JPH04282903A - Array antenna system - Google Patents

Abstract

PURPOSE:To realize an antenna capable of miniaturizing having a characteristic usable for multi-frequencies by providing plural element antennas used for a single frequency band and a feeder whose conductor is formed thinner than the wavelength operated independently to the surface of the dielectric layer. CONSTITUTION:Plural element antennas 13, a parallel 2-wire line 15, and a microstrip line 16 are provided to the surface of dielectric boards 14a, 14b respectively and plural antenna parts 11, 12 whose operating frequency differs are stacked. Then the feeders 15, 16 of the antenna part 11 are used for a high frequency band and the feeders 15, 16 of the antenna part 12 are used for a low frequency band. The antenna part 11 interrupts part of a radiation wave from the antenna part 12 and the degree of interruption is reduced by employing the lines 15, 16 thinner than the wavelength for the conductor of the feeders. Since the antenna for multi-frequency use is simply and freely designed, the antenna is easily made small.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication array antenna device that is integrated with a feed line and can be used for multiple frequencies and polarizations.

0002

2. Description of the Related Art FIG. 16 shows, for example, J. R. James,
P. S. “Handbook of
Microstrip Antennas vol.
．． 2”, Peter Peregrinus Lt.
d, London, pp1282, fig. 23.26
．． FIG. 2 is a diagram of a dual frequency shared array antenna shown in FIG. In the figure, 1 is an element antenna radiation conductor, 2 is a feed line, 3 is a dielectric substrate as a dielectric layer, and 4 is a ground conductor.

[0003] In this antenna, two element antennas are used.
Using various types of microstrip antennas, one conductor plate provided under the element antenna radiation conductor 1 is shared as the ground conductor 4 of the microstrip antenna and the microstrip line, thereby obtaining two-frequency common characteristics.

FIGS. 14 and 15 are, for example, published by the Institute of Electronics and Communication Engineers, Proceedings of the 1985 National Conference of the Optical and Radio Division of the Institute of Electronics and Communication Engineers, 67 "Shared Aperture X, Ku Band Printed Slot Array Antenna", Presenter: Tadashi Numazaki FIG. 3 is a plan view and a cross-sectional view of a dual-frequency dual-polarization array antenna shown in FIG. In each figure, 5 is a slot antenna for a high frequency band, 6 is a slot antenna for a low frequency band, 7 is a through hole, 8 is a triplate line, 9 is a high frequency band feeding connector, and 10 is a low frequency band feeding connector.

[0005] In this antenna, slot antennas 5 and 6 that use different frequencies are arranged so that their respective polarizations are orthogonal, and eight layers of triplate lines are provided at the bottom of the antenna opening for each frequency. By making connections using through holes 7, an array antenna that emits orthogonally polarized waves at two frequencies is obtained.

[0006]

[Problems to be Solved by the Invention] In conventional multi-frequency and dual-polarization array antennas, for example, when all the feed lines are provided below the element antenna, the number of feed line layers increases, and furthermore, the number of layers of the feed lines increases. There were problems in that through-holes and the like were required for connection, making the configuration of the feeder circuit complicated, and that each antenna section could not be designed independently.

[0007] Furthermore, if some of the components of the feed line or element antenna, such as the ground conductor, are shared by each, the parameters of each antenna or feed line, such as the thickness of the dielectric substrate, cannot be selected independently. First, there was a problem in that the degree of freedom in design was reduced.

[0008] In addition, since the conventional multi-frequency and dual-polarization array antenna has a planar conductor ground plate at the antenna aperture with the same area as the aperture, the radiation directivity of the array antenna can be changed by bending the ground plate. There was a problem that the gain could not be changed.

[0009] Furthermore, when the radiation conductor of the element antenna and the feed line are provided in the same plane, the area of the antenna increases due to the area occupied by the feed line. There is a problem in that radiation occurs, and if the feed line becomes long, the loss can no longer be ignored.

[0010] This invention was made to solve the above-mentioned problems, and can be designed independently for each frequency and polarization, and can be used for multiple frequencies and polarizations, and can achieve the desired wide-angle directivity. It is an object of the present invention to obtain an array antenna device that has all or some of the characteristics of obtaining gain, reducing unnecessary radiation from a feed line, reducing the occupied area, and reducing loss of the feed line.

