JP6953807B2 - Antenna device - Google Patents

Description

The present invention relates to an antenna device capable of transmitting or receiving circularly polarized waves having a plurality of frequencies.

Conventionally, as an antenna device capable of transmitting and receiving circularly polarized waves, a configuration in which a patch antenna is provided with two feeding points is known. In such a configuration, the two feeding points need to be arranged on two straight lines orthogonal to each other. Further, each feeding point needs to be connected to a phase adjusting path adjusted so that the phase difference of the current flowing on the radiating element is 90 °.

Further, Patent Document 1 discloses a configuration in which an annular second radiating element is arranged outside a square first radiating element as a patch antenna capable of transmitting and receiving circularly polarized waves of a plurality of frequencies. Two feeding points are provided for each of the first radiating element and the second radiating element. In addition, a 90 ° hybrid circuit as a phase adjusting circuit is also provided for each radiating element (in other words, for each frequency). According to such a configuration, it is possible to receive circularly polarized waves of two frequencies.

Japanese Unexamined Patent Publication No. 2003-152431

In the configuration disclosed in Patent Document 1, it is necessary to provide two feeding points for each frequency to be transmitted and received. For example, in order to operate the antenna device disclosed in Patent Document 1 at two frequencies, it is necessary to provide a total of four feeding points. As a matter of course, the larger the number of feeding points, the more complicated the feeding system circuit such as the phase adjustment circuit and the impedance adjustment circuit.

The present invention has been made based on this circumstance, and an object of the present invention is to provide an antenna device capable of receiving circularly polarized waves of two frequencies and suppressing the number of feeding points. To provide. The circularly polarized wave here is not limited to circularly polarized waves having an axial ratio of 1 dB (that is, a perfect circle), and for example, elliptically polarized waves having an axial ratio of 3 dB also correspond to circularly polarized waves. And.

The first antenna device for achieving the purpose is an antenna for transmitting or receiving each of a predetermined first frequency circular polarization and a predetermined second frequency circular polarization higher than the first frequency. A device, which is a plate-shaped conductor member (1) which is a plate-shaped conductor member and a plate-shaped conductor member installed so as to face the main plate at a predetermined distance, and the angle formed by each other is regarded as a quadrangle. A patch pattern (2) formed in a line-symmetrical shape with respect to each of the first axis (Ax1) and the second axis (Ay1), which are two axes having an angle of formation, and as a feeding point. A first feeding point (5) and a second feeding point (6) as a feeding point provided at a position different from the first feeding point are provided, and the length of the patch pattern in the first axial direction and the second feeding point are provided. The length in the axial direction is electrically set to a length corresponding to half of the first wavelength, which is the wavelength of the radio wave of the first frequency, and in the patch pattern, the propagation of the current of the first frequency is set. At least one slit (4) having a width that does not hinder the propagation of the current of the second frequency is arranged, and the slit has a shape similar to the patch pattern and is a straight line parallel to the first axis. Subpatch portions (21) having a shape symmetrical with respect to each of the straight lines parallel to the second axis are arranged so as to cooperate with a part of the edge portion of the patch pattern, and the subpatch portion of the subpatch portion has a second shape. The length in the direction in which the third axis extends, which is a straight line parallel to one axis and acts as the axis of symmetry of the subpatch portion, and the straight line parallel to the second axis and acting as the axis of symmetry of the subpatch portion. The length in the direction in which the four axes extend is electrically set to a length corresponding to half of the second wavelength, which is the wavelength of the radio wave of the second frequency, and is a region other than the subpatch portion in the patch pattern. The surplus area and the subpatch portion are electrically connected at at least one place, and the first feeding point is arranged at the point where the first axis and the fourth axis intersect in the subpatch portion, and the second feeding point. Is arranged at a point where the second axis and the third axis intersect in the subpatch portion.
Further, the second antenna device for achieving the above object transmits or receives each of a predetermined first frequency circular polarization and a predetermined second frequency circular polarization higher than the first frequency. The antenna device of the above, the main plate (1) which is a plate-shaped conductor member, and the plate-shaped conductor member installed so as to face the main plate at a predetermined distance, and the angles formed by each other are parallel. A patch pattern (2) formed in a line-symmetrical shape with respect to each of the first axis (Ax1) and the second axis (Ay1), which are two axes having an angle that can be seen, and a feeding point. The first feeding point (5) as a feeding point and the second feeding point (6) as a feeding point provided at a position different from the first feeding point are provided, and the length of the patch pattern in the first axial direction and The length in the second axis direction is electrically set to a length corresponding to half of the first wavelength, which is the wavelength of the radio wave of the first frequency, and the patch pattern includes the current of the first frequency. At least one slit (4) having a width that hinders the propagation of the current of the second frequency while not hindering the propagation is arranged, and the slit has a shape similar to the patch pattern and is parallel to the first axis. A subpatch portion (21) having a line-symmetrical shape with respect to each of the straight line and the straight line parallel to the second axis is arranged so as to cooperate with a part of the edge portion of the patch pattern, and the subpatch portion is formed. , The length in the direction in which the third axis extends, which is a straight line parallel to the first axis and acts as the axis of symmetry of the subpatch portion, and the straight line parallel to the second axis and acting as the axis of symmetry of the subpatch portion. The length in the direction in which a certain fourth axis extends is electrically set to a length corresponding to half of the second wavelength, which is the wavelength of the radio wave of the second frequency, and is a region other than the subpatch portion in the patch pattern. The surplus area and the subpatch portion are electrically connected at at least one place, and the first feeding point is centered on the intersection of the first axis and the second axis and has a predetermined first length. A first circle, which is a circle having a radius, and a second circle, which is a circle centered on the intersection of the third and fourth axes and having a predetermined second length shorter than the first length as a radius. The second feeding point is arranged at any one of the intersections of the above, and the second feeding point is arranged at the other of the intersections of the first circle and the second circle.
Further, the third antenna device for achieving the above object transmits or receives each of a predetermined first frequency circular polarization and a predetermined second frequency circular polarization higher than the first frequency. The antenna device of the above, the main plate (1) which is a plate-shaped conductor member, and the plate-shaped conductor member installed so as to face the main plate at a predetermined distance, and the angles formed by each other are parallel. A patch pattern (2) formed in a line-symmetrical shape with respect to each of the first axis (Ax1) and the second axis (Ay1), which are two axes having an angle that can be seen, and a feeding point. The first feeding point (5) as a feeding point and the second feeding point (6) as a feeding point provided at a position different from the first feeding point are provided, and the length of the patch pattern in the first axial direction and The length in the second axis direction is electrically set to a length corresponding to half of the first wavelength, which is the wavelength of the radio wave of the first frequency, and the patch pattern includes the current of the first frequency. At least one slit (4) having a width that hinders the propagation of the current of the second frequency while not hindering the propagation is arranged, and the slit has a shape similar to the patch pattern and is parallel to the first axis. A subpatch portion (21) having a line-symmetrical shape with respect to each of the straight line and the straight line parallel to the second axis is arranged so as to cooperate with a part of the edge portion of the patch pattern, and the subpatch portion is formed. , The length in the direction in which the third axis extends, which is a straight line parallel to the first axis and acts as the axis of symmetry of the subpatch portion, and the straight line parallel to the second axis and acting as the axis of symmetry of the subpatch portion. The length in the direction in which a certain fourth axis extends is electrically set to a length corresponding to half of the second wavelength, which is the wavelength of the radio wave of the second frequency, and is a region other than the subpatch portion in the patch pattern. The surplus area and the subpatch portion are electrically connected at at least one place, the first feeding point and the second feeding point are arranged in the subpatch portion, and the third axis overlaps with the first axis. It is characterized in that the slit is formed so that the fourth axis does not overlap with the second axis.

