JPH09172318A - Circularly polarized wave micro strip line antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a circularly polarized wave whose directivity is high as mush as possible and in which an axial ratio is approximated to 0dB as much as possible on a correlation between the lengths of respective upper edges, side edges and bottom edges, which constitute the square wave shapes of micro strip lines in a circularly polarized wave micro strip line antenna and line wavelength. SOLUTION: A substrate 1 is constituted by a flexible film 2 on an upper stage, a dielectric sheet 3 in a middle stage and a metallic base 4 on a lower stage. The dielectric rates of the flexible film 2 and the dielectric sheet 3 are approximated to '1' as much as possible. The microstrip lines 5 are formed on the face of the flexible film 2. The sets of length 2a, (b) and (c) of the upper edges 22, the side edges 24 and the base edges 23, which constitute the square waveform shapes of the micro strip lines 5, become 2a≈0.90λg, b≈0.35λg, c≈0.40λg with respect to the line wavelength λg.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circular polarized microstrip line antenna, and more particularly to a circular polarized microstrip line antenna used for transmitting and receiving satellite broadcasting and satellite communication.

[0002]

2. Description of the Related Art This type of circularly polarized microstrip line antenna has a plurality of microstrip lines formed on the surface of a substrate.
The back side of the board is used as a whole ground plane. Each microstrip line bridges the left and right ends of the substrate and is bent in a square wave shape. The length of each of the upper side, the side and the bottom which form this square wave shape has a certain correlation with the line wavelength λg of the traveling wave propagating on the microstrip line, and as a result, the circle The polarized microstrip line antenna can transmit and receive circularly polarized waves in a predetermined frequency band.

Here, the "certain correlation" is not unique to the line wavelength λg, and various relational expressions have been conventionally proposed (for example, Japanese Examined Patent Publication No. 61-45401, Japanese Examined Patent Publication No. 63-50882, etc.). . The goal of these proposals is to enhance the directivity of circularly polarized waves and ultimately to create perfect circularly polarized waves (circularly polarized waves with an axial ratio of the long axis and the short axis of 0 dB). I have not reached the point where I can be satisfied.

Further, when it is attempted to receive both left-handed circularly polarized wave and right-handed circularly polarized wave transmitted from one satellite by one circularly polarized wave microstrip line antenna, the circularly polarized wave It is necessary to increase the directivity of the microwave microstrip line antenna as much as possible, and the numerical values currently proposed are not sufficient.

Therefore, the directivity is as high as possible and the axial ratio is as high as possible with respect to the correlation between the length of each upper side, side and bottom forming the square wave shape of the microstrip line and the line wavelength. Further, there is a technical problem to be solved in order to realize circular polarization close to 0 dB, and the present invention aims to solve the problem.

[0006]

The present invention has been proposed in order to solve the above-mentioned problems, and a square wave-shaped microstrip line is formed on the front surface of a substrate, and a ground plane is formed on the back surface of the substrate. As a result, in a circularly polarized microstrip line antenna capable of transmitting and receiving circularly polarized waves, the length of each of the upper side, the side and the bottom forming the square wave shape is approximately 0.90 of the line wavelength.
Double, approximately 0.35 times and approximately 0.40 times the circularly polarized microstrip line antenna, and by forming a square wave microstrip line on the substrate surface and forming a ground plane on the substrate back surface. In a circularly polarized microstrip line antenna capable of transmitting and receiving circularly polarized waves, the length of each of the upper side, side, and bottom of the square wave shape is approximately 0.9 of the free space wavelength.
0 γ times, about 0.35 γ times and about 0.40 γ times (where
γ is a correction factor) and a circularly polarized microstrip line whose value of γ is 1.042 ± 5% when the dielectric constant of the substrate is as close to 1 as possible. It provides an antenna.