[0011]

[Means for Solving the Problems] In order to solve the above problems, the array antenna device according to the present invention has a first aspect of the present invention, in which a dielectric layer (
A plurality of element antennas (printed dipoles 13
), and feeder lines (two parallel lines 15, microstrip line 16, converter 17) whose conductor parts are thinner than the wavelength and can operate independently by themselves are simultaneously installed, and these independent layers ( In addition, in the second invention, by stacking a plurality of antenna parts 11, 12), when obtaining polarized wave characteristics, one layer of element antennas (
By keeping the polarization direction of the printed dipole 13) constant and arranging the polarizations of different layers in different directions, in the third invention, in order to obtain the desired wide-angle directivity and gain, Element antenna (printed dipole 1
3) and a dielectric layer (dielectric substrate 14a,
Desired characteristics can be obtained by providing a conductor reflector 22 or a frequency selective reflector 23 of an appropriate shape below the 14b).

0012

[Operation] In this invention, the element antenna (printed dipole 13) and its feed line (two parallel lines 15, microstrip line 16) at each frequency and each polarization are provided.
, converter 17) can operate independently on their own, design is easy.Furthermore, the conductor part is thinner than the wavelength of the feed line (two parallel lines 15, microstrip 16, converter 17). ), the influence on radiation directivity due to interference between each element antenna (printed dipole 13) and feed line (two parallel lines 15, microstrip line 16, converter 17) can be reduced. moreover,
Since it is not necessary to provide a planar conductive ground plate (ground conductor 4) of the same size as the opening at the antenna opening, a conductive reflector 22 or a frequency selective reflector 23 of an arbitrary shape is provided at the bottom of the antenna.
can be provided, and the wide-angle radiation directivity and gain of the antenna can be made as desired.

[0013]

[Example] Example 1. An embodiment corresponding to claim 1 of the present invention will be described below with reference to the drawings. Figure 1, Figure 2, Figure 3,
FIG. 4 is a configuration diagram when obtaining a printed dipole array antenna for two frequency bands in the present invention. Hereinafter, the two frequency bands will be referred to as a high frequency band and a low frequency band. FIG. 1 is a cross-sectional view of this antenna. In FIG. 1, 11 is a high frequency band antenna section, 12 is a low frequency band antenna section, 13 is a printed dipole as an element antenna, and 14a and 14b are dielectric layers. The dielectric substrate 15 is two parallel lines whose conductor portion is thinner than the wavelength, and this is a dielectric substrate 15H as shown in FIG.
Parallel conductors 15I, 15I are provided on both sides of the. 16
This is a microstrip line in which the conductor portion is thinner than the wavelength, and as shown in FIG. 3, the conductor 16I is provided on the surface of a single insulating substrate 16H. FIG. 4 is a top view of the high frequency band antenna section 11 and the low frequency band antenna section 12. In FIG. 4, 17 is a microstrip line parallel two-line converter in which the conductor portion is thinner than the wavelength. That is, two dielectric substrates 14a and 14b are sequentially arranged in two layers in the direction of radio wave input and output (direction of arrow a), and printed dipoles 13 facing each other are placed on the front and back surfaces of each dielectric substrate 14a and 14b. 2 parallel to each dipole 13.
A line 15, a converter 17, and a microstrip line 16 are connected to form high-frequency and low-frequency antenna sections 11 and 12. In this case, the high frequency band antenna section 11
is the dipole 13 rather than the low frequency band antenna section 12.
The area is small so that it is suitable for high frequency bands. The two parallel lines 15, the microstrip line 16, and the converter 17 constitute a feed line.

Next, the operation will be explained. When transmitting and receiving electromagnetic waves in a high frequency band, use the antenna section 11,
A feeder line on the layer of the antenna section 11 is used. When transmitting and receiving electromagnetic waves in a low frequency band, the antenna section 12 is used, and a feed line on the layer of the antenna section 12 is used. The antenna section 11 blocks a part of the radiation waves from the antenna section 12, but by using a microstrip line 16 and two parallel lines 15, each of which has a conductor section thinner than the wavelength, as a feed line, this can be avoided in practice. has been reduced. Further, with such a configuration, each part of the antenna sections 11 and 12 can be designed independently, so there is an advantage that the design becomes very simple. Further, in this embodiment, a two-frequency common array antenna is used, but if the antenna needs to be operated at even more frequencies, the number of layers in the antenna section can be increased by the number of required frequencies. Even in that case, the advantage remains that each antenna section can be designed independently for each layer. Similar characteristics can also be obtained by bending each layer of the antenna into a curved shape.

