JP2559001B2 - Antenna device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used as an antenna for a base station in, for example, quasi-microwave band mobile communication,
The present invention relates to an antenna device configured by combining dipole antennas.

[0002]

2. Description of the Related Art A conventional dipole antenna is constructed by connecting a center conductor of a coaxial line to one dipole element and an outer conductor to the other dipole element as a power feeding means. A balun circuit is added to convert between an unbalanced line and a parallel line.

FIG. 4 shows the structure of a conventional dipole antenna. In the case of the dipole antenna shown in FIG. 4A, one dipole element 1a and the center conductor 2 of the coaxial line are provided.
Are connected, and the other dipole element 1b is connected to the outer conductor 3 of the coaxial line. In this case, the balun 4 is added to prevent the unbalanced current flowing on the coaxial line.

Further, in the case of the dipole antenna shown in FIG. 4B, one dipole element 5a is also processed in the same manner as above.
Is connected to the center conductor 6 of the coaxial line, and the other dipole element 5b is connected to the outer conductor 7 of the coaxial line. Then, the balun 8 is added.

The dipole antenna as described above is usually used in the VHF and UHF bands, but the dimensions of each part except the dipole element length and the balun length are electric characteristics.
It is required to be sufficiently small for the wavelength.

Therefore, in a dipole antenna used in a high frequency band having a shorter wavelength such as a quasi-microwave band exceeding the UHF band, it is necessary to make the structure of each part extremely small.

[0007]

However, when an attempt is made to manufacture a dipole antenna for use in a higher frequency band having a shorter wavelength, such as the quasi-microwave band, with the structure of the conventional dipole antenna, an extremely small structure is required. , A special support structure and power feeding structure are required. Especially, when stacking or combining reflective elements to obtain the desired directivity and high gain, the structure becomes more complicated and not only expensive but also electrical. There are many instability factors in terms of physical characteristics and there is a problem that it is difficult to realize.

The present invention has been made in view of the above problems.
For example, even when used in a high frequency band having a shorter wavelength such as a quasi-microwave band, stacking and reflector combination according to desired directivity and gain can be easily performed without requiring complicated feeding and supporting structure. It is an object of the present invention to provide an antenna device capable of performing the above.

[0009]

That is, an antenna device according to the present invention is a dipole element pattern formed on the front surface of a printed circuit board, and a microstrip formed between the dipole element pattern and the board feeding point. A pattern, a ground pattern formed on the back surface of the printed circuit board, and a central conductor provided on the back surface of the printed circuit board connected to a feeding point on the front surface of the circuit board and an outer conductor of the ground conductor on the back surface of the circuit board. A coaxial connector to be connected to the pattern, and a short stub circuit pattern formed by extending from a feeding point on the front surface of the printed circuit board and having its end connected to a ground plane on the rear surface of the circuit board. .

[0010]

In other words, a fine feeding pattern and antenna pattern can be easily obtained, and a special support structure can be used even for a dipole antenna having an extremely small structure used in a high frequency band with a short wavelength such as a quasi-microwave band. In particular, stacking for obtaining desired directivity and high gain and a combination of reflectors can be economically configured with a simple structure without requiring a power feeding structure.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the configuration of a dipole antenna according to an embodiment of the antenna device of the present invention. FIG. 1A is its front view, FIG. 1B is its side view, and FIG. ) Is the rear view.

In FIG. 1, dipole elements 12a and 12b are formed on the left side of the center of the front side of the printed circuit board 11 by about 1/4 wavelength, and the dipole elements 12a and 12b are formed along the vertical direction of the printed circuit board 11. Power is supplied through a macrostrip line 13 extending leftward from the center of 11, and to the other dipole element 12b, the same macrostrip line 13 and a phase inversion circuit 14 having an electrical length of about ½ wavelength. Reverse-phase power is supplied.

Further, the dipole elements 12a, 12 are
The dipole elements 15a and 15b are formed along the vertical direction on the right side of about 1/4 wavelength from the center of the front side of the printed circuit board 11 which is left-right symmetric with a distance of about 1/2 wavelength from b. The printed circuit board 1 is provided on the element 15a.
Macro strip line 1 extending to the right from the center of 1
Power is supplied via 6 and the other dipole element 15
b is supplied with opposite phase power through the same macro strip line 16 and a phase inverting circuit 17 having an electrical length of about ½ wavelength.

The center of the printed circuit board 11, that is, the connection point between the left macro strip line 13 and the right macro strip line 16 is defined as a feeding point 18.
A two-stack dipole antenna is constructed.

A central conductor 19a of a coaxial plug 19 arranged at the center of the back side of the printed circuit board 11 is connected to the feeding point 18 by penetrating it, and an outer conductor 19b of the coaxial plug 19 is connected.
Are connected to a ground plane 20 formed in a cross shape on the back surface of the printed circuit board 11.

A line of about ¼ wavelength is formed downward from the feeding point 18 on the front side of the printed circuit board 11,
At the short point 21 at the end, the ground plane 20
And a short stub circuit 22 is formed.

By providing this short stub circuit 22, the impedance characteristic can be broadened and the induced lightning protection for the radio device (not shown) connected via the coaxial plug 19 can be achieved.