[0007]

Embodiments of the present invention will be described below in detail with reference to the drawings. In FIGS. 1 and 2, reference numeral 1 is a substrate that constitutes a circularly polarized microstrip line antenna, and the substrate 1 is composed of three layers of a flexible film 2, a dielectric sheet 3 and a metal base 4 from above. . The flexible film 2 is made of a synthetic resin whose material has a dielectric constant extremely close to 1, and is formed in a flexible thin plate shape. On its surface, microstrip lines 5 are patterned by etching a conductive foil or screen-printing a conductive paste. Has been done. The dielectric sheet 3 is made of a dielectric material having a permittivity extremely close to 1, such as foamed sponge. Further, the metal base 4 has a function as a ground plane that covers the entire back surface of the substrate 1, and the flexible film 2
Also, since the dielectric sheet 3 is extremely soft, it also has a role as a supporting member for reinforcing it and holding it in a planar shape.

Further, each of the microstrip lines 5 is formed along the left-right direction of the flexible film 2, and these 10 lines are arranged side by side at predetermined intervals in the front-back direction of the flexible film 2. To form an antenna array. Furthermore, each microstrip line 5 is composed of two arms 6 and 7,
The arms 6 and 7 are bent in the same square wave shape, and the arm 7 is 18 times larger than the arm 6.
It is formed so that the phase relationship is shifted by 0 degrees.

Further, rectangular waveguides 8 are disposed below the left and right ends of the substrate 1 in the front-rear direction. In the embodiment of the present invention, as the rectangular waveguides 8 and 8, standard products of the WRJ-120 (Japan Electronic Machinery Manufacturers Association standard) type for transmitting the TE ₁₀ fundamental mode are used. On the upper surface of the rectangular waveguides 8, 8, ten holes 9, 9, ... Are opened at regular intervals along the tube axis direction at the left and right intermediate positions, and these holes 9, 9 ,. They are formed so as to face the left and right ends of the microstrip lines 5 in a one-to-one relationship.

Further, at positions facing the holes 9, 9 ... In the metal base 4, holes 10, 10 ...
Has been perforated. The vertical portions 12 of the inverted L-shaped power supply pins 11 are inserted into the holes 9, 9, ... And the holes 10, 10 ,. This inverted L-shaped power supply pin 11
After laying the dielectric sheet 3 on the metal base 4 and before laying the flexible film 2 on the dielectric sheet 3, from the top surface of the dielectric sheet 3 to the holes 9,
9 ... and holes 10, 10 ... At this time, since the dielectric sheet 3 is made of foam sponge or the like as described above, the power feeding pin 11 can be penetrated without separately opening a hole. Further, the horizontal portion 13 of the power supply pin 11 is directed to the inside of the left and right of the substrate 1. Thus,
When the flexible film 2 is laid, the end portion 5a of the microstrip line 5 on the surface thereof and the horizontal portion 13 are opposed to each other in parallel via the flexible film 2 which is a dielectric. Further, a dielectric spacer 14 is loaded in the space between the power feeding pin 11 and the holes 9 and 10.

Here, the microstrip line 5
The end portion 5a and the length L ₁ of the horizontal portion 13 of the power supply pin 11 are set so that they can be electromagnetically coupled to each other with respect to the radio wave to be transmitted and received. Specifically, with respect to the line wavelength λg when the radio wave to be transmitted / received propagates through the microstrip line 5, L ₁ = λg /
4 is preferable. In the embodiment of the present invention, since the dielectric constant of the substrate 1 is extremely close to 1, if the free space wavelength of the radio wave to be transmitted / received is λ ₀ , then λ
g ≒ lambda _0, and the thus the L ₁ ≒ λ _0/4.

A hole 15 is formed in the center of the lower surface of the rectangular waveguide 8 and a transmitter 16 is provided in the hole 15.
(Or the outer tube conductor 19 of the coaxial cable 18 extended from the receiver 17 is fitted, and the center conductor 20 of the coaxial cable 18 projects into the inner cavity of the rectangular waveguide 8 so that the probe 21 Is formed. In this way, the feeding pin 11 and the probe 21 are electromagnetically bridged via the rectangular waveguide 8 to form a feeding device.

