JP3487135B2 - Antennas and array antennas - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin antenna formed by disposing conductors on a substrate, and more particularly to a diversity antenna and an array antenna.

[0002]

2. Description of the Related Art FIG. 16 shows the structure of a sleeve antenna. 161 is a radiating element having an electric length of ¼ wavelength, 162 is a sleeve (cylindrical tube) having an electric length of ¼ wavelength,
Reference numeral 163 is a power feeding coaxial cable. This sleeve antenna operates in the same manner as a dipole antenna composed of the radiating element 161 and the sleeve 162, has high efficiency, good directivity, and stable impedance.

In FIG. 17, the central conductor 171 and the outer tube 1 are shown.
It is an inverted coaxial dipole antenna configured by replacing 72 with the same operation as that of the sleeve antenna described above, and it has high efficiency, good directivity, and stable impedance. Further, this antenna can be arrayed.

FIG. 18 shows a planar antenna in which the sleeve antenna is formed on a substrate, that is, a conductor is arranged on the substrate. 181 is a dielectric substrate, 182 is a microstrip line formed of a thin film conductor, and 183 is a surface opposite to the surface on which the microstrip line is arranged (ground surface;
This drawing shows a dipole antenna element made of a conductor provided on the ground surface), 184 is a feeding slot, and 185 is a notch having an electrical length of ¼ wavelength. The operation of this antenna is equivalent to that of the sleeve antenna described above, and the efficiency is good, the directivity is good, and the impedance is stable.

[0005]

The conventional sleeve antenna and tumbling type coaxial dipole antenna have a structure in which a feeding coaxial cable and a sleeve are connected to each other, and therefore, their processing and adjustment are complicated. It will cause instability.

On the other hand, the plane antenna solves the above-mentioned problems, but since the slot is provided in the ground plane, it cannot be made into a diversity. Diversification is to increase the transmission / reception capability by using a plurality of antennas in combination.

Therefore, an object of the present invention is to solve the above-mentioned problems and to provide an antenna and an array antenna capable of diversity.

[0008]

In order to achieve the above object, the antenna of the present invention comprises a microstrip line made of a conductor, a feeding line in contact with the microstrip line, and a feeding line on a substrate made of a dielectric or a semiconductor. An antenna in which one radiating element connected to a line is arranged, and a ground conductor is provided on the surface of the substrate opposite to the surface on which the microstrip line is arranged , wherein the feed line is the mark.
From the middle of the cross trip line to a predetermined position
The radiating element is provided with an electric length of 1/2 wavelength in the longitudinal direction
Radiation having the length of
Position the element in the longitudinal direction at a position other than the end of the radiating element.
It has been adjusted .

The radiating element may be arranged on the surface opposite to the surface on which the microstrip line is arranged, and these radiating element and the feed line may be connected by through holes or wiring.

A parasitic element may be provided along the radiating element.

The radiating element may be provided on both sides of the microstrip line.

Any one of the midpoint in the longitudinal direction of the radiating element, the microstrip line or the parasitic element may be short-circuited to the ground conductor at one point.

[0013] The antenna is the microstrip
Instead of tracks, coplanar lines, triplate lines, or
May use parallel plate lines.

The array antenna is a base of the antenna .
Board, microstrip line and ground conductor in the longitudinal direction
In the middle of the extended microstrip line
The second-stage power supply line is installed at the position
The second stage radiating element is connected to the electric line .

[0015] The distance may be arranged by changing the between first and second stages of the feed point.

[0016] The array antenna, instead of the microstrip line, coplanar line, may be used triplate line, or a parallel plate line.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG . 1, the substrate 1 of this antenna is made of a dielectric material and is formed in a rectangular shape. On this substrate 1, a microstrip line 2 is provided which is made of a conductor having a narrow line width and extending from a substantially central portion of the short side to a predetermined position in the longitudinal direction. A feeding line 3 made of a conductor having a narrow line width is provided from a position in the middle of the microstrip line 2 to a predetermined position. This feeder line 3
Is sometimes called a power supply microstrip line.
The tip side of the microstrip line 2 from the position where the feeding line 3 is provided is not connected to any part, and this portion is referred to as an open tip microstrip line 4. A radiating element 5 made of a conductor is provided at the tip of the feed line 3. The radiating element 5 may be called an antenna radiating element.
This radiating element 5 has a length of an electric length of ½ wavelength in the longitudinal direction. A matching circuit 6 based on a distributed constant is formed on the base end side of the microstrip line 2. This board 1
On the opposite surface, a grounding conductor 7 is provided facing the microstrip line 2 and wider than the line width of the microstrip line 2 and having a rectangular shape, for example. The ground conductor 7 may be called a ground plane. Each of the conductor portions on the substrate 1 described above is manufactured by pasting a conductive foil film, or by a fine processing step and a printed circuit board processing step.

The operation of the antenna of FIG . 1 and the impedance matching method will be described.

