JP2021197564A - Antenna device - Google Patents

Abstract

To provide an antenna device that improves the isolation of diffraction electric waves in which a transmission circular polarization is diffracted above a head apex portion of a conductor wall.SOLUTION: An antenna device includes: a transmission array antenna portion; a reception array antenna portion; and a conductor wall that is disposed between the transmission arrange antennal portion and the reception array antenna portion, and shuts down the direct waves of transmission circular polarization to the reception array antenna portion. The conductor wall has: a transmission side side wall portion of the conductive wall formed on the transmission array antenna portion; a reception array antenna portion; a reception side side wall portion of the conductor wall opposite to the transmission side side wall portion and formed on the reception array antenna portion; and a head apex portion of the conductor wall continuing to the transmission side wall portion and the reception side wall portion. The conductor wall has an isolation acting portion that acts on diffraction electric waves in which the transmission circular polarization is diffracted above the head apex portion, to improve isolation between the transmission array antenna portion and the reception array antenna portion.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to an antenna device having a conductor wall that blocks a direct wave of a transmitted radio wave to a receiving antenna.

Conventionally, some antenna devices have a conductor wall (metal wall) that blocks a direct wave of a transmitted radio wave to a receiving antenna (see, for example, Patent Document 1). In addition, Patent Document 1 also discloses that a radio wave absorber (absorbent body) is provided instead of the conductor wall (metal wall). Some radio wave absorbers have a waveform or the like to absorb radio waves having different wavelengths (see, for example, Patent Document 2).

Furthermore, regarding the use of the radio wave absorber, in the wireless system, the radio wave absorber is placed between the transmitting antenna of the main base station and the receiving antenna of the sub base station to block the wave directly to the sub base station. Is based on a reflection path and allows a reflected wave to reach (see, for example, FIG. 1 of Patent Document 3).

On the other hand, FIG. 8 of Patent Document 3 discloses that a phase change plate is arranged between a main base station and a sub base station in place of the radio wave absorber as shown in FIG. 1 above. Has been done. The phase change plate is made of a dielectric. The phase change plate is arranged in a linear path of a direct wave, changes the phase of the direct wave, and aligns the phases of the direct wave and the reflected wave.

Japanese Unexamined Patent Publication No. 10-126146 (Fig. 12) Japanese Unexamined Patent Publication No. 2003-115649 (Fig. 5) JP-A-2009-204344 (Figs. 1 and 8)

However, when the antenna device disclosed in Patent Document 1 is applied to a transmitting antenna unit and a receiving array antenna unit arranged on a coplanar surface, it only deals with direct wave isolation and diffracts radio waves. There was a problem that (diffraction phenomenon) was not taken into consideration. Patent Document 2 and Patent Document 3 also have similar problems and differences in application situations.

The present disclosure is made in order to solve the above-mentioned problems, and relates to an antenna device having improved isolation of diffracted radio waves in which transmitted circularly polarized waves are diffracted over the crown of a conductor wall.

The antenna device according to the present disclosure includes a transmitting array antenna unit that transmits transmitted circularly polarized waves, a receiving array antenna unit that is arranged on the same plane as the transmitting array antenna unit and receives received circularly polarized waves, and the above. The transmitting array antenna section and the receiving antenna section extend in an extending direction intersecting the arranged arrangement direction, and are arranged between the transmitting array antenna section and the receiving antenna section to receive the receiving. The conductor wall is provided with a conductor wall that blocks the direct wave of the transmission circularly polarized wave with respect to the transmission array antenna portion, and the conductor wall includes a transmission side side wall portion of the conductor wall formed on the side of the transmission array antenna portion and the transmission side side wall portion. The receiving side side wall portion of the conductor wall facing the transmitting side side wall portion and formed on the side of the receiving array antenna portion, and the crown portion of the conductor wall continuous with the transmitting side wall portion and the receiving side wall portion. The conductor wall has, and the transmission circular polarization acts on the diffracted radio wave diffracted on the crown to improve the isolation between the transmission array antenna portion and the reception array antenna portion. It is characterized by having an isolation acting portion that causes the antenna to move.

As described above, according to the present disclosure, it is possible to obtain an antenna device that can deal with diffracted radio waves by forming an isolation acting portion on the conductor wall in addition to the conductor wall.

