JP2004260667A - Patch array antenna and excitation method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a blind patch array antenna and its excitation method at IMT-2000 services in mobile communications with reduced amount of coupling between antennas, where two of patch array antennas are arranged separately by combining them at their back sides. <P>SOLUTION: The patch array antenna comprises patch array antennas having a choke structure 10 formed in a state of encompassing the surrounding peripheral region of a passive element substrate 30 on which a patch antenna element 4 is formed, and a patch antenna element substrate 40; two of the patch array antennas are arranged separately by combining them at their back sides; and the patch array antenna comprises an antenna power supply circuit for setting and exciting a voltage level which excites each patch antenna element. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
[Industrial applications]
The present invention relates to a patch array antenna and a method of exciting the patch array antenna, and more particularly, to a patch array antenna in which two sets of patch array antennas are spaced apart from each other in a back-to-back manner, in which the amount of coupling between the antennas is reduced. The present invention relates to a terrestrial patch array antenna and its excitation method.
[0002]
[Prior art]
In a patch antenna, an array of patch antenna elements has been conventionally used to improve the gain in the main beam direction. However, when the patch antenna elements are arrayed, there is a problem that side lobes become large. When the side lobes become large, when two patch array antennas are spaced apart from each other, the amount of coupling between the array antennas becomes large, which leads to an effective reduction in radiated power.
[0003]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION The present invention provides a patch array antenna which solves the above-mentioned disadvantages and a method of exciting the patch array antenna.
[0004]
[Means for Solving the Problems]
Two patch array antennas each having a choke structure 50 are spaced apart from each other in the peripheral region of the surface on which the patch antenna element 4 is formed, and the excitation amplitude of each patch antenna element 4 is changed to reduce the FS ratio, thereby reducing mutual interference between the antennas. A patch array antenna excitation method to control the coupling was constructed.
An antenna power supply circuit for arranging two patch array antennas each having a choke structure 50 in the peripheral end region of the surface on which the patch antenna element 4 is formed, back to back, and setting and outputting the voltage level for exciting each patch antenna element 4 to each of them. A patch array antenna comprising:
[0005]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described with reference to the drawings.
1 and 2 show a set of 4 × 4 patch array antennas having a choke structure. 1A is a diagram viewed from the front side, which is the electromagnetic wave radiation surface side, FIG. 1B is a longitudinal sectional view of FIG. 1A, and FIG. 2C is FIG. 1A. FIG.
1 and 2, reference numeral 1 denotes a reference numeral indicating the entire antenna case. The antenna case includes a frame 11 made of a metal material, a peripheral side wall 12 formed in parallel with the frame 11 made of a metal material, a frame 11 made of a metal material, and a frame 11 made of a metal material parallel to the frame 11. It comprises a peripheral side wall 12 to be formed and covers 13 and 13 ′ for closing a front opening edge of the peripheral side wall 12. Reference numeral 40 denotes a patch antenna element substrate made of a dielectric material, which is attached and fixed to the front opening edge of the frame 11. The patch antenna elements 4 are formed in a matrix on the front surface of the patch antenna element substrate 40, and a total of 16 patch antenna elements 4 constitute a set of patch array antennas. Reference numeral 30 denotes a parasitic element substrate, which is fixed to the front surface of the radiating element substrate 40 at a distance via an element fixing member 7 made of a metal material. The parasitic element 3 is formed on the surface of the parasitic element substrate 30. Reference numeral 50 denotes a feeder circuit board, which is attached and fixed to the patch antenna element substrate 40 via the coaxial tube 6 at a distance. Power is supplied to the patch antenna element 4 through a feed circuit board 50 and a coaxial cable inserted into the coaxial tube 6.
[0006]
The choke structure 10 is formed by the frame 11 made of the metal material as described above and the peripheral side wall 12 formed of the same metal material and formed in parallel with the frame 11. That is, the choke structure 10 is formed so as to surround the peripheral end regions of the parasitic element substrate 30 and the patch antenna element substrate 40. When the patch antenna element 4 is fed through a feed circuit board 50 and a coaxial cable inserted into the coaxial tube 6 and emits an electromagnetic wave, the parasitic element substrate 30 and the patch antenna element substrate on which the patch antenna element 4 is formed Since the radiated electromagnetic wave is formed so as to surround the peripheral end region of the forty, the wraparound of the radiated electromagnetic wave is reduced by the choke structure 10.
