JP6611238B2 - Waveguide / transmission line converter, array antenna, and planar antenna - Google Patents

Description

  The present invention includes (1) a waveguide / transmission line converter for mutually converting power transmitted by a waveguide and power transmitted by a transmission line, and (2) antenna elements arranged linearly on a plane. The present invention relates to an array antenna fed by a waveguide / transmission line converter, and (3) a planar antenna in which antenna elements are arranged in a lattice on a plane and fed by a waveguide / transmission line converter.

  The waveguide / transmission line converter is applied to power feeding to an array / planar antenna, and is disclosed in Patent Documents 1 and 2 and the like. First, in Patent Document 1, a transmission line is inserted at a position where the electric field strength is high in the waveguide. However, in Patent Document 1, a waveguide short-circuit surface is required at a position that is separated from the transmission line along the waveguide by a distance equal to approximately ¼ of the wavelength of the electromagnetic wave in the waveguide. Therefore, in Patent Document 1, the waveguide / transmission line converter cannot be reduced in size, and the structure that forms the short-circuited surface exists in front of the surface that forms the array / planar antenna. This causes the directivity of the planar antenna to deteriorate.

JP 2004-320460 A JP 2000-244212 A

  Next, in Patent Document 2, a technique of coupling a transmission line to a matching element and propagating radio waves from the transmission line to a waveguide is used. As is clear from the following description, in Patent Document 2, the waveguide / transmission line converter can be reduced in size compared to Patent Document 1, which causes the directivity of the array / planar antenna to deteriorate. The structure that forms the short-circuit surface can be eliminated.

  The configuration of a prior art waveguide / transmission line converter is shown in FIG. The top row shows a side sectional view of the waveguide / transmission line converter 1 '. The second stage shows a cross-sectional view of the waveguide / transmission line converter 1 'taken along the arrow A'-A'. The third stage shows a cross-sectional plan view of the waveguide / transmission line converter 1 ′ taken along the arrow B′-B ′. The bottom row shows the electric field distribution in the direction of the resonance length of the matching element 17 'described later.

  The waveguide / transmission line converter 1 ′ has a short circuit for the dielectric substrate 13 ′ to convert between the power transmitted by the waveguide 11 ′ and the power transmitted by the transmission line 12 ′. A metal layer 14 ', a metal member 15', a ground metal layer 16 'and a matching element 17' are provided.

  The dielectric substrate 13 ′ is disposed so as to close the opening of the waveguide 11 ′. The surface of the dielectric substrate 13 ′ is a surface perpendicular to the waveguide direction of the waveguide 11 ′. In the second and third stages of FIG. 1, the portion of the dielectric substrate 13 ′ where the pattern is arranged is shown in white, and the portion of the dielectric substrate 13 ′ where the pattern is not arranged is shown in diagonal lines.

  The short-circuit metal layer 14 'is disposed on the surface of the dielectric substrate 13' and outside the waveguide 11 ', and the metal member 15' penetrating the dielectric substrate 13 'and the surface of the dielectric substrate 13' and the waveguide. The ground metal layer 16 'disposed on the outer frame of 11' is held at the same potential as the waveguide 11 '.

The matching element 17 ′ is disposed on the surface of the dielectric substrate 13 ′ and inside the waveguide 11 ′, and is electromagnetically coupled to the transmission line 12 ′ via the dielectric substrate 13 ′. The resonance length (approximately λ _g ′ / 2) for raising an electromagnetic wave having an effective wavelength λ _g ′ as a standing wave in the above environment is in the direction of the electric field in the waveguide 11 ′ and the feeding direction of the transmission line 12 ′.

  FIG. 2 shows an outline of a first planar antenna using the prior art. The planar antenna P1 'is not disclosed in Patent Documents 1 and 2. In the planar antenna P <b> 1 ′, antenna elements are arranged in a grid pattern on the plane. The antenna elements arranged in a lattice pattern are divided into array antennas A1 'in each column. The array antenna A1 ′ in each column is guided by a single transmission line 12 ′ connected to a waveguide / transmission line converter 1 ′ that is arranged in the approximate center of each column and performs central feeding for each column. Power is supplied in the opposite direction with the opposite phase across the tube / transmission line converter 1 '. This is because the antenna element in the reverse direction across the waveguide / transmission line converter 1 ′ obtains the same electric field and directivity in the same direction. The dielectric substrate 13 'is a plane on which the antenna elements are arranged in a lattice pattern. The cross section of the wide wall surface of the waveguide 11 'is arranged in a direction parallel to the direction of the array antenna A1' in each row. The cross section of the narrow wall surface of the waveguide 11 'is arranged in a direction perpendicular to the direction of the array antenna A1' in each row.

  FIG. 3 shows an outline of the second planar antenna using the prior art. The planar antenna P2 'is not disclosed in Patent Documents 1 and 2. In the planar antenna P2 ', antenna elements are arranged in a grid pattern on the plane. The antenna elements arranged in a grid pattern are divided into array antennas A2 'in each column. The array antenna A2 ′ in each column is guided by two transmission lines 12 ′ connected to a waveguide / transmission line converter 1 ′ that is arranged in the approximate center of each column and performs central feeding for each column. Power is supplied in the opposite direction with the opposite phase across the tube / transmission line converter 1 '. This is because the antenna element in the reverse direction across the waveguide / transmission line converter 1 ′ obtains the same electric field and directivity in the same direction. The dielectric substrate 13 'is a plane on which the antenna elements are arranged in a lattice pattern. The cross section of the narrow wall surface of the waveguide 11 'is arranged in a direction parallel to the direction of the array antenna A2' in each row. The cross section of the wide wall surface of the waveguide 11 'is arranged in a direction perpendicular to the direction of the array antenna A2' in each row.

