JP2010118941A - Antenna - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antenna which has a planar shape to be downsized and can exhibit excellent characteristics. <P>SOLUTION: An antenna 105 has: feeding lines LN1 and LN2 connected to radiation elements 11 and 12, respectively; a feeding line LN3 connecting the feeding lines LN1 and LN2; and a feeding line LN4 having a tapered shape with a width at a first end connected to the feeding line LN3 larger than a width at a second end. The radiation elements 11 and 12 and the feeding lines LN1 to LN4 are formed integrally by a plane conductor PCD. Further, the antenna has a sleeve conductor 65 and a sleeve conductor 66. The sleeve conductor 65 faces the area, in which the feeding line LN1 is formed, on a principal surface of the plane conductor PCD, and the sleeve conductor 66 is provided at the same side as the sleeve conductor 65 with respect to the plane conductor PCD and facing the area, in which the feeding line LN2 is formed, on the principal surface of the plane conductor PCD. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an antenna, and more particularly to a sleeve antenna having a planar shape.

One of the structures adopted in the planar antenna is a double loop antenna. As an example of a double loop antenna, for example, Patent Document 1 discloses the following double loop antenna. That is, a planar reflecting plate is provided on the back surface of a planar radiating element composed of a triangular double loop element. The side portions on both sides of the reflecting plate are bent toward the radiating element, and the distance between the tip edge of the side portion and the side edge of the radiating element is reduced. Thereby, even if the space | interval of a radiation element and a reflecting plate is narrowed, the electrical property of a planar antenna with a reflecting plate can be made favorable.
JP 2005-73226 A

  Incidentally, the radiator of the double loop antenna has a balanced feeding point. On the other hand, a coaxial cable generally used as a feeder line is an unbalanced feeder line. For this reason, when a coaxial cable is connected to the feed point of the radiator of the double loop antenna, a matching unit is required to convert between balanced feed and unbalanced feed. However, when a matching device is inserted between the radiator and the coaxial cable, an insertion loss of the matching device occurs.

  Therefore, an object of the present invention is to provide an antenna that can be reduced in size and have good characteristics by having a planar shape.

  In order to solve the above problems, an antenna according to an aspect of the present invention includes a first radiating element, a second radiating element spaced apart from the first radiating element, and a first radiating element. And a first feed line and a second feed line connected to the second radiation element, a third feed line connecting the first feed line and the second feed line, and a third feed line, respectively. A fourth feed line having a first end connected to the second end and a second end located on the opposite side of the first end, and having a tapered shape in which the width at the first end is larger than the width at the second end The first radiating element, the second radiating element, and the first feed line to the fourth feed line are integrally formed of a planar conductor, and have a width larger than the width of the first feed line. And at least the first feed line is formed on the main surface of the planar conductor. A first sleeve conductor facing the region, provided on the same side as the first sleeve conductor with respect to the planar conductor, having a width larger than the width of the second feeder line, And a second sleeve conductor facing at least a region where the second feed line is formed.

  Preferably, the first sleeve conductor and the second sleeve conductor are integrally formed by a common first conductor plate.

  More preferably, the first conductor plate faces the region where the first feed line to the fourth feed line are formed on the main surface of the planar conductor.

  More preferably, the antenna further includes a first impedance adjusting conductor facing a region where the third feed line and the fourth feed line are formed on the main surface of the planar conductor, The sleeve conductor, the second sleeve conductor, and the first impedance adjusting conductor are integrally formed of the first conductor plate.

  Preferably, the antenna further has a width larger than the width of the first feed line, and is opposite to the first sleeve conductor with respect to the planar conductor so as to sandwich the first feed line together with the first sleeve conductor. A third sleeve conductor provided on the side and a width greater than the width of the second feed line, and a second conductor with respect to the planar conductor so as to sandwich the second feed line together with the second sleeve conductor And a fourth sleeve conductor provided on the opposite side of the sleeve conductor.

  More preferably, the third sleeve conductor and the fourth sleeve conductor are integrally formed of a common second conductor plate.

  More preferably, the second conductor plate is provided on the opposite side of the first conductor plate with respect to the planar conductor so as to sandwich the first feeder line or the fourth feeder line together with the first conductor plate. .

  More preferably, the antenna further includes a second impedance adjusting conductor facing a region where the third feeding line and the fourth feeding line are formed on the main surface of the planar conductor. The sleeve conductor, the fourth sleeve conductor, and the second impedance adjusting conductor are integrally formed of the second conductor plate.

  More preferably, the first power supply line and the second power supply line are disposed substantially in parallel, and each of the first conductor plates is disposed substantially parallel to the main surface of the planar conductor, A first end portion located on the side closer to the first radiating element and the second radiating element in the extending direction of the feed line and the second feeding line, and the first radiating element and the second radiating element in the extending direction. First and second plate-like portions having a second end located on the side far from the element, and a connecting portion for connecting the first ends of the first and second plate-like portions to each other In addition, the main surface of the second conductor plate is arranged substantially parallel to the planar conductor and is formed in a flat plate shape.

  More preferably, the first feed line and the second feed line are arranged substantially in parallel, and each of the first conductor plate and the second conductor plate is arranged substantially in parallel with the main surface of the planar conductor. And a first end located on the side closer to the first radiating element and the second radiating element in the extending direction of the first feeding line and the second feeding line, and a first radiating element in the extending direction. And first and second plate-like portions each having a second end portion located on the side far from the second radiating element, and first ends of the first and second plate-like portions. Connection part to be connected.

  More preferably, each of the first and second conductor plates has a main surface that is disposed substantially parallel to the planar conductor and is formed in a flat plate shape.

  Preferably, the antenna further includes a reflector provided on the opposite side of the planar conductor with respect to the first sleeve conductor and the second sleeve conductor.

  More preferably, the distance between the planar conductor and the reflector is less than ¼ of the resonance wavelength of the antenna.

  According to the present invention, by having a planar shape, it is possible to achieve downsizing and realize good characteristics.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

<First Embodiment>
FIG. 1 is a perspective view of an antenna according to a first embodiment of the present invention. FIG. 2 is a plan view of the antenna according to the first embodiment of the present invention. FIG. 2 shows a state where the antenna 101 is viewed from the direction opposite to the Z direction shown in FIG. FIG. 3 is a plan view of the antenna according to the first embodiment of the present invention viewed from the same direction as FIG. 2 when the planar conductor plate 21 is removed. FIG. 4 is a side view of the antenna according to the first embodiment of the present invention. FIG. 4 shows a state in which the antenna 101 is viewed from the Y direction shown in FIG.

  The X direction shown in FIG. 1 indicates the extending direction of the feed lines LN1, LN2. The Y direction indicates a direction parallel to the planar conductor plates 21 and 22 and perpendicular to the X direction. The Y direction corresponds to the width direction of the feeder lines LN1 and LN2. The Z direction is a direction orthogonal to both the X direction and the Y direction, and corresponds to the arrangement direction of the radiator 2 and the reflector 4.