It is a perspective view of the antenna device which concerns on Embodiment 1. FIG. It is a perspective view of the antenna device which is a comparative example of the antenna device which concerns on Embodiment 1. FIG. It is a figure which looked at the antenna device which concerns on Embodiment 2 from the side. It is sectional drawing of the antenna device (with a radome) which concerns on Embodiment 2. FIG. It is a figure which looked at the antenna device which concerns on Embodiment 2 from the side. It is a figure which looked at the antenna device which concerns on Embodiment 3 from the side. It is a figure which looked at the antenna device which concerns on Embodiment 3 from the side. It is a figure which looked at the antenna device which concerns on Embodiment 4 from the side. It is a figure which looked at the antenna device which concerns on Embodiment 5 from the side.

In the present application, the same reference numerals indicate the same or corresponding parts in the drawings, and detailed description thereof will be omitted. Further, the X-axis direction is the arrangement direction, the Y-axis direction is the extension direction, and the Z-axis direction is the height direction. The X-axis and the Y-axis intersect. It is preferably orthogonal. The Z-axis direction is orthogonal to the X-axis and the Y-axis, respectively. The arrangement direction, extension direction, and height direction will be described later. The view seen from the side such as FIG. 3 is a view seen from the Y-axis direction or the X-axis direction. However, FIGS. 7 (B) and 8 (B) are views partially viewed from the Z-axis direction.

Embodiment 1.
Hereinafter, the first embodiment will be described with reference to FIGS. 1 and 2. In FIGS. 1 and 2, the transmission array antenna unit 1 transmits the transmitted circularly polarized wave. An example is an example in which a plurality of patch conductors 3 which are antenna elements are formed on the main surface of a dielectric substrate 2. A ground conductor layer is formed on the other main surface of the dielectric substrate 2. The ground conductor layer is in contact with the base plate 4 of the conductor and is electrically connected. The receiving array antenna unit 5 is arranged on the same plane as the transmitting array antenna unit 1 and receives the received circularly polarized wave. An example is an example in which a plurality of patch conductors 7 which are antenna elements are formed on the main surface of a dielectric substrate 6. A ground conductor layer is formed on the other main surface of the dielectric substrate 6. The ground conductor layer is in contact with the base plate 4 and electrically connected.

In FIGS. 1 and 2, the conductor wall 8 extends in the extending direction (Y-axis direction) where the transmitting array antenna portion 1 and the receiving antenna portion 5 intersect in the arrangement direction (X-axis direction). It is arranged between the transmitting array antenna unit 1 and the receiving antenna unit 5. The conductor wall 8 may be in contact with the base plate 4 and electrically connected, or the conductor wall 8 and the base plate 4 may be integrated. The conductor wall 8 may project in the orthogonal direction (Z-axis direction) so as to stand up from the base plate 4. Such a conductor wall 8 blocks the direct wave of the transmission circularly polarized wave from the transmission array antenna unit 1 with respect to the reception array antenna unit 5. That is, when the height direction (Z-axis direction) orthogonal to the arrangement direction (X-axis direction) and the extension direction (Y-axis direction) is set, the height of the conductor wall 8 is the transmission from the transmission array antenna unit 1. It can be said that the circularly polarized direct wave can be blocked so as not to be received by the receiving array antenna unit 5.

In FIGS. 1 and 2, the conductor wall 8 faces the transmitting side side wall portion 9 and the transmitting side side wall portion 9 of the conductor wall 8 formed on the side of the transmitting array antenna portion 1, and the receiving array antenna portion 5 It has a receiving side wall portion 10 of the conductor wall 8 formed on the side of the above side, and a crown portion 11 of the conductor wall 8 continuous with the transmitting side wall portion 9 and the receiving side wall portion 10. The conductor wall 8 exemplifies a case where the cross-sectional shape where the X-axis and the Z-axis intersect is a quadrangle, but the conductor wall 8 may be a triangle or a trapezoid. That is, the crown 11 may be a flat surface or a sharp surface. That is, the conductor wall 8 may be any as long as it can form the isolation acting portion 12 described below. Specifically, the conductor wall 8 acts on the diffracted radio wave (radio wave due to the diffraction phenomenon) in which the transmission circular polarization is diffracted on the crown 11, and is between the transmission array antenna unit 1 and the reception array antenna unit 5. It has an isolation action unit 12 that improves the isolation of the antenna.