  The array antennas A1 ′ and A2 ′ of each column are fed at the center of each column, so that the excitation phase of each antenna element constituting each column is changed at a frequency shifted from the center frequency of the planar antennas P1 ′ and P2 ′. Even if they deviate from each other, the combined result of the antenna elements constituting each column can form a high gain directivity in any one direction in a wide frequency range.

However, in the waveguide / transmission line converter 1 ′, among the sizes of the patterns arranged on the surface of the dielectric substrate 13 ′, the size p in the direction along the cross section of the narrow wall surface and the wide wall surface of the waveguide 11 ′. _N ′ and p _W ′ (see FIG. 1) must be large. Therefore, the planar antenna P1 ', P2' in each column of the array antenna A1 adjacent to each other ', A2' distance d 'is less than half the length equal lambda _0/2 of the wavelength lambda ₀ of the electromagnetic wave having radiated It must be wide. As a result, the visible region in the array antennas A1 ′ and A2 ′ must be widened, and the directivity in the planar antennas P1 ′ and P2 ′ is particularly adjusted by adjusting the phase information of each antenna element, so that the beam can be transmitted to a wide angle. When scanning, a grating lobe is likely to occur.

  Accordingly, in order to solve the above-described problems, the present invention provides a waveguide / transmission line converter in which each of the rows adjacent to each other in the planar antenna is reduced by reducing the size of the pattern disposed on the surface of the dielectric substrate. The array antennas of the antennas are narrowed so that the directivity of the planar antennas can be reduced, especially when adjusting the phase information of each antenna element and scanning the beam to a wide angle. Objective.

  In order to achieve the above object, the effective dielectric constant in the environment around the transmission line is increased by forming a dielectric layer in close contact with or close to the transmission line formed on the surface of the dielectric substrate. The size of the pattern around the transmission line was reduced.

  Specifically, the present invention is a waveguide / transmission line converter that mutually converts power transmitted by a waveguide and power transmitted by a transmission line, A dielectric substrate disposed so as to close the opening; the transmission line disposed on the surface of the dielectric substrate and outside the waveguide; and the surface of the dielectric substrate and the interior of the waveguide. A waveguide / transmission line converter comprising: a matching element to be disposed; and a transmission line side dielectric layer formed on a surface of the transmission line.

  According to this configuration, in the waveguide / transmission line converter, the size of the pattern around the transmission line formed on the surface of the dielectric substrate can be reduced.

  In the invention, it is preferable that the thickness of the dielectric layer on the transmission line side is 0.2 times or less the effective wavelength of the electromagnetic wave in the environment around the transmission line. It is a converter.

  According to this configuration, it is sufficient to form a dielectric layer having a minimum thickness in order to cover a region where the electric field leaks from the dielectric substrate between the transmission line and the matching element.

  In order to achieve the above object, by forming a dielectric layer in close contact with or close to the matching element formed on the surface of the dielectric substrate, the effective dielectric constant in the environment around the matching element is increased. Therefore, the size of the pattern around the matching element is reduced.

  Specifically, the present invention is a waveguide / transmission line converter that mutually converts power transmitted by a waveguide and power transmitted by a transmission line, A dielectric substrate disposed so as to close the opening; the transmission line disposed on the surface of the dielectric substrate and outside the waveguide; and the surface of the dielectric substrate and the interior of the waveguide. A waveguide / transmission line converter comprising: a matching element disposed; and a matching element-side dielectric layer formed on a surface of the matching element.

  According to this configuration, in the waveguide / transmission line converter, the size of the pattern around the matching element formed on the surface of the dielectric substrate can be reduced.

  The waveguide / transmission line according to the invention is characterized in that the thickness of the dielectric layer on the matching element side is not more than 0.2 times the effective wavelength of the electromagnetic wave in the environment around the matching element. It is a converter.

  According to this configuration, it is sufficient to form a dielectric layer having a minimum thickness in order to cover a region where the electric field leaks from the dielectric substrate between the transmission line and the matching element.

  Further, the present invention is an array antenna in which antenna elements are arranged in a straight line on a plane, and the antenna elements arranged in a straight line are arranged almost at the center of one row and perform central feeding for one row. The transmission line connected to the waveguide / transmission line converter (including the transmission line side dielectric layer) sandwiches the waveguide / transmission line converter (including the transmission line side dielectric layer). The array is fed in the opposite direction and in the opposite phase, disposed on the surface of the dielectric substrate on which the transmission line is disposed, and the surface of the element is covered with the dielectric layer on the transmission line side. It is an antenna.

  Further, the present invention is a planar antenna in which antenna elements are arranged in a grid pattern on a plane, and the antenna elements arranged in a grid pattern are arranged almost at the center of each column and perform central feeding for each column. The waveguide / transmission line converter (including the transmission line side dielectric layer) is connected to the waveguide / transmission line converter (including the transmission line side dielectric layer). Power is fed in opposite phase in the opposite direction, and is disposed on the surface of the dielectric substrate where the transmission line is disposed, and the surface of the element is covered by the transmission line-side dielectric layer. Is a planar antenna.

  According to this configuration, in the waveguide / transmission line converter, the size of the pattern arranged on the surface of the dielectric substrate can be reduced, and in the planar antenna, the interval between the array antennas in the adjacent columns can be reduced. Can be narrowed. Thereby, the directivity in the planar antenna can make it difficult to generate a grating lobe particularly when adjusting the phase information of each antenna element and scanning the beam to a wide angle.