Although not specifically shown, the power supply pin
Of the vertical portion 12 of the rectangular waveguide 8
Length L of the portion 12a depending from the upper surface_TwoIs a rectangle
The closer to the center of the waveguide 8, the shorter the front and rear ends.
It is getting longer as you reach the club. Send this reason
In the case of, the rectangular guide from the probe 21 is used.
The electric wave radiated to the inner lumen of the wave tube 8 is directed toward the front and rear ends of the inner lumen.
Once it is attenuated as it propagates, all
Length L of the hanging portion 12a of the power supply pin 11_TwoTo be the same
Then, the power supply pin 1 located far from the probe 21.
The energy received by 1 becomes smaller. This is the above
Amplitude of current supplied to microstrip line 5
However, the closer to the center of the substrate 1, the larger the
It becomes smaller toward the front and back edges, and the characteristics of the antenna array
Deteriorate. Therefore, receive all the power supply pins 11.
The length of the drooping part 12a
L _TwoIs adjusted as described above to compensate for the transmission loss of the rectangular waveguide 8.
It is.

The distance L ₃ between adjacent ones of the feed pins 11, that is, the distance between adjacent microstrip lines 5 is equal to the guide wavelength λg ₁ in the rectangular waveguide 8. Is set. This is because it is necessary to match the in-tube phase at the position where the power supply pins 11 are arranged for all the power supply pins 11. As a result, all the power supply pins 11 can supply currents having the same phase and the same amplitude to the microstrip line 5.

Thus, the transmitter 16 (or the receiver 1)
7) has a function of selecting one of the left and right coaxial cables 18 to conduct electricity and disconnect the other. Therefore, in the case of transmission, if the left coaxial cable 18 is selected by the transmitter 16, the transmitter 1
The high frequency current oscillated from 6 is the coaxial cable 1 on the left side.
8 is introduced into the probe 21 at the tip of the rectangular waveguide 8, and the rectangular waveguide 8 on the left side is excited by this, and its energy is fed along the feeding pin 11 on the upper surface of the rectangular waveguide 8, that is, the left end of the substrate 1. It propagates to the power supply pin 11 provided. Further, this energy propagates from the horizontal portion 13 of the power supply pin 11 to the left end 5a of the microstrip line 5 immediately above the power supply pin 11 by electromagnetic coupling. Thus, the high frequency current is supplied from the left end 5a to the microstrip line 5. Such a case where the left power feeding pin 11 acts as a power feeding point is hereinafter referred to as a "left power feeding point".

In the case of such a left feeding point, the right-handed circularly polarized wave is radiated by the interaction between the temporal and spatial sine wave of the high frequency current and the spatial square wave shape of the microstrip line 5. Will be done. The process of the right-handed circularly polarized radiation will be outlined with reference to FIGS.

As shown in FIG. 3A, the surface of the substrate 1 is taken as the origin and the Z-axis is taken in the direction of the normal line of the substrate 1 (the front side of the drawing is the plus direction), and the horizontal direction of the substrate 1 is taken. The X axis (the right direction is the plus direction) and the Y axis (the front direction (the direction on the paper surface) is the plus direction) are taken in the front-rear direction. Therefore, the upper side 22 and the bottom side 23 forming the square wave shape of the arms 6 and 7 of the microstrip line 5 are parallel to the X axis, and the side 24 is parallel to the Y axis. Since the high-frequency current flows on the arms 6 and 7, the directions of the high-frequency current are X-axis plus and minus directions and Y-axis plus and minus directions.

By the way, in this type of microstrip line antenna, an electromagnetic wave having the same direction of the high frequency current on the microstrip line and an electric field having a magnitude proportional to the magnitude of the high frequency current is generated. It is emitted in the direction normal to the substrate surface. Therefore, the electric field E of the electromagnetic wave emitted from the substrate 1 has a component E _X vibrating in the X-axis direction and a component E _Y vibrating in the Y-axis direction, and propagates in the positive direction of the Z-axis. The electric field component E _X is caused by the high frequency current flowing through the top side 22 and the bottom side 23,
The electric field component E _Y is due to the high frequency current flowing through the side edge 24.