In the above configuration, the first axis is one axis of symmetry for the patch pattern, and the second axis is a symmetry axis other than the first axis for the patch pattern, and is considered to be orthogonal to the first axis. Is the axis of symmetry that can be created. Further, the third axis is one axis of symmetry for the patch pattern, and the fourth axis is a symmetry axis other than the third axis for the patch pattern, and can be regarded as orthogonal to the fourth axis. It is the axis of symmetry. Since the third axis is parallel to the first axis and the fourth axis is parallel to the second axis, the angle formed by the third axis and the fourth axis is also an angle that can be regarded as a right angle. There is.

The length of the patch pattern in the direction in which the first axis extends (that is, the direction of the first axis) and the length in the direction in which the second axis extends (that is, the direction of the second axis) are both electrically half of the first wavelength. It is set to a corresponding length. Further, since the width of the slit is set to a value that does not hinder the propagation of the current at the first frequency, the existence of the slit can be ignored in exciting the patch pattern at the first frequency.

Therefore, by passing a current having a first frequency and a phase shift of 90 ° from each of the first feeding point and the second feeding point, 90 two currents flowing in directions orthogonal to each other are passed on the patch pattern. Can be excited in ° phase. That is, according to the above configuration, the circularly polarized wave of the first frequency can be transmitted.

Further, the width of the slit is set to a width that hinders the propagation of the current of the second frequency, and the first feeding point and the second feeding point are arranged in the subpatch portion, so that the second feeding point is the second from each feeding point. When a frequency current is input, the second frequency current is mainly distributed in the subpatch portion. That is, the subpatch portion is excited independently of the region other than the subpatch portion (hereinafter, the surplus region).

The length in the direction in which the third axis of the subpatch portion extends (that is, the direction in which the third axis extends) and the length in the direction in which the fourth axis extends (that is, in the direction of the fourth axis) are both electrically of the second wavelength. It is set to a length equivalent to half. According to such a configuration, by passing a current having a second frequency and a phase shift of 90 ° from each of the first feeding point and the second feeding point, the directions are orthogonal to each other on the subpatch portion. The two flowing currents can be excited in 90 ° phase. That is, according to the above configuration, the circularly polarized wave of the second frequency can be transmitted.

Since the transmission and reception of circularly polarized waves are reversible, the fact that the first frequency circularly polarized waves can be transmitted means that the first frequency circularly polarized waves can be received. That is, according to the above configuration, it is also possible to receive the circularly polarized wave of the first frequency. The same applies to the second frequency.

That is, according to the configuration described above, it is possible to transmit and receive the circularly polarized waves of the first frequency and the second frequency. Further, according to the above configuration, the number of feeding points required to transmit and receive the circularly polarized waves of the first frequency and the second frequency may be two. That is, according to the above configuration, the number of feeding points can be suppressed in the antenna device capable of receiving circularly polarized waves of two frequencies.

The reference numerals in parentheses described in the claims indicate, as one embodiment, the correspondence with the specific means described in the embodiments described later, and limit the technical scope of the present invention. is not it.

It is an external perspective view of the antenna device 100 in this embodiment. It is sectional drawing of the antenna device 100. It is a figure for demonstrating the role of the L-shaped slit 4. It is a figure for demonstrating the structure of the patch pattern 2. It is a figure for demonstrating operation at a 1st frequency. It is a figure for demonstrating operation at a 2nd frequency. It is a figure which shows the result of having tested the axial ratio and gain for each frequency. It is a figure which shows the result of having tested the directivity in the vertical plane at the 1st frequency. It is a figure which shows the result of having tested the directivity in the vertical plane at the 2nd frequency. It is a figure for demonstrating the structure of the modification 1. FIG. It is a figure which showed the structure of the modification 2. It is a figure which showed an example of the structure of the modification 3. It is a figure which showed an example of the structure of the modification 3. It is a figure which showed an example of the structure of the modification 3. It is a figure which showed an example of the structure of the modification 3. It is a figure which showed an example of the structure of the modification 4. It is a figure which showed an example of the structure of the modification 4.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The antenna device 100 according to the present embodiment is configured to transmit and receive right-handed circularly polarized waves of two predetermined frequencies, the first frequency and the second frequency, as described below. Here, as an example, the first frequency is set to 1170 MHz, and the second frequency is set to 1550 MHz. Of the two frequencies to be transmitted and received, the one that is relatively low corresponds to the first frequency.