  Then, similarly to the transmission line formed on one surface of the dielectric substrate, the antenna element is formed in close contact with or close to the antenna element conductor formed on the surface of the dielectric substrate. The electromagnetic wave radiated from the conductor can be incident on the dielectric layer in a substantially spherical wave state. Then, for the electromagnetic wave incident on the dielectric layer at an incident angle of 0 degrees, the propagation distance inside the dielectric layer becomes shorter and the phase delay due to the dielectric layer becomes smaller. On the other hand, for electromagnetic waves incident on the dielectric layer at a finite incident angle, the propagation distance inside the dielectric layer becomes longer and the phase delay due to the dielectric layer becomes larger. Therefore, the electromagnetic wave emitted from the dielectric layer can have a wide-angle directivity as compared with the electromagnetic wave when the dielectric layer is not provided.

  Further, when the dielectric layer is formed in close contact with or in close proximity to the antenna element conductor, the effective dielectric in the environment around the antenna element conductor is more than when only the dielectric substrate is disposed without forming the dielectric layer. Since the rate increases, the antenna element conductor can be reduced in size while maintaining high radiation efficiency, and the antenna element can have wide-angle directivity.

  As described above, in the waveguide / transmission line converter according to the present invention, the size of the pattern arranged on the surface of the dielectric substrate is reduced, and the spacing between the array antennas in the adjacent columns in the planar antenna is reduced. Thus, the directivity in the planar antenna can be made narrow, and in particular, when adjusting the phase information of each antenna element and scanning the beam to a wide angle, it is possible to make it difficult to generate a grating lobe.

It is a figure which shows the structure of the waveguide / transmission line converter of a prior art. It is a figure which shows the outline | summary of the 1st planar antenna using a prior art. It is a figure which shows the outline | summary of the 2nd planar antenna using a prior art. It is a figure which shows the structure of the 1st waveguide / transmission line converter of this invention. It is a figure which shows the structure of the 2nd waveguide / transmission line converter of this invention. It is a figure which shows the structure of the 3rd waveguide / transmission line converter of this invention. It is a figure which shows the structure of the 4th waveguide / transmission line converter of this invention. It is a figure which shows the structure of the 5th waveguide / transmission line converter of this invention. It is a figure which shows the outline | summary of the 1st planar antenna of this invention. It is a figure which shows the outline | summary of the 2nd planar antenna of this invention. It is a figure which shows the structure of the antenna element of this invention. It is a figure which shows the structure of the 1st array antenna of this invention. It is a figure which shows the structure of the 2nd array antenna of this invention. It is a figure which shows the structure of the 1st planar antenna of this invention. It is a figure which shows the structure of the 2nd planar antenna of this invention.

  Embodiments of the present invention will be described with reference to the accompanying drawings. The embodiments described below are examples of the present invention, and the present invention is not limited to the following embodiments.

(Configuration of waveguide / transmission line converter)
The configuration of the first waveguide / transmission line converter of the present invention is shown in FIG. The uppermost stage shows a side sectional view of the waveguide / transmission line converter 1. The second stage shows an AA plane cross-sectional view of the waveguide / transmission line converter 1. The third stage shows a cross-sectional view taken along the line B-B of the waveguide / transmission line converter 1. The bottom row shows the electric field distribution in the direction of the resonance length of the matching element 17 described later.

  The waveguide / transmission line converter 1 includes a dielectric substrate 13, a short-circuited metal layer 14, and the like in order to mutually convert power transmitted through the waveguide 11 and power transmitted through the transmission line 12. A metal member 15, a ground metal layer 16, a matching element 17, and dielectric layers 10L and 10P are provided.

  The dielectric substrate 13 is disposed so as to close the opening of the waveguide 11. The surface of the dielectric substrate 13 is a surface perpendicular to the waveguide direction of the waveguide 11. In the second and third stages of FIG. 4, the portion of the dielectric substrate 13 where the pattern is arranged is shown in white, and the portion of the dielectric substrate 13 where the pattern is not arranged is shown in diagonal lines.

  The short-circuit metal layer 14 is disposed on the surface of the dielectric substrate 13 and outside the waveguide 11, and is disposed on the surface of the metal member 15 penetrating the dielectric substrate 13 and the surface of the dielectric substrate 13 and on the outer frame of the waveguide 11. The ground metal layer 16 is held at the same potential as the waveguide 11.

The matching element 17 is disposed on the surface of the dielectric substrate 13 and inside the waveguide 11, is electromagnetically coupled to the transmission line 12 via the dielectric substrate 13, and has an effective wavelength λ in the environment around the matching element 17. The resonance length (approximately λ _g / 2) for standing up the electromagnetic wave of _g (described later together with the dielectric layer) as a standing wave is provided in the electric field direction in the waveguide 11 and the feeding direction of the transmission line 12.

  Here, the matching element 17 and the transmission line 12 exist in different layers. And the front-end | tip shape of the transmission line 12 is a stub or slot with a notch. Therefore, the matching element 17 and the transmission line 12 can realize electromagnetic coupling.

  In the description of FIG. 4, the metal member 15 is formed by “through holes” that penetrate the dielectric substrate 13 along the cross sections of the two wide wall surfaces and the two narrow wall surfaces of the waveguide 11. As a modification of FIG. 4, the metal member 15 may be a “conductor wall” that penetrates the dielectric substrate 13 along the cross sections of the two wide wall surfaces and the two narrow wall surfaces of the waveguide 11. .

The dielectric layer 10 </ b> L is formed in close contact with or close to the surfaces of the transmission line 12 and the short-circuit metal layer 14. Therefore, in FIG. 4, compared to FIG. 1, the effective dielectric constant in the environment around the transmission line 12 and the short-circuit metal layer 14 can be increased, and in the environment around the transmission line 12 and the short-circuit metal layer 14. it is possible to shorten the effective wavelength lambda _g of the electromagnetic wave, the narrow walls and broad walls size p _N direction along the cross section of the waveguide _11, it is possible to reduce the p _W.