Assuming that the lengths of the upper side 22, the bottom side 23, and the side side 24 are 2a, c, and b, respectively, their specific dimensions have a constant correlation with the line wavelength λg, as will be described later. have. And this "certain correlation"
As a result, the electric field component E _X created at an arbitrary point on the Z axis (plus direction) by the action of the high-frequency current flowing through the top side 22 and the bottom side 23 is zero at a certain time, as shown in FIG.
, And the electric field component E _Y created at the arbitrary point by the action of the high frequency current flowing through the side 24.
Will draw the vibration waveform shown in FIG. 7C with the same time as zero. As can be seen from these figures, both the electric field component E _X, E _Y are both sine wave of the high frequency current and the same cycle, and one cycle of 4 minutes towards the electric field component E _Y is than the electric field component E _X ( It is configured to vibrate in an early phase by 90 degrees). In FIGS. 7B and 7C, when the electric field component E _X or E _Y is on the plus side, the direction of the electric field component E _X or E _Y is the plus direction of the X axis or the plus direction of the Y axis. When it is on the negative side, it indicates that the direction of the electric field component E _X or E _Y is the negative direction of the X axis or the negative direction of the Y axis.

FIG. 4 is based on FIGS. 3 (b) and 3 (c), and electric field components E _X and E _Y (middle row in the figure) at the arbitrary points on the Z axis and combining them. Electric field E
The size of (the rightmost column in the figure) is shown as a vector for each ⅛ cycle while also considering its direction. As can be seen from this, the electric field E is in the paper surface direction (negative direction of the Z axis,
That is, it rotates counterclockwise in the same cycle as the high frequency current in the direction opposite to the traveling direction of the electromagnetic wave. Whether the circularly polarized wave is a right-handed circularly polarized wave or a left-handed circularly polarized wave is determined by the direction of rotation of the electromagnetic field when traveling in the traveling direction (plus direction of the Z axis). It is a circularly polarized wave.

As described above, in the case of the left feeding point, the right-handed circularly polarized wave is radiated. Then, the case where the feeding point is changed to the feeding pin 11 arranged at the right end of the substrate 1 to serve as the right feeding point will be outlined next.

The transmitter 16 is connected to the coaxial cable 18 on the right side in order to use the power supply pin 11 on the right end as a power supply point. As a result, the rectangular waveguide 8 on the right side is excited, and a high frequency current is supplied from the end portion 5a on the right side of the microstrip line 5 via the feeding pin 11 on the right end. That is, in the case of this right side feeding point, the direction of the current is reversed by 180 degrees with respect to the X-axis direction as compared with the case of the left side feeding point described above. This means that the electric field component E _X shown in FIG. 3B is inverted by 180 degrees at the right feeding point,
The result is the vibration waveform shown in FIG.

On the other hand, in the Y-axis direction, of the side edges 24, 24 ... Of the microstrip line 5, the edge edge 24 (outgoing path) which has formed the positive flow and the negative edge flow. Since the side edge 24 (return path) that had been used is only replaced, the electric field component E _Y produced by these side edges 24 as a whole is the same as that at the left feeding point, and its vibration waveform is shown in FIG. Show. This FIG.
As can be seen from (b) and (b), in the case of the right side feeding point, in contrast to the case of the left side feeding point described above, the electric field component E _Y has a phase that is a quarter cycle (90 degrees) later than the electric field component E _X. Vibrating.

FIG. 6 shows the electric field vector change for each ⅛ cycle in the case of the right side feeding point based on FIG. 5, and FIG. 4 in the case of the left side feeding point described above.
Is equivalent to As shown in the rightmost column of FIG. 6,
In the case of the right feeding point, the electric field E at any point on the Z axis
Rotates clockwise in the same direction as the high-frequency current in the paper surface direction (negative direction of the Z axis). Therefore, this electromagnetic wave is left-handed circularly polarized wave.