  2 and 3 do not show the portions of the dielectric substrate B other than the radiating elements 11 and 12 and the feed lines LN1 to LN4 so that the structure of the antenna 101 can be easily understood.

  1 to 3, the antenna 101 includes a radiator 2 and a reflector 4. The antenna 101 can be used as a receiving antenna that receives the radio wave 5 arriving at the antenna 101, and can also be used as a transmitting antenna that radiates the radio wave 6. The antenna 101 receives, for example, UHF band television broadcast, that is, terrestrial digital broadcast.

  Radiator 2 includes radiating elements 11 and 12, feed lines LN <b> 1 to LN <b> 4, and planar conductor plates 21 and 22. The planar conductor plate 21 is formed by integrally forming a sleeve conductor corresponding to the feed line LN1 and a sleeve conductor corresponding to the feed line LN2. The planar conductor plate 22 is formed by integrally forming a sleeve conductor corresponding to the feed line LN1 and a sleeve conductor corresponding to the feed line LN2. Further, the planar conductor plates 21 and 22 also have a function as impedance adjusting conductors facing the feeder lines LN3 and LN4. As described above, the antenna can be easily manufactured by integrating the two sleeve conductors and the one impedance adjusting conductor.

  The radiating element 11 radiates or receives radio waves. The radiating element 12 is disposed at a distance from the radiating element 11 and radiates or receives radio waves.

  The feed line LN1 and the feed line LN2 are arranged so as to extend in the X direction, and are connected to the radiation element 11 and the radiation element 12, respectively, and a second end located on the opposite side of the first end, Have

  The feed line LN3 is disposed so as to extend in the Y direction, and connects the second end of the feed line LN1 and the second end of the feed line LN2.

  The feed line LN4 has a first end T1 connected to the feed line LN3 and a second end T2 located on the opposite side of the first end T1. The feed line LN4 has a tapered shape in which the width at the first end T1 is larger than the width at the second end T2.

  The radiating element 11, the radiating element 12, and the feed line LN1 to the feed line LN4 are integrally formed by a planar conductor PCD. Here, the “planar conductor” specifically refers to a conductor thin film and a conductor plate on a dielectric substrate, and the length in the direction perpendicular to the two-dimensional direction is longer than the length in the two-dimensional direction. (Thickness) is a sufficiently small conductor. In the antenna according to the first embodiment of the present invention, the radiating element 11, the radiating element 12, and the feed line LN1 to the feed line LN4 are formed by a conductive thin film on the dielectric substrate B as an example.

  As shown in FIG. 2, the planar conductor plate 21 is formed by a conductor plate having a width larger than the width of the feed lines LN <b> 1 to LN <b> 4, and the region where the feed lines LN <b> 1 to LN <b> 4 are formed on the main surface of the planar conductor PCD. Opposite to.

  As shown in FIG. 3, the planar conductor plate 22 is formed of a conductor plate having a width larger than the width of the feed lines LN <b> 1 to LN <b> 4, and the planar conductor PCD is sandwiched with the planar conductor plate 21 so as to sandwich the feed lines LN <b> 1 to LN4. On the other hand, it is provided on the side opposite to the planar conductor plate 21.

  Referring to FIG. 4, radiator 2 is connected to coaxial cable 7. Specifically, the feeder line LN4 is connected to the inner conductor 8 of the coaxial cable 7, and the planar conductor plates 21 and 22 are connected to the outer conductor 9 of the coaxial cable 7.

  Further, the planar conductor plates 21 and 22 are formed in a flat plate shape with their main surfaces being arranged substantially parallel to the planar conductor PCD. With such a configuration, it is possible to further reduce the size of the antenna 101 and stabilize the impedance.

  The planar conductor plate 22 is provided on the opposite side to the planar conductor plate 21 with respect to the planar conductor PCD so as to sandwich the feeder lines LN1 to LN4 together with the planar conductor plate 21. That is, the planar conductor plate 22 is provided on the side opposite to the planar conductor plate 21 with respect to the feed lines LN1 to LN4, and faces the feed lines LN1 to LN4. The planar conductor plates 21 and 22 may be formed of a conductor thin film on a dielectric substrate.

  The planar conductor plate 21 includes an end portion 21a located on the side closer to the radiating elements 11 and 12 in the X direction and an end portion 21b located on the side farther from the radiating elements 11 and 12 in the X direction. The end 21 a is electrically opened, and the end 21 b is connected to the outer conductor 9 of the coaxial cable 7. The shortest distance between the planar conductor plate 21 and the feed lines LN1 to LN4 is d3.

  The planar conductor plate 22 includes an end 22a located on the side close to the radiating elements 11 and 12 in the X direction and an end 22b located on the side far from the radiating elements 11 and 12 in the X direction. The end 22 a is electrically opened, and the end 22 b is connected to the outer conductor 9 of the coaxial cable 7. The shortest distance between the planar conductor plate 22 and the feed lines LN1 to LN4 is d4. The shortest distance d1 between the planar conductor plate 22 and the reflector 4 is set to a predetermined length so that the performance of the antenna 101 is good.

  The reflector 4 is formed of a conductor plate (a flat conductor), and is provided on the opposite side of the planar conductor PCD with respect to the planar conductor plate 22. The distance d2 between the radiating elements 11 and 12 and the reflector 4 is less than ¼ of the resonance wavelength λ of the antenna 101, that is, the wavelength of the radio signal to be received by the antenna 101, preferably about 0.056λ to about 0.067λ. Set to range. The distance d2 is, for example, 35 mm to 40 mm. With such a configuration, the antenna 101 can be downsized. Further, both ends of the reflector 4 in the X direction are bent 90 degrees toward the radiator 2 side. Note that both ends of the reflector 4 may be bent toward the radiator 2 at an angle other than 90 degrees.

  When the antenna 101 is used as a receiving antenna, the reflector 4 realizes a function of reflecting the radio wave arriving at the antenna 101 and guiding it to the radiating elements 11 and 12. On the other hand, when the antenna 101 is used as a transmission antenna, the reflector 4 realizes a function of reflecting the radio waves radiated from the radiating elements 11 and 12 and guiding them in the direction of a waveguide (not shown).

  FIG. 5 is a diagram showing a planar conductor plate in the antenna according to the first embodiment of the present invention. FIG. 6 is a diagram showing a dielectric substrate in the antenna according to the first embodiment of the present invention. FIG. 7 is a diagram showing a reflector in the antenna according to the first embodiment of the present invention. FIG. 8 is a diagram showing in detail the pattern of the dielectric substrate in the antenna according to the first embodiment of the present invention.

