JPH05283928A - Micro strip antenna - Google Patents

Abstract

PURPOSE:To suppress an excess radiation at the back of an antenna by providing a 2nd earth conductor near a radiation conductor and electrically connecting the earth conductor and the 2nd earth conductor. CONSTITUTION:A radiation conductor 1 is formed at the central surface of a 1st dielectric layer 2 consisting of dielectric substrates. At the back peripheral section of the layer 2, a 2nd earth conductor 2 is formed. An earth conductor 3 is formed through a 2nd dielectric layer 10 consisting of air layers at the back of the layer 2 opposite to the conductor 1, and the conductor 3 is integrally formed with a connection section 7 at the peripheral section. The connection section 7 consists of a flange section having the conductor 3 at the back side of the layer 2 and electrically connected to the conductor 6 formed at the back of the layer 2 and step sections connecting the flange section 7 and the conductor 3 and forming the 2nd dielectric layer 10 consisting of the air layer between the back of the layer 2 and conductor 3 while mounting the conductor 3 on the back of the layer 2. Thus, the conductor 6 can be located closer to the conductor 1 than to the conductor 3, and the excess backward radiation can be suppressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microstrip antenna used for mobile satellite communication or the like.

[0002]

2. Description of the Related Art In recent years, mobile communication and satellite communication have been actively performed with the development of information society, and a navigation system such as GPS for receiving the radio wave of an artificial satellite to detect the position and speed of the mobile is put into practical use. Has been converted. In GPS, radio waves of frequencies in the L band are used, and microstrip antennas, helical antennas, etc. have been put to practical use as receiving antennas.

FIG. 7 shows a conventional example of a microstrip antenna. In the figure, reference numeral 2 is a dielectric substrate, and the radiation conductor 1 is formed on the dielectric substrate 2 by etching or the like. Reference numeral 5 is a degenerate separation element, 4 is a feeding point, and a ground conductor (not shown) is provided on the back surface of the dielectric substrate 2.
To form a microstrip antenna.

In the microstrip antenna shown in FIG. 7, the current fed from the feeding point 4 is degenerate separation element 5.
Perturbed by and 90 ° out of phase with each other 2
One resonance mode is formed on the radiation conductor 1 to operate as a circularly polarized microstrip antenna.

[0005]

There is a strong demand for miniaturization of antennas used for mobile communication and the like, and therefore the size of the ground conductor is also required to be small. In addition, the dielectric substrate thickness may be increased or a multi-layered structure may be used to suppress the variation of the resonance frequency due to the widening of the band and the variation of the characteristics of the substrate. In this case, the distance between the radiation conductor and the ground conductor becomes large.

When the dimension of the grounding conductor is small and the distance between the radiation conductor and the grounding conductor is relatively large, the grounding conductor resonates at the used frequency, and does not operate completely as a grounding conductor with respect to the radiationing conductor. There is a problem in that it operates, and unnecessary backward radiation increases.

[0007]

In order to solve the above problems, the present invention provides a microstrip antenna in which a radiation conductor and a ground conductor are formed on both sides of a dielectric layer made of a single or a plurality of dielectrics, respectively. A second ground conductor is provided closer to the radiation conductor than the ground conductor, and the ground conductor and the second ground conductor are electrically connected.

[0008]

In the microstrip antenna in which the radiation conductor and the ground conductor are formed via the dielectric substrate, when the dimensions of the ground conductor are the same, unnecessary rearward radiation increases when the distance between the ground conductor and the radiation conductor increases. Become. Since the present invention has a configuration in which the second ground conductor electrically connected to the ground conductor is provided closer to the radiation conductor than the ground conductor, the distance between the ground conductor and the radiation conductor can be apparently reduced. The ground conductor does not act as a director depending on the used frequency, and unnecessary backward radiation can be suppressed.