[0007]
FIG. 3 is a diagram for explaining a case where all the patch antenna elements 4 of the set of patch array antennas shown in FIGS. 1 and 2 are excited with the same amplitude.
FIG. 3A shows a radiation pattern when each of the patch antenna elements 4 is excited with the same amplitude 1. The excitation frequency is 1.92 GHz. As for the size of the radiation pattern, the level of the center point is represented by -20 dB, and the outermost circumference circle is represented by 20 dB.
Referring to the radiation pattern of the E plane with reference to FIG. 3B, the front lobe direction is 0 °, and the half width is about 20 °. The side lobe suppression shows about 15 dB.
[0008]
Referring to the radiation pattern on the H plane with reference to FIG. 3C, the front lobe direction is 0 ° and the half width is about 23 °. The side lobe suppression shows about 16 dB.
FIG. 4 is a diagram for explaining a case where the amplitude of the elements arranged in the column direction on both the left and right sides of the patch antenna element 4 is set to half of the amplitude of the elements arranged in the central column direction, thereby affecting the H plane. is there.
FIG. 4A shows the radiation pattern when the amplitude of the patch antenna elements arranged in the left and right column directions is set to half the amplitude of the patch antenna elements arranged in the central column direction and the H plane is affected. FIG. The excitation frequency is 1.92 GHz.
As for the size of the radiation pattern, the level of the center point is represented by -20 dB, and the outermost circumference circle is represented by 20 dB.
[0009]
Referring to the radiation pattern of the E plane with reference to FIG. 4B, the front lobe direction is 0 °, and the half width is about 20 °. The side lobe suppression shows about 15 dB.
Referring to the radiation pattern of the H plane with reference to FIG. 4C, the front lobe direction is 0 ° and the half width is about 28 °. The side lobe suppression shows about 35 dB. The FS ratio (front lobe / side lobe) is greatly reduced.
FIG. 5 is a diagram for explaining a case where the amplitude of the elements arranged in the upper and lower rows in the patch antenna element 4 is set to half the amplitude of the elements arranged in the central row, and affects the E plane. is there.
[0010]
FIG. 5A shows the radiation pattern when the amplitude of the elements arranged in the upper and lower rows in the patch antenna element 4 is set to half that of the elements arranged in the central row, and the E-plane is affected. FIG. The excitation frequency is 1.92 GHz. As for the size of the radiation pattern, the level of the center point is represented by -20 dB, and the outermost circumference circle is represented by 20 dB.
Referring to the radiation pattern of the E plane with reference to FIG. 5B, the front lobe direction is 0 °, and the half width is about 24 °. The side lobe suppression shows about 31 dB.
Referring to the radiation pattern of the H plane with reference to FIG. 5C, the front lobe direction is 0 °, and the half width is about 23 °. The side lobe suppression shows about 16 dB.
[0011]
FIG. 6 is a diagram for explaining the case where the amplitude of the outer element is set to half the amplitude of the element at the center in the row direction.
FIG. 6A is a diagram showing a radiation pattern when the amplitude of the outer element is half the amplitude of the element at the center in the row direction. That is, the amplitude of upper and lower patch antenna elements arranged in the left and right column directions is set to half of the amplitude of the patch antenna elements arranged in the central column direction to affect the H plane, It is a figure which shows the radiation pattern when the amplitude of the left and right thing of the patch antenna element arranged in the direction is made into half of the amplitude of the patch antenna element arranged in the center row direction, and has affected the H plane. The excitation frequency is 1.92 GHz. As for the size of the radiation pattern, the level of the center point is represented by -20 dB, and the outermost circumference circle is represented by 20 dB.
[0012]
Referring to the radiation pattern of the E plane with reference to FIG. 6B, the front lobe direction is 0 °, and the half width is about 24 °. The side lobe suppression shows about 32 dB.
Referring to the radiation pattern of the H plane with reference to FIG. 5C, the front lobe direction is 0 °, and the half width is about 23 °. The side lobe suppression shows about 36 dB.