  The X direction and the Y direction shown in FIGS. 5 to 8 correspond to the X direction and the Y direction shown in FIG. 1, respectively. In addition, lengths WA to WL shown in FIGS. 5 to 8 are appropriately set so that the performance of the antenna 101 is good except for those described below.

  With reference to FIGS. 5 to 8, the length of the planar conductor plates 21 and 22 in the X direction is WB, and the length in the Y direction is WA. The length WB is set to a predetermined length (for example, about λ / 4). WA is determined to be larger than the width of the feed lines LN1 and LN2, that is, the length WG in the Y direction. Furthermore, when the length of the radiating elements 11 and 12 in the Y direction (width direction) is WI, WI is larger than the width WG of the feed lines LN1 and LN2. The width WG and the distances d3 and d4 shown in FIG. 4 are determined so that the impedance of the feed line LN4 substantially matches the impedance of the coaxial cable 7.

  Further, the length WH in the X direction of the radiating elements 11 and 12 is set to a predetermined length (for example, about λ / 4). The length WJ in the X direction of the feed lines LN1 and LN2 is not particularly limited, but is determined to be a length suitable for connection between the coaxial cable 7 and the feed lines LN1 and LN2, for example.

  The radiating elements 11 and 12 are synthesized by the feed lines LN1 to LN3. The feed line LN1 forms a strip line together with the planar conductor plates 21 and 22. The feed line LN2 forms a strip line together with the planar conductor plates 21 and 22. The impedance R of the feed lines LN1, LN2 is appropriately set by the width WG and the distances d3, d4 of the feed lines LN1, LN2.

  The node P1 is a node where the two radiating elements 11 and 12 are combined, and the impedance at the node P1 is R / 2.

  Generally, the radiation impedance of the sleeve antenna is 75Ω, and in this case, the impedance of the node P1 is 37.5Ω.

  In order to feed the antenna 101 with a 75Ω coaxial cable, the impedance of the feed line LN4 must also be matched to 75Ω.

  Therefore, the antenna 101 performs impedance conversion by using the feeder line LN4 as a taper line. That is, the feed line LN4 has a tapered shape in which the width W1 at the node P1 is larger than the width W2 at the node P2.

  That is, the impedance of the node P1 is 37.5Ω, but the impedance of the node P2 is 75Ω due to the feeding line LN4 having a tapered shape. As a result, since the coaxial cable 7 can be directly connected to the node P2, there is no need to insert a two-distributor, a matching unit, or the like between the coaxial cable 7 and the antenna 101, and loss due to these insertions can be prevented. Can be prevented.

  By the way, the radiator 2 has a configuration equivalent to a so-called sleeve antenna. This will be described in detail below.

  FIG. 9 is a diagram showing one form of a sleeve antenna which is a comparative example of the antenna according to the first embodiment of the present invention.

  Referring to FIG. 9, the sleeve antenna 151 includes a coaxial line 140 including an inner conductor 141 and an outer conductor 142, and a sleeve conductor 143. The inner conductor 141 is a linear conductor. The outer conductor 142 is formed in a cylindrical shape extending in the same direction as the inner conductor 141, and is arranged so that its central axis coincides with the central axis of the inner conductor 141. In order to electrically insulate the inner conductor 141 and the outer conductor 142, for example, a gap may be provided between them, or an insulator may be filled therein.

  The inner conductor 141 has two end portions 144 and 145. The outer conductor 142 includes an inner surface 146 that faces a part of the inner conductor 141, an end 147 that is positioned between the ends 144 and 145 of the inner conductor 141, and an opposite side to the end 147, that is, the inner conductor. 141 and an end portion 148 located on the end portion 145 side. Assuming that the resonance wavelength of the sleeve antenna 151 is λ, a portion of the inner conductor 141 having a length of about λ / 4 from the end portion 144 is exposed without being covered by the outer conductor 142, and the remaining portion is exposed to the outer conductor 142. Opposite the inner surface 146. That is, the end portion 147 of the outer conductor 142 is located at a position away from the end portion 144 of the inner conductor 141 by about λ / 4.

  The sleeve conductor 143 is disposed outside the coaxial line 140 and is electrically connected to the outer conductor 142 at the end 147 of the outer conductor 142. The sleeve conductor 143 extends in a direction from the end 147 to the end 148 of the outer conductor 142 and has a length of about λ / 4. The end of the sleeve conductor 143, which is located about λ / 4 away from the end 147 of the outer conductor 142, is electrically open.

  The outer conductor 142 and the sleeve conductor 143 constitute a super top. When the portion of the inner conductor 141 exposed without being covered by the outer conductor 142, that is, the portion of the inner conductor 141 from the position of the end portion 147 to the end portion 144 of the outer conductor 142 functions as a quarter-wavelength nanopole antenna In addition, the super top formed by the outer conductor 142 and the sleeve conductor 143 prevents a standing wave current (leakage current) from flowing on the surface of the outer conductor 142.

  FIG. 10 is a diagram showing another form of a sleeve antenna which is a comparative example of the antenna according to the first embodiment of the present invention. Referring to FIG. 10, sleeve antenna 152 differs from sleeve antenna 151 in that it includes a branch conductor 149 instead of sleeve conductor 143. The length of the branch conductor 149 is about λ / 4. The branch conductor 149 is electrically connected to the outer conductor 142 at the position of the end 147 of the outer conductor 142, and the opposite end of the branch conductor 149 is electrically opened.

  The sleeve antenna shown in FIGS. 9 and 10 is formed by processing a coaxial line (for example, a coaxial cable). In this case, the inner conductor of the coaxial cable and the braided wire (thin knitted thin copper wire) correspond to the inner conductor 141 and the outer conductor 142, respectively. However, it is considered that manufacturing the sleeve antenna shown in FIG. 9 or FIG. 10 by processing the coaxial cable increases the labor required for processing, and thus increases the manufacturing cost. On the other hand, in the antenna according to the first embodiment of the present invention, the radiating elements 11 and 12 each constituted by a planar conductor, the feed lines LN1 and LN2, and the sleeve conductors corresponding to the feed lines LN1 and LN2 Planar conductor plates 21 and 22 functioning as According to the antenna of the first embodiment of the present invention, for example, a conductive pattern is formed on the dielectric substrate B, and the metal plate is processed using a known processing method such as press processing, thereby radiating. Each element constituting the container 2 can be easily manufactured. Furthermore, since the reflector 4 is also formed of a conductor plate, it can be easily manufactured. Therefore, according to the antenna according to the first embodiment of the present invention, the cost required for manufacturing the antenna can be reduced.

