed coaxially with 5b, and
By inserting the power feeding pin 35p into the power feeding hole 41h formed along the axis of the cylindrical dielectric resonator 41 as shown in FIG. 2, the locking conductor 35 and the dielectric resonator 41 are electromagnetically and mechanically connected. Combined, dielectric antenna system 4
0 is formed. Further, the synthetic resin layer 42 having an appropriate hardness is fixed to the large diameter portion 35b of the locking conductor 35 to cover the dielectric resonator 41.

In this embodiment, the dielectric antenna system 40 and the linear conductor 31 of the whip antenna system 30 are used.
Are electrically separated from each other by a spacer 34 made of an insulating material.

In this embodiment, as the dielectric resonator 41, a material having a relative dielectric constant ε of 10 or more, for example, a ceramic material is used. The relative permittivity ε of the material used in this example is approximately 10, and the diameter D41 and the length L41 of the cylinder are set.
Is appropriately set according to the operating frequency band.

Further, the length and insertion position of the feeding pin 35p are adjusted so that the impedance matching of the dielectric resonator antenna is in a good state, and the diameter D1h and the length L1h of the feeding hole 41h are appropriately set.

In this embodiment, when the antenna is pulled out, the monopole antenna is pulled out, so that the support conductor 33 and the antenna support spring 37 are formed as shown in FIG.
Are electrically and mechanically connected. As a result, the monopole antenna is fed and operates as a monopole antenna with the ground plate (earth plate) of the circuit board and the shield case as the ground. The radiation pattern is generally omnidirectional in the horizontal plane and 8-shaped in the vertical plane.

When the antenna is housed, as shown in FIG. 1, the support conductor 35 electromagnetically coupled to the dielectric resonator antenna is electrically and mechanically connected to the antenna support spring 37. It As a result, the dielectric resonator is supplied with power and operates as a dielectric resonator antenna with the ground plate of the circuit board and the shield case as the ground. In general, the radiation pattern is omnidirectional in the horizontal plane and has an 8-shape in the vertical plane.

As described above, since the dielectric resonator 41 having a relatively simple shape is generally manufactured by molding using a mold, mass production is markedly greater than that of the helical antenna as described above. It will be easy. The dielectric resonator 41 and the synthetic resin layer 42 may be integrally molded.

In this embodiment, as shown in FIG. 1, the linear conductor 31 of the whip antenna system 30 is connected to the housing 12.
When housed inside, dielectric resonator 41
Is excited by the power supply pin 35p, and with good efficiency,
Emit and receive radio waves.

The voltage standing wave ratio (VSWR) of the dielectric antenna 41 in the used frequency band is about 1.5.

In the above embodiment, the case where the cylindrical dielectric resonator is used has been described, but the dielectric resonator may have another shape such as a rectangular parallelepiped. The material is not limited to ceramics as long as the relative permittivity ε is 10 or more.

In the above example, the radiation patterns of the monopole antenna and the dielectric resonator antenna are omnidirectional in the horizontal plane and 8 in the vertical plane, but the radiation patterns of these antennas are Of course, it may vary depending on the length, the size of the main plate, and the housing shape.

[0037]

As described above, according to the present invention, the second antenna is arranged while being aligned in the axial direction of the first antenna made of the linear conductor, and the first and second antennas are arranged. In the composite antenna device provided with the power feeding means for selectively feeding power to the respective feeding points of the antenna, since the second antenna is constituted by the dielectric resonator antenna, the second antenna is different from the conventional helical antenna. Mass production is significantly facilitated, and the manufacturing cost of the composite antenna device is reduced.

Along with this, the cost of the portable radio device using this composite antenna device is also reduced.

[Brief description of drawings]

FIG. 1 is a sectional view showing the configuration of an embodiment of the present invention.

FIG. 2 is a sectional view showing the configuration of an embodiment of the present invention.

FIG. 3 is a perspective view showing a configuration of a main part of an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Portable radio main body 11 Housing 13 Antenna mounting metal fitting 21 Circuit board 22 Feeding spring 23 Matching circuit 24 Signal source 30 Whip antenna system 31 Linear conductor 32 Insulating layers 33, 35 Supporting conductor 34 Spacer 35p Feeding pin 40 Dielectric antenna system 41 Dielectric Resonator

Claims (3)

[Claims] 1. A second antenna is arranged so as to be aligned in the axial direction of a first antenna made of a linear conductor, and the feeding points of the first and second antennas are alternatively arranged. An antenna device provided with a power feeding means for feeding power, wherein the second antenna is a dielectric resonator antenna. 2. The antenna device according to claim 1, wherein the dielectric resonator antenna is made of a cylindrical ceramic. 3. A second antenna is arranged so as to be aligned in the axial direction of the first antenna made of a linear conductor, and the first and second antennas each have an antenna having a feeding point. A portable radio device provided with power feeding means for selectively feeding power to the power feeding points of the first and second antennas when the first antenna is stored in a housing so as to be hidden. A portable wireless device in which the antenna is composed of a dielectric resonator antenna.