Of course, the radio wave to be transmitted and received (hereinafter, the target radio wave) may be appropriately designed, and may be, for example, a radio wave of 1276 MHz, 760 MHz, 900 MHz, 1.575 GHz, 5.9 GHz, or the like as another embodiment. Further, the antenna device 100 may be configured to be able to transmit and receive radio waves in a predetermined frequency band determined with reference to the first frequency. The same applies to the second frequency. The antenna device 100 may be configured to transmit and receive left-handed circularly polarized waves instead of right-handed circularly polarized waves. Further, the antenna device 100 may be provided for only one of transmission and reception.

Hereinafter, the wavelength of the radio wave of the first frequency will be referred to as the first wavelength, and the wavelength of the radio wave of the second frequency will be referred to as the second wavelength. Hereinafter, λ1 refers to the first wavelength, and λ2 refers to the second wavelength. For example, 0.5 × λ1 means half the length of the first wavelength, and 0.25 × λ2 means one quarter of the length of the second wavelength.

The antenna device 100 is connected to a radio (not shown) via a coaxial cable, for example, and the signals received by the antenna device 100 are sequentially output to the radio. Further, the antenna device 100 converts an electric signal input from the radio into radio waves and radiates it into space. The radio uses the signal received by the antenna device 100 and supplies high-frequency power corresponding to the transmission signal to the antenna device 100.

A circuit for matching impedance (so-called impedance matching circuit) may be provided at the connection portion between the antenna device 100 and the coaxial cable. Further, in addition to the impedance matching circuit, a phase adjusting circuit may be provided at the connection portion between the antenna device 100 and the coaxial cable. The phase adjustment circuit is a circuit that distributes and outputs a current of a predetermined frequency (hereinafter, operating frequency) input from the inner conductor of a coaxial cable to two currents having a phase difference of 90 °. The phase adjustment circuit may be realized by using a well-known 90 ° hybrid circuit (in other words, a branch line coupler). In the present embodiment, the case where the antenna device 100 and the radio are connected by a coaxial cable will be described, but other well-known power feeding cables such as a feeder wire may be used for the connection.

<Configuration of antenna device 100>
Hereinafter, a specific configuration of the antenna device 100 will be described. As shown in FIGS. 1 and 2, the antenna device 100 includes a main plate 1, a patch pattern 2, a support portion 3, an L-shaped slit 4, a first feeding point 5, and a second feeding point 6. For convenience, each part will be described below with the side where the patch pattern 2 is provided on the main plate 1 as the upper side for the antenna device 100.

The main plate 1 is a plate-shaped (including foil) conductor member made of a conductor such as copper. The main plate 1 is electrically connected to the outer conductor of the coaxial cable to provide a ground potential (in other words, a ground potential) in the antenna device 100. The main plate 1 may have a size necessary for stable operation of the antenna device 100. The main plate 1 may be set to a size of at least patch pattern 2 or more. Here, as an example, it is assumed that the size is set to about 1.1 times that of the patch pattern 2, but as another configuration, the main plate 1 may be formed to have the same dimensions as the patch pattern 2.

Further, the shape of the main plate 1 viewed from above (hereinafter referred to as a planar shape) may be appropriately designed. Here, as an example, the plane shape of the base plate 1 is a square shape, but as another aspect, the plane shape of the base plate 1 may be a rectangle other than a square shape, or may be another polygonal shape. Further, it may be circular (including an ellipse). Of course, the shape may be a combination of a straight portion and a curved portion.

The patch pattern 2 is a plate-shaped conductor member made of a conductor such as copper. The patch pattern 2 is arranged so as to face the main plate 1 by the support portion 3. Here, as an example, the planar shape of the patch pattern 2 is a square. As another aspect, the patch pattern 2 may be a circle, a regular hexagon, a regular octagon, a regular triangle, or the like.

The length of one side of the patch pattern 2 (hereinafter referred to as the patch length) L1 is electrically set to a length corresponding to 0.5 × λ1 so as to resonate at the first frequency. The electrical length here is an effective length in consideration of the fringing electric field and the wavelength shortening effect of the dielectric. If the first wavelength λ1 is shortened by the support portion 3 made of a dielectric material, the length may be half of the shortened wavelength. Here, as an example, it is assumed that the first wavelength λ1 is shortened to 44 mm by the support portion 3.

Considering the fringed electric field, the actual length of one side can be set to half or less of the first wavelength λ1. For example, the patch length L1 may be set to a length of about 40% of the first wavelength λ1. Further, the patch length L1 can resonate at the first frequency even if it is set to a length of about 60% of the first wavelength λ1. The patch length L1 is a parameter that should be fine-tuned to obtain the desired antenna characteristics (eg, axial ratio and gain).

For convenience, the configuration of the antenna device 100 will be described below by appropriately introducing the concept of a three-dimensional coordinate system having X, Y, and Z axes orthogonal to each other. The X-axis is an axis parallel to one side of the patch pattern 2, and the Y-axis is an axis orthogonal to the X-axis in a plane parallel to the patch pattern 2 including the X-axis. The Z-axis is orthogonal to each of the X-axis and the Y-axis, and the direction from the main plate 1 to the patch pattern 2 is the positive direction.

The patch pattern 2 is provided with a first feeding point 5 and a second feeding point 6 as feeding points. The first feeding point 5 and the second feeding point 6 are portions where the inner conductor of the coaxial cable and the patch pattern 2 are electrically connected via the phase adjustment circuit, respectively. The installation positions of the first feeding point 5 and the second feeding point 6 on the patch pattern 2 will be described later separately.

The support portion 3 is a member for supporting the position and posture of the patch pattern 2 with respect to the main plate 1. Here, as an example, the support portion 3 is a plate-shaped member made of a dielectric material such as resin and having a predetermined thickness. The thickness of the support portion 3 may be appropriately designed according to the first wavelength λ1 and the second wavelength λ2. For example, the thickness is set to 5 mm.