  In the sleeve antenna shown in FIGS. 9 and 10, the thickness of the inner conductor 141 is the same between the portion covered by the outer conductor 142 and the portion exposed from the outer conductor 142. On the other hand, in the antenna according to the first embodiment of the present invention, the length WI in the width direction of the radiating elements 11 and 12 is made larger than the length WG in the width direction of the feed lines LN1 and LN2. While the frequency band of the sleeve antenna shown in FIGS. 9 and 10 is relatively narrow, by configuring the radiating elements 11 and 12 as described above, the frequency band can be made higher than that of the sleeve antenna shown in FIGS. 9 and 10. Can be spread. This point will be described in detail later. In the present specification, a frequency band is defined as a frequency range in which a value indicating a standing wave ratio (generally referred to as SWR (Standing Wave Ratio) or VSWR (Voltage Standing Wave Ratio)) is a predetermined value or less. .

  Next, the performance of the antenna according to the first embodiment of the present invention will be specifically described. The performance of the antenna 101 described below is obtained by configuring the antenna 101 so that radio waves in the frequency band (470 to 770 MHz) of UHF television broadcasting in Japan can be transmitted and received. Specifically, the parameters of length, width, and distance shown in FIGS. 1 to 8 are designed so that the antenna 101 is an antenna suitable for transmission / reception of the UHF band radio wave. This frequency band includes the terrestrial digital broadcasting frequency band (470 to 710 MHz) in Japan.

  In the following, the gain, VSWR, front-to-back ratio, and half width are shown as the performance of the antenna 101. The higher the numerical value indicating the gain, the better the performance of the antenna. Moreover, it shows that the characteristic of an antenna is excellent, so that the numerical value which shows VSWR is low.

  The front-to-back ratio is defined as the ratio of the radiated electric field in the specified direction (the direction at an angle of 0 degrees) and the maximum radiated electric field in the direction of 180 ° ± 60 degrees with respect to that direction. A high front-to-back ratio indicates that the gain in the 0 degree direction of the antenna increases, and therefore the directivity of the antenna increases in that direction. The half-value width is an angle width at which the radiation intensity (radiation power) is ½ of the maximum value.

  FIG. 11 is a diagram showing a result of comparing gains of the antenna according to the first embodiment of the present invention and a general 8-element Yagi antenna. In FIG. 11, a graph G1 shows the gain of the 8-element Yagi antenna, and a graph G2 shows the gain of the antenna 101.

  Referring to FIG. 11, in the frequency range of 470 to 770 MHz, the gain of antenna 101 is about 5.0 dB or more. In particular, in the frequency range of 470 to 590 MHz, that is, in the frequency band of terrestrial digital broadcasting, the antenna 101 has good characteristics equivalent to or better than the 8-element Yagi antenna.

  FIG. 12 is a diagram showing a result of comparing the VSWR between the antenna according to the first embodiment of the present invention and a general 8-element Yagi antenna. In FIG. 12, a graph G1 shows the VSWR of the 8-element Yagi antenna, and a graph G2 shows the VSWR of the antenna 101.

  Referring to FIG. 12, in the frequency range of 470 to 770 MHz, VSWR of antenna 101 is about 2.0, and has a characteristic of 2.5 or less, which is a practical value.

  FIG. 13 is a diagram showing a result of comparison of front-rear ratios between the antenna according to the first embodiment of the present invention and a general 8-element Yagi antenna. In FIG. 13, a graph G <b> 1 shows the front / rear ratio of the 8-element Yagi antenna, and a graph G <b> 2 shows the front / rear ratio of the antenna 101.

  Referring to FIG. 13, the front-rear ratio of antenna 101 is 12 dB to 18 dB in the frequency range of 470 to 770 MHz. In particular, at 470 to 680 MHz and 770 MHz, the antenna 101 has better characteristics than the 8-element Yagi antenna.

  FIG. 14 is a diagram showing a result of comparing the half-value widths of the antenna according to the first embodiment of the present invention and a general 8-element Yagi antenna. In FIG. 14, a graph G <b> 1 shows the half width of the 8-element Yagi antenna, and a graph G <b> 2 shows the half width of the antenna 101.

  Referring to FIG. 14, in the frequency range of 470 to 770 MHz, the half width of antenna 101 is about 70 degrees, and the half width of antenna 101 is larger than that of the 8-element Yagi antenna. This indicates that when the antenna 101 is attached to a wall such as a veranda, the direction adjustment is easy with respect to the 8-element Yagi antenna.

  Further, according to the present embodiment, the frequency band of the antenna can be expanded as compared with the sleeve antenna shown in FIGS. The characteristics of the λ / 4 sleeve antenna shown in FIGS. 9 and 10 are theoretically equivalent to the characteristics of the λ / 4 monopole antenna or the half-wave dipole antenna. Therefore, the result of verifying the characteristics of the half-wave dipole antenna will be described below.

FIG. 15 is a schematic diagram of a half-wave dipole antenna.
Referring to FIG. 15, half-wave dipole antenna 153 includes linear radiating elements DA and DB arranged on the same straight line. The distance from the tip of the radiating element DA to the tip of the radiating element DB is the full length Ld of the half-wave dipole antenna 153. Ld is about half the resonance wavelength of the half-wave dipole antenna.

  FIG. 16 is a diagram showing the VSWR characteristics of the half-wave dipole antenna 153 shown in FIG. FIG. 16A is a diagram showing the VSWR characteristics of the half-wavelength dipole antenna 153 when Ld shown in FIG. 15 is set to about 280 mm. FIG. 16B is a diagram showing the VSWR characteristics of the half-wavelength dipole antenna 153 when Ld is set to about 230 mm. FIG. 16C is a diagram showing the VSWR characteristics of the half-wavelength dipole antenna 153 when Ld shown in FIG. 15 is set to about 200 mm.

  Since the frequency range where the value of VSWR is 3.0 or less is a practical frequency range of the antenna, this frequency range is defined as the frequency band of the antenna. As shown in FIGS. 16 (A) to 16 (C), in order to make the value of VSWR 3.0 or less in the UHF television broadcast frequency band (470 to 770 MHz) in Japan, the lengths are different from each other. Three types of half-wave dipole antennas are required.

  On the other hand, as shown in FIG. 12, according to the antenna according to the first embodiment of the present invention, the VSWR is 3.0 or less over the UHF band (470 to 770 MHz) using one kind of antenna. Can be. That is, according to the antenna according to the first embodiment of the present invention, the frequency band can be broadened compared to the conventional λ / 4 sleeve antenna (same for half-wave dipole antenna or λ / 4 monopole antenna).

  In the antenna according to the first embodiment of the present invention, the radiator 2 is configured to include the planar conductor plates 21 and 22. However, the present invention is not limited to this. Even if the radiator 2 includes one of the planar conductor plates 21 and 22, it is possible to achieve the object of the present invention to achieve downsizing and realizing good characteristics.

  Next, another embodiment of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

<Second Embodiment>
The present embodiment relates to an antenna in which the configuration of the radiator is changed as compared with the antenna according to the first embodiment. The contents other than those described below are the same as those of the antenna according to the first embodiment.

