JPH06268547A - Antenna system for portable radio equipment - Google Patents

Abstract

PURPOSE:To obtain an antenna system without causing gain deterioration due to a polarized wave loss in spite of the attitude of the portable radio equipment. CONSTITUTION:A blade antenna 7 is energized through a coaxial line 5 from a metallic case 3 covered by a resin made case 1. A cylindrical choke 4 whose electric length is lambda/4 is connected to an outer sheath of an upper end of the coaxial line 5, and the performance equal to that of a lambda/2 dipole antenna together with the blade antenna 7 and the object is attained by using a movable connection section 8 so as to keep the blade antenna 7 perpendicular regardless of the attitude of the portable radio equipment.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna of a portable radio such as a car telephone.

[0002]

2. Description of the Related Art In recent years, portable wireless devices have been widely used not only in special places such as work sites but also in general. Particularly in telephones, mobile phones and cordless telephones that communicate wirelessly have come into widespread use due to diversification of places of use and restrictions on the distance of cords. These wireless devices are equipped with a transmitting / receiving antenna in the device body, and communicate with other wireless devices or a relay station or the like in each communication area through the antenna.

An example of a conventional mobile phone antenna device is shown in FIG. In the figure, reference numeral 1 is a resin housing that covers the metal housing 3. Reference numeral 6 is a dielectric substrate, 9 is a microstrip line, 11 is a strip conductor in which the ground side conductor 10 is folded back on both sides, and is an open termination at a position where the electrical length is λ / 4, and 2 is a helical antenna. .

Next, the operation will be described. The λ / 4 strip conductor 11 constitutes a resonator whose one end is short-circuited and whose other end is open, and exhibits characteristics as a λ / 2 dipole antenna with the helical antenna 2. When stored, the microstrip line 9
By short-circuiting the lower end to the ground via a leaf spring or the like, the influence of the microstrip line 9 is eliminated, and the helical antenna 2 has the same characteristics as the λ / 4 whip antenna by itself.

[0005]

The conventional portable wireless device is constructed as described above, and the antenna is fixed in the vertical direction with respect to the housing. On the other hand, when the antenna transmits and receives radio waves, the electric field pattern spreads in the direction orthogonal to the antenna as shown in FIG. In the figure, 13 is an antenna body. And since the radio waves transmitted and received to and from distant points travel almost horizontally,
It is necessary to put the antenna in a vertical position in order to maintain better reception. However, when actually using the wireless device, since the device body is placed near the ears and mouth, as shown in FIG. 8, the wireless device body leans left and right with respect to the front surface where the microphone and speaker are arranged. It is used as it is. Therefore, in such a portable wireless device, since the antenna is fixed in the vertical direction with respect to the device body, the antenna also has a fixed angle (for example, 60 °).
In some cases, it becomes tilted, and it is not possible to maintain the state orthogonal to the radio waves, which may interfere with transmission and reception. That is, there is a problem that gain deterioration occurs with respect to vertically polarized waves.

At this time, it is conceivable to tilt the entire antenna, but in the case of transmitting and receiving at the time of storage, it is impossible to tilt the antenna inside the housing, and this problem cannot be solved yet.

The present invention has been made to solve the above-mentioned problems, and occurs during communication even when the radio device is used in a tilted state and the antenna is housed. An object of the present invention is to obtain an antenna device capable of eliminating gain deterioration due to polarization loss.

[0008]

An antenna device according to the present invention is housed in a casing of a portable radio and has an electrical length of λ.
/ 4, a first antenna, a second antenna provided on the first antenna and having an electrical length of λ / 4, and between the first antenna and the second antenna. A connection portion is provided which holds the second antenna so as to be tiltable.

[0009]

In the antenna device according to the present invention, since the second antenna having an electric length of λ / 4 has the tiltable connecting portion under the second antenna, the antenna can be tilted even when it is stored, and the vertically polarized wave is generated. On the other hand, gain deterioration does not occur.