The support portion 3 may be formed by using a dielectric material having a predetermined relative permittivity. For example, the support portion 3 may be realized by using a dielectric having a relative permittivity of about 36. If the support portion 3 is realized by using a dielectric having a relative permittivity of 36, the first wavelength λ1 and the second wavelength λ2 are 6 minutes of the length in vacuum due to the wavelength shortening effect of the support portion 3. It is shortened to about 1. Specifically, the first wavelength λ1 is shortened to 43 mm, and the second wavelength λ2 is shortened to 32 mm. Of course, the relative permittivity of the dielectric material constituting the support portion 3 may be appropriately designed, and may be 30, 38, 40, or the like.

The support portion 3 may fulfill the above-mentioned role, and the shape of the support portion 3 is not limited to the plate shape. As another embodiment, the support portion 3 may be a plurality of pillars that support the main plate 1 and the patch pattern 2 so as to face each other at a predetermined interval. Further, in the present embodiment, it is assumed that the space between the main plate 1 and the patch pattern 2 is filled with a resin (that is, the support portion 3), but the present invention is not limited to this. A part or all of the space sandwiched between the main plate 1 and the patch pattern 2 may be hollow. When the antenna device 100 is realized by using the printed wiring board, the plurality of conductor layers provided in the printed wiring board are used as the main plate 1 and the patch pattern 2, and the resin layer separating the conductor layers is supported. It may be used as a part 3.

The L-shaped slit 4 is a slit extending in an L shape in the patch pattern 2. The corner portion of the L-shaped slit 4 is located on one diagonal line of the patch pattern 2, and the straight line portion is arranged so as to be parallel to each of the X-axis and the Y-axis. As a result, the region surrounded by the L-shaped slit 4 and the edge portion of the patch pattern 2 (the region with hatching in FIG. 3) has a shape similar to that of the patch pattern 2. In other words, the L-shaped slit 4 is arranged so as to form a sub-patch portion 21 having a similar shape to the patch pattern 2 in cooperation with a part of the edge portion of the patch pattern 2. The subpatch section 21 is a region in which a resonance current flows at the second frequency, as will be described later. Since the patch pattern 2 of the present embodiment has a square shape, the sub-patch portion 21 also has a square shape.

The corners of the L-shaped slit 4 are located on the diagonal line of the patch pattern 2 so that the length L2 of one side of the subpatch portion 21 (hereinafter referred to as the subpatch length) L2 electrically has a length corresponding to 0.5 × λ2. Have been placed. That is, they are arranged at a position 0.5 × λ2 away from one corner of the patch pattern 2 in the X-axis direction and 0.5 × λ2 away from the corner in the Y-axis direction.

The region indicated by reference numeral 22 in FIG. 3 is a region (hereinafter, a surplus region) other than the subpatch portion 21 in the patch pattern 2. Since the sub-patch portion 21 of the present embodiment is formed so as to share one corner portion of the patch pattern 2, the surplus region 22 is approximately L in which the length in the X-axis direction and the length in the Y-axis direction are substantially equal. It becomes a character shape. The X-axis direction corresponds to the first axis direction according to the claim, and the Y-axis direction corresponds to the second axis direction according to the claim.

For convenience, hereinafter, the portion of the L-shaped slit 4 parallel to the X-axis will be referred to as the X-axis parallel portion 4X, and the portion parallel to the Y-axis will be referred to as the Y-axis parallel portion 4Y. In other words, the X-axis parallel portion 4X is a linear slit formed so as to face one side parallel to the X-axis included in the patch pattern 2 with 0.5 × λ2. Further, the Y-axis parallel portion 4Y is, in other words, a linear slit formed so as to face one side parallel to the Y-axis included in the patch pattern 2 with 0.5 × λ2.

The lengths of the X-axis parallel portion 4X and the Y-axis parallel portion 4Y may be appropriately designed. The length of the X-axis parallel portion 4X and the Y-axis parallel portion 4Y is half of the subpatch length L2 (that is, 0. It is preferable that the value is set longer than 25 × λ2). However, the lengths of the X-axis parallel portion 4X and the Y-axis parallel portion 4Y are set to a value smaller than the subpatch length L2 so that the subpatch portion 21 and the remainder region 22 are not completely separated. do. That is, the lengths of the X-axis parallel portion 4X and the Y-axis parallel portion 4Y are set to values longer than 0.25 × λ2 and shorter than 0.5 × λ2, respectively.

Here, as an example, it is assumed that the lengths of the X-axis parallel portion 4X and the Y-axis parallel portion 4Y are set to 0.9 × L2 = 0.45 × λ2. Of course, the value to be multiplied by L2 is not limited to 0.9, and may be 0.6, 0.7, 0.8, or the like. The X-axis parallel portion 4X and the Y-axis parallel portion 4Y do not necessarily have the same length. The X-axis parallel portion 4X and the Y-axis parallel portion 4Y may be set to different lengths.

The width (hereinafter, slit width) W of the X-axis parallel portion 4X and the Y-axis parallel portion 4Y does not hinder the propagation of the current of the first frequency, but hinders (in other words, suppresses) the propagation of the current of the second frequency. It is set to the length. According to such a setting, in the L-shaped slit 4, the subpatch portion 21 and the surplus region are capacitively coupled at the first frequency to excite the entire patch pattern 2, while the subpatch portion 21 is the surplus region 22 at the second frequency. It has the effect of exciting independently of.

For example, if the slit width W is set to 1/10 or more of the second wavelength λ2, the propagation of the current of the second frequency to the remainder region 22 can be suppressed (in other words, hindered) to some extent. Further, the larger the slit width W, the more the propagation of the current of the second frequency to the remainder region 22 can be suppressed. Therefore, the slit width W is preferably set to 1/10 or more of the second wavelength λ2. However, if the slit width W is too large, the L-shaped slit 4 hinders the propagation of the current of the second frequency. Therefore, it is preferable that the slit width W is set to a value of 1/10 or more of the second wavelength λ2 and 1/10 or less of the first wavelength λ1.