  FIG. 17 is a perspective view of an antenna according to the second embodiment of the present invention. FIG. 18 is a side view of an antenna according to the second embodiment of the present invention. FIG. 18 shows a state where the antenna 102 is viewed from the Y direction shown in FIG.

  Referring to FIG. 17, antenna 102 includes radiator 51 instead of radiator 2 as compared with the antenna according to the first embodiment of the present invention.

  Radiator 51 includes radiating elements 11 and 12, feed lines LN <b> 1 to LN <b> 4, and planar conductor plates 21 and 32. The planar conductor plate 32 is formed by integrally forming a sleeve conductor corresponding to the feed line LN1 and a sleeve conductor corresponding to the feed line LN2. Further, the planar conductor plate 32 also has a function as an impedance adjusting conductor facing the feeder lines LN3 and LN4. As described above, the antenna can be easily manufactured by integrating the two sleeve conductors and the one impedance adjusting conductor.

  Referring to FIG. 18, radiator 51 is connected to a coaxial cable (not shown). Specifically, the feed line LN4 is connected to the inner conductor of the coaxial cable, and the planar conductor plates 21 and 32 are connected to the outer conductor of the coaxial cable.

  Further, the planar conductor plates 21 and 32 are formed in a flat plate shape with their main surfaces being arranged substantially parallel to the planar conductor PCD.

  The planar conductor plate 32 is provided on the opposite side to the planar conductor plate 21 with respect to the planar conductor PCD so as to sandwich the feeder lines LN1 to LN4 together with the planar conductor plate 21. That is, the planar conductor plate 32 is provided on the opposite side of the planar conductor plate 21 with respect to the feed lines LN1 to LN4 and faces the feed lines LN1 to LN4. The planar conductor plates 21 and 32 may be formed of a conductor thin film on a dielectric substrate.

  The planar conductor plate 21 includes an end portion 21a located on the side closer to the radiating elements 11 and 12 in the X direction and an end portion 21b located on the side farther from the radiating elements 11 and 12 in the X direction. The end 21a is electrically opened, and the end 21b is connected to an outer conductor of a coaxial cable (not shown). The shortest distance between the planar conductor plate 21 and the feed lines LN1 to LN4 is d3.

  The planar conductor plate 32 is formed by folding one conductor plate, that is, bending one conductor plate twice in a right angle direction. The planar conductor plate 32 includes plate-like portions 43 and 44 and a connection portion 46.

  The plate-like portion 43 is disposed substantially parallel to the main surface of the planar conductor PCD, and has an end portion 43a located on the side closer to the radiating element 11 and the radiating element 12 in the X direction, and the radiating element 11 in the X direction. And an end portion 43 b located on the side far from the radiating element 12. The end 43b is connected to an outer conductor of a coaxial cable (not shown).

  The plate-like portion 44 is disposed substantially parallel to the main surface of the planar conductor PCD, and has an end portion 44a located on the side close to the radiating element 11 and the radiating element 12 in the X direction, and the radiating element 11 in the X direction. And an end portion 44 b located on the side far from the radiating element 12. The end 44b is electrically open.

  The connecting portion 46 connects the end portion 43 a of the plate-like portion 43 and the end portion 44 a of the plate-like portion 44.

  The shortest distance between the planar conductor plate 32 and the feed lines LN1 to LN4 is d4. The shortest distance d1 between the planar conductor plate 32 and the reflector 4 is set to a predetermined length so that the performance of the antenna 102 is good.

  The reflector 4 is formed of a conductor plate (a flat conductor), and is provided on the opposite side of the planar conductor PCD with respect to the planar conductor plate 32. The distance d2 between the radiating elements 11 and 12 and the reflector 4 is set to less than ¼ of the resonance wavelength λ of the antenna 102, that is, the wavelength of the radio signal to be received by the antenna 102. Moreover, both ends of the reflector 4 in the X direction are bent 90 degrees toward the radiator 51 side. Note that both ends of the reflector 4 may be bent toward the radiator 51 at an angle other than 90 degrees.

  Since other configurations and operations are the same as those of the antenna according to the first embodiment, detailed description thereof will not be repeated here.

  Even if the antenna according to the second embodiment of the present invention has the above-described configuration, the antenna can be reduced in size by having a planar shape like the antenna according to the first embodiment of the present invention. And good characteristics can be realized.

  Next, another embodiment of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

<Third Embodiment>
The present embodiment relates to an antenna in which the configuration of the radiator is changed as compared with the antenna according to the first embodiment. The contents other than those described below are the same as those of the antenna according to the first embodiment.

  FIG. 19 is a perspective view of an antenna according to the third embodiment of the present invention. FIG. 20 is a side view of an antenna according to the third embodiment of the present invention. FIG. 20 shows a state where the antenna 103 is viewed from the Y direction shown in FIG.

  Referring to FIG. 19, antenna 103 includes radiator 52 instead of radiator 2 as compared with the antenna according to the first embodiment of the present invention.

  Radiator 52 includes radiating elements 11 and 12, feed lines LN <b> 1 to LN <b> 4, and planar conductor plates 31 and 22. The planar conductor plate 31 is formed by integrally forming a sleeve conductor corresponding to the feed line LN1 and a sleeve conductor corresponding to the feed line LN2. Further, the planar conductor plate 31 also has a function as an impedance adjusting conductor facing the feed lines LN3 and LN4. As described above, the antenna can be easily manufactured by integrating the two sleeve conductors and the one impedance adjusting conductor.

  Referring to FIG. 20, radiator 52 is connected to a coaxial cable (not shown). Specifically, the feed line LN4 is connected to the inner conductor of the coaxial cable, and the planar conductor plates 31 and 22 are connected to the outer conductor of the coaxial cable.

  Further, the planar conductor plates 31 and 22 are formed in a flat plate shape with their main surfaces being arranged substantially in parallel with the planar conductor PCD.

  The planar conductor plate 22 is provided on the opposite side of the planar conductor plate 31 with respect to the planar conductor PCD so as to sandwich the feeder lines LN1 to LN4 together with the planar conductor plate 31. That is, the planar conductor plate 22 is provided on the opposite side of the planar conductor plate 31 with respect to the feed lines LN1 to LN4 and faces the feed lines LN1 to LN4. The planar conductor plates 31 and 22 may be formed of a conductor thin film on a dielectric substrate.

  The planar conductor plate 22 includes an end 22a located on the side close to the radiating elements 11 and 12 in the X direction and an end 22b located on the side far from the radiating elements 11 and 12 in the X direction. The end 22a is electrically opened, and the end 22b is connected to an outer conductor of a coaxial cable (not shown). The shortest distance between the planar conductor plate 22 and the feed lines LN1 to LN4 is d4.

  The planar conductor plate 31 is formed by folding one conductor plate, that is, bending one conductor plate twice in a right angle direction. The planar conductor plate 31 includes plate-like portions 41 and 42 and a connection portion 45.