The feed signal applied to the microstrip line 2 is applied to the radiating element 5 through the feed line 3. That is, the radiating element 5 is powered. As a result, a radio wave is radiated from the radiating element 5. Impedance matching between the radiating element 5 and the feeding line 3 is performed by adjusting the line width of the feeding line 3 or by changing the longitudinal position of the radiating element 5 to which the feeding line 3 is connected, that is, the feeding position. Whether to adjust, or to adjust the length of the open microstrip line 4,
It is taken by adjusting the shape and size of the matching circuit 6. Optimal impedance matching is achieved using a combination of these matching methods. Further, the gain can be increased by adjusting the distance between the radiating element 5 and the ground conductor 7.

The antenna shown in FIG . 1 is thin and lightweight because the conductor is arranged on the substrate 1. Further, the dimensional accuracy is very good because it is manufactured by the fine processing step and the printed circuit board processing step. Further, since the substrate and the conductors are integrated, there is no need for assembly and no adjustment is required, so mass productivity is excellent. Further, since the microstrip line made of a conductor, the feeding line, and the radiation element are provided, diversity can be achieved.

[0022] illustrating another embodiment of the present invention.

In the antenna shown in FIG . 2, the microstrip line 2, the feed line 3 and the radiating element 5 are arranged on the same surface of the substrate 1 in the antenna of FIG. It is located on the opposite side. Therefore, the ground conductor 7 and the radiating element 5 are on the same plane.
The radiating element 5 and the feed line 3 are connected by a through hole 8.

The operation and effect of the antenna of FIG . 2 are almost the same as those of the antenna of FIG. 1, but the ground conductor 7 and the radiating element 5 are used.
Since and exist on the same plane, it is possible to reduce the contribution of the feed line 3 to the antenna radiation pattern.

The antennas shown in FIGS. 3 and 4 are obtained by providing a parasitic element 9 on the antenna shown in FIG.
The parasitic element 9 is provided along the radiating element 5. In FIG. 3, the parasitic element 9 is arranged on the surface opposite to the surface on which the radiating element 5 is arranged. Since the microstrip line 2, the feeding line 3 and the radiating element 5 are arranged on the same surface of the substrate, the parasitic element 9 and the ground conductor 7 are on the same surface. In FIG. 4, the parasitic element 9 is arranged on the same surface as the surface on which the radiating element 5 is arranged. As illustrated, the parasitic element 9 is provided outside the radiating element 5 (on the side opposite to the microstrip line 2) in parallel. The antenna shown in FIG. 5 is provided with a plurality of parasitic elements.
The external parasitic element 9 is added to the antenna. The operations and effects of these antennas are almost the same as those of the antenna of FIG. 1, but in addition to this, the parasitic element 9 is arranged along the radiating element 5 to achieve a wider band.

The antenna shown in FIG. 6 and FIG.
In the antenna of FIG. 2, the radiating element 5 is arranged on one side of the microstrip line 2, whereas the radiating element 5 is arranged on both sides of the microstrip line 2. The operation and effect of these antennas are almost the same as those of the antennas of FIGS. 1 and 2, but in addition to this, the radiation elements 5 are arranged on both sides of the microstrip line 2 to stabilize the directivity. . Therefore, the polarization characteristic can be made close to omnidirectional.

The antennas shown in FIGS. 8 and 9 are similar to those shown in FIG.
In the antenna of FIG. 2, the radiating element 5 is short-circuited to the ground conductor 7 at one point. Since the radiating element 5 is arranged on the surface opposite to the ground conductor 7 in FIG.
A line 10 is drawn from the line 10, and the line 10 and the radiating element 5 are connected by a through hole 8. The connection position is
It is the midpoint in the longitudinal direction of the radiating element 5. In the case of FIG. 9, since the radiating element 5 is arranged on the same plane as the ground conductor 7,
A line 10 is drawn from the ground conductor 7 and the line 10
Is crossed with the radiating element 5. The antenna shown in FIG. 10 is different from the antenna of FIG. 3 in that the parasitic element 9 is short-circuited to the ground conductor 7 at one point. Since the parasitic element 9 is arranged on the same plane as the ground conductor 7, the line 10 is drawn from the ground conductor 7 and the line 10 intersects with the parasitic element 9. The connection position is the midpoint in the longitudinal direction of the parasitic element 9. Although not shown, there is also an antenna having a structure in which the tip of the microstrip line 2 is short-circuited to the ground conductor.

The antenna shown in FIG . 13 is different from the antenna of FIG. 6 in that a stub 11 is provided. Since the electrical length ¼ wavelength stub 11 is provided on the base end side of the position where the feeding line 3 intersects with the microstrip line 2 and impedance matching is achieved by this, mismatch is reduced. Although the operation and effect of the antenna are almost the same as those of the antenna of FIG. 6, since the stub 11 is provided, the gain can be increased. As described above, the antenna of the present invention can be provided with a matching circuit or a distribution circuit using a distributed constant or an electric length ¼ wavelength stub.

In any of the above embodiments, the antenna is lightweight and thin and can be easily used. Moreover, since the dimensional accuracy is high, the quality is stable and the reliability is high.
Further, since the processing is simple, it can be manufactured at low cost.