The antenna device 100 described above is used in a moving body such as a vehicle, for example. When the antenna device 100 is used in a vehicle, it may be installed on the roof of the vehicle so that the main plate 1 is substantially horizontal and the direction from the main plate 1 to the patch pattern 2 substantially coincides with the zenith direction. ..

<About the installation position of the feeding point>
Here, the shape of the patch pattern 2 will be described again with reference to FIG. 4, and the installation positions of the first feeding point 5 and the second feeding point 6 in the patch pattern 2 will be described. First, as a premise, since the patch pattern 2 in the present embodiment has a square shape, the patch pattern 2 passes through the center C1 of the patch pattern 2 and is parallel to the X axis (hereinafter, the first horizontal axis) Ax1. It is line symmetric. The patch pattern 2 is also axisymmetric with respect to a straight line (hereinafter, the first vertical axis) Ay1 that passes through the center C1 and is parallel to the Y axis. That is, the patch pattern 2 is formed in a shape that is line-symmetrical with respect to each of the two axes of symmetry that are orthogonal to each other.

Further, since the sub-patch portion 21 has a similar shape to the patch pattern 2, the sub-patch portion 21 is also formed in a shape that is axisymmetric with respect to each of the two axes of symmetry orthogonal to each other. That is, the subpatch portion 21 is line-symmetric with respect to the straight line (hereinafter, the second horizontal axis) Ax2 that passes through the center C2 of the subpatch portion 21 and is parallel to the X axis, and is parallel to the Y axis through the center C2. It is also axisymmetric with respect to the straight line (hereinafter, the second vertical axis) Ay2. The second horizontal axis Ax2 corresponds to the third axis according to the claim, and the second vertical axis Ay2 corresponds to the fourth axis according to the claim.

As shown in FIG. 4, the first feeding point 5 and the second feeding point 6 are arranged in at least the region that becomes the subpatch portion 21. Specifically, the first feeding point 5 is arranged at the intersection of the first horizontal axis Ax1 and the second vertical axis Ay2, and the second feeding point 6 is the intersection of the first vertical axis Ay1 and the second horizontal axis Ax2. Place in. For the patch pattern 2, such a layout corresponds to a configuration in which one feeding point is arranged on each of two axes Ax1 and Ay1 orthogonal to each other passing through the center C1. Further, the subpatch portion 21 also corresponds to a configuration in which one feeding point is arranged on each of two axes Ax2 and Ay2 orthogonal to each other passing through the center C2. The first horizontal axis Ax1 corresponds to the first axis according to the claim, and the first vertical axis Ay1 corresponds to the second axis according to the claim.

The feeding to the first feeding point 5 may be realized by using a conductive pin (hereinafter, feeding pin) that is electrically connected to the inner conductor of the coaxial cable. The feeding pin penetrates the main plate 1 and the support portion 3 to connect one point of the patch pattern 2 (that is, the first feeding point 5) and the internal conductor. The second feeding point 6 may also be realized by using the feeding pin. A hole is provided in the main plate 1 at a position overlapping the first feeding point 5 to ensure non-contact with the feeding pin. Further, a hole portion for ensuring non-contact with the feeding pin forming the second feeding point 6 is also provided at a position of the main plate 1 overlapping the second feeding point 6. The mode in which the internal conductor of the coaxial cable and the feeding pin are electrically connected is not only a mode in which they are directly connected, but also a mode in which an impedance matching circuit or a phase adjustment circuit is interposed between them. included.

In this embodiment, a direct power feeding method using a conductive pin is adopted as a power feeding method for the patch pattern 2, but the present invention is not limited to this. As another embodiment, an electromagnetic coupling power feeding method using a microstrip line or the like may be adopted.

<Operation of antenna device 100>
The above-mentioned installation mode of the first feeding point 5 and the second feeding point 6 has a configuration in which the feeding points are arranged one by one on two axes Ax1 and Ay1 orthogonal to each other passing through the center C1 for the patch pattern 2. Equivalent to. Further, the length in the direction in which the first horizontal axis Ax1 of the patch pattern 2 extends and the length in the direction in which the first vertical axis Ay1 extends are both electrically set to lengths corresponding to 0.5 × λ1. .. Therefore, by passing a current having a first frequency and a phase shift of 90 ° from each of the first feeding point 5 and the second feeding point 6, two currents orthogonal to each other are patched as shown in FIG. It can be excited on the pattern 2.

That is, according to the above configuration, the circularly polarized wave of the first frequency can be transmitted. Since the transmission / reception of radio waves is reversible, the fact that the circularly polarized waves of the first frequency can be transmitted means that the circularly polarized waves of the first frequency can be received. That is, according to the above configuration, it is also possible to receive the circularly polarized wave of the first frequency.

Further, in the above-mentioned installation mode of the first feeding point 5 and the second feeding point 6, for the subpatch portion 21, one feeding point is arranged one by one on two axes Ax2 and Ay2 orthogonal to each other passing through the center C2. Corresponds to the configuration. Further, the length of the subpatch portion 21 in the direction in which the second horizontal axis Ax2 extends and the length in the direction in which the second vertical axis Ay2 extends are both electrically set to lengths corresponding to 0.5 × λ2. .. Therefore, as shown in FIG. 6, two currents orthogonal to each other are generated by passing a current having a second frequency and a phase shift of 90 ° from each of the first feeding point 5 and the second feeding point 6. It can be excited on the sub-patch portion 21.

That is, according to the above configuration, the circularly polarized wave of the second frequency can be transmitted. Further, since the transmission / reception of radio waves is reversible, the fact that the circularly polarized waves of the second frequency can be transmitted means that the circularly polarized waves of the second frequency can be received. That is, according to the above configuration, it is also possible to receive the circularly polarized wave of the second frequency.

As described above, the antenna device 100 of the present embodiment can receive the circularly polarized waves of the first frequency and the second frequency, respectively. Further, the number of feeding points required to receive the circularly polarized waves of the first frequency and the second frequency may be two. That is, according to the above configuration, the number of feeding points can be suppressed in the antenna device capable of receiving circularly polarized waves of two frequencies.

