JPH0715229A - Transmission line antenna device - Google Patents

Abstract

PURPOSE:To provide a transmission line antenna device which can transmit/ receive a radio wave with high gain even when the radio wave is vibrated in any direction inside a plane orthogonal to a main transmission/reception direction concerning the relevant direction. CONSTITUTION:Concerning a transmission line antenna system 2 on a metallic casing 1, the length from a feeding terminal 2a to a feeding terminal 2o and the length from the feeding terminal 2a to a ground terminal 2t are made the 1/2 of a resonant wavelength, the length near the equally bisecting point of parallel elements 21 and 2q is made the 1/4 of the resonant wavelength so that a vertical antenna can look like only one antenna composed of a vertical element 2b, and parallel elements 2j, 2m and 2r and these mirror images are integrated so as to look like one horizontal antenna.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission line antenna device for use in a portable wireless communication device or the like, which is arranged on a metal housing thereof.

[0002]

2. Description of the Related Art Conventionally, a transmission line antenna device used in a portable radio communication device or the like has been shown in FIG. 4, for example. That is, a rectangular parallelepiped metal housing 1
The transmission line antenna device 2 in which the feeding end 2a and the grounding end 2i are formed on the upper side surface 1a is composed of a plurality of integrally molded elements, and the vertical elements 2b and 2h are perpendicular to the upper side surface 1a. (That is, parallel to the Z axis shown in the drawing), the parallel elements 2c and 2g are the upper surface 1
parallel to a (ie parallel to the XY plane), parallel elements 2d, 2e, 2f parallel to side 1b (ie Z
(Parallel to the Y plane), the total length, that is, the length from the feeding end 2a to the grounding end 2i is about one half of the resonance wavelength.
Further, when transmitting and receiving using this transmission line antenna device 2, the X-axis direction is to be oriented in the transmitting and receiving direction.

The operating principle of the transmission line antenna device as described above can be explained by the basic form of the transmission line antenna device shown in FIG. This basic form is entirely in the ZY plane, and the vertical elements 2b and 2h are erected perpendicularly to the XY plane which is the ground plane, and the parallel elements 2
e is parallel to the Y axis, a feeding end 2a is provided between the vertical element 2b and the XY plane (earth plane), and a connecting portion between the vertical element 2h and the XY plane is a grounding end 2i. The total length is ½ of the resonance wavelength as above. In such a basic form, the current distribution is shown in FIG. 5B, and the feeding end 2a and the grounding end 2i are
It becomes the maximum at 0 and becomes 0 at the central part. The S on the horizontal axis in the figure is the origin where the feeding end 2a is provided as shown in FIG.
b, the parallel element 2e, and the vertical element 2h, the distances from the origin to the respective positions are shown, and the same applies to the next FIG. 5C. Further, the phase characteristics of the basic form are shown in FIG. 5C, and are inverted at the feeding end 2a and the grounding end 2i. (B) and (c) of FIG.
As can be seen from the above, a large current flows in the vertical elements 2b and 2h with their phases shifted by 180 °, and from the viewpoint of the positive direction and the negative direction of the Z-axis, currents always flow in the same direction, This part is an antenna array in which current flows in the same direction. Therefore, when focusing only on the vertical elements 2b and 2h, the XY plane and the XZ
The antenna pattern in the plane is (a) and (b) of FIG.
As shown in FIG. 5, it is strong in the X-axis direction and weak in the Y-axis direction and the Z-axis direction. Also, XZ by the parallel element 2e
The antenna pattern in the plane is combined with the mirror image by the ground plane (XY plane) as shown in FIG. 6C, so that it is 0 in the X-axis direction and the Y-axis direction and strong in the Z-axis direction.

