JP2012004714A - Antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antenna capable of sending and receiving electric waves in a side frequency bandwidth, and freely and finely adjusting an amplitude of a used frequency bandwidth.SOLUTION: An antenna 10 is formed of an unbalanced feed material 11 having a feed part 17 and a non-feed part 18, a resonating conductor 12 resonated with the feed part 17, and a conductor 13 for ground resonated with the non-feed part 18. The resonating conductor 12 has a first fixing part 19 electrically connected with the feed material 11, and a pair of first free parts 20 extending forward in an axial direction in parallel to the feed part 11. The conductor 13 for the ground has a second fixing part 25 electrically connected with the feed material 11, and a pair of second free parts 26 extending backward in the axial direction in parallel to the non-feed part 18. The feed part 17 of the feed material 11 has a parallel part 23 in parallel to the first free part 20 of the resonating conductor 12, and an extension portion 24 extending forward in the axial direction from the first free part 20 of the resonating conductor 12.

Description

  The present invention relates to an antenna including an unbalanced power supply material, a resonance conductor, and a ground conductor.

  A first insulation having a first waveguide having a predetermined length and a second waveguide having a predetermined length connected to the first waveguide, wherein the first waveguide covers the core wire and the core wire of the coaxial cable. The second waveguide section is formed of a first conductor tube fixed to the second insulator of the coaxial cable and a second conductor tube slidably attached to the first conductor tube. There is an antenna (see Patent Document 1). This antenna adjusts the length of the second waveguide portion so that the efficiency of the antenna at the communication frequency is increased by moving the second conductor tube in the length direction with respect to the first conductor tube. Can do.

Japanese Patent Laid-Open No. 2002-10091

  In the antenna disclosed in Patent Document 1, the resonance frequency can be changed by moving the second conductor tube in the length direction, but the use frequency band (specific frequency band) can be used as an antenna. It only covers about 10% of the band, and it is difficult to widen the use frequency band, and it cannot be used in a wide band. In addition, this antenna cannot move its frequency band higher.

  An object of the present invention is to provide an antenna that can transmit and receive radio waves in a wide frequency band and can finely adjust the level of a used frequency band freely.

  An antenna according to the present invention for solving the above-described problems includes an unbalanced power supply member having a power supply unit having a predetermined length and a non-feeding unit having a predetermined length connected to the power supply unit, and a resonance with the power supply unit of the unbalanced power supply member. The first fixing portion is formed of a resonance conductor that performs resonance, a non-feeding portion of the unbalanced power supply material, and a ground conductor that resonates, and the resonance conductor is electrically connected to the unbalanced power supply material through fixing means. And a pair of first free portions connected to the first fixed portion and spaced radially outward of the unbalanced power supply material, and extending in the axial direction of the unbalanced power supply material in parallel with the power supply portion, The ground conductor is electrically connected to the unbalanced power supply material via a fixing means, and is connected to the second fixed portion to be separated radially outward of the unbalanced power supply material. A pair of second free parts extending in the axial direction rearward in parallel with the parts And the feeding part of the unbalanced feeding material is connected to the parallel part parallel to the first free part of the resonance conductor, and the extension part connected to the parallel part and extending forward from the first free part of the resonance conductor in the axial direction And have.

  As an example of the antenna of the present invention, the first free parts of the resonance conductor are in a plane-symmetrical relationship with respect to the axis of the unbalanced power supply, and the second free parts of the ground conductor are of the unbalanced power supply. It is in a plane-symmetric relationship with respect to the axis.

  As another example of the antenna of the present invention, the first free part of the resonance conductor is connected to the first fixed part and extends in a direction intersecting the axial direction, and is connected to the first cross part. An inclination angle of the first intersecting portion with respect to the axis of the unbalanced power supply member, the first separation portion being spaced radially outward from the power supply portion of the unbalanced power supply material and extending forward in the axial direction in parallel with the power supply portion Is in the range of 30 to 90 degrees.

  As another example of the antenna of the present invention, the maximum separation distance between the center of the feeding portion of the unbalanced feeding member and the first separated portion of the first free portion of the resonance conductor is in the range of 2 to 8 mm. .