The thickness of the dielectric layer 10L is preferably not more than 0.2 times the electromagnetic radiation of an effective wavelength lambda _g of the environment surrounding the transmission line 12 and the short-circuit metal layer 14. Then, in order to cover the region where the electric field leaks from the dielectric substrate 13 between the transmission line 12 and the matching element 17, it is sufficient to form the dielectric layer 10L having a minimum thickness. In the description of FIG. 4, the dielectric layer 10 </ b> L is formed only on the surfaces of the transmission line 12 and the short-circuit metal layer 14. As a modification of FIG. 4, the dielectric layer 10 </ b> L may be formed on the entire surface of the dielectric substrate 13. As a further modification, the dielectric layer 10L is formed, but the dielectric layer 10P may be omitted.

The dielectric layer 10P is formed in close contact with or close to the surface of the matching element 17. Therefore, in FIG. 4, that in comparison with FIG. 1, it is possible to increase the effective dielectric constant around the environment of the matching element 17, to reduce the electromagnetic effective wavelength lambda _g of at surrounding environment of the matching element 17 The resonance length (approximately λ _g / 2) of the matching element 17 can be shortened, and the sizes p _N and p _W along the cross-sections of the narrow wall surface and the wide wall surface of the waveguide 11 can be reduced. it can.

The thickness of the dielectric layer 10P is desirably not more than 0.2 times the effective wavelength lambda _g of the electromagnetic wave in the environment around the matching element 17. Then, in order to cover the region where the electric field leaks from the dielectric substrate 13 between the transmission line 12 and the matching element 17, it is sufficient to form the dielectric layer 10P having a minimum thickness. In the description of FIG. 4, the dielectric layer 10 </ b> P is formed only on the surface of the matching element 17 and the inside of the waveguide 11. As a modification of FIG. 4, the dielectric layer 10P may be formed on the entire surface of the dielectric substrate 13 as long as grounding is ensured. As a further modification, the dielectric layer 10P is formed, but the dielectric layer 10L may not be provided.

  The configuration of the second waveguide / transmission line converter of the present invention is shown in FIG. The uppermost stage shows a side sectional view of the waveguide / transmission line converter 2. The second stage shows a cross-sectional plan view taken along the line CC of the waveguide / transmission line converter 2. The third stage shows a cross-sectional view taken along the line DD of the waveguide / transmission line converter 2. The bottom row shows the electric field distribution in the direction of the resonance length of the matching element 27 described later.

  The waveguide / transmission line converter 2 includes a dielectric substrate 23, a short-circuit metal layer 24, and the like, in order to mutually convert the power transmitted through the waveguide 21 and the power transmitted through the transmission line 22. A metal member 25, a ground metal layer 26, a matching element 27, and dielectric layers 20L and 20P are provided.

  The waveguide 21, transmission line 22, dielectric substrate 23, short-circuit metal layer 24, metal member 25, ground metal layer 26, and dielectric layers 20L and 20P in FIG. 5 are the waveguide 11 and transmission line 12 in FIG. The dielectric substrate 13, the short-circuit metal layer 14, the metal member 15, the ground metal layer 16, and the dielectric layers 10L and 10P are substantially the same.

In FIG. 5, a metal member having a resonance length approximately equal to ¼ of the effective wavelength of the electromagnetic wave in the environment surrounding the patch, and having one end in the direction of the resonance length at the same potential as the metal ground plane by a metal member penetrating the dielectric substrate. Retained patch antenna applied. That is, the matching element 27, the resonant length equal to approximately 1/4 of the electromagnetic waves of the effective wavelength lambda _g of the surrounding environment of the matching element 27 has the feeding direction of the electric field direction and the transmission line 22 in the waveguide 21 The one end in the direction of the resonance length is held at the same potential as the waveguide 21 by the metal member 25 penetrating the dielectric substrate 23.

Therefore, in FIG. 5, the size _PN in the direction along the cross section of the narrow wall surface of the waveguide 21 can be reduced as compared with FIG. In FIG. 5, the size p _W in the direction along the cross section of the wide wall surface of the waveguide 21 can be reduced as in FIG. 4.

  The configuration of the third waveguide / transmission line converter of the present invention is shown in FIG. The uppermost stage shows a side sectional view of the waveguide / transmission line converter 3. The second stage shows a cross-sectional view taken along the line EE of the waveguide / transmission line converter 3. The third stage shows an FF plane cross-sectional view of the waveguide / transmission line converter 3 as viewed in the direction of the arrows. The bottom row shows the electric field distribution in the direction of the resonance length of the matching element 37 described later.

  The waveguide / transmission line converter 3 includes a dielectric substrate 33, a short-circuit metal layer 34, and the like so as to mutually convert the power transmitted by the waveguide 31 and the power transmitted by the transmission line 32. A metal member 35, a ground metal layer 36, a matching element 37, and dielectric layers 30L and 30P are provided.

  The waveguide 31, transmission line 32, dielectric substrate 33, matching element 37, and dielectric layers 30L, 30P in FIG. 6 are the transmission line 12, dielectric substrate 13, matching element 17, and dielectric layer 10L in FIG. 10P, which is almost the same.

  In FIG. 6, in the waveguide slot antenna, when the current flowing through the narrow wall surface flows in a direction parallel to the cross section of the narrow wall surface, when the slot provided in the narrow wall surface is provided in the direction parallel to the cross section of the narrow wall surface, Applied that electromagnetic waves are not emitted. That is, the metal member 35 and the ground metal layer 36 for extending the waveguide 31 into the dielectric substrate 33 and maintaining the short-circuit metal layer 34 at the same potential as the waveguide 31 (the short-circuit metal layer 34 is also provided). The electromagnetic wave is inadvertently emitted except for the two surfaces of the waveguide 31 that are left along the cross section of the wide wall surface of the waveguide 31 and the cross section of one of the two surfaces of the waveguide 31 or the narrow wall surface of the single surface. Do not be.