That is, in the dipole antenna having the above structure, the dipole elements 12a and 12b on the left side of the front side of the substrate and the dipole elements 15a and 15 on the right side of the front side of the substrate which are symmetrical with respect to the dipole elements 12a and 12b on the left side of the front side are fed by feeding through the coaxial plug 19.
b is to operate as a two-stack dipole antenna, and the 1/4 short stub circuit 22 prevents unnecessary leakage current.

In this case, the dipole elements 12a, 12a
2b, 115a, 15b, the macro strip lines 13, 16 and the phase inversion circuits 14, 17 as well as the short stub circuit 22 and the ground plane 20 are all formed by a substrate copper foil or the like through a pattern etching process on the printed circuit board 11. Therefore, it is possible to easily perform fine pattern processing, and even with a very small structure for high frequencies,
It can be easily manufactured. Further, since a coaxial plug 19 is provided at the feeding point 18 for feeding power, connection with a coaxial line (not shown) can be easily performed. 2A and 2B show the structure of a dipole antenna provided with a reflector. FIG. 2A is a front view thereof and FIG. 2B is a side view thereof. In FIG. 2, the same components as those of the dipole antenna in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted.

That is, on the back surface of the printed circuit board 11,
A reflector 24 having substantially the same size and shape as the printed circuit board 11 has spacers 23a to 23d each having a length of about 0.15 wavelength.
Are arranged in parallel facing each other via
A sharper directional characteristic can be obtained. 3A and 3B show the electrical characteristics of a dipole antenna provided with the above-mentioned reflector. FIG. 3A is a standing wave ratio characteristic diagram thereof, and FIG. 3B is a directional characteristic diagram thereof. That is, by providing the reflection plate 24, a two-stack dipole antenna having a wide band and a simple directivity is constructed.

Therefore, according to the dipole antenna having the above-described structure, the printed circuit board 11 is used, and the microstrip lines 1 are provided on the front surface of the printed circuit board 11 from the central feeding point 18.
Two stacked dipole elements 12a, 12b, 1 which are fed via 3, 16 and phase inversion circuits 14, 17
5a and 15b are formed, and a ground surface 20 is formed on the back surface of the printed circuit board 11, the center conductor 19a of the coaxial plug 19 is connected to the feeding point 18, and the outer conductor 19b is connected to the ground surface 20. Further, by forming the short stub 22 by the line connecting the feeding point 18 and the short pin 21 of the ground plane 20, it is possible to easily obtain a fine feeding pattern or antenna pattern, for example, a quasi-microwave band or the like. As a dipole antenna with an extremely small structure for use in a high frequency band with a short wavelength, no special support structure or feeding structure is required, and in particular, stacking or reflecting plate for obtaining desired directivity and high gain is required. The combination can be economically constructed with a simple structure.

[0023]

As described above, according to the present invention, a dipole element pattern formed on the front surface of a printed circuit board,
The microstrip pattern formed between the dipole element pattern and the board feeding point, the ground pattern formed on the back surface of the printed circuit board, and the center conductor provided on the back surface of the printed circuit board, the central conductor being the front surface of the board. A coaxial plug which is connected to the upper feeding point and whose outer conductor is connected to the ground pattern on the back side of the board, and an end formed by extending from the feeding point on the front side of the printed circuit board whose ground surface is on the back side of the board. Since it is configured with a short stub circuit pattern that is connected to the target, even if it is used in a high frequency band with a shorter wavelength such as a quasi-microwave band, the desired directivity can be obtained without requiring a complicated power feeding and support structure. It is possible to provide an antenna device that can be easily stacked or combined with a reflector according to the characteristics and gain.

[Brief description of drawings]

FIG. 1 is a front view, a side view, and a rear view showing a configuration of a dipole antenna according to an embodiment of an antenna device of the present invention.

2A and 2B are a front view and a side view showing a configuration of a dipole antenna including a reflector.

3A and 3B are a standing wave ratio characteristic diagram and a directional characteristic diagram showing electric characteristics of a dipole antenna including the reflector.

FIG. 4 is a diagram showing a configuration of a conventional dipole antenna.

[Explanation of symbols]

11 ... Printed circuit boards, 12a, 12b, 15a, 15b
... Dipole element, 13, 16 ... Microstrip line, 14, 17 ... Phase inversion circuit, 18 ... Feed point, 19
... coaxial connector, 19a ... central conductor, 19b ... outer conductor, 2
0 ... Ground plane, 21 ... Short point, 22 ... Short stub circuit, 23 ... Spacer, 24 ... Reflector.

Claims (1)

(57) [Claims] 1. A die formed on the front surface of a printed circuit board.
Pole element pattern and this dipole element patternOne element patternAnd base
Microstrip pattern formed between plate feed point
AndThe dipole element of this microstrip pattern
The connection point of one element of the pattern with the above-mentioned dipo
Is formed between the element pattern and the other element pattern.
Phase inversion circuit pattern  Earth pattern formed on the back surface of the printed circuit board
And the center conductor is on the back side of the printed circuit board.
At the feeding point on the front of the boardPenetrationConnected with its outer conductor on
Coaxial plug connected to the ground pattern on the back of the board
And from the feeding point on the front of the printed circuit boardOn the front of the board
The extension is formed and its end is grounded on the back side of the board.putter
TheToPenetrationAn antenna device comprising: a short stub circuit pattern to be connected.