  The plate-like portion 41 is disposed substantially parallel to the main surface of the planar conductor PCD, and has an end portion 41a located on the side close to the radiating element 11 and the radiating element 12 in the X direction, and the radiating element 11 in the X direction. And an end portion 41 b located on the side far from the radiating element 12. The end 41b is connected to an outer conductor of a coaxial cable (not shown).

  The plate-like portion 42 is disposed substantially parallel to the main surface of the planar conductor PCD, and has an end portion 42a located on the side close to the radiating element 11 and the radiating element 12 in the X direction, and the radiating element 11 in the X direction. And an end portion 42 b located on the side far from the radiating element 12. The end 42b is electrically open.

  The connecting portion 45 connects the end portion 41 a of the plate-like portion 41 and the end portion 42 a of the plate-like portion 42.

  The shortest distance between the planar conductor plate 31 and the feed lines LN1 to LN4 is d3. The shortest distance d1 between the planar conductor plate 22 and the reflector 4 is set to a predetermined length so that the performance of the antenna 103 is good.

  The reflector 4 is formed of a conductor plate (a flat conductor), and is provided on the opposite side of the planar conductor PCD with respect to the planar conductor plate 22. The distance d2 between the radiating elements 11 and 12 and the reflector 4 is less than ¼ of the resonance wavelength λ of the antenna 103, that is, the wavelength of the radio signal to be received by the antenna 103, preferably about 0.056λ to about 0.067λ. Set to range. The distance d2 is, for example, 35 mm to 40 mm. With such a configuration, the antenna 103 can be downsized. Further, both ends of the reflector 4 in the X direction are bent 90 degrees toward the radiator 52 side. Note that both ends of the reflector 4 may be bent toward the radiator 52 at an angle other than 90 degrees.

  Since other configurations and operations are the same as those of the antenna according to the first embodiment, detailed description thereof will not be repeated here.

  Even if the antenna according to the third embodiment of the present invention has the above-described configuration, the antenna can be reduced in size by having a planar shape like the antenna according to the first embodiment of the present invention. And good characteristics can be realized.

  Next, another embodiment of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

<Fourth embodiment>
The present embodiment relates to an antenna in which the configuration of the radiator is changed as compared with the antenna according to the third embodiment. The contents other than those described below are the same as those of the antenna according to the third embodiment.

  FIG. 21 is a perspective view of an antenna according to the fourth embodiment of the present invention. FIG. 22 is a side view of an antenna according to the fourth embodiment of the present invention. FIG. 22 shows a state where the antenna 104 is viewed from the Y direction shown in FIG.

  Referring to FIG. 21, antenna 104 includes radiator 53 instead of radiator 2 as compared with the antenna according to the first embodiment of the present invention.

  Radiator 53 includes radiating elements 11 and 12, feed lines LN <b> 1 to LN <b> 4, and planar conductor plates 31 and 32. The planar conductor plate 32 is formed by integrally forming a sleeve conductor corresponding to the feed line LN1 and a sleeve conductor corresponding to the feed line LN2. Further, the planar conductor plate 32 also has a function as an impedance adjusting conductor facing the feeder lines LN3 and LN4. As described above, the antenna can be easily manufactured by integrating the two sleeve conductors and the one impedance adjusting conductor.

  Referring to FIG. 22, radiator 53 is connected to a coaxial cable (not shown). Specifically, the feeder line LN4 is connected to the inner conductor of the coaxial cable, and the planar conductor plates 31 and 32 are connected to the outer conductor of the coaxial cable.

  Each of the planar conductor plates 31 and 32 is formed in a flat plate shape with each main surface being disposed substantially parallel to the planar conductor PCD.

  The planar conductor plate 32 is provided on the opposite side to the planar conductor plate 31 with respect to the planar conductor PCD so as to sandwich the feeder lines LN1 to LN4 together with the planar conductor plate 31. That is, the planar conductor plate 32 is provided on the opposite side of the planar conductor plate 31 with respect to the feed lines LN1 to LN4 and faces the feed lines LN1 to LN4. The planar conductor plates 31 and 32 may be formed of a conductor thin film on a dielectric substrate.

  The planar conductor plate 32 is formed by folding one conductor plate, that is, bending one conductor plate twice in a right angle direction. The planar conductor plate 32 includes plate-like portions 43 and 44 and a connection portion 46.

  The plate-like portion 43 is disposed substantially parallel to the main surface of the planar conductor PCD, and has an end portion 43a located on the side closer to the radiating element 11 and the radiating element 12 in the X direction, and the radiating element 11 in the X direction. And an end portion 43 b located on the side far from the radiating element 12. The end 43b is connected to an outer conductor of a coaxial cable (not shown).

  The plate-like portion 44 is disposed substantially parallel to the main surface of the planar conductor PCD, and has an end portion 44a located on the side close to the radiating element 11 and the radiating element 12 in the X direction, and the radiating element 11 in the X direction. And an end portion 44 b located on the side far from the radiating element 12. The end 44b is electrically open.

  The connecting portion 46 connects the end portion 43 a of the plate-like portion 43 and the end portion 44 a of the plate-like portion 44.

  The shortest distance between the planar conductor plate 32 and the feed lines LN1 to LN4 is d4. The shortest distance d1 between the planar conductor plate 32 and the reflector 4 is set to a predetermined length so that the performance of the antenna 104 is good.

  The reflector 4 is formed of a conductor plate (a flat conductor), and is provided on the opposite side of the planar conductor PCD with respect to the planar conductor plate 32. The distance d2 between the radiating elements 11 and 12 and the reflector 4 is less than ¼ of the resonance wavelength λ of the antenna 104, that is, the wavelength of the radio signal to be received by the antenna 104, preferably about 0.056λ to about 0.067λ. Set to range. The distance d2 is, for example, 35 mm to 40 mm. With such a structure, the antenna 104 can be downsized. Further, both ends of the reflector 4 in the X direction are bent 90 degrees toward the radiator 53 side. Note that both ends of the reflector 4 may be bent toward the radiator 53 at an angle other than 90 degrees.

  Since other configurations and operations are the same as those of the antenna according to the third embodiment, detailed description thereof will not be repeated here.

  Even if the antenna according to the fourth embodiment of the present invention has the above-described configuration, the antenna can be reduced in size by having a planar shape like the antenna according to the first embodiment of the present invention. And good characteristics can be realized.

  Next, another embodiment of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

<Fifth embodiment>
The present embodiment relates to an antenna in which the configuration of the radiator is changed as compared with the antenna according to the first embodiment. The contents other than those described below are the same as those of the antenna according to the first embodiment. The definitions of the X direction, the Y direction, and the Z direction are the same as those in the first embodiment of the present invention.