  As another example of the antenna according to the present invention, the second free portion of the ground conductor is connected to the second fixed portion and extends in a direction intersecting the axial direction, and is connected to the second cross portion. A second spaced-apart portion spaced radially outward from the non-feeding portion of the unbalanced power supply member and extending in the axial direction rearward in parallel with the non-feeding portion; The inclination angle is in the range of 30 to 60 degrees.

  As another example of the antenna of the present invention, the maximum separation distance between the outer peripheral surface of the non-feeding portion of the unbalanced feeding member and the second separation portion of the second free portion of the ground conductor is 3.5 to 10 mm. It is in the range.

  As another example of the antenna of the present invention, the maximum separation distance between the outer peripheral surface of the non-feeding portion of the unbalanced feeding material and the second separated portion of the second free portion of the ground conductor is the unbalanced feeding material. It is larger than the maximum separation distance between the center of the power feeding portion and the first separation portion of the first free portion of the resonance conductor.

  As another example of the antenna of the present invention, the unbalanced feeding material includes a first conductor, a first insulator that covers the outer peripheral surface of the first conductor, and a first insulator that covers the outer peripheral surface of the first insulator. The first conductor is made of at least the first and second conductors of the two conductors and the second insulator covering the outer peripheral surface of the second conductor, and the first insulator. And the first insulator, and the non-feeding portion of the unbalanced power supply member includes at least the first and second conductors and the first insulator of the first and second conductors and the first and second insulators. Formed from.

  As another example of the antenna of the present invention, in the power supply portion of the unbalanced power supply material, the first conductor is exposed from the first insulator to the front in the axial direction by a predetermined length.

  As another example of the antenna of the present invention, a third insulator having a predetermined length extending in the axial direction is fixed to an extension portion of the power supply portion of the unbalanced power supply material.

  As another example of the antenna of the present invention, the antenna is provided with a radio wave reflecting material disposed behind the antenna and extending in the direction around the antenna, and the antenna bisects the axis of the unbalanced feeding material and the radio wave reflecting material in the circumferential direction. The center line of the radio wave reflecting material coincides with the first free portion of the resonance conductor in plane symmetry with respect to the center line, and the second free portion of the ground conductor has plane symmetry with respect to the center line. Is arranged.

  As another example of the antenna of the present invention, an arc is drawn in the direction around the antenna so that the radio wave reflecting material surrounds the rear of the antenna.

  As another example of the antenna of the present invention, the separation distance between the center of the power feeding portion of the unbalanced power feeding material and the radio wave reflecting material is λ / 4.

  The antenna according to the present invention is capable of obtaining a plurality of resonance frequencies by resonating the power feeding portion and the resonance conductor parallel thereto and resonating the parasitic portion and the ground conductor parallel thereto. Since the obtained plurality of resonance frequencies are adjacent to each other in one direction and a part of the resonance frequencies overlap, the frequency band used in the antenna can be greatly expanded. An antenna can transmit or receive radio waves in all of the frequency bands in which it can be used, and can be used in a wide band. The antenna can freely set the length dimension of the first free part of the resonance conductor parallel to the feeding part, and the length dimension of the second free part of the ground conductor pipe parallel to the parasitic part. Since it can be set freely, it is possible to change only the length dimension of the first free portion of the resonance conductor, and it is possible to change only the length dimension of the second free portion of the ground conductor. Both of these length dimensions can be changed. In this antenna, by changing the length dimension of at least one of the length dimension of the first free part of the resonance conductor and the length dimension of the second free part of the ground conductor, the use frequency band is changed. It can be moved to either the higher side or the lower side, and the level of the used frequency band can be finely adjusted freely.