Based on the characteristics in the basic form as described above, the characteristics of the conventional transmission line antenna device shown in FIG. 4 are obtained. That is, the vertical elements 2b and 2h in the conventional example (FIG. 4) are in the basic form, that is, (a) in FIG.
Corresponding to the vertical elements 2b, 2h in FIG. 1 and the parallel elements 2c, 2d, 2e, 2f, 2 in the conventional example.
Each of g corresponds to the parallel element 2e in the above basic form. Therefore, in the XY plane and Z in the conventional example described above.
The antenna patterns in the X plane are as shown in FIGS. 7 (a) and 7 (b), respectively (E _θ shown by a solid line and E _{θ shown by a} dotted line in FIG. 7). _φ represents the vertical and horizontal components of the electric field strength, respectively).

[0005]

In the above-mentioned conventional example, from the viewpoint of reception, as can be seen from the antenna pattern shown in FIG. 7, the horizontal direction of the radio wave coming along the X-axis, which is the direction in which the radio wave is strongest. There is a problem that the component (horizontal polarized wave) cannot be received, and the gain of the vertical component (vertical polarized wave) of the radio wave that goes from the negative side to the positive side of the X axis decreases. The present invention has been made in view of the circumstances as described above, and with respect to the main transmission / reception direction, transmission can be performed with high gain even if the radio wave vibrates in any direction within a plane orthogonal to the direction. An object is to provide a line antenna device.

[0006]

In order to achieve the above-mentioned object, the present invention provides a transmission line antenna device which is orthogonal to any two parallel side surfaces of a metal housing whose side surface is an earth plane. The standing portion and the standing portion which are arranged on three continuous side surfaces including the other one side surface and are arranged on the other one side surface, one end of which serves as a feeding point and which is vertically erected on the side surface. The first grounding end is disposed on one side surface of one of the two parallel side surfaces and a central portion having a parallel portion that is connected to the upper end portion of the portion and is parallel to the side surface. And a first vertical portion that is vertically installed on the side surface and a first vertical portion that is connected to the upper end portion of the first vertical portion and has the other end connected to the parallel portion of the central portion and that is parallel to the side surface. A first side having a portion and one of the other two parallel side surfaces And one end is connected to the side face to form a second ground end, one end is connected to the second vertical portion vertically installed on the side face and the upper end portion of the second vertical portion, and the other end is A second side part having a second part connected to the parallel part of the central part and parallel to the side face, and a first part of the first side part from the feeding point of the central part, and a first part The length from the vertical portion to the first grounding end is one half of the resonance wavelength, and the sum of the length of the first portion of the first side portion and the length of the first vertical portion is about the resonance wavelength. And the second part of the second side from the feeding point,
And the length from the second vertical portion to the second ground end is one half of the resonance wavelength, and the sum of the length of the second portion of the second side portion and the length of the second vertical portion is the resonance. About a quarter of a wavelength
I took measures to become.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to an embodiment shown in the drawings. FIG. 1 shows the configuration of the first embodiment ((a) of the figure is an external perspective view, (b) is a front view, (c) is a top view, (d) is a left side view, (E) is a right side view, and X as shown in (a) above,
Y, Z coordinate system is given). In the present embodiment, in the transmission line antenna device 2, parallel elements are arranged in parallel on the upper side surface 1a, side surfaces 1b, 1c of the metal housing 1 with a constant distance. That is, the upper side surface 1a of the metal housing 1
A feed end 2a is provided on the upper side, and a vertical element 2b whose lower end is the feed end 2a is erected vertically on the upper side surface 1a, and one end of the parallel element 2j is connected to the upper end of the vertical element 2b. Extends parallel to the upper side surface 1a in the positive direction of the Y-axis and is connected to one ends of the parallel elements 2k and 2p. The parallel element 2k
Is parallel to the upper side surface 1a and extends in the positive direction of the X-axis and is connected to one end of the parallel element 2l. The parallel element 2l is parallel to the side surface 1b and extends in the negative direction of the Z-axis and is connected to one end of the parallel element 2m. However, this parallel element 2m has a side surface 1
It extends in the negative direction of the Y-axis parallel to b and is connected to one end of the grounding element 2n, which extends in the negative direction of the X-axis and is in vertical contact with the side surface 1b. Has become. Further, the parallel element 2p is
The parallel element 2q extends in the negative direction of the X-ray axis parallel to the upper side surface 1a and is connected to one end of the parallel element 2q. The parallel element 2q extends in the negative direction of the Z axis parallel to the side surface 1c.
It is connected to one end of r (see (d) of the same figure). And
The parallel element 2r extends in the negative direction of the Y-axis parallel to the side surface 1c and is connected to one end of the ground element 2s, which extends in the positive direction of the X-axis and contacts the side surface 1c vertically. The contact portion is the grounding end 2t (see FIG. 7C). Then, from the feeding end 2a to the grounding end 2
The length up to o, that is, the sum of the lengths of the vertical element 2b, the parallel elements 2j, 2k, 2l, 2m, and the grounding element 2n is about one half of the resonance wavelength, which is 2 times the above-mentioned length. The bisector is near the bisector of the parallel element 2l (however, the parallel element 2l
Is short, the parallel element can be approximately regarded as a bisection point), and the length from the feeding end 2a to the grounding end 2t, that is, the vertical element 2b, the parallel elements 2j, 2p, 2q, 2r. , And the sum of the lengths of the grounding elements 2s is about one half of the resonance wavelength, and the bisector of the length is near the bisector of the parallel element 2q ( Similarly to the above, the parallel element 2q itself can be approximately regarded as a bisector.