[0009]

1 is a perspective view of a first embodiment of the present invention, and FIG. 2 is a sectional view of FIG. 1 and 2,
Reference numeral 1 is a radiation conductor formed by a printed wiring technique or the like at the center of the surface of a first dielectric layer 2 made of a dielectric substrate such as glass epoxy resin, and 6 is a backside peripheral green of the first dielectric layer 2. It is a second ground conductor formed in the portion by using a printed wiring technique or the like. The second ground conductor 6 is formed on the back surface of the first dielectric layer 2 in the peripheral green portion at a position facing the radiation conductor 1.

Reference numeral 3 is a second dielectric layer 1 formed of an air layer on the back side of the first dielectric layer 2 facing the radiation conductor 1.
The ground conductor 3 is formed through 0, and the ground conductor 3 is integrally formed with the connecting portion 7 in the peripheral green portion. The connecting portion 7 attaches the ground conductor 3 to the back surface side of the first dielectric layer 2 and electrically connects to the second ground conductor 6 formed on the back surface side of the first dielectric layer 2. Of the first dielectric layer 2 in a state in which the flange part for effecting the connection is connected to the ground conductor 3 and the ground conductor 3 is attached to the back surface of the first dielectric layer 2. A second dielectric layer 10 composed of an air layer between the back surface and the ground conductor 3
And a step portion for forming.

Reference numeral 9 indicates that the ground conductor 3 is attached to the back surface of the first dielectric layer 2 and the second ground conductor 6 formed on the back surface of the first dielectric layer 2 is grounded via the connecting portion 7. Mounting screws for electrically connecting to the first dielectric layer 2 are provided at appropriate positions such as four corners of the first dielectric layer 2.

Reference numeral 8 is a connector provided on the back surface of the ground conductor 3, and the center conductor 11 of the connector 8 penetrates the second and first dielectric layers 10 and 2 to form the radiation conductor 1.
It is connected to the feeding point 4 provided in. Reference numeral 5 is a degenerate separation element.

With the above structure, the second ground conductor 6 can be installed closer to the radiation conductor 1 than the ground conductor 3, and unnecessary rear portions can be provided as in the case where the radiation conductor and the ground conductor are provided close to each other. Can be suppressed.

FIG. 3 is a sectional view of the second embodiment of the present invention. The parts corresponding to the first embodiment shown in FIGS. 1 and 2 are designated by the same reference numerals and the description thereof will be omitted. In FIG. 3, the difference from the first embodiment shown in FIG. 2 is that the flange portion forming the connecting portion 7 is directly pressed onto the back surface of the first dielectric layer 2,
The second grounding conductor 6 in the embodiment is omitted. In this case, the flange portion of the connecting portion 7 pressed against the back surface peripheral green portion of the first dielectric layer 2 is the second portion in the first embodiment.
Plays the role of the ground conductor 6.

FIG. 4 is a sectional view of the third embodiment of the present invention. The parts corresponding to the first embodiment shown in FIGS. 1 and 2 are designated by the same reference numerals and the description thereof will be omitted. In FIG. 4, reference numeral 61 denotes a surface peripheral green portion of the first dielectric layer 2, which is a second ground conductor formed at a position separated from the radiation conductor 1, and 71 denotes a peripheral green portion of the ground conductor 3, which is the ground. It is a connecting portion that is integrally formed at an angle with the conductor 3. The connection portion 71 forms a side surface portion of the main body of the microstrip antenna, and an upper end portion thereof is electrically connected to the peripheral green portion of the second ground conductor 61, and the back surface of the first dielectric layer 2 and the ground conductor 3 are connected. The second dielectric layer 10 composed of an air layer is formed between them.

FIGS. 5 and 6 show the second ground conductors 6 and 61 or the connecting portion 7 instead of the second ground conductors 6 and 61 in the respective embodiments of the present invention.
7 corresponds to the conventional example shown in FIG. 7, and parts corresponding to the configurations shown in FIGS. 1 to 4 are given the same reference numerals and explanations thereof will be omitted. In FIG. 5, 12 is a spacer for forming the second dielectric layer 10 composed of an air layer between the back surface of the first dielectric layer 2 and the ground conductor 3, and 72 in FIG. 6 is the ground conductor 3 and It is a conductor that is integrally formed at an angle and forms the side surface of the microstrip antenna body.