Next, FIGS. 5 and 6 show an embodiment of a two-frequency common array antenna in which a microstrip antenna is used as the element antenna. FIG. 5 is a cross-sectional view of this antenna, where 18 is a microstrip antenna radiation conductor and 19 is a microstrip antenna ground conductor. FIG. 6 is a top view of each layer of this antenna. The operation is the same as that of the printed dipole array antenna shown in FIGS. 1, 2, 3, and 4, so a description thereof will be omitted.

With the above configuration, a dual frequency band common array antenna corresponding to claim 1 can be obtained.

Example 2. Next, an embodiment of a polarized wave array antenna corresponding to claim 2 will be described. FIG. 7 is a configuration diagram of a dual polarization array antenna when a printed dipole antenna similar to that in FIG. 4 is used as an element antenna. In FIG. This is the antenna section for use. antenna part 2
0 and 21 are arranged so that their polarization directions are orthogonal to each other.

Next, the operation will be explained. If you want to obtain horizontally polarized waves, feed the power to the feed line in the layer of the antenna section 20,
If it is desired to obtain vertically polarized waves, power is fed to the feed line in the layer of the antenna section 21. With such a configuration, for example, when it is desired to obtain a polarized wave array antenna at the same frequency, the same element antenna can be used as is by simply changing the arrangement between layers, thereby simplifying the design. Of course, different types of element antennas may be used for each layer. Furthermore, if it is desired to obtain two polarized waves with different frequencies, element antennas having desired frequency characteristics may be used in each layer. Furthermore, as described in the first embodiment, since each antenna layer can be designed independently, it is also possible to easily obtain a polarization shared antenna at multiple frequencies. In that case, it is only necessary to design antenna layers for the desired number of polarizations in the desired frequency band and stack them on top of each other.

With the above configuration, a dual polarization array antenna corresponding to claim 2 can be obtained.

Example 3. Here, an embodiment of the present invention corresponding to claim 3 will be described. FIG. 8 shows a plurality of antenna sections 1
This is an example of a dual frequency band shared array antenna in which a conductor reflection plate 22 is provided under layers 1 and 12 to improve wide-angle directivity. In FIG. 8, 11 is a high frequency antenna section using the printed dipole array antenna of FIG.
2 is a low frequency antenna section using the printed dipole array antenna shown in Fig. 1, and 22 is a conductive reflector.The configuration is such that the reflector is loaded at the bottom of the dual frequency band common array antenna shown in Figs. 1 and 4. It's in shape.

Next, the operation will be explained. The distance from the antenna parts 11 and 12 to the conductor reflection plate 22 is appropriately selected, and the direct waves from the antenna parts 11 and 12 and the conductor reflection plate 22 are
By adjusting the interference intensity of the reflected waves and diffracted waves from the beam, the desired wide-angle directivity is obtained in each frequency band. Furthermore, in this embodiment, it is possible to improve not only the wide-angle directivity but also the gain in the front direction of the antenna. Since this example uses a printed dipole antenna as the element antenna, by selecting the distance from the antenna parts 11 and 12 to the reflector 22 to about 1/4 wavelength in each frequency band, the printed dipole antenna with a reflector can be used. It can be operated as a dipole array antenna and the gain is improved. Furthermore, since the reflecting plate 22 can be shared, the structure becomes simpler. In addition, the reflector 22 is arranged in order from the dipole antenna layer with the highest frequency used.
By stacking them on top of each other, it is possible to easily obtain a dipole array antenna with a reflector that can be used in multiple frequency bands.

Next, FIG. 9 shows an embodiment of a printed dipole array antenna for two frequency bands in which a frequency selective reflector 23 is provided under the antenna layer. In FIG. 9, 23 is a frequency selective reflector that transmits one of the two used frequency bands and reflects the other, and the overall configuration is shown in FIG.
In this example, the conductive reflector plate 22 is replaced with a frequency selective reflector plate 23.