When transmitting / receiving using the transmission line antenna device 2, the direction of the X axis is the transmitting / receiving direction.

The operation of this embodiment having the above-described structure will be described below. Consider a case where this transmission line antenna device is driven at a frequency related to the resonance wavelength (that is, a resonance frequency). In this case, the distribution of the current induced in this transmission line antenna device can be approximated by a transmission line whose length is ½ of the resonance wavelength and whose tip is grounded. It can be considered that the current is approximately 0 in the relatively short parallel elements 2l and 2q having the point where the length is about 1/4 of the resonance wavelength in the vicinity of the bisector. Therefore, only the vertical element 2b can transmit and receive the vertically polarized wave, and when only the vertically polarized wave is focused, it becomes equivalent to the case where only one vertical antenna including the vertical element 2b exists. The parallel element 2k current and the parallel element 2p current always flow in equal and opposite directions, and the ground element 2n current and the ground element 2s current also always flow in equal opposite directions, so these cancel each other out. Its function as a horizontal antenna can be ignored. On the other hand, the currents of the parallel elements 2j, 2m, and 2r always flow in the same direction, so they strengthen each other. However, the flow direction is reversed, so in the end it will flow in the same direction). Therefore, these parallel elements 2
The three elements j, 2m, and 2r and the mirror images of these ground planes (side surfaces of the metal housing 1) are integrated to function as one horizontal antenna.

As the elements function as described above, the antenna pattern of the transmission line antenna device 2 becomes as shown in FIG. That is, as shown in (a) of the figure, the vertical polarization pattern (E _θ ) in the horizontal plane (in the XY plane) becomes omnidirectional, and the horizontal polarization pattern (E _φ ) becomes maximum in the X-axis direction. It becomes a character pattern. Further, as shown in (b) of the same figure, the horizontal polarization pattern (E _φ ) in the vertical plane (in the XZ plane) can be regarded as almost omnidirectional, and the vertical polarization pattern (E _θ ) is the X-axis. It becomes an 8-shaped pattern with the maximum direction.

As described above, in this embodiment, an antenna pattern can be realized by one vertical antenna and one horizontal antenna, and vertical and horizontal polarized waves (vertical and horizontal components) in the X-axis direction, which is the transmission / reception direction. Can both send and receive with high gain.