In this way, in one substrate 1, right-handed circularly polarized waves are radiated when the left feeding point is set, and left-handed circular polarized waves are radiated when the right feeding point is set. Further, if the transmitter 16 is replaced with a receiver 17, circular polarized waves having the same characteristics as the circular polarized waves radiated at the time of transmission can be received. In the case of, the right-hand circular polarization can be received, and in the case of the right feeding point, the left-hand circular polarization can be received.

As described above, in the circularly polarized microstrip line antenna capable of transmitting and receiving the left-handed and right-handed circularly polarized waves, it is required to improve the directivity as much as possible. That is, when the directivity is bad, if the direction of the antenna is matched with one circular polarized wave, the angle shift will double when switched to the other circular polarized wave, so the direction must be adjusted again. This is because the merit of being able to send and receive both circular polarized waves is diminished. In addition, various proposals have been made on the correlation equation between the length of each side forming a square wave shape and the line wavelength λg in order to improve the antenna characteristics of this type of circularly polarized microstrip line antenna, but they are not perfect. There is still nothing to say, and it was not suitable especially for the above-mentioned circularly polarized microstrip line antenna that transmits and receives left-handed and right-handed circularly polarized waves.

By the way, of the upper side, the side and the bottom which form the square wave shape, it is the side that plays an important role for the characteristics of circular polarization, and if the length of the side is specified. The lengths of the top side and the bottom side can be calculated empirically. Also,
It is an empirically recognized condition that the total length (2a + b + c in FIGS. 1 and 3 (b)) of each of the upper side, the side, and the bottom is twice the line wavelength λg.

Therefore, the applicant of the present application uses the circularly polarized microstrip line antenna having the structure described in FIGS. 1 and 2 under the condition of 2a + b + c = 2λg.
By changing the value of g variously, the axial ratio between the long axis and the short axis of the circularly polarized wave radiated from the antenna was measured. FIG. 7 shows the result. As shown in the figure, approximately b
It was found that when /λg=0.35, the axial ratio was minimum in dB. The axial ratio of so-called perfect circular polarization in which the length of the major axis and the length of the minor axis match is 0 dB, and the axial ratio with which good characteristics as a circularly polarized antenna can be obtained is 3.
Although it is within dB, in this experiment, it is approximately b / λg = 0.3.
At 5, the axial ratio was about 1.5 dB, which proved to have excellent characteristics.

Thus, it is determined that the length b of the side edge 24 should be approximately 0.35 times the line wavelength λg. Based on this, the length 2a of the upper edge 22 is approximately 0 of the line wavelength λg. .9
0 times (that is, a is approximately 0.45 times the line wavelength λg),
In addition, the length c of the base 23 is approximately 0.4 of the line wavelength λg.
It was decided that it should be 0 times.

As described above, the dielectric constant of the substrate 1 is 1
Can be regarded as₀So the above result
Is a≈0.45λ₀, B≈0.35λ₀, C≈0.4
0λ ₀It can be expressed as. However, the dielectric constant of substrate 1
Can not be ignored at all, so free a, b, c
Spatial wavelength λ₀In case of, consider the dielectric constant of this substrate 1.
Using the correction factor γ considered, a = 0.45γλ₀, B =
0.35γλ₀, C = 0.40γλ₀Becomes

Therefore, the applicant of the present application has found that the value of the correction factor γ
First, a = 0.45λ ₀, B = 0.35λ
₀, C = 0.40λ₀Circular polarized microstrip
Use a line antenna and set its directivity to the left feeding point.
Measured both for the case of
I decided to do it. The result is shown in FIG. Figure (a) is left
This is the case of the side feeding point, and the figure (b) is for the right side feeding point.
It is. As you can see, the left feeding point, that is, the right turn
Circular polarization directionality is tilted to the left by the angle θ (about 4 degrees) and to the right
Side feeding point, that is, the directivity of left-handed circularly polarized wave is angle θ to the right
It is only tilted (about 4 degrees). From this angle θ, a square waveform
Traveling wave corresponding to the length of one cycle (2a + b + c)
Is about 691 degrees, which is 720 degrees
In order to achieve the above, multiply a, b, and c by approximately 1.042, respectively.
It turned out to be good. Therefore, the value of the correction factor γ is γ
= 1.042 ± 5% (here ± 5% also considers the error
It is. ).