[0010]

EXAMPLES Example 1. An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, 1 is a resin housing that covers the metal housing 3, and 5 is a coaxial line, one end of which is supplied with power from the inside of the metal housing 3, and the other end of which has an electrical length of λ / 4. A cylindrical choke 4 is connected. A blade antenna 7 formed on a dielectric plate 6 is connected to the upper portion of the coaxial line 5 by a movable connecting portion 8. This movable connection 8
As for the configuration, for example, there is a case where it is made of a resin having flexibility or a case where the blade antenna 7 and the cylindrical choke 4 are covered with separate members as shown in FIG. To be In the figure, 71
Is an upper member that covers the blade antenna 7, 41 is a lower member that covers the cylindrical choke, and 81 is a pin that rotatably connects the upper member 71 and the lower member 41. At this time, the movable connection portion 8 may be tilted at least in the direction of the arrow shown in the drawing, that is, in the longitudinal direction of the housing 1, and may be tilted in another direction.

Next, the operation will be described. A cylindrical choke 4 having an electric length of λ / 4 constitutes a resonator having one end short-circuited and the other end opened, and a blade antenna 7 having a length of λ / 4 forms a λ / 2 dipole antenna. Shows equivalent properties. Since the blade antenna 7 is connected to the coaxial wire 5 by the movable connection portion 8, it can be tilted at least 60 ° to the right or left (direction of arrow), and the housing 1 is tilted at about 60 ° from the vertical. The blade antenna 7 can be kept vertical to the ground even during a held call. Further, even if the housing 1 is tilted by 60 ° or more from the vertical, the antenna can be tilted correspondingly. Therefore, the polarization loss with respect to the vertically polarized wave can be eliminated, and a good gain can be obtained.

At the time of storage, only the blade antenna 7 may protrude from the housing 1. At this time, the blade antenna 7 alone exhibits the same characteristics as the λ / 4 whip antenna. Further, the influence of the coaxial line 5 can be eliminated by short-circuiting the lower end of the coaxial line 5. At this time, by tilting the blade antenna 7 to the right or left as in the case of pulling out, the polarization loss at the time of a call can be eliminated and a good gain can be obtained. This is different from the case where the entire antenna is tilted. The blade antenna 7
Also, when not transmitting / receiving, the data is stored in the housing 1.

Example 2. FIG. 3 is a diagram showing a second embodiment of the antenna device according to the present invention. Reference numeral 2 denotes a helical antenna which is an antenna element having a length of λ / 4. By tilting the helical antenna to the right or left by the movable connection portion 8, the same effect as that of the first embodiment can be obtained.

Example 3. FIG. 4 is a diagram showing a third embodiment of the antenna device according to the present invention. Reference numeral 12 denotes a whip antenna having a length of λ / 4, and by tilting the whip antenna to the right or left by the movable connecting portion 8, the same effect as that of the first embodiment can be obtained.

Example 4. FIG. 5 is a diagram showing a fourth embodiment of the antenna device according to the present invention. In this embodiment, a movable connection portion 8 is further provided in the configuration shown in FIG. 6 as a conventional example. Also in this case, the same effect as that of the first embodiment can be obtained by tilting the movable connection portion 8 to the right or left.

In the above-described embodiment, the movable connecting portion 8 is provided only between the upper antenna and the lower antenna, but it may be provided in the lower antenna mounting portion. With such a configuration, the entire antenna can be tilted when it is pulled out, and the gain is further increased.

[0017]

As described above, according to the present invention, since the second antenna having the electrical length of λ / 4 has the tiltable connecting portion under the second antenna, the antenna can be tilted even during storage. Therefore, there is an effect that the gain deterioration does not occur with respect to the vertically polarized wave. That is, there is an effect that good sensitivity can be obtained during a call of the portable wireless device.

[Brief description of drawings]

FIG. 1 is a diagram showing an antenna device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing an antenna device according to a first embodiment of the present invention.

FIG. 3 is a diagram showing a second embodiment of the present invention.

FIG. 4 is a diagram showing a third embodiment of the present invention.

FIG. 5 is a diagram showing a fourth embodiment of the present invention.

FIG. 6 is a diagram showing an example of a conventional antenna device.

FIG. 7 is a diagram illustrating a problem of a conventional antenna device.

FIG. 8 is a diagram illustrating a problem of a conventional antenna device.

[Explanation of symbols]

 3 Metal housing 4 Cylindrical choke 5 Coaxial wire 6 Dielectric plate 7 Blade antenna 8 Movable connection part

Claims (1)

[Claims] 1. A first antenna housed in a housing of a portable wireless device and having an electrical length of λ / 4; and an electrical length of λ / 4 provided above the first antenna. An antenna device for a portable wireless device, comprising: a second antenna, and a connecting portion that is provided between the first antenna and the second antenna and that holds the second antenna in a tiltable manner.