Next, a second embodiment of the present invention will be described. FIG. 3 shows the configuration of this embodiment (note that
The components having the same functions as the components in FIG. 1 showing the configuration of the first embodiment are designated by the same reference numerals as those in FIG. 1). In this embodiment, the parallel elements 2j, 2k, 2l and 2m in the first embodiment are replaced with V-shaped elements 2x, and the parallel elements 2j, 2p, 2q and 2r are replaced with V.
The V-shaped element 2y is replaced by the V-shaped element 2y, and the V-shaped element 2x is composed of a portion parallel to the upper side surface 1a and a portion parallel to the side surface 1b.
And a portion parallel to the side surface 1c. Further, similarly to the first embodiment, the feeding end 2a to the grounding end 2 are
The length up to o and the length from the feeding end 2a to the grounding end 2t are 1/2 of the resonance wavelength, and the length from the feeding end 2a to V
Length up to the bending portion of the V-shaped element 2x and the feeding end 2
The length from a to the refraction portion of the V-shaped element 2y is 1/4 of the resonance wavelength. That is, this embodiment is simplified by modifying the first embodiment.

Also in this case, since the transmission line whose tip is grounded can be approximated, as in the case of the first embodiment, the vertical element 2b is one vertical antenna, each of the other elements and their mirror images are one body. Since it can be regarded as one horizontal antenna, the antenna pattern is as shown in FIG. 2 as in the first embodiment, and the same effect as in the first embodiment can be obtained.

[0014]

As described in detail above, the present invention is a transmission line capable of transmitting and receiving with a high gain, with respect to a main transmission / reception direction, a radio wave oscillating in any direction within a plane orthogonal to the direction. It is possible to provide an antenna device.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a first exemplary embodiment of the present invention.

FIG. 2 is a diagram showing an antenna pattern in the above embodiment.

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

FIG. 4 is a diagram showing a conventional example.

FIG. 5 is a diagram for explaining a conventional example.

FIG. 6 is a diagram for explaining a conventional example.

FIG. 7 is a diagram showing an antenna pattern of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Metal housing 1a Upper side surface 1b, 1c Side surface 2 Transmission line antenna device 2a Feeding end 2b, 2h Vertical element 2c-2g, 2j-2m, 2p-2r Parallel element 2i, 2o, 2t Grounding end 2n, 2s Grounding element 2x 2y V-shaped element

Claims (1)

[Claims] 1. A transmission line antenna device arranged on three continuous side faces, each of which has two parallel side faces and one side face orthogonal to the parallel two side faces of a metal housing whose side faces are ground planes. Yes, one side is placed on the other side surface, one end of which serves as a feeding point, and a standing portion that stands vertically on the side surface and a parallel portion that is connected to the upper end portion of the standing portion and is parallel to the side surface. A first vertical portion which is disposed on one side surface of the arbitrary parallel two side surfaces and has one end connected to the side surface to form a first grounding end and which stands upright on the side surface. And connected to the upper end of the first vertical portion and the other end to the parallel portion of the central portion,
And a first side portion having a first portion which is parallel to the side surface, and is disposed on the other side surface of the arbitrary two parallel side surfaces,
One end is connected to the side surface to form a second ground end, a second vertical portion that is vertically installed on the side surface, and one end is connected to the upper end portion of the second vertical portion and the other end is the central portion. A second side portion that is connected to the parallel portion and has a second portion that is parallel to the side surface, and from the feeding point of the central portion to the first portion of the first side portion, the first vertical portion, and the like. The length from the first side to the first grounding end is ½ of the resonance wavelength, and the length of the first portion of the first side portion is equal to the first wavelength.
The sum of the length of the vertical portion is about a quarter of the resonance wavelength, and the second grounding is performed from the feeding point in the central portion to the second portion on the second side and the second vertical portion. The length to the end is one half of the resonance wavelength, and the length of the second portion of the second side part and the second part
A transmission line antenna device, wherein the sum of the length of the vertical portion and the length of the vertical portion is about ¼ of the resonance wavelength.