In the antenna device according to the first embodiment, the isolation acting portion 12 may be formed on the crown portion 11, and the isolation acting portion 12 is further formed on the transmitting side side wall portion 9 and the receiving side side wall portion 10. You may. FIG. 1 (A) illustrates the case where the isolation acting portion 12 is formed only on the crown portion 11, and FIG. 1 (B) shows the case where the isolation acting portion 12 is formed on the crown portion 11, the transmitting side wall portion 9, and the receiving portion 11. The case where it is formed on the side wall portion 10 is shown. The isolation acting portion 12 may be formed on any of the crown portion 11, the transmitting side wall portion 9, and the receiving side wall portion 10. The operation of the isolation action unit 12 will be described with reference to FIG. FIG. 2 is a perspective view of an antenna device which is a comparative example of the antenna device according to the first embodiment, and shows an antenna device in which the isolation acting portion 12 is not formed on the conductor wall 8. Other than that, Embodiment 1

In the present application, a phased array antenna is suitable for the transmitting array antenna unit 1 and the receiving antenna unit 5 shown in FIGS. 1 and 2. Further, in order to generate circularly polarized waves in both the transmitting array antenna unit 1 and the receiving antenna unit 5, each antenna element is fed with two ports, and a phase difference of 90 degrees is provided between the ports. .. The frequency (frequency band) used for the transmitted circularly polarized light and the received circularly polarized light may be several GHz to several tens of GHz (for example, X band, Ku band, Ka band, etc.). A transmission circuit is formed after the transmission array antenna unit 1. A receiving circuit is formed after the receiving array antenna unit 5.

When the wireless communication system in which the antenna device shown in FIG. 2 (preferably a phased array antenna) is used is, for example, a time-divided duplex system, transmission of transmitted radio waves (transmitted circularly polarized waves) and received radio waves (received circularly polarized waves) are used. The reception of the wave) is performed in a time-divided manner. Therefore, the antenna device shown in FIG. 2 can sufficiently secure isolation of the transmitted radio wave (transmitted circularly polarized wave) from the receiving circuit regardless of the presence or absence of the conductor wall 8. On the other hand, when the wireless communication system in which the antenna device shown in FIG. 2 (preferably a phased array antenna) is used is, for example, a frequency-divided duplex system, transmission of transmitted radio waves (transmitted circularly polarized waves) and received radio waves (reception). The reception of the circularly polarized wave) is performed at the same time. Therefore, the antenna device shown in FIG. 2 requires isolation of the transmitted radio wave (transmitted circularly polarized wave) from the receiving circuit. In addition, the noise of the transmitting circuit may leak, and the noise figure of the receiving circuit may be deteriorated.

The antenna device shown in FIG. 2 is provided with a conductor wall 8 to realize isolation between circularly polarized waves. That is, the transmitting array antenna unit 1 and the receiving antenna unit 5 are separated from each other by the eight conductor walls, and the direct wave of the transmitted radio wave (transmitted circularly polarized wave) propagating in space is simply blocked by the conductor wall 8. Instead, a conductor such as the conductor wall 8 or the base plate 4 can block the leakage of noise from the transmission circuit. In addition to providing the conductor wall 8, it is also conceivable to form a filter circuit in the transmission circuit and the reception circuit, and to cut off a required frequency band such as the frequency band used by this filter circuit.

However, the scale of the filter circuit and the loss due to it increase depending on the bandwidth between the transmitted radio wave (transmitted circularly polarized wave) and the received radio wave (received circularly polarized wave) and the required amount of cutoff. Further, in the case of a phased array antenna, since it is necessary to provide a filter circuit for each antenna element, it becomes difficult to arrange the element intervals of the antenna elements at a narrow pitch. It is also possible to realize isolation between circular polarizations by providing an adaptive canceling circuit, but in the case of a phased array antenna, it is necessary to provide an adaptive canceling circuit for each system, so the circuit scale is very large. turn into.

However, although the antenna device shown in FIG. 2 can block the direct wave by the conductor wall 8, it diffracts the conductor wall 8 and diffracts the direct wave toward the transmission array antenna portion 5 beyond the crown portion 11. Is difficult to prevent. If the conductor wall 8 is raised in the height direction, the total height of the antenna device becomes high. On the other hand, the antenna device according to the first embodiment shown in FIG. 1 can deal with the diffracted radio wave of the direct wave toward the transmission array antenna unit 5 by forming the isolation acting unit 12 on the conductor wall 8 as described above. .. That is, the isolation between the transmitting array antenna unit 1 and the receiving array antenna unit 5 can be improved.