The operation will be explained next. The frequency selective reflector 23 does not contribute to the antenna radiation directivity characteristics in the transmission frequency band, but contributes to the antenna radiation directivity characteristics in the same way as the conductor reflector 22 in the reflection frequency band (hereinafter referred to as frequency The transmission frequency band and reflection frequency band of the selective reflection plate 23 are simply referred to as a transmission frequency band and a reflection frequency band, respectively). Using this property, in the antenna shown in Figure 9, the array antenna layer in the transmission frequency band radiates radio waves in front of and behind the array antenna aperture, and the array antenna layer in the reflection frequency band has a strong radiation direction in front of the antenna aperture. The characteristic of having gender is realized. In this case, the radiation directivity characteristics of the array antenna in the reflection frequency band can be set to desired wide-angle directivity and gain, similar to the case where the conductor reflector plate 22 is used as a reflector plate. Furthermore, even if the number of antenna layers is increased, reflection and transmission characteristics can be obtained in each frequency band by appropriately designing the characteristics of the frequency selective reflector 23, so this characteristic can also be applied to a multi-frequency common array antenna. is easily extended.

Next, FIG. 10 shows an embodiment of a printed array antenna for dual frequency bands in which a frequency selective reflector 23 and a conductor reflector 22 are provided at the same time under the antenna layer. FIG. 10 shows the frequency selective reflector 2 in the embodiment of FIG.
A conductive reflector plate 22 is further loaded at the bottom of 3. Further, 22 is bent into a wedge shape.

The operation of FIG. 10 will be explained. Similar to the embodiment shown in FIG. 9, the frequency selective reflector 23 does not contribute to the antenna radiation directivity characteristics in the transmission frequency band, and contributes to the antenna radiation directivity characteristics in the same way as the conductor reflector 22 in the reflection frequency band. make a significant contribution. In addition, the conductor reflection plate 22
acts as a reflector only for incident electromagnetic waves in the transmission frequency band of the frequency selective reflector 23. Such a configuration is
This is equivalent to having a conductive reflector 22 independently for each frequency band of transmission and reflection, and the degree of freedom in designing the radiation directivity characteristics of the antenna layer for each frequency band increases. In the embodiment of FIG. 10, the frequency selective reflector 23 increases the antenna aperture front gain in the reflected frequency band. In addition, the conductor reflector 22 bent into a wedge shape is used as a reflector for the antenna in the transmission frequency band, and the direct waves from the antenna in the transmission frequency band to the observation point, the reflection plate from the conductor reflection plate 22, and the diffraction By appropriately interfering with waves, it has a wide-angle characteristic with little gain reduction. In this case, since the conductor reflector 22 is shaped like a bent plane, the intensity of the reflected waves and diffracted waves from the conductor reflector 22 can be adjusted to the desired intensity by appropriately selecting the opening angle. This increases the degree of freedom in designing the antenna radiation directivity characteristics compared to when a flat plate is used. Of course, the frequency selective reflector 23 may be used as the bendable reflector. As described above, if the frequency selective reflector 23 and the conductor reflector 22 are provided at the same time as in this embodiment, or if a reflector with a bent plane shape is used, the conductor reflector 22 of FIG. 8 alone can be used. It is also possible to realize a delicate design of antenna radiation directivity at each frequency, which is difficult to realize due to the limited degree of design freedom. Further, when the number of antenna layers is increased and the antenna is used in many frequency bands, it is also possible to use a method such as increasing the number of frequency selective reflectors 23 to a plurality.

As described above, FIGS. 8, 9, and 10 show an embodiment corresponding to claim 3 of the printed dipole array antenna device for dual frequency bands loaded with a reflector, but this array antenna device has the following features: For example, it is applicable to other element antennas such as the microstrip antenna shown in FIGS. 5 and 6, and also to the dual polarization antenna shown in FIG.