  FIG. 23 is a plan view of an antenna according to the fifth embodiment of the present invention. FIG. 23 shows a state where the antenna 105 is viewed from the opposite direction to the Z direction. FIG. 24 is a plan view of the antenna according to the fifth embodiment of the present invention viewed from the same direction as FIG. 23 when the sleeve conductor plates 63 and 64 and the impedance adjusting conductor plate 67 are removed. FIG. 25 is a side view of an antenna according to the fifth embodiment of the present invention. FIG. 25 shows a state in which the antenna 105 is viewed from the Y direction shown in FIGS. 23 and 24.

  23 to 25, the antenna 105 includes a radiator 54 instead of the radiator 2 as compared with the antenna according to the first embodiment of the present invention.

  The antenna according to the first embodiment of the present invention includes a planar conductor plate 21 integrally formed with a sleeve conductor corresponding to the feed line LN1 and a sleeve conductor corresponding to the feed line LN2, and a sleeve corresponding to the feed line LN1. A planar conductor plate 22 integrally formed with a conductor and a sleeve conductor corresponding to the feeder line LN2, and the planar conductor plates 21 and 22 also have a function as an impedance adjusting conductor facing the feeder lines LN3 and LN4. However, the present invention is not limited to this.

  That is, radiator 54 includes radiating elements 11 and 12, feed lines LN <b> 1 to LN <b> 4, sleeve conductor plates 63 to 66, and impedance adjusting conductor plates 67 and 68. Each sleeve conductor plate and each impedance adjusting conductor plate are provided separately.

  As shown in FIG. 23, the sleeve conductor plate 63 is formed of a conductor plate having a width larger than the width of the feed line LN1, and faces the region where the feed line LN1 is formed on the main surface of the planar conductor PCD. Yes.

  The sleeve conductor plate 64 is provided on the same side as the sleeve conductor plate 63 with respect to the planar conductor PCD, and is formed by a conductor plate having a width larger than the width of the feeder line LN2, and the feeder line on the main surface of the planar conductor PCD. It faces the region where LN2 is formed.

  The sleeve conductor plates 63 and 64 and the impedance adjusting conductor plate 67 are electrically connected by wiring or the like.

  As shown in FIG. 24, the sleeve conductor plate 65 is formed of a conductor plate having a width larger than the width of the power feed line LN1, and the sleeve conductor with respect to the planar conductor PCD so as to sandwich the power feed line LN1 together with the sleeve conductor plate 63. It is provided on the side opposite to the plate 63.

  The sleeve conductor plate 66 is formed of a conductor plate having a width larger than the width of the feeder line LN2, and is provided on the opposite side of the sleeve conductor plate 64 with respect to the planar conductor PCD so as to sandwich the feeder line LN2 together with the sleeve conductor plate 64. It has been.

  The sleeve conductor plates 65 and 66 and the impedance adjusting conductor plate 68 are electrically connected by wiring or the like.

  As described above, FIG. 25 illustrates a state where the antenna 105 is viewed from the Y direction illustrated in FIGS. 23 and 24. Therefore, in FIG. 25, the sleeve conductor plates 63 and 65 are not shown, but their structure and position are the same as those of the sleeve conductor plates 64 and 66. To do.

  Referring to FIG. 25, radiator 54 is connected to coaxial cable 7. Specifically, the feed line LN4 is connected to the inner conductor 8 of the coaxial cable 7, and the impedance adjusting conductor plates 67 and 68 are connected to the outer conductor 9 of the coaxial cable 7.

  In addition, the sleeve conductor plates 63 to 66 and the impedance adjusting conductor plates 67 and 68 are each formed in a flat plate shape with their main surfaces arranged substantially parallel to the planar conductor PCD.

  The sleeve conductor plates 65 and 66 are provided on the side opposite to the sleeve conductor plates 63 and 64 with respect to the feed lines LN1 to LN4, and face the feed lines LN1 to LN4. The sleeve conductor plates 63 to 66 and the impedance adjusting conductor plates 67 and 68 may be formed of a conductive thin film on a dielectric substrate.

  The sleeve conductor plate 64 (63) includes an end portion 64a (63a) located on the side closer to the radiating elements 11 and 12 in the X direction. The impedance adjusting conductor plate 67 includes an end portion 67b positioned on the side far from the radiating elements 11 and 12 in the X direction. The end portion 64 a (63 a) is electrically opened, and the end portion 67 b is connected to the outer conductor 9 of the coaxial cable 7. The shortest distance between the sleeve conductor plates 63 and 64 and the impedance adjusting conductor plate 67 and the feed lines LN1 to LN4 is d3.

  The sleeve conductor plate 66 (65) includes an end portion 66a (65a) located on the side close to the radiating elements 11 and 12 in the X direction. The impedance adjusting conductor plate 68 includes an end portion 68b positioned on the side far from the radiating elements 11 and 12 in the X direction. The end portion 66a (65a) is electrically opened, and the end portion 68b is connected to the outer conductor 9 of the coaxial cable 7. The shortest distance between the sleeve conductor plates 65 and 66 and the impedance adjusting conductor plate 68 and the feed lines LN1 to LN4 is d4. The shortest distance d1 between the sleeve conductor plates 65 and 66 and the impedance adjusting conductor plate 68 and the reflector 4 is set to a predetermined length so that the performance of the antenna 105 is good.

  The reflector 4 is formed of a conductor plate (a flat conductor), and is provided on the opposite side of the planar conductor PCD with respect to the sleeve conductor plates 65 and 66 and the impedance adjusting conductor plate 68. The distance d2 between the radiating elements 11 and 12 and the reflector 4 is less than ¼ of the resonance wavelength λ of the antenna 105, that is, the wavelength of the radio signal to be received by the antenna 105, preferably about 0.056λ to about 0.067λ. Set to range. The distance d2 is, for example, 35 mm to 40 mm. With such a structure, the antenna 105 can be downsized. Further, both ends of the reflector 4 in the X direction are bent 90 degrees toward the radiator 54 side. Note that both ends of the reflector 4 may be bent toward the radiator 54 at an angle other than 90 degrees.

  Since other configurations and operations are the same as those of the antenna according to the first embodiment, detailed description thereof will not be repeated here.