Preferably, the isolation action unit 12 may change the characteristics of the vertically polarized wave or the horizontally polarized wave of the diffracted radio wave (circularly polarized wave) of the direct wave to substantially cancel each other. The offset here includes processing in the circuit after reception. In this case, the isolation action unit 12 preferably has a first periodic structure periodically arranged in the extending direction or a second periodic structure periodically arranged in the height direction. Further, the isolation acting unit 12 may absorb the diffracted radio wave by serving as a resonance circuit or an antenna element for the diffracted radio wave (circularly polarized wave) of the direct wave. In this case, instead of the second periodic structure, the isolation acting unit 12 has a first periodic structure periodically arranged in the extending direction or a third periodic structure periodically arranged in the arrangement direction. But it may be.

Embodiment 2.
Hereinafter, the second embodiment will be described with reference to FIGS. 3, 4, and 5. In the antenna device according to the second embodiment, the isolation action unit 12 is periodically arranged in the first periodic structure (FIGS. 3 and 4) in the extending direction or periodically in the height direction. This is an example of a structure having a second periodic structure (FIG. 5). Specifically, it can be said that it relates to the isolation between circularly polarized waves in which the transmitted circularly polarized waves (diffracted radio waves) are orthogonal to each other. Note that FIG. 4 is a cross-sectional view of a plane where the X-axis and the Y-axis pass through the portion where the dielectric plate 14 is arranged.

In FIGS. 3, 4, and 5, the isolation acting unit 12 is a phase changing unit 13 formed on the crown 11 and changing the phase of the diffracted radio wave. The phase changing unit 13 changes the phase of the vertically polarized wave of the diffracted radio wave by the first periodic structure periodically arranged in the extending direction, or by the second periodic structure periodically arranged in the height direction. It changes the phase of the horizontally polarized wave of the diffracted radio wave. In the first periodic structure and the second periodic structure, the dielectric plates 14 are periodically arranged. The radome 15 covers the transmitting array antenna unit 1, the receiving array antenna unit 5, and the conductor wall 8. The radome 15 is in contact with either the first period structure or the second period structure. The dielectric plate support portion 16 supports a plurality of dielectric plates 14 periodically arranged in the height direction. Illustration of a structure that supports a plurality of dielectric plates 14 periodically arranged in the extending direction is omitted. The base of the dielectric plate 14 may be fixed to the crown 11.

The antenna device according to the second embodiment will be specifically described with reference to FIG. FIG. 3A is a view of the antenna device viewed from the Y-axis direction. FIG. 3B is a view of the antenna device as viewed from the X-axis direction. In the antenna device shown in FIG. 2 described above, since the transmitting array antenna unit 1 and the receiving array antenna unit 5 are arranged side by side on the coplanarity, they mainly form a coupling between vertically polarized waves. Span loss is the main coupling. Further, as described above, since the diffraction phenomenon occurs in the vicinity of the crown 11, the diffraction loss is added in addition to the span loss. However, due to the configuration of the antenna device (the transmitting array antenna unit 1 and the receiving array antenna unit 5 are arranged side by side on the same plane), the angle from the antenna element to the crown portion 11 is not horizontal, so that the polarized light is horizontally polarized. The level also rises, and the receiving array antenna unit 5 receives both the horizontally polarized wave and the vertically polarized wave of the circularly wave polarized wave due to the diffraction phenomenon. If the transmit and receive polarizations are orthogonal, these polarizations will be combined in phase.

On the other hand, in the antenna device shown in FIG. 3, the phase changing unit 13 changes the phase of the vertically polarized wave of the diffracted radio wave by a plurality of dielectric plates 14 having a first periodic structure periodically arranged in the extending direction. be able to. This is because the dielectric plate 14 is arranged parallel to the plane of polarization of vertically polarized waves. Therefore, it is easy to change the phase of the vertically polarized wave of the diffracted radio wave to the opposite phase of the horizontally polarized wave depending on the arrangement, spacing, and dimensions of the dielectric plate 14 shown in FIG. In the part 5, the vertically polarized wave and the horizontally polarized wave are synthesized in opposite phases, so that the isolation between transmission and reception is improved.