Therefore, in FIG. 6, the size p _W in the direction along the cross section of the wide wall surface of the waveguide 31 can be reduced by 2 _nW or n _W compared to FIG. 4. In FIG. 6, as in FIG. 4, the size _PN in the direction along the cross section of the narrow wall surface of the waveguide 31 can be reduced.

  The configuration of the fourth waveguide / transmission line converter of the present invention is shown in FIG. The first column in the left column shows a side sectional view of the waveguide / transmission line converter 4. The second column in the left column shows a cross-sectional view taken along the line GG of the waveguide / transmission line converter 4. The uppermost column in the right column shows an HH plane cross-sectional view of the waveguide / transmission line converter 4 as viewed in the direction of the arrows. The second column in the right column shows an I-I plane cross-sectional view of the waveguide / transmission line converter 4 as viewed in the direction of the arrows. The third column on the right column shows the electric field distribution in the direction of the resonance length of the matching element 48 described later. The lowermost column in the right column shows the electric field distribution in the direction of the resonance length of the parasitic element 49 described later.

  The waveguide / transmission line converter 4 includes dielectric substrates 43 and 44, a short-circuit metal layer, in order to mutually convert the power transmitted by the waveguide 41 and the power transmitted by the transmission line 42. 45, a metal member 46, a ground metal layer 47, a matching element 48, a parasitic element 49, and dielectric layers 40L and 40P.

  The waveguide 41, the transmission line 42, the dielectric substrates 43 and 44, the short-circuit metal layer 45, the metal member 46, the ground metal layer 47, and the dielectric layers 40L and 40P in FIG. The line 12, the dielectric substrate 13, the short-circuit metal layer 14, the metal member 15, the ground metal layer 16, and the dielectric layers 10L and 10P are substantially the same.

  In FIG. 7, in the patch antenna, the application of widening the band by arranging a parasitic element in the vicinity of the patch element is applied. That is, by providing the parasitic element 49 in a layer different from the matching element 48 in the waveguide direction in the vicinity of the matching element 48, the bandwidth can be increased, and the pattern placement accuracy of the dielectric substrates 43 and 44 and Even in an actual case where the positional accuracy between the pattern of the dielectric substrates 43 and 44 and the waveguide 41 is assumed to be low, low reflection characteristics and high transmission characteristics can be satisfied with good reproducibility.

Therefore, in FIG. 7, as in FIG. 4, the size _PN in the direction along the cross section of the narrow wall surface of the waveguide 41 can be reduced. In FIG. 7, the size p _W in the direction along the cross section of the wide wall surface of the waveguide 41 can be reduced as in FIG. 4.

  The configuration of the fifth waveguide / transmission line converter of the present invention is shown in FIG. The uppermost stage shows a side sectional view of the waveguide / transmission line converter 5. The second stage shows a cross-sectional view taken along the line JJ of the waveguide / transmission line converter 5. The third stage shows a cross-sectional view taken along the line KK of the waveguide / transmission line converter 5. The bottom row shows the electric field distribution in the direction along the current of the matching element 57 described later.

  The waveguide / transmission line converter 5 includes a dielectric substrate 53, a short-circuit metal layer 54, and the like so as to mutually convert power transmitted through the waveguide 51 and power transmitted through the transmission line 52. A metal member 55, a ground metal layer 56, a matching element 57, and dielectric layers 50L and 50P are provided.

  8, the waveguide 51, the transmission line 52, the dielectric substrate 53, the short-circuit metal layer 54, the metal member 55, the ground metal layer 56, and the dielectric layers 50L and 50P are the waveguide 11 and the transmission line 12 in FIG. The dielectric substrate 13, the short-circuit metal layer 14, the metal member 15, the ground metal layer 16, and the dielectric layers 10L and 10P are substantially the same.

  In FIG. 8, the fact that the equivalent dielectric constant of the dielectric substrate 53 is increased by forming the opening hole 58 in which the peripheral edge is opened in the matching element 57 is applied.

Before the opening hole 58 is formed in the matching element 57, the current direction of the matching element 57 is parallel to the length direction of the matching element 57. Therefore, the length a of the matching element 57 is equal to the length of the current path of the matching element 57 (for example, both ends of the matching element 57 in the length direction with respect to the effective wavelength λ _g of the electromagnetic wave in the environment around the matching element 57. Is equal to λ _g / 2.

After the opening hole 58 is formed in the matching element 57, the current direction of the matching element 57 is a direction that bypasses the opening hole 58. Therefore, the length a of the matching element 57 is equal to the length of the current path of the matching element 57 (for example, both ends of the matching element 57 in the length direction with respect to the effective wavelength λ _g of the electromagnetic wave in the environment around the matching element 57. Is shorter than λ _g / 2.

  Thus, after the opening hole 58 is formed in the matching element 57, the length a of the matching element 57 with respect to the same resonance frequency of the matching element 57 is greater than before the opening hole 58 is formed in the matching element 57. It seems that the equivalent dielectric constant of the dielectric substrate 53 is increased.

Therefore, in FIG. 8, the size _PN in the direction along the cross section of the narrow wall surface of the waveguide 51 can be reduced as compared with FIG. In FIG. 8, as in FIG. 4, the size p _W in the direction along the cross section of the wide wall surface of the waveguide 51 can be reduced.