  Even if the antenna according to the fifth embodiment of the present invention has the above-described configuration, the antenna can be downsized by having a planar shape as in the antenna according to the first embodiment of the present invention. And good characteristics can be realized.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 is a perspective view of an antenna according to a first embodiment of the present invention. 1 is a plan view of an antenna according to a first embodiment of the present invention. It is a top view of the antenna which concerns on the 1st Embodiment of this invention seen from the same direction as FIG. 2 when the planar conductor board 21 is removed. It is a side view of the antenna which concerns on the 1st Embodiment of this invention. It is a figure which shows the planar conductor board in the antenna which concerns on the 1st Embodiment of this invention. It is a figure which shows the dielectric substrate in the antenna which concerns on the 1st Embodiment of this invention. It is a figure which shows the reflector in the antenna which concerns on the 1st Embodiment of this invention. It is a figure which shows the pattern of the dielectric substrate in the antenna which concerns on the 1st Embodiment of this invention in detail. It is the figure which showed one form of the sleeve antenna which is a comparative example of the antenna which concerns on the 1st Embodiment of this invention. It is the figure which showed another form of the sleeve antenna which is a comparative example of the antenna which concerns on the 1st Embodiment of this invention. It is a figure which shows the result of having compared the gain with the antenna which concerns on the 1st Embodiment of this invention, and the general 8 element Yagi antenna. It is a figure which shows the result of having compared VSWR with the antenna which concerns on the 1st Embodiment of this invention, and the general 8 element Yagi antenna. It is a figure which shows the result of having compared the front-back ratio with the antenna which concerns on the 1st Embodiment of this invention, and the general 8 element Yagi antenna. It is a figure which shows the result of having compared the half value width with the antenna which concerns on the 1st Embodiment of this invention, and the general 8 element Yagi antenna. It is the schematic of a half-wave dipole antenna. (A) is a figure which shows the VSWR characteristic of the half-wavelength dipole antenna 153 when Ld shown in FIG. 15 is set to about 280 mm. (B) is a figure which shows the VSWR characteristic of the half-wavelength dipole antenna 153 when Ld is set to about 230 mm. (C) is a figure which shows the VSWR characteristic of the half-wavelength dipole antenna 153 when Ld shown in FIG. 15 is set to about 200 mm. It is a perspective view of the antenna which concerns on the 2nd Embodiment of this invention. FIG. 18 is a side view of an antenna according to the second embodiment of the present invention. The state which looked at the antenna 102 from the Y direction shown in FIG. 17 is shown. It is a perspective view of the antenna which concerns on the 3rd Embodiment of this invention. It is a side view of the antenna which concerns on the 3rd Embodiment of this invention. It is a perspective view of the antenna which concerns on the 4th Embodiment of this invention. It is a side view of the antenna which concerns on the 4th Embodiment of this invention. It is a top view of the antenna which concerns on the 5th Embodiment of this invention. FIG. 24 is a plan view of an antenna according to a fifth embodiment of the present invention viewed from the same direction as in FIG. 23 when the sleeve conductor plates 63 and 64 and the impedance adjusting conductor plate 67 are removed. It is a side view of the antenna which concerns on the 5th Embodiment of this invention.

Explanation of symbols

  2,51-54 radiator, 4 reflector, 5,6 radio wave, 7 coaxial cable, 11,12 radiating element, 21,22,31,32 planar conductor plate, 63-66 sleeve conductor plate, 67,68 impedance adjustment Conductor plate, 101-105 antenna, LN1-LN4 feed line, PCD plane conductor.

Claims (13)

A first radiating element;
A second radiating element spaced from the first radiating element;
A first feed line and a second feed line connected to the first radiating element and the second radiating element, respectively;
A third feed line connecting the first feed line and the second feed line;
A taper shape having a first end connected to the third feed line and a second end located on the opposite side of the first end, wherein the width at the first end is larger than the width at the second end A fourth feed line having
The first radiating element, the second radiating element, and the first feed line to the fourth feed line are integrally formed by a planar conductor,
further,
A first sleeve conductor having a width larger than a width of the first feed line, and facing at least a region of the main surface of the planar conductor where the first feed line is formed;
Provided on the same side as the first sleeve conductor with respect to the planar conductor, has a width larger than the width of the second feeder line, and at least the second feeder line of the main surface of the planar conductor And a second sleeve conductor facing the region where the antenna is formed.   The antenna according to claim 1, wherein the first sleeve conductor and the second sleeve conductor are integrally formed by a common first conductor plate.   The antenna according to claim 2, wherein the first conductor plate is opposed to a region where the first feed line to the fourth feed line are formed on a main surface of the planar conductor. The antenna further comprises:
A first impedance adjusting conductor facing a region where the third feeder line and the fourth feeder line are formed on the main surface of the planar conductor;
The antenna according to claim 2, wherein the first sleeve conductor, the second sleeve conductor, and the first impedance adjusting conductor are integrally formed by the first conductor plate. The antenna further comprises:
The first conductor has a width greater than that of the first power supply line, and at least the first power supply line is sandwiched with the first sleeve conductor on the side opposite to the first sleeve conductor with respect to the planar conductor. A third sleeve conductor provided;
It has a width larger than the width of the second feed line, and at least opposite to the second sleeve conductor with respect to the planar conductor so as to sandwich at least the second feed line with the second sleeve conductor The antenna according to any one of claims 1 to 4, further comprising a fourth sleeve conductor provided.   The antenna according to claim 5, wherein the third sleeve conductor and the fourth sleeve conductor are integrally formed by a common second conductor plate.   The second conductor plate is provided on the side opposite to the first conductor plate with respect to the planar conductor so as to sandwich the first feeder line or the fourth feeder line together with the first conductor plate. The antenna according to claim 6. The antenna further comprises:
A second impedance adjusting conductor facing a region where the third feeder line and the fourth feeder line are formed on the main surface of the planar conductor;
The antenna according to claim 6, wherein the third sleeve conductor, the fourth sleeve conductor, and the second impedance adjusting conductor are integrally formed by the second conductor plate. The first feed line and the second feed line are arranged substantially in parallel,
The first conductor plate is
Each of the first radiating element and the second radiating element is disposed substantially parallel to the main surface of the planar conductor and extends in the extending direction of the first feed line and the second feed line. A first end portion located on a side close to the first end portion and a second end portion located on a side farther from the first radiating element and the second radiating element in the extending direction. A plate-shaped part;
A connecting portion that connects the first end portions of the first and second plate-shaped portions;
The second conductor plate is
The antenna according to any one of claims 6 to 8, wherein the main surface is disposed substantially parallel to the planar conductor and is formed in a flat plate shape. The first feed line and the second feed line are arranged substantially in parallel,
Each of the first conductor plate and the second conductor plate is
A side that is disposed substantially parallel to the main surface of the planar conductor and that is close to the first radiating element and the second radiating element in the extending direction of the first feed line and the second feed line First and second plate-like members each having a first end portion located on a side farther from the first radiating element and the second radiating element in the extending direction, respectively. And
The antenna according to any one of claims 6 to 8, further comprising a connecting portion that connects the first end portions of the first and second plate-like portions.   9. The antenna according to claim 6, wherein each of the first and second conductor plates has a main surface that is disposed substantially parallel to the planar conductor and is formed in a flat plate shape. The antenna further comprises:
The antenna according to any one of claims 1 to 11, further comprising a reflector provided on a side opposite to the planar conductor with respect to the first sleeve conductor and the second sleeve conductor.   The antenna according to claim 12, wherein a distance between the planar conductor and the reflector is less than ¼ of a resonance wavelength of the antenna.

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