As described above, FIG. 4 is a cross-sectional view of a plane where the X-axis and the Y-axis pass through the portion where the dielectric plate 14 is arranged. The difference between the antenna device shown in FIG. 3 and the antenna device shown in FIG. 4 is the presence or absence of the radome 15. The positional relationship between the radome 15 and other configurations is as shown in FIG. 4, and it is preferable that the dielectric plate 14 is as close to the radome 15 as possible, or is integrated with the radome 15. By doing so, it is possible to reduce the influence of the deterioration of isolation due to the reflection from the radome 15. The radome 15 can also be applied to the antenna device of the present application other than FIG.

The antenna device shown in FIGS. 3 and 4 is expected to act only on vertically polarized waves, and the following structure can be considered. The method of fixing the dielectric plate 14 is, for example, a comb-shaped dielectric structure 14 in which the bases of a plurality of dielectric plates 14 are integrated, or a plurality of dielectric plates 14 are arranged side by side and fixed as shown in FIGS. 3 and 4. And so on. The length of the dielectric plate 14 in the X-axis direction may be such that the passing phase difference between the case without the dielectric plate 14 and the case with the dielectric plate 14 is about 180 degrees.

The antenna device according to another second embodiment will be specifically described with reference to FIG. FIG. 5A is a view of the antenna device viewed from the Y-axis direction. FIG. 5B is a view of the antenna device as viewed from the X-axis direction. In the antenna device shown in FIG. 5, the phase changing unit 13 may change the phase of the horizontally polarized wave of the diffracted radio wave by a plurality of dielectric plates 14 having a second periodic structure arranged periodically in the height direction. can. This is because the dielectric plate 14 is arranged in parallel with the plane of polarization of horizontally polarized waves. Therefore, it is easy to change the phase of the horizontally polarized wave of the diffracted radio wave to the opposite phase of the vertically polarized wave depending on the arrangement, spacing, and dimensions of the dielectric plate 14 shown in FIG. In the part 5, the horizontally polarized wave and the vertically polarized wave are synthesized in opposite phases, so that the isolation between transmission and reception is improved.

The antenna device shown in FIG. 5 is expected to act only on vertically polarized waves, and the following structure can be considered. The dielectric plates 14 are arranged with a gap between them and fixed at the ends by the dielectric plate support portion 16. The length of the dielectric plate 14 in the X-axis direction may be such that the passing phase difference between the case without the dielectric plate 14 and the case with the dielectric plate 14 is about 180 degrees.

As described above, the isolation acting unit 12 (phase changing unit 13) shown in FIGS. 3, 4, and 5 uses the dielectric plate 14 to vertically polarize the diffracted radio wave (circularly polarized wave) of the direct wave. It can be said that the characteristics of horizontally polarized waves are changed and substantially offset. It can be said that the dielectric plate 14 is formed intermittently due to the phase change with respect to a specific polarization. In other words, it can be said that the whole is not a single dielectric block but a plate-like structure, and by arranging a plurality of them, it acts only on the specific polarization of the radio wave arriving at the dielectric plate 14 portion. If the whole is one dielectric block, it acts on both vertical and horizontal polarizations, and the desired effect of controlling the phase difference between the two polarizations cannot be obtained.

The antenna device according to the second embodiment controls the incoming phase difference between the polarized waves, and by combining the phase difference with the phase difference in the T-branch synthesis circuit of the feeding unit of the receiving array antenna unit 5, the receiving antenna unit 5 is vertically biased. Since the phase difference between the wave arrival wave and the horizontally polarized wave arrival wave can be inverted and then combined, the isolation between transmission and reception is improved.

Embodiment 3.
Hereinafter, the third embodiment will be described with reference to FIGS. 6 and 7. In the antenna device according to the third embodiment, similarly to the antenna device according to the second embodiment, the isolation acting unit 12 has a first periodic structure (FIG. 6) periodically arranged in the extending direction, or This is an example of a structure having a second periodic structure (FIG. 7) periodically arranged in the height direction. Specifically, it can be said that it relates to the isolation between circularly polarized waves in which the transmitted circularly polarized waves (diffracted radio waves) are orthogonal to each other. FIG. 6B is a view of the antenna device as viewed from the X-axis direction. FIG. 7A is a view of the antenna device viewed from the Y-axis direction. FIG. 7B is a view of the antenna device as viewed from the X-axis direction.