The array antenna shown in FIG . 14 has the configuration shown in FIG.
The collinear antenna is configured by connecting the two antennas in two stages. That is, the substrate 1 and the microstrip line 2
The ground conductor 7 is extended in the longitudinal direction, the second-stage feed line 13 is provided at an intermediate position of the extended microstrip line 12, and the second-stage radiating element 15 is connected to the feed line 13. ing. The distance L between the feeding points of the first and second stages is the electrical length of ½ wavelength or ½ wavelength or more. By changing the distance L between the feeding points, it is possible to give a directivity change, that is, a tilt. Such an array antenna is lightweight and thin and can be easily used. Further, since the dimensional accuracy is high, the quality is stable. Further, since the processing is simple, it can be manufactured at low cost. In addition, a feed line (coaxial cable, coplanar line, etc.) to the upper antenna on the ground conductor side
Can be arranged, so that a multi-stage diversity antenna can be constructed.

The array antenna shown in FIG . 15 is similar to that shown in FIG.
The crank-shaped connecting portion is inserted in the microstrip line 12 between the antennas of the array antenna 4 of FIG.

Although the microstrip line is used in the above embodiments, a coplanar line, a triplate line, a parallel plate line or the like may be used instead.

[0033]

The present invention exhibits the following excellent effects.

[0034] (1) radiation characteristics by a single antenna element
To realize a sufficient half-wave antenna.

[Brief description of drawings]

FIG. 1 is a plan view of an antenna showing an embodiment of the present invention.

FIG. 2 is a plan view of an antenna showing another embodiment of the present invention.

FIG. 3 is a plan view of an antenna showing another embodiment of the present invention.

FIG. 4 is a plan view of an antenna showing another embodiment of the present invention.

FIG. 5 is a plan view of an antenna showing another embodiment of the present invention.

FIG. 6 is a plan view of an antenna showing another embodiment of the present invention.

FIG. 7 is a plan view of an antenna showing another embodiment of the present invention.

FIG. 8 is a plan view of an antenna showing another embodiment of the present invention.

FIG. 9 is a plan view of an antenna showing another embodiment of the present invention.

FIG. 10 is a plan view of an antenna showing another embodiment of the present invention.

FIG. 11 is a plan view of an antenna showing a modified example of the present invention.

FIG. 12 is a plan view of an antenna showing a modified example of the present invention.

FIG. 13 is a plan view of an antenna showing another embodiment of the present invention.

FIG. 14 is a plan view of an array antenna showing an embodiment of the present invention.

FIG. 15 is a plan view of an array antenna showing another embodiment of the present invention.

FIG. 16 is a perspective view of a conventional sleeve antenna.

FIG. 17 is a cross-sectional view of a conventional inverted coaxial dipole antenna.

FIG. 18 is a plan view of a conventional planar antenna.

[Explanation of symbols]

1 substrate 2 microstrip lines 3 feeder lines 5 Radiating element 7 Ground conductor 8 through holes 9 Parasitic element

─────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-8-204433 (JP, A) JP-A-8-97624 (JP, A) JP-A-5-22018 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) H01Q 9/30 H01Q 1/38 H01Q 21/10 H01Q 21/12

Claims (9)

(57) [Claims] A microstrip line made of a conductor, a feeding line in contact with the microstrip line, and one radiating element connected to the feeding line are arranged on a substrate made of a dielectric material or a semiconductor. a of antenna in which the microstrip line is provided with a ground conductor on the opposite surface of the placed surface, the feed line above microspheres
From the middle of the trip track to the specified position
The above radiating element has a length of an electric length of ½ wavelength in the longitudinal direction.
And of the radiating element to which the feed line is connected
Adjust the longitudinal position to a position other than the ends of the radiating element.
Antenna, characterized by being. 2. The radiating element is arranged on the surface opposite to the surface on which the microstrip line is arranged, and the radiating element and the feed line are connected by through holes or wiring. antenna. 3. The antenna according to claim 1, wherein a parasitic element is provided along the radiating element. 4. The antenna according to claim 1, wherein the radiating element is provided on both sides of a microstrip line. 5. The method according to claim 1, wherein any one of the midpoint in the longitudinal direction of the radiating element, the microstrip line and the parasitic element is short-circuited to the ground conductor at one point.
Any of the listed antennas. 6. The microstrip line is replaced with
Coplanar line, triplate line, or parallel plate line
The antenna according to claim 1 , wherein the antenna is used. 7. The antenna substrate and microphone according to claim 1.
Extend the loss strip line and ground conductor in the longitudinal direction
2 at a position in the middle of the extended microstrip line
The power feeding line of the second stage is provided, and the power feeding line of the second stage is 2
An array antenna characterized in that the radiating element in the stage is connected . 8. Change the distance between the first and second feed points
Characterized by The array antenna according to claim 7.
Na. 9. Instead of the microstrip line,
Coplanar line, triplate line, or parallel plate line
9. The array according to claim 7 or 8, characterized in that
E antenna.