Example 4. FIG. 11 shows a film substrate 24 as an antenna layer in the array antenna device of Example 3.
This is an array antenna device in which a portion of the feed line, whose conductor portion is thinner than the wavelength, is folded into the lower part of the reflector plate 22 using a bendable material such as . In FIG. 11, 24 is a film substrate, 25 is a foam for fixing the antenna layer, and 26 is a film substrate.
is a power supply port, and a part of the power supply line on the film substrate 24 is folded into the lower part of the reflection plate 22. FIG. 12 shows an array antenna device in which a part of the film substrate 24 of the antenna parts 11 and 12 is lowered in the direction of the conductor reflection plate 22, brought into close contact with the conductor reflection plate 22, and that part is made into a triplate line 27. 13 is provided with a frequency selective reflector 23 and a conductor reflector 22 under the antenna parts 11 and 12;
A film substrate 24 including a part of the feed line is connected to a conductive reflector 2
This is an array antenna device that is placed in close contact with the upper and lower parts of 2.

Next, the operation will be explained. As shown in FIG. 11, by using a bendable material such as a film substrate 24 as the antenna layer and folding a part of the feed line, whose conductor is thinner than the wavelength, into the lower part of the reflector 22, an array antenna device can be constructed. The installation area is extremely small. In addition, when this structure is used, since the power supply ports 26 are concentrated at the bottom of the reflector plate 22, it is possible to install a transmitter/receiver in this part, or connect a separate power supply line to a transmitter/receiver installed in another location. This has the advantage of making it easier to extend the process. Further, if the film substrate 24 is used as the dielectric material of the antenna layer and a foam material is used as the fixing foam 25 of the antenna layer, there is an advantage that the antenna device can be made lighter and less expensive. Furthermore, the structure of FIG. 9 is applicable to all types of antenna devices described in the first, second, and third embodiments.

Next, the operation of the antenna shown in FIGS. 12 and 13 will be explained. In the array antenna device shown in FIG. 12, a part of the film substrate 24 is lowered toward the conductor reflection plate 22, the film substrate 24 is brought into close contact with the conductor reflection plate 22, and that part is made into the triplate line 27, thereby creating a triplate line. They share 27 ground conductors and reflectors. By using such a structure, the length of the feed line can be kept to the minimum necessary, and since the triplate line 27 is used, there is less unnecessary radiation, so the loss of the feed line can be reduced. , the installation space for the power supply line can be almost eliminated. Furthermore, since the feed line is brought into close contact with the conductive reflector plate 22, blocking of the antenna by the feed line, which may occur if the feed line is suspended in the air, is reduced. Furthermore, the conductor reflection plate 2
The tri-plate feed line 27 portion that is in close contact with 2 becomes a conductive reflector, and the electrical shape of the entire antenna device becomes close to the ideal shape of just an array antenna loaded with a reflector, minimizing design errors. It also has the effect of being held down. FIG. 13 shows an example in which the area of the feeder line portion that is brought into close contact with the conductor reflection plate 22 is larger than that in FIG. 12. If such a shape is used, effects similar to those shown in FIG. 12 can be obtained.

[0030]

As explained above, according to the array antenna device of the present invention, when obtaining multi-frequency sharing characteristics, the surface of the dielectric layer (dielectric substrates 14a, 14b) can be used in a single frequency band. At the same time, multiple element antennas (printed dipoles 13) and feed lines (two parallel lines 15, microstrip lines 16, converter 17) whose conductor portions are thinner than the wavelength and operate independently on their own are installed and used. By stacking multiple independent layers (antenna parts 11, 12) with different frequency bands, or when obtaining polarization sharing characteristics, the polarization direction of the element antenna (printed dipole 13) of one layer can be stacked. In order to obtain the desired wide-angle directivity and gain, the element antenna (printed dipole 13) and the feed line (parallel 2 At the bottom of the dielectric layer (dielectric substrates 14a, 14b) provided with the line 15, microstrip line 16), a conductive reflector 22 or a frequency selective reflector 23 of an appropriate shape is placed.
By providing the desired characteristics, the desired characteristics can be obtained. This suppresses the increase in the number of layers in the power supply line, eliminates the need for through holes, and simplifies the configuration of the power supply circuit. In addition, the parameters of each antenna and feed line can be selected independently, increasing the degree of freedom in design. Therefore, each frequency and polarization can be easily designed independently, multiple frequencies and polarizations can be shared, the desired wide-angle directivity and gain are achieved, there is little unnecessary radiation from the feed line, and the area occupied is small. It is possible to obtain an array antenna device that shares all or part of the characteristics of , low loss in the feed line.