In FIGS. 6 and 7, in the first periodic structure and the second periodic structure, the conductor plate 17 is arranged between the adjacent dielectric plates 14. In the first period structure and the second period structure, it can be said that the dielectric plates 14 and the conductor plates 17 are alternately arranged. The conductor plate 17 is electrically continuous or integrally with the conductor wall 8. It can be said that the antenna device shown in FIG. 6 has a conductor plate 17 inserted between the dielectric plates 14 of the antenna devices shown in FIGS. 3 and 4. It can be said that the antenna device shown in FIG. 7 has a conductor plate 17 inserted between the dielectric plates 14 of the antenna device shown in FIG.

In the antenna device according to the second embodiment, a plurality of dielectric plates 14 are arranged in the Y-axis direction or the Z-axis direction on the crown portion 11 protruding from the metal base plate 4. On the other hand, the antenna device according to the third embodiment has a structure in which the dielectric plate 14 is sandwiched between the metals on the corrugated. That is, the structure is such that the dielectric plate 14 is sandwiched between the comb-shaped conductor plates 17.

In the antenna device according to the second embodiment, the isolation between transmission and reception is improved by controlling the phase difference between the vertically polarized wave and the horizontally polarized wave passing through the dielectric plate 14 portion by the dielectric plate 14. Is. On the other hand, in the antenna device according to the third embodiment, in the configuration in which the dielectric plate 14 is sandwiched between the conductor plates 17, not only the dielectric plate 14 but also the passing path between the polarizations is combined with the phase difference due to the separation. The phase difference between the polarizations can be controlled. FIG. 6A is a view of the antenna device viewed from the Y-axis direction.

For example, in the antenna device shown in FIG. 6, vertically polarized waves pass between the conductor plates 17, but horizontally polarized waves are cut off due to the size of the gap between the metal plates and cannot pass through. Therefore, the path through which the radio wave passes differs between the vertically polarized wave and the horizontally polarized wave, so that a phase difference occurs. A phase difference between vertically polarized waves and horizontally polarized waves is generated by this phase difference and the phase difference when passing through the dielectric plate 14, and the isolation between transmission and reception is improved as in the second embodiment. Can be done. In the antenna device according to the third embodiment, since a phase difference other than the dielectric plate 14 can be generated, the size of the dielectric plate 14 can be reduced. Further, since the structure is such that the substrate is sandwiched between metals, there is an advantage that the holding is easy.

Similarly, in the antenna device shown in FIG. 7, horizontally polarized waves pass between the conductor plates 17, but vertically polarized waves cannot pass due to a cutoff due to the size of the gap between the metal plates. Therefore, the path through which the radio wave passes differs between the horizontally polarized wave and the vertically polarized wave, so that a phase difference occurs. The phase difference between the horizontally polarized wave and the vertically polarized wave is generated by the phase difference and the phase difference when passing through the dielectric plate 14, and the isolation between transmission and reception is improved as in the second embodiment. Can be done. In the antenna device according to the third embodiment, since a phase difference other than the dielectric plate 14 can be generated, the size of the dielectric plate 14 can be reduced.

Embodiment 4.
Hereinafter, the fourth embodiment will be described with reference to FIG. In the antenna device according to the fourth embodiment, similarly to the antenna device according to the second and third embodiments, the isolation acting unit 12 has a first periodic structure or a height periodically arranged in the extending direction. This is an example of a structure having a second periodic structure that is periodically arranged in a direction. Specifically, it can be said that it relates to isolation by absorbing transmitted circularly polarized waves (diffracted radio waves) by an antenna element. FIG. 8 shows the case of having both the first structure and the second structure.

In FIG. 8, the isolation acting portion 12 is a plurality of antenna elements 18 formed on at least one of the crown portion 11, the transmitting side side wall portion 9, and the receiving side side wall portion 10 to absorb diffracted radio waves. An example is an example in which a monopole antenna element, which is a plurality of antenna elements 18, is supported by a dielectric substrate 19. Each of the plurality of antenna elements 18 is connected to a terminal circuit (not shown). The dielectric substrate 19 is a rectangular substrate extending in the Y-axis direction.

In FIG. 8, each of the plurality of antenna elements 18 is terminated, a first periodic structure is formed on at least one of the crown 11, the transmitting side side wall portion 9, and the receiving side side wall portion 10, and the second periodic structure is on the transmitting side. It is formed on at least one of the side wall portion 9 or the receiving side side wall portion 10. The plurality of antenna elements 18 may have a third periodic structure in which they are periodically arranged in the arrangement direction. FIG. 8A is a view of the antenna device viewed from the Y-axis direction. FIG. 8B is a view of a plurality of antenna elements 18 and a dielectric substrate 19 of the antenna device as viewed from the Z-axis direction.