(Outline of array antenna and planar antenna)
An overview of the first planar antenna of the present invention is shown in FIG. In the planar antenna P1, antenna elements are arranged in a grid pattern on a plane. The antenna elements arranged in a lattice shape are divided into array antennas A1 in each column. The array antenna A1 of each column is arranged in the waveguide / transmission line converters 1 to 5 which are arranged at substantially the center of each column and perform central feeding for each column. Power is fed in the opposite direction across the transmission line converters 1-5. This is because an antenna element in the opposite direction across the waveguide / transmission line converters 1 to 5 obtains the same electric field and directivity in the same direction. The dielectric substrate of the waveguide / transmission line converters 1 to 5 is a plane on which the antenna elements are arranged in a lattice shape. The cross section of the wide wall surface of the waveguide connected to the waveguide / transmission line converters 1 to 5 is arranged in a direction parallel to the direction of the array antenna A1 in each row. The cross-section of the narrow wall surface of the waveguide connected to the waveguide / transmission line converters 1 to 5 is arranged in a direction perpendicular to the direction of the array antenna A1 in each row.

  An outline of the second planar antenna of the present invention is shown in FIG. In the planar antenna P2, the antenna elements are arranged in a lattice pattern on the plane. The antenna elements arranged in a lattice shape are divided into array antennas A2 in each column. The array antenna A2 in each row is arranged in the waveguide / transmission line converters 1 to 5 that are arranged in the approximate center of each row and are connected to the waveguide / transmission line converters 1 to 5 that perform central feeding for each row. Power is fed in the opposite direction across the transmission line converters 1-5. This is because an antenna element in the opposite direction across the waveguide / transmission line converters 1 to 5 obtains the same electric field and directivity in the same direction. The dielectric substrate of the waveguide / transmission line converters 1 to 5 is a plane on which the antenna elements are arranged in a lattice shape. The cross-section of the narrow wall surface of the waveguide connected to the waveguide / transmission line converters 1 to 5 is arranged in a direction parallel to the direction of the array antenna A2 in each row. The cross section of the wide wall surface of the waveguide connected to the waveguide / transmission line converters 1 to 5 is arranged in a direction perpendicular to the direction of the array antenna A2 in each row.

  By feeding the array antennas A1 and A2 of each column at the center of each column, even if the excitation phases of the antenna elements constituting each column are shifted from each other at a frequency shifted from the center frequency of the planar antennas P1 and P2. The combined result of the antenna elements constituting each column can form a high directivity with a high gain in any one direction over a wide frequency range.

In the waveguide / transmission line converters 1 to 5, among the sizes of the patterns arranged on the surface of the dielectric substrate, the sizes p _N and p in the direction along the cross-sections of the narrow wall surface and the wide wall surface of the waveguide. _W (see FIGS. 4 to 8) can be reduced. In particular, in the waveguide / transmission line converters 2 and 5, the size p _N (see FIGS. 5 and 8) in the direction along the cross section of the narrow wall surface of the waveguide can be further reduced. In the waveguide / transmission line converter 3, the size p _W (see FIG. 6) in the direction along the cross section of the wide wall surface of the waveguide can be further reduced. Therefore, in the planar antenna P1, P2, the distance d of the array antenna A1, A2 in each column adjacent to each other, can be narrower than a half length equal to lambda _0/2 of the wavelength lambda ₀ of the electromagnetic wave having radiated The visible regions in the array antennas A1 and A2 can be narrowed, and the directivity in the planar antennas P1 and P2 is particularly determined when the phase information of each antenna element is adjusted and the beam is scanned to a wide angle. Can be made difficult to occur.

(Configuration of antenna element)
The configuration of the antenna element of the present invention is shown in FIG. The antenna element 6 of the present invention includes a dielectric substrate 61, a ground plane conductor 62, an antenna element conductor 63, and a dielectric layer 64. The dielectric substrate 61 is a dielectric substrate of the waveguide / transmission line converters 1 to 5. The ground plane conductor 62 is a ground metal layer of the waveguide / transmission line converters 1 to 5 and is formed on one surface of the dielectric substrate 61. The antenna element conductor 63 is a patch antenna element conductor or the like, and is formed on the other surface of the dielectric substrate 61. The dielectric layer 64 is a dielectric layer formed on the surface of the transmission line connected to the waveguide / transmission line converters 1 to 5 and the surface of the antenna element conductor 63.

The dielectric layer 64 has a radome function and is formed in close contact with or close to the antenna element conductor 63. The thickness of the dielectric layer 64 is set in the environment around the antenna element conductor 63 so that the antenna element 6 has a wide-angle directivity and does not cause a frontal null of the directivity of the antenna element 6. more than 0.2 times 0.1 times the effective wavelength lambda _g of the electromagnetic wave.

In order to form the dielectric layer 64 in close contact with or close to the antenna element conductor 63, for example, after applying a prepreg (adhesive) to the other surface of the dielectric substrate 61 and the surface of the antenna element conductor 63, A dielectric thin film substrate may be mounted. In this case, the total thickness of the dielectric thin film substrate and prepreg (adhesive agent), 0.2 times 0.1 times the electromagnetic radiation of an effective wavelength lambda _g of the environment around the antenna element conductor 63 It only has to be.

  As described above, the dielectric layer 64 is in close contact with or close to the antenna element conductor 63 that is a wave source of electromagnetic waves. Therefore, it can be considered that the electromagnetic wave radiated from the antenna element conductor 63 is incident on the dielectric layer 64 in a substantially spherical wave state.

  Then, for the electromagnetic wave incident on the dielectric layer 64 at an incident angle of 0 degrees, the propagation distance inside the dielectric layer 64 is shorter, and the phase delay due to the dielectric layer 64 is less. On the other hand, for electromagnetic waves incident on the dielectric layer 64 at a finite incident angle, the propagation distance inside the dielectric layer 64 is longer and the phase delay due to the dielectric layer 64 is more. Therefore, the electromagnetic wave emitted from the dielectric layer 64 has a wide-angle directivity compared to the electromagnetic wave when the dielectric layer 64 is not provided.