Two sets of patch array antennas as described above are prepared, and a patch array antenna in which these are spaced apart from each other is configured. Here, “back-to-back” refers to disposing the covers 13 ′ of the case 1 so as to face each other. FIG. 7 shows the mutual coupling amount when the 4 × 4 patch array antennas are arranged back-to-back at a distance of 4λ from each other.
[0013]
The back-to-back patch array antenna as described above can use one for reception and the other for transmission. However, by controlling the excitation amplitude of each patch antenna element, the side lobe level of both patch array antennas is controlled. Can be reduced, the amount of mutual coupling between the patch array antennas can be reduced. As a specific example, when the two patch array antennas are arranged back-to-back with 4λ between each other, the excitation amplitude of the outer patch antenna element is set to half the excitation amplitude of the central patch antenna element. 7, it can be seen from FIG. 7 that the mutual coupling amount can be reduced by 15 dB or more as compared with the case where the inner and outer patch antenna elements are excited with the same amplitude.
Each of the data in FIGS. 3 to 7 uses software for numerically calculating the electromagnetic field distribution, including the type of antenna, the dielectric constant, dielectric loss tangent, and thickness of the dielectric between the parasitic element substrate and the patch antenna element. An excitation source including a shape and dimensions of an antenna, an excitation frequency, an amplitude, and a phase, a feeding point, and other conditions were input and calculated by an electronic computer.
Illustration of detailed numerical values is omitted. The software for numerically calculating the electromagnetic field distribution used "MWStudio".
[0014]
【The invention's effect】
As described above, according to the present invention, the excitation amplitudes of the upper and lower patch antenna elements arranged in the left and right column directions are made smaller than the excitation amplitude of the patch antenna elements arranged in the central column direction. In addition to affecting the H plane, the excitation amplitude of the left and right patch antenna elements arranged in the upper and lower row directions is made smaller than the excitation amplitude of the patch antenna elements arranged in the center row direction, thereby affecting the H plane. , The level of the side lobe is extremely small in both the E plane and the H plane. As a result, as shown in FIG. 7, the amount of coupling between the two patch array antennas, which are formed by arranging two sets of patch array antennas separately from each other, is smaller than that of any of FIGS. Is also reduced, which reduces the reduction in effective radiated power.
[Brief description of the drawings]
FIG. 1 illustrates an embodiment.
FIG. 2 is a continuation of FIG. 1;
FIG. 3 is a diagram illustrating a case where each patch antenna element of a patch array antenna is excited with the same amplitude.
FIG. 4 is a diagram illustrating a case where the amplitude of the patch antenna elements of the patch array antenna arranged in the left and right column directions is excited by half of the patch antenna elements arranged in the central column direction;
FIG. 5 is a diagram illustrating a case where the amplitude of the patch antenna elements of the patch array antenna arranged in the upper and lower row directions is excited by half of the patch antenna elements arranged in the central row direction;
FIG. 6 is a diagram illustrating a case in which the amplitude of the patch antenna element outside the patch array antenna is excited at half the amplitude of the element at the center.
FIG. 7 is a diagram showing the mutual coupling amount when the patch array antennas are arranged back to back at a distance of 4λ.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Antenna case 10 Choke structure 11 Frame 12 Peripheral side wall 13 and 13 'cover 3 Parasitic element 30 Parasitic element board 4 Patch antenna element 40 Patch antenna element substrate 50 Feeding circuit board 6 Coaxial tube 7 Element substrate fixing material

Claims (2)

A parasitic element substrate on which the patch antenna element is formed and a patch array antenna having a choke structure formed so as to surround the peripheral end region of the patch antenna element substrate are separately arranged back to back, and each patch antenna element A method for exciting a patch array antenna, comprising: changing an excitation amplitude to reduce an FS ratio to control mutual coupling between array antennas. A parasitic element substrate on which a patch antenna element is formed and a patch array antenna having a choke structure formed so as to surround the peripheral end region of the patch antenna element substrate are separately arranged back to back, and each patch antenna element is A patch array antenna comprising an antenna power supply circuit for setting and exciting a voltage level to be excited for each individual.

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