In the antenna device according to the fourth embodiment, a plurality of antenna elements 18 are provided on the conductor wall 8 and the antenna elements 19 are terminated by a termination circuit to absorb incoming waves (including diffracted radio waves), so that transmission and reception can be performed. The isolation between them is improved. As described above, the plurality of antenna elements 18 may be formed on at least one of the crown portion 11, the transmitting side side wall portion 9, and the receiving side side wall portion 10.

The antenna device exemplified in FIG. 8 shows a case where a plurality of antenna elements 18 (three dielectric substrates 19) are formed on each of the crown portion 11, the transmitting side side wall portion 9, and the receiving side side wall portion 10. Looking at FIG. 8B, it can be seen that a plurality of antenna elements 18 are formed (arranged) on the crown 11 as a first periodic structure periodically arranged in the extending direction (Y-axis direction). Similarly, a plurality of antenna elements 18 are formed (arranged) on the transmitting side side wall portion 9 and the receiving side side wall portion 10 as a first periodic structure periodically arranged in the extending direction (Y-axis direction). Further, looking at FIG. 8A, as a second periodic structure in which the antenna elements 18 are periodically arranged in the height direction (Z-axis direction), a plurality of antenna elements 18 are arranged on the transmitting side side wall portion 9 and the receiving side side wall portion 10. It can be seen that it is formed (arranged). Further, looking at FIGS. 8A and 8B, a plurality of antenna elements 18 are formed (arranged) on the crown 11 as a third periodic structure periodically arranged in the arrangement direction (X-axis direction). You can see that. This is based on the above-mentioned "the plurality of antenna elements 18 may have a third periodic structure periodically arranged in the arrangement direction."

Embodiment 5.
Hereinafter, the fifth embodiment will be described with reference to FIG. In the antenna device according to the fourth embodiment, the isolation acting unit 12 has a second periodic structure periodically arranged in the height direction or a third periodic structure periodically arranged in the arrangement direction. This is just one example. Specifically, it can be said that it relates to isolation by resonating transmitted circularly polarized waves (diffracted radio waves) with an antenna element. FIG. 9 shows the case of having both the first structure and the third structure.

In FIG. 9, the isolation acting portion 12 is a plurality of choke grooves 20 formed in at least one of the crown portion 11, the transmitting side side wall portion 9, and the receiving side side wall portion 10 to block diffracted radio waves. The plurality of choke grooves 20 have a depth corresponding to 1/4 wavelength of the wavelength of the diffracted radio wave, and the second period structure is formed on at least one of the transmitting side side wall portion 9 or the receiving side side wall portion 10, and the third period structure is formed. The structure is formed on the crown 11. The choke groove 20 is a groove of the conductor wall 8 cut along the Y-axis direction.

By providing the choke groove 20 having a wavelength of 1/4 of the wavelength of the depth diffracted radio wave on the conductor wall 8, the operation of blocking the incoming wave is performed. The plurality of choke grooves 20 may be formed in at least one of the crown portion 11, the transmitting side side wall portion 9, and the receiving side side wall portion 10.

The antenna device exemplified in FIG. 9 shows a case where a plurality of choke grooves 20 are formed in each of the crown portion 11, the transmitting side side wall portion 9, and the receiving side side wall portion 10. Looking at FIG. 9A, as a second periodic structure periodically arranged in the height direction (Z-axis direction), a plurality of choke grooves 20 are formed on the transmitting side side wall portion 9 and the receiving side side wall portion 10 ( It can be seen that it is arranged). Further, looking at FIGS. 9A and 9B, a plurality of choke grooves 20 are formed (arranged) on the crown 11 as a third periodic structure periodically arranged in the arrangement direction (X-axis direction). You can see that.

As described above, in the antenna device according to the first to fifth embodiments, the isolation acting unit 12 changes the characteristics of the vertically polarized wave or the horizontally polarized wave of the diffracted radio wave (circularly polarized wave) of the direct wave. It can be substantially offset, or the isolation working unit 12 can absorb the diffracted radio wave by becoming a resonance circuit or an antenna element for the diffracted radio wave (circularly polarized wave) of the direct wave. Therefore, the antenna device according to the first to fifth embodiments can deal with the diffracted radio wave by forming the isolation acting portion 12 on the conductor wall 8.