  In the case where the dielectric layer 64 is formed in close contact with or close to the antenna element conductor 63, the area around the antenna element conductor 63 is larger than the case where only the dielectric substrate 61 is disposed without forming the dielectric layer 64. Since the effective dielectric constant in the environment is increased, the antenna element conductor 63 can be reduced in size while maintaining high radiation efficiency, and the antenna element 6 can have wide-angle directivity. In particular, an advantageous effect is obtained in a center-fed traveling wave array antenna.

(Configuration of array antenna and planar antenna)
The configuration of the first and second array antennas of the present invention is shown in FIGS. In the array antennas A1 and A2 of the present invention, the antenna elements 6 are linearly arranged, and the single dielectric substrate 61, the single ground plane conductor 62, and the single dielectric layer 64 are linearly arranged. Shared by the plurality of antenna element conductors 63. Array antennas A1 and A2 described with reference to FIGS. 12 and 13 are center-fed traveling wave array antennas. The horizontal direction of the array antennas A1 and A2 is defined as a direction perpendicular to the extending direction of the array antennas A1 and A2. The vertical direction of the array antennas A1 and A2 is defined as a direction parallel to the extending direction of the array antennas A1 and A2.

  The configuration of the first and second planar antennas of the present invention is shown in FIGS. In the planar antennas P1 and P2 of the present invention, the antenna elements 6 are arranged in a lattice shape, and a single dielectric substrate 61, a single ground plane conductor 62, and a single dielectric layer 64 are arranged in a lattice shape. Shared by the plurality of antenna element conductors 63. The planar antennas P1 and P2 described with reference to FIGS. 14 and 15 are center-feed traveling wave planar antennas. The horizontal direction of the planar antennas P1 and P2 is defined as a direction perpendicular to the extending direction of the array antennas A1 and A2. The vertical direction of the planar antennas P1 and P2 is defined as a direction parallel to the extending direction of the array antennas A1 and A2.

  Here, as shown in FIGS. 12 and 14, the array antenna A1 is connected to the waveguide / transmission line converters 1 to 5 which are arranged in the approximate center of each column and perform central feeding for each column. With one transmission line, power is fed in the opposite direction in the opposite direction across the waveguide / transmission line converters 1 to 5. For example, as shown in FIGS. 12 and 14, the feeding point of one transmission line connected to the waveguide / transmission line converters 1 to 5 has a phase of 90 degrees from the center position of the array antenna A1. The position is shifted by the line length corresponding to the rotation. Alternatively, although not shown, the transmission path length from the feeding point of one transmission line connected to the waveguide / transmission line converters 1 to 5 to the antenna element in one direction, and the waveguide / transmission line The transmission path length from the feeding point of one transmission line connected to the converters 1 to 5 to the antenna element in the other direction has a line length difference corresponding to the phase rotation of 90 degrees.

  As shown in FIGS. 13 and 15, the array antenna A <b> 2 is connected to waveguide / transmission line converters 1 to 5 that are arranged substantially at the center of each column and perform central feeding for each column 2. By the transmission line, power is fed in the opposite direction in the opposite direction across the waveguide / transmission line converters 1 to 5. For example, as shown in FIGS. 13 and 15, the feeding phases of the two transmission lines connected to the waveguide / transmission line converters 1 to 5 are opposite to each other.

  While the resonant wave type array antenna has a narrow band characteristic, the traveling wave type array antenna has a wide band characteristic. Therefore, the traveling wave type array antenna is used in a wide band application. The inventor of the present application has identified the following problems regarding traveling wave type array antennas.

  That is, when all the antenna elements of the traveling wave array antenna are excited in the same phase, reflection occurs in the same phase from all the antenna elements, so that the reflection loss increases at this frequency and the radiation efficiency decreases. On the other hand, when each antenna element of a traveling wave array antenna is excited in a different phase, reflection occurs in a different phase from each antenna element, so that radiation occurs in a direction tilted from the front direction, but reflection loss is reduced in a wide band. Increases radiation efficiency.

  When the traveling wave array antenna is fed at one end, the angle of the radial direction with respect to the front direction changes when the operating frequency changes. On the other hand, when the traveling wave array antenna is fed at the center, the angle of the radial direction with respect to the front direction does not change even if the operating frequency changes. Therefore, when the traveling wave type array antenna is used in a wide band, it is aimed to feed power at the center of the array.

  When power is supplied at the center of the array, it is necessary to maintain the vertical size of the array (ie, the number of antenna elements), as in the case of power supply at one end of the array. In other words, when feeding at the center of the array, two arrays, each of which has half the vertical size (ie, the number of antenna elements) compared to feeding at one end of the array, sandwiching the feed section Will form.

  Here, the traveling wave type array antenna radiates a part of the feed power at the antenna element close to the power feeding part, and radiates a part of the remaining power at the antenna element far from the power feeding part. The remaining power is dissipated. Therefore, when power is supplied at the center of the array, the radiation efficiency is lower than when power is supplied at one end of the array.

  In the case of feeding at the center of the array, as in the case of feeding at one end of the array, it is conceivable to increase the radiation amount of each antenna element in order to increase the radiation efficiency, that is, widen the width of each antenna element. It is possible. However, if the width of each antenna element is increased, the horizontal directivity of the array is reduced. The inventor of the present application has found that this becomes a problem in applications such as radar that wants to expand the monitoring area.

  Therefore, as shown in FIGS. 12 and 13, by applying the antenna element 6, it is possible to downsize the antenna element 6 in the width direction while maintaining high radiation efficiency, and horizontally to the antenna element 6. A wide-angle directivity can be provided.