The applicant of the present invention has calculated the value of γ by using the above equations a = 0.45γλ ₀ , b = 0.35γλ ₀ ,
As a result of performing the experiment again by applying to c = 0.40γλ ₀ ,
As shown in FIG. 9, the phase shift is eliminated both in the right-handed circularly polarized wave by the left feeding point (FIG. 9A) and in the left-handed circular polarized wave by the right feeding point (FIG. 9B). Then, it started to show excellent directivity.

The present invention can be variously modified without departing from the spirit of the present invention, and it goes without saying that the present invention extends to the modified ones.

[0034]

As described above, according to the present invention, the length of each of the upper side, the side and the bottom forming the square wave shape of the microstrip line are approximately 0.90 times the line wavelength and approximately 0.
35 times and about 0.40 times, or about 0.90 γ times, about 0.35 γ times and about 0.40 γ times the free space wavelength, respectively, so that the axial ratio is set to 0 dB as much as possible and the ideal circular deviation is set. It can approach waves and improve directivity. Further, when the dielectric constant of the substrate is as close to 1 as possible, the value of γ is set to 1.042 ± 5% to completely eliminate the phase shift and obtain excellent directivity. .

As described above, even when the circularly polarized microstrip line antenna is configured to be capable of transmitting and receiving both left-handed and right-handed circularly polarized waves, sufficiently satisfactory antenna characteristics can be exhibited. .

[Brief description of the drawings]

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

FIG. 2 is a partially cutaway front view of FIG.

FIG. 3A is an explanatory plan view showing XYZ space coordinates set on a substrate. (B) at any point on the Z axis, a graph showing the time variation of the electric field component E _X where the certain time zero, the graph in the case of the left feed. (C) A graph showing the change over time of the electric field component E _Y under the condition of (b) above.

4A and 4B are explanatory diagrams in which directions and magnitudes of electric field components E _X and E _Y , and electric field E obtained by combining the electric field components E _X and E 8 in each cycle are represented by vectors based on FIGS. 3B and 3C.

5 (a) is a graph of time that is at the arbitrary point shows temporal changes in the electric field components E _X was zero on the Z-axis, the graph in the case of the right feed. (B) A graph showing the time change of the electric field component E _Y under the condition of (b) above.

6A and 6B are explanatory diagrams showing, based on FIGS. 5A and 5B, electric field components E _X and E _Y and directions and magnitudes of electric fields E synthesized by the electric field E for each ⅛ cycle in vectors. .

FIG. 7 is a graph of experimental results obtained by measuring the relationship between the axial ratio of circularly polarized waves and b / λg.

FIG. 8 a = 0.45λ ₀ , b = 0.35λ ₀ , c =
It is explanatory drawing which shows the experimental result of the directivity of the circular polarization microstrip line antenna set to 0.40 (lambda) ₀ , (a).
Shows the directivity of right-handed circular polarization, and (b) shows the directivity of left-handed circular polarization.

FIG. 9 a = 0.45γλ ₀ , b = 0.35γλ ₀ , c
= 0.40 γλ ₀ (where γ = 1.042) is an explanatory diagram showing the experimental results of the directivity of the circularly polarized microstrip line antenna, and (a) shows the directivity of the right-handed circularly polarized wave. , (B) show the directivity of left-handed circularly polarized waves.

[Explanation of symbols]

 1 substrate 2 flexible film 3 dielectric sheet 4 metal base 5 microstrip line 6, 7 arm 22 top side 23 bottom side 24 side

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] November 22, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0018

[Correction method] Change

[Correction contents]

By the way, the In microstrip line antenna此種, in the same direction as the direction of the high-frequency current on a microstrip line, electromagnetic waves and having an electric field having a magnitude proportional to the magnitude of the high frequency current, It is emitted in the direction normal to the substrate surface. Therefore, the electric field E of the electromagnetic wave emitted from the substrate 1 has a component E _X vibrating in the X-axis direction and a component E _Y vibrating in the Y-axis direction, and propagates in the positive direction of the Z-axis. The electric field component E _X is caused by the high frequency current flowing through the top side 22 and the bottom side 23,
The electric field component E _Y is due to the high frequency current flowing through the side edge 24.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0019