Now, a glass epoxy substrate having a thickness of 0.6 mm is used as the first dielectric layer 2, the second dielectric layer 10 is an air layer having a thickness of 3.5 mm, and the first dielectric layer 10 has a thickness of 3.5 mm. The received power level of the antenna was measured when a right-handed circularly polarized wave antenna having the dielectric layer 2 and the ground conductor 3 each having a size of 70 mm was formed.

In this case, the difference between the right-handed circularly polarized wave reception power in the front direction and the left-handed circularly polarized wave reception power in the rear direction is greater in the configuration shown in FIG. 6 than in the configuration shown in FIG. About 3
While the improvement in dB was observed, in each of the embodiments of the present invention in which the second grounding conductor 6, 61 as shown in FIGS. , Compared to the case of the configuration shown in FIG. 5, an improvement of about 10 dB has been made, and it has been experimentally confirmed that by providing the second ground conductor, unnecessary backward radiation is significantly suppressed. did it.

The directivity of the microstrip antenna can be controlled by appropriately selecting the shape and size of the second grounding conductors 6, 61 or the flange portion of the connecting portion 7 which substitutes for them.

In the perspective view of the first embodiment of the present invention shown in FIG. 1, the radiation conductor 1 is provided with a notch,
This is to reduce the size of the radiation conductor,
The shape of the radiation conductor 3 is not limited to this,
Any arbitrary shape such as a square or a circle can be similarly implemented. Further, although each embodiment is a circular polarization antenna, it can be similarly applied to a linear polarization antenna such as a horizontal polarization antenna or a vertical polarization antenna.

Further, in the first and second embodiments of the present invention shown in FIGS. 1, 2 and 3, the second ground conductor 6 or the flange portion of the connecting portion 7 instead of the second ground conductor 6 and the radiation conductor 1 are used. The positional relationships of No. do not overlap each other when seen through in a front view and a plan view, but these positional relationships may overlap each other. Further, although the mounting screw 9 is used for joining the ground conductor 3 and the second ground conductor 6, any connection method can be used as long as it is a method for electrically connecting the two.

Furthermore, in each of the embodiments of the present invention, the air layer is used as the second dielectric layer 10, but a dielectric substance having an arbitrary relative dielectric constant can be used, and a single layer or It may have a multilayer structure of two or more layers. Further, the power feeding method may be another power feeding method such as electromagnetic coupling power feeding.

[0023]

Since the present invention has the above-mentioned structure, unnecessary rearward radiation can be effectively suppressed by a simple structure in which the second grounding conductor is provided in the peripheral portion in the vicinity of the radiation conductor.

[Brief description of drawings]

FIG. 1 is a perspective view of a first embodiment of the present invention.

FIG. 2 is a sectional view of FIG.

FIG. 3 is a sectional view of a second embodiment of the present invention.

FIG. 4 is a sectional view of a third embodiment of the present invention.

FIG. 5 is an explanatory diagram of the present invention.

FIG. 6 is an explanatory diagram of the present invention.

FIG. 7 is a configuration diagram of a conventional example.

[Explanation of symbols]

 1 Radiation conductor 2 1st dielectric layer 3 Ground conductor 6,61 2nd ground conductor 7 Connection part 10 2nd dielectric layer

Claims (1)

[Claims] 1. A microstrip antenna in which a radiating conductor and a grounding conductor are formed on both sides of a single dielectric layer or a plurality of dielectric layers, and a microstrip antenna is located closer to the radiating conductor than the grounding conductor. A microstrip antenna, wherein a second ground conductor is provided, and the ground conductor and the second ground conductor are electrically connected.