  As shown in FIGS. 12 and 13, by arranging the stub 66 on the path of the transmission line 65, even when all the antenna elements 6 are excited in the same phase, the same phase from all the antenna elements 6 can be obtained. Therefore, reflection loss is reduced at this frequency, radiation efficiency is increased, and radiation occurs in the front direction.

  Further, as shown in FIGS. 12 and 13, by arranging the termination element 67 at the end of the transmission line 65, the array antennas A <b> 1 and A <b> 2 use the termination element 67 to dissipate the power originally dissipated in the termination resistance. The radiation efficiency can be further improved.

  In FIG.14 and FIG.15, the waveguide / transmission line converters 1-5 are arrange | positioned at zigzag form in the horizontal direction of the planar antennas P1 and P2. As a modification, the waveguide / transmission line converters 1 to 5 may be arranged linearly in the horizontal direction of the planar antennas P1 and P2.

  The waveguide / transmission line converter, the array antenna, and the planar antenna of the present invention can form a high directivity with a high gain in any one direction in a wide frequency range, and a grating lobe is hardly generated. A planar antenna arranged in a grid pattern on a plane can be applied for the purpose of downsizing and cost reduction.

1 ', 1, 2, 3, 4, 5: Waveguide / transmission line converters 10L, 10P, 20L, 20P, 30L, 30P, 40L, 40P, 50L, 50P: Dielectric layers 11', 11, 21 , 31, 41, 51: Waveguides 12 ′, 12, 22, 32, 42, 52: Transmission lines 13 ′, 13, 23, 33, 43, 44, 53: Dielectric substrates 14 ′, 14, 24, 34, 45, 54: Short-circuit metal layers 15 ', 15, 25, 35, 46, 55: Metal members 16', 16, 26, 36, 47, 56: Ground metal layers 17 ', 17, 27, 37, 48 57: matching element 49: parasitic element 58: open hole 6: antenna element 61: dielectric substrate 62: ground plane conductor 63: antenna element conductor 64: dielectric layer 65: transmission line 66: stub 67: termination element P1 ′ , P2 ′, P1, P2: Planar antennas A1 ′, A2 ′, A1, A : Array antenna

Claims (6)

Power transmitted by the waveguide;
Power transmitted by the transmission line;
A waveguide / transmission line converter for converting between
A dielectric substrate disposed to close the opening of the waveguide;
The transmission line disposed on the surface of the dielectric substrate and outside the waveguide;
A matching element disposed on the surface of the dielectric substrate and inside the waveguide;
A transmission line side dielectric layer formed on the surface of the transmission line;
The dielectric substrate is disposed on the surface of the dielectric substrate and outside the waveguide. (1) While penetrating the dielectric substrate along the cross section of the two wide wall surfaces of the waveguide, By a metal member that does not penetrate the dielectric substrate along the cross section of the two narrow walls, or (2) the narrow wall of any one of the two wide walls and the two surfaces of the waveguide The waveguide is guided by a metal member that penetrates the dielectric substrate along a cross-section while not penetrating the dielectric substrate along a cross-section of a narrow wall surface of one of the two surfaces of the waveguide. A short-circuit metal layer held at the same potential as the tube;
A waveguide / transmission line converter comprising:   2. The waveguide / transmission according to claim 1, wherein a thickness of the dielectric layer on the transmission line side is 0.2 times or less of an effective wavelength of electromagnetic waves in an environment around the transmission line. Line converter. Power transmitted by the waveguide;
Power transmitted by the transmission line;
A waveguide / transmission line converter for converting between
A dielectric substrate disposed to close the opening of the waveguide;
The transmission line disposed on the surface of the dielectric substrate and outside the waveguide;
A matching element disposed on the surface of the dielectric substrate and inside the waveguide;
A matching element-side dielectric layer formed on the surface of the matching element;
The dielectric substrate is disposed on the surface of the dielectric substrate and outside the waveguide. (1) While penetrating the dielectric substrate along the cross section of the two wide wall surfaces of the waveguide, By a metal member that does not penetrate the dielectric substrate along the cross section of the two narrow walls, or (2) the narrow wall of any one of the two wide walls and the two surfaces of the waveguide The waveguide is guided by a metal member that penetrates the dielectric substrate along a cross-section while not penetrating the dielectric substrate along a cross-section of a narrow wall surface of one of the two surfaces of the waveguide. A short-circuit metal layer held at the same potential as the tube;
A waveguide / transmission line converter comprising:   The waveguide / transmission according to claim 3, wherein a thickness of the matching element side dielectric layer is not more than 0.2 times an effective wavelength of an electromagnetic wave in an environment around the matching element. Line converter. An array antenna in which antenna elements are arranged linearly on a plane,
The antenna elements arranged in a straight line are arranged at substantially the center of one row and perform central feeding for one row. The transmission line connected to the waveguide / transmission line converter according to claim 1 or 2 The power supply is fed in opposite phase in the opposite direction across the waveguide / transmission line converter according to Item 1 or 2, and is disposed on a surface of the dielectric substrate on which the transmission line is disposed, and the transmission An array antenna, wherein the surface of the element is covered with a line-side dielectric layer. A planar antenna in which antenna elements are arranged in a lattice pattern on a plane,
The antenna elements arranged in a lattice form are arranged at substantially the center of each row and perform central feeding for each row by the transmission line connected to the waveguide / transmission line converter according to claim 1 or 2. In addition, power is fed in opposite phase in the opposite direction across the waveguide / transmission line converter according to claim 1 or 2, and disposed on a surface of the dielectric substrate on which the transmission line is disposed, A planar antenna, wherein a surface of an element is covered with the transmission line side dielectric layer.

Images