[Correction method] Change

[Correction contents]

Assuming that the lengths of the upper side 22, the bottom side 23, and the side side 24 are 2a, c, and b, respectively, their specific dimensions have a constant correlation with the line wavelength λg, as will be described later. have. And this "certain correlation"
As a result, the electric field component E _X created at an arbitrary point on the Z axis (plus direction) by the action of the high-frequency current flowing through the top side 22 and the bottom side 23 is zero at a certain time, as shown in FIG.
, And the electric field component E _Y created at the arbitrary point by the action of the high frequency current flowing through the side 24.
Will draw the vibration waveform shown in FIG. 7C with the same time as zero. As can be seen from these figures, both the electric field component E _X, E _Y are both sine wave of the high frequency current and the same cycle, and one cycle of 4 minutes towards the electric field component E _Y is than the electric field component E _X ( and is configured to vibrate at 90 degrees) only slow it has phase. In FIGS. 7B and 7C, when the electric field component E _X or E _Y is on the plus side, the direction of the electric field component E _X or E _Y is the plus direction of the X axis or the plus direction of the Y axis. When it is on the negative side, it indicates that the direction of the electric field component E _X or E _Y is the negative direction of the X axis or the negative direction of the Y axis.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0023

[Correction method] Change

[Correction contents]

On the other hand, in the Y-axis direction, of the side edges 24, 24 ... Of the microstrip line 5, the edge edge 24 (outgoing path) which has formed the positive flow and the negative edge flow. Since the side edge 24 (return path) that had been used is only replaced, the electric field component E _Y produced by these side edges 24 as a whole is the same as that at the left feeding point, and its vibration waveform is shown in FIG. Show. This FIG.
And as seen from (b), contrary to the case of the left feed point described above in the case of the right feed point, the electric field component E _Y is one cycle (90 degrees) of the quarter than the electric field component E _X only have early phase Is vibrating at.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0032

[Correction method] Change

[Correction contents]

The applicant of the present invention has calculated the value of γ by using the above equations a = 0.45γλ ₀ , b = 0.35γλ ₀ ,
As a result of performing the experiment again by applying to c = 0.40γλ ₀ ,
As shown in FIG. 9, there is a phase shift both in the right-handed circularly polarized wave by the left feeding point (FIG. 9A ) and in the left-handed circular polarized wave by the right feeding point (FIG. 9B). It has been resolved to show excellent directivity.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] Fig. 5

[Correction method] Change

[Correction contents]

5 (a) is a graph of time that is at the arbitrary point shows temporal changes in the electric field components E _X was zero on the Z-axis, the graph in the case of the right feed. (B) A graph showing the change over time of the electric field component E _Y under the condition ( a ).

Claims (3)

[Claims] 1. A circularly polarized microstrip line antenna in which a circularly polarized microstrip line is formed on the front surface of a substrate and a ground plane is formed on the rear surface of the substrate so that circularly polarized waves can be transmitted and received. The length of each of the upper side, the side and the bottom forming the square wave shape is approximately 0.90 times, approximately 0.35 times and approximately 0.40 times the line wavelength, respectively. Wave microstrip line antenna. 2. A circularly polarized microstrip line antenna, wherein a square wave-shaped microstrip line is formed on the front surface of a substrate and a ground plane is formed on the back surface of the substrate so that circularly polarized waves can be transmitted and received. The length of each of the upper side, the side and the bottom forming the square wave shape is approximately 0.90γ times the free space wavelength and approximately 0.35.
A circularly polarized microstrip line antenna characterized by being γ times and approximately 0.40 γ times (where γ is a correction factor). 3. The circularly polarized microstrip line antenna according to claim 2, wherein the value of γ is 1.042 ± 5% when the dielectric constant of the substrate is as close to 1 as possible.