1 Transmission array antenna, 2 Dielectric board, 3 Patch conductor,
4 base plate, 5 receiving array antenna, 6 dielectric board,
7 patch conductor, 8 conductor wall, 9 transmitting side side wall, 10 receiving side side wall,
11 crown, 12 isolation action part, 13 phase change part, 14 dielectric plate,
15 radome, 16 dielectric plate support, 17 conductor plate, 18 antenna element,
19 Dielectric substrate, 20 Choke groove.

Claims (13)

A transmission array antenna unit that transmits transmission circular polarization, a reception array antenna unit that is arranged on the same plane as the transmission array antenna unit and receives reception circular polarization, a transmission array antenna unit, and the reception unit. The transmitting antenna portion extends in the extending direction intersecting the arranged arrangement direction, is arranged between the transmitting array antenna portion and the receiving antenna portion, and the transmitting circle with respect to the receiving array antenna portion. Equipped with a conductor wall that blocks the direct wave of polarization,
The conductor wall faces the transmitting side side wall portion of the conductor wall formed on the transmitting array antenna portion and the transmitting side side wall portion, and the conductor formed on the receiving array antenna portion side. It has a receiving side wall portion of the wall and a crown portion of the conductor wall continuous with the transmitting side wall portion and the receiving side wall portion.
The conductor wall is an isolation that improves the isolation between the transmitting array antenna portion and the receiving array antenna portion by acting on the diffracted radio wave that the transmitting circularly polarized wave diffracts over the crown portion. An antenna device characterized by acting. The isolation working part is a first periodic structure periodically arranged in the extending direction, or a second periodic structure periodically arranged in the arrangement direction and a height direction orthogonal to the extending direction. The antenna device according to claim 1, wherein the antenna device comprises. The isolation acting portion is a phase changing portion formed on the crown and changing the phase of the diffracted radio wave.
The phase changing unit is characterized in that the phase of the vertically polarized wave of the diffracted radio wave is changed by the first periodic structure, or the phase of the horizontally polarized wave of the diffracted radio wave is changed by the second periodic structure. The antenna device according to claim 2. The antenna device according to claim 3, wherein the first periodic structure and the second periodic structure are formed by periodically arranging dielectric plates. The antenna device according to claim 4, wherein the first periodic structure and the second periodic structure have a conductor plate arranged between adjacent dielectric plates. The antenna device according to claim 3, wherein the first periodic structure and the second periodic structure are formed by alternately arranging dielectric plates and conductor plates. The antenna device according to claim 5 or 6, wherein the conductor plate is electrically continuous or integrally with the conductor wall. The antenna device according to any one of claims 1 to 7 further includes the transmitting array antenna unit, the receiving array antenna unit, and a radome covering the conductor wall.
The radome is an antenna device characterized in that it is in contact with either the first periodic structure or the second periodic structure. The isolation acting portion is a plurality of antenna elements formed on at least one of the crown portion, the transmitting side side wall portion, and the receiving side side wall portion, and absorbs the diffracted radio wave.
Each of the plurality of antenna elements is terminated, the first periodic structure is formed on at least one of the crown, the transmitting side side wall portion, and the receiving side side wall portion, and the second periodic structure is the transmitting side side wall portion. The antenna device according to claim 2, wherein the antenna device is formed on at least one of the portions or the side wall portion on the receiving side. The antenna device according to claim 8, wherein the plurality of antenna elements further include a third periodic structure periodically arranged in the arrangement direction. The antenna device according to claim 9, wherein the plurality of antenna elements are connected to a terminal circuit, respectively. The isolation action unit has a second periodic structure periodically arranged in the arrangement direction and a height direction orthogonal to the extension direction, or a third periodic structure periodically arranged in the arrangement direction. The antenna device according to claim 1, wherein the antenna device is provided. The isolation acting portion is a plurality of choke grooves formed in at least one of the crown portion, the transmitting side side wall portion, and the receiving side side wall portion to block the diffracted radio wave.
The plurality of choke grooves have a depth corresponding to 1/4 wavelength of the wavelength of the diffracted radio wave, and the second periodic structure is formed on at least one of the transmitting side side wall portion and the receiving side side wall portion. The antenna device according to claim 12, wherein a third period structure is formed on the crown.

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