[Brief explanation of the drawing]

FIG. 1 is an embodiment of the array antenna device of the present invention, in which two
FIG. 2 is a cross-sectional view of a frequency sharing printed dipole array antenna device.

FIG. 2 is a sectional view of two parallel lines of the printed array antenna.

FIG. 3 is a sectional view of a microstrip line of the printed array antenna.

FIG. 4 is a top view of each antenna layer of the printed array antenna.

FIG. 5 is an embodiment of the array antenna device of the present invention, in which two
FIG. 2 is a cross-sectional view of a frequency band shared microstrip array antenna device.

FIG. 6 is a top view of each antenna layer of the microstrip array antenna.

FIG. 7 is an embodiment of the array antenna device of the present invention, in which two
FIG. 2 is a diagram of a dual polarization array antenna.

FIG. 8 is an embodiment of the array antenna device of the present invention, which is a diagram of a dual frequency band common array antenna device loaded with a conductive reflector.

FIG. 9 is a diagram of an array antenna device for dual frequency bands, which is an embodiment of the array antenna device of the present invention, and is loaded with a frequency selective reflector.

FIG. 10 is an embodiment of the array antenna device of the present invention,
FIG. 2 is a diagram of a dual frequency band common array antenna device loaded with a conductor reflector and a frequency selective reflector.

FIG. 11 is an embodiment of the array antenna device of the present invention,
FIG. 3 is a diagram of an array antenna device in which a part of the feed line is bent under a reflector.

FIG. 12 is an embodiment of the array antenna device of the present invention,
FIG. 2 is a diagram of an array antenna device in which a part of the feed line is lowered toward the reflector, the reflector is brought into close contact with the feed line, and the part is made into a triplate line.

FIG. 13 is an embodiment of the array antenna device of the present invention,
FIG. 3 is a diagram of an array antenna device in which a part of the feed line is lowered toward the reflector and brought into close contact with the upper and lower parts of the reflector.

FIG. 14 shows a conventional technology corresponding to the present invention in two frequency bands;
FIG. 2 is a top view of a dual polarization array antenna.

FIG. 15: Conventional technology corresponding to the present invention, two frequency bands,
FIG. 2 is a cross-sectional view of a dual polarization array antenna.

FIG. 16 is a diagram showing a dual frequency band common array antenna according to the prior art corresponding to the present invention.

[Explanation of symbols]

1 Element antenna radiation conductor 2 Feed line 3, 14a, 14b Dielectric substrate 4 Ground conductor 5 Slot antenna for high frequency band 6 Slot antenna for low frequency band 7 Through hole 8, 27 Tri-plate line 9 Feed connector for high frequency band 10 Low Frequency band feed connector 11 High frequency band antenna section 12 Low frequency band antenna section 13 Printed dipole 15 Parallel two lines 16 Microstrip line 17 Microstrip line parallel two line converter 18
Microstrip antenna radiation conductor 19 Microstrip antenna ground conductor 20 Horizontal polarization antenna section 21 Vertical polarization antenna section 22 Conductor reflector 23 Frequency selective reflector 24 Film substrate 25 Form 26 Feeding port

Claims (3)

[Claims] Claim 1. An array antenna device consisting of a plurality of element antennas and a feed line provided on the surface of a plurality of flat or curved dielectric layers, in which a single frequency band is used on the surface of each dielectric layer. Multi-frequency common characteristics are obtained by simultaneously installing multiple element antennas and feeding lines whose conductors are thinner than the wavelength and can operate independently on their own, and by stacking multiple independent layers with different operating frequency bands. An array antenna device characterized by: [Claim 2] An element antenna is provided on the front and back sides of the dielectric layer, and both element antennas are used in the same frequency band and are formed with orthogonal polarization directions, so that the antenna element can be used in one or more frequency bands. 2. The array antenna device according to claim 1, wherein said array antenna device obtains characteristics of polarization sharing. 3. A conductor reflector, a frequency selective reflector, or the frequency selective reflector and the conductor reflector are provided at the same time under the plurality of dielectric layers. 2 array antenna device.