FIG. 7 shows the results of testing the axial ratio and gain of circularly polarized waves for each frequency having the above configuration. The solid line in FIG. 7 represents the axial ratio for each frequency, and the broken line represents the gain for each frequency. As shown in FIG. 7, according to the above configuration, at 1170 MHz, which is the first frequency, an axial ratio of 2.5 dB can be achieved and a gain of 4.4 dBic can be realized. Further, at 1550 MHz, which is the second frequency, an axial ratio of 2 dB can be achieved, and a gain of 4.3 dBic can be realized. That is, it is possible to achieve both the axial ratio and the gain at each of the first frequency and the second frequency. As an antenna for transmitting / receiving circularly polarized waves, it is sufficient if the axial ratio is suppressed to 3 dB or less.

FIG. 8 is a diagram showing the results of testing the radiation directivity on the vertical plane at the first frequency, and FIG. 9 is a diagram showing the results of testing the radiation directivity on the vertical plane at the second frequency. As shown in FIGS. 8 and 9, the gain of right-handed circularly polarized wave can be set sufficiently larger than the gain of left-handed circularly polarized wave at both the first frequency and the second frequency. That is, the performance is sufficient as an antenna for transmitting or receiving right-handed circularly polarized waves of the first frequency.

By the way, as another configuration for transmitting or receiving the right-handed circularly polarized wave of the first frequency (hereinafter referred to as a comparative configuration), a patch pattern for the first frequency and a patch pattern for the second frequency are laminated. , An antenna device capable of transmitting and receiving circularly polarized waves of the first and second frequencies is assumed. In such a comparative configuration, it is necessary to stack patch patterns corresponding to each frequency, so that the height of the antenna device as a whole may increase. On the other hand, according to the antenna device 100 of the present embodiment, since a region operating at the first frequency and a region operating at the second frequency are formed in one plane, the height of the antenna device 100 is suppressed. be able to.

Further, the antenna device 100 forms a region to be excited at the second frequency in the patch pattern 2 by providing a slit in the patch pattern 2. That is, the subpatch portion 21 that provides the receiving function of the circularly polarized wave of the second frequency is formed inside the patch pattern 2. Therefore, the size of the antenna device 100 in the XY plane can be suppressed.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications described below are also included in the technical scope of the present invention, and other than the following. Can be implemented with various changes within the range that does not deviate from the gist. The members having the same functions as the members described in the above-described embodiment are designated by the same reference numerals, and the description thereof will be omitted. Further, when only a part of the configuration is referred to, the configuration of the embodiment described above can be applied to the other parts.

[Modification 1]
In the above-described embodiment, the configuration in which the feeding points are arranged at the intersections of the first horizontal axis Ax1 and the second vertical axis Ay2 and the intersections of the first vertical axis Ay1 and the second horizontal axis Ax2 is disclosed. Not limited to this. Each feeding point may be arranged at a position deviated from each axis. The first feeding point 5 may be arranged at a position where the distance from the first horizontal axis Ax1 is within a predetermined allowable distance and the distance from the second vertical axis Ay2 is within the allowable distance. Further, the second feeding point 6 may be arranged at a position where the distance from the first vertical axis Ay1 is within the permissible distance and the distance from the second horizontal axis Ax2 is within the permissible distance. Ar1 in FIG. 10 conceptually represents a region in which the distance from the first horizontal axis Ax1 is within a predetermined allowable distance and the distance from the second vertical axis Ay2 is within the allowable distance. Further, Ar2 in FIG. 10 conceptually represents a region in which the distance from the first vertical axis Ay1 is within the permissible distance and the distance from the second horizontal axis Ax2 is within the permissible distance.

The permissible distance here is an upper limit value of the distance at which the deterioration of the axial ratio and the gain due to the impedance mismatch is within a predetermined permissible range. The permissible distance with respect to the first vertical axis Ay1 and the first horizontal axis Ax1 and the permissible distance with respect to the second vertical axis Ay2 and the second horizontal axis Ax2 may be set to different values. In that case, the permissible distance with respect to the first vertical axis Ay1 and the first horizontal axis Ax1 is a value obtained by multiplying the first wavelength λ1 by a predetermined ratio (for example, 1/20), and the second vertical axis Ay2 and the second horizontal axis Ax2. The permissible distance to the second wavelength λ2 may be a value obtained by multiplying the second wavelength λ2 by a predetermined ratio (for example, 1/20).

[Modification 2]
As another aspect, as shown in FIG. 11, a circle having a radius R1 centered on the center C1 (hereinafter, the first circle) and a circle having a radius R2 centered on the center C2 (hereinafter, the first circle). A feeding point may be arranged at the intersection of the second circle). The radius R1 may be set to a value larger than the length from the center C1 to the center C2. Further, the value of the radius R2 is preferably set so that the ratio of the radius R1 and the radius R2 matches the ratio of the first wavelength λ1 and the second wavelength λ2. The radius R1 corresponds to the first length according to the claim, and the radius R2 corresponds to the second length according to the claim.

According to the above configuration, the distances from each of the center C1 and the center C2 to each feeding point are equal, so that the impedances at the two frequencies are close to each other. As a result, one impedance matching circuit can be shared by two frequencies, and the circuit configuration can be simplified. The impedance matching state is not limited to a perfect matching state, but includes a state in which the loss due to impedance mismatching is within a predetermined allowable range.

[Modification 3]
In the above-described embodiment and the like, an embodiment in which the sub-patch portion 21 is formed by providing an L-shaped slit formed in a single connection is disclosed, but the embodiment of the slit for realizing the sub-patch portion 21 is described in this embodiment. Not exclusively.

For example, as shown in FIG. 12, the subpatch portion 21 may be formed by arranging the linear slits 41 and 42 along the edge portion of the subpatch portion 21. Such a configuration corresponds to a configuration in which the X-axis parallel portion 4X and the Y-axis parallel portion 4Y of the L-shaped slit 4 are separated by a corner portion. The slit 41 and the X-axis parallel portion 4X correspond to the first slit according to the claim, and the slit 42 and the Y-axis parallel portion 4Y correspond to the second slit according to the claim.

Further, as shown in FIG. 13, instead of setting the X-axis parallel portion 4X and the Y-axis parallel portion 4Y to be relatively short, the subpatch portion 21 is provided by arranging linear slits 41 and 42 on the extension lines thereof. May be formed. The total length of the slits arranged in series in the X-axis direction may be electrically equivalent to 0.5 × λ2. Similarly, the total length of the slits arranged in series in the Y-axis direction may be electrically equivalent to 0.5 × λ2. In such a configuration, the subpatch portion 21 and the surplus region 22 are electrically inserted in the middle of the L-shaped slit 4 having the X-axis parallel portion 4X and the Y-axis parallel portion 4Y set to 0.5 × λ2. It corresponds to a configuration divided into a plurality of sections by providing a bridging portion to be connected.

Further, the sub-patch portion 21 may be realized by intermittently arranging a plurality of slits along the virtual contour line of the sub-patch portion 21. In that case, the total length of the slits arranged along the portion parallel to the X-axis of the contour line of the sub-patch portion 21 may be 0.25 × λ2 or more. Of the contour lines of the subpatch portion 21, the slits arranged along the portion parallel to the Y axis may also have a total length of 0.25 × λ2 or more. The sub-patch portion 21 and the surplus region 22 need only be electrically connected at at least one place, and as shown in FIG. 14, even if the slit 41 and the slit 42 are connected to the edge portion of the patch pattern 2. good.

Further, the sub-patch portion 21 may be formed by providing a U-shaped slit (hereinafter, U-shaped slit) 4B as shown in FIG. Naturally, the U-shaped slit 4B shown in FIG. 15 may be divided into a plurality of sections. Further, the lengths of the two portions (in other words, the left and right legs) parallel to the Y axis in the U-shaped slit 4B may be set to different values.

The subpatch portion 21 does not necessarily have to be arranged at the corner portion. As shown in FIG. 15, the symmetry axis of the patch pattern 2 and the symmetry axis of the subpatch portion 21 may be formed at positions where they do not overlap. However, if it is arranged at the corner, the portion where the edge portion of the patch pattern 2 can be used as the edge portion of the subpatch portion 21 becomes longer, so that the subpatch portion 21 can be stably operated as a region for exciting at the second frequency. can. Further, the length of the slit formed in the patch pattern 2 can be reduced, and the labor of processing can be suppressed. Therefore, it is preferable that the subpatch portion 21 is arranged at the corner portion.

[Modification example 4]
In the above, the aspect in which the shape of the patch pattern 2 is a square shape is disclosed, but the present invention is not limited to this. The patch pattern 2 may be formed in a shape that is line-symmetrical with respect to each of the two axes whose angles formed by each other can be regarded as right angles. The angle that can be regarded as a right angle here is an angle included in a predetermined angle range centered on 90 °. Here, an angle from 60 ° to 120 ° can be regarded as a right angle. Therefore, in addition to squares, circles (including ellipses), rectangles other than squares, regular octagons, regular hexagons, regular triangles, etc., have two axes whose angles are considered to be right angles. It corresponds to a shape that is line-symmetrical with respect to each.

Therefore, for example, the patch pattern 2 may be formed in a rectangular shape as shown in FIG. However, when the patch pattern 2 is formed in a rectangular shape, the lengths of the long side and the short side are electrically set so that the axial ratio of circularly polarized waves is within a predetermined allowable range (for example, 3 dB). It is assumed that the length corresponding to 0.5 × λ2 and the value determined as a reference are set.

Further, the patch pattern 2 may be formed in a circular shape as shown in FIG. In that case, by arranging the arc-shaped slit (hereinafter, arc-shaped slit) 4C, a circular subpatch portion 21 having a diameter half the length of the second wavelength λ2 may be formed. The length of the arc-shaped slit 4C is preferably half or more, more preferably 70% or more of one circumference. The circle corresponds to a shape having innumerable axes of symmetry. As the axis corresponding to the first horizontal axis Ax1 and the first vertical axis Ay1, two lines that pass through the center of the circle and are orthogonal to each other may be adopted. Two lines that pass through the center of the circle and form an angle of 60 ° or more with each other may be adopted as the first horizontal axis Ax1 or the first vertical axis Ay1. The second horizontal axis Ax2 may be a line parallel to the first horizontal axis Ax1 and passing through the center of the subpatch portion 21. The second vertical axis Ay2 may be a line parallel to the first vertical axis Ay1 and passing through the center of the subpatch portion 21.

100 Antenna device, 1 base plate, 2 patch pattern, 3 support part, 4 L-shaped slit, 5 1st feeding point, 6th 2nd feeding point, 21 sub-patch part, Ax1 1st horizontal axis, Ay1 1st vertical axis, Ax2 1st 2 horizontal axis, Ay2 2nd vertical axis

Claims (9)

An antenna device for transmitting or receiving each of a predetermined first frequency circularly polarized wave and a predetermined second frequency circularly polarized wave higher than the first frequency.
The main plate (1), which is a plate-shaped conductor member, and
The first axis (Ax1), which is a plate-shaped conductor member installed so as to face the main plate at a predetermined distance, and the angle formed by each other is an angle that can be regarded as a right angle. ) And the patch pattern (2) formed in a line-symmetrical shape with respect to each of the second axis (Ay1).
The first feeding point (5) as a feeding point and
A second feeding point (6) as a feeding point provided at a position different from the first feeding point is provided.
The length in the first axis direction and the length in the second axis direction of the patch pattern are both electrically set to a length corresponding to half of the first wavelength, which is the wavelength of the radio wave of the first frequency. Ori,
In the patch pattern, at least one slit (4) having a width that hinders the propagation of the current of the first frequency while not hindering the propagation of the current of the second frequency is arranged.
The patch pattern has a subpatch portion (21) having a shape similar to the patch pattern and having a shape symmetrical with respect to each of a straight line parallel to the first axis and a straight line parallel to the second axis. Arranged to form in collaboration with part of the edge of the
The length of the subpatch portion in the direction in which the third axis, which is the straight line parallel to the first axis and acts as the axis of symmetry of the subpatch portion, extends, and the subpatch parallel to the second axis. The length in the direction in which the fourth axis, which is the straight line acting as the axis of symmetry of the unit, extends is electrically set to a length corresponding to half of the second wavelength, which is the wavelength of the radio wave of the second frequency. And
In the patch pattern, the surplus area, which is a region other than the subpatch portion, and the subpatch portion are electrically connected at at least one place.
The first feeding point is arranged at a point where the first axis and the fourth axis intersect in the subpatch portion.
The antenna device is characterized in that the second feeding point is arranged at a point where the second axis and the third axis intersect in the subpatch portion. An antenna device for transmitting or receiving each of a predetermined first frequency circularly polarized wave and a predetermined second frequency circularly polarized wave higher than the first frequency.
The main plate (1), which is a plate-shaped conductor member, and
The first axis (Ax1), which is a plate-shaped conductor member installed so as to face the main plate at a predetermined distance, and the angle formed by each other is an angle that can be regarded as a right angle. ) And the patch pattern (2) formed in a line-symmetrical shape with respect to each of the second axis (Ay1).
The first feeding point (5) as a feeding point and
A second feeding point (6) as a feeding point provided at a position different from the first feeding point is provided.
The length in the first axis direction and the length in the second axis direction of the patch pattern are both electrically set to a length corresponding to half of the first wavelength, which is the wavelength of the radio wave of the first frequency. Ori,
In the patch pattern, at least one slit (4) having a width that hinders the propagation of the current of the first frequency while not hindering the propagation of the current of the second frequency is arranged.
The patch pattern has a subpatch portion (21) having a shape similar to the patch pattern and having a shape symmetrical with respect to each of a straight line parallel to the first axis and a straight line parallel to the second axis. Arranged to form in collaboration with part of the edge of the
The length of the subpatch portion in the direction in which the third axis, which is the straight line parallel to the first axis and acts as the axis of symmetry of the subpatch portion, extends, and the subpatch parallel to the second axis. The length in the direction in which the fourth axis, which is the straight line acting as the axis of symmetry of the unit, extends is electrically set to a length corresponding to half of the second wavelength, which is the wavelength of the radio wave of the second frequency. And
In the patch pattern, the surplus area, which is a region other than the subpatch portion, and the subpatch portion are electrically connected at at least one place.
The first feeding point is a first circle centered on the intersection of the first axis and the second axis and having a predetermined first length as a radius, and the third axis and the first feeding point. It is arranged at one of the intersections with the second circle, which is a circle centered on the intersection with the four axes and having a predetermined second length shorter than the first length as the radius.
An antenna device characterized in that the second feeding point is arranged at the other of the intersections of the first circle and the second circle. The antenna device according to claim 2.
Each of the first length and the second length is set so that the ratio of the first length to the second length is equal to the ratio of the first wavelength to the second wavelength. Characterized antenna device. The antenna device according to any one of claims 1 to 3.
An antenna device characterized in that the slit is formed so that the third axis does not overlap with the first axis and the fourth axis does not overlap with the second axis. An antenna device for transmitting or receiving each of a predetermined first frequency circularly polarized wave and a predetermined second frequency circularly polarized wave higher than the first frequency.
The main plate (1), which is a plate-shaped conductor member, and
The first axis (Ax1), which is a plate-shaped conductor member installed so as to face the main plate at a predetermined distance, and the angle formed by each other is an angle that can be regarded as a right angle. ) And the patch pattern (2) formed in a line-symmetrical shape with respect to each of the second axis (Ay1).
The first feeding point (5) as a feeding point and
A second feeding point (6) as a feeding point provided at a position different from the first feeding point is provided.
The length in the first axis direction and the length in the second axis direction of the patch pattern are both electrically set to a length corresponding to half of the first wavelength, which is the wavelength of the radio wave of the first frequency. Ori,
In the patch pattern, at least one slit (4) having a width that hinders the propagation of the current of the first frequency while not hindering the propagation of the current of the second frequency is arranged.
The patch pattern has a subpatch portion (21) having a shape similar to the patch pattern and having a shape symmetrical with respect to each of a straight line parallel to the first axis and a straight line parallel to the second axis. Arranged to form in collaboration with part of the edge of the
The length of the subpatch portion in the direction in which the third axis, which is the straight line parallel to the first axis and acts as the axis of symmetry of the subpatch portion, extends, and the subpatch parallel to the second axis. The length in the direction in which the fourth axis, which is the straight line acting as the axis of symmetry of the unit, extends is electrically set to a length corresponding to half of the second wavelength, which is the wavelength of the radio wave of the second frequency. And
In the patch pattern, the surplus area, which is a region other than the subpatch portion, and the subpatch portion are electrically connected at at least one place.
The first feeding point and the second feeding point are arranged in the subpatch portion .
An antenna device characterized in that the slit is formed so that the third axis does not overlap with the first axis and the fourth axis does not overlap with the second axis. The antenna device according to any one of claims 1 to 5.
The patch pattern is a square shape in which the length of one side is set to a length corresponding to half of the first wavelength.
The patch pattern includes a first slit (4X, 41) which is a slit extending parallel to the first axis and a slit extending parallel to the second axis as the slit. A second slit (4Y, 42) is provided.
An antenna device characterized in that the lengths of the first slit and the second slit are both set to a value shorter than half of the second wavelength. The antenna device according to claim 6.
An antenna device characterized in that the length of each of the first slit and the second slit is longer than a quarter of the second wavelength. The antenna device according to claim 6 or 7.
The antenna device is characterized in that the slit is L-shaped as a whole, and one corner portion of the patch pattern is arranged so as to be one corner portion of the sub-patch portion. The antenna device according to any one of claims 1 to 8.
An antenna device characterized in that the width of the slit is set to a value smaller than one tenth of the first wavelength and larger than one tenth of the second wavelength.

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