  The first free parts of the resonance conductor are in a plane-symmetrical relationship with respect to the axis of the unbalanced feed material, and the second free parts of the ground conductor are in a plane-symmetrical relationship with respect to the axis of the unbalanced feed material. In some antennas, the feeding portion and the first free portion of the resonance conductor resonate at a plurality of resonance frequencies in the same band, and the parasitic portion and the second free portion of the ground conductor are in a plurality of the same band. It is possible to obtain a plurality of resonance frequencies by resonating at the resonance frequency, and the obtained resonance frequencies are continuously adjacent to each other in one direction and a part of the resonance frequencies is overlapped. The frequency band can be greatly expanded. This antenna can transmit or receive radio waves in all of the frequency bands in which it can be used, and can be used in a wide band.

  The first free portion of the resonance conductor has a first intersecting portion extending in a direction intersecting the axial direction and a first spaced portion extending radially outward from the feeding portion and extending forward in the axial direction, and is unbalanced An antenna in which the inclination angle of the first intersecting portion with respect to the axis of the power supply material is in a range of 30 to 90 degrees is resonated with the power supply portion by setting the inclination angle of the first intersecting portion with respect to the axis of the unbalanced power supply material within that range. It is possible to reliably resonate the conductor. The antenna can obtain a plurality of resonance frequencies by resonating the power feeding part and the resonance conductor and resonating the non-feeding part and the ground conductor. Since adjacent to each other in the direction and some of the resonance frequencies overlap, the frequency band used in the antenna can be greatly expanded. This antenna can transmit or receive radio waves in all of the frequency bands in which it can be used, and can be used in a wide band.

  An antenna having a maximum separation distance in the range of 2 to 8 mm between the center of the power supply portion of the unbalanced power supply member and the first separation portion of the first free portion of the resonance conductor has the maximum separation distance in that range. Thus, the reflection efficiency of radio waves between the power feeding unit and the resonance conductor is optimized, and the power feeding unit and the resonance conductor can be efficiently resonated. The antenna can resonate efficiently between the power feeding part and the resonance conductor, and can efficiently obtain a plurality of resonance frequencies by efficiently resonating the parasitic part and the ground conductor. Since the resonance frequencies are adjacent to each other in one direction and a part of the resonance frequencies overlap, the frequency band used in the antenna can be greatly expanded. This antenna can transmit or receive radio waves in all of the frequency bands in which it can be used, and can be used in a wide band.

  A second intersecting portion in which the second free portions of the ground conductor extend in a direction intersecting the axial direction, and a second spaced portion that extends away from the non-feeding portion of the unbalanced feed member in the radial direction and extends rearward in the axial direction. And the inclination angle of the second intersecting portion with respect to the axis of the unbalanced feed member is in the range of 30 to 60 degrees, and the inclination angle of the second intersecting portion with respect to the axis of the unbalanced feed member is within that range. Thus, the non-feeding portion and the ground conductor can be reliably resonated. The antenna can obtain a plurality of resonance frequencies by resonating the power feeding part and the resonance conductor and resonating the non-feeding part and the ground conductor. Since adjacent to each other in the direction and some of the resonance frequencies overlap, the frequency band used in the antenna can be greatly expanded. This antenna can transmit or receive radio waves in all of the frequency bands in which it can be used, and can be used in a wide band.

  An antenna having a maximum separation distance of 3.5 to 10 mm between the outer peripheral surface of the non-feeding portion of the unbalanced feeding member and the second separation portion of the second free portion of the ground conductor has a maximum separation distance. By setting it within this range, the reflection efficiency of radio waves between the parasitic part and the ground conductor is optimized, and the parasitic part and the ground conductor can be efficiently resonated. The antenna can resonate efficiently between the power feeding part and the resonance conductor, and can efficiently obtain a plurality of resonance frequencies by efficiently resonating the parasitic part and the ground conductor. Since the resonance frequencies are adjacent to each other in one direction and a part of the resonance frequencies overlap, the frequency band used in the antenna can be greatly expanded. This antenna can transmit or receive radio waves in all of the frequency bands in which it can be used, and can be used in a wide band.

  The maximum separation distance between the outer peripheral surface of the non-feeding portion of the unbalanced feeding material and the second separated portion of the second free portion of the ground conductor is the same as the center of the feeding portion of the unbalanced feeding material and the resonance conductor. For an antenna that is larger than the maximum separation distance between the first free space and the first separation portion, the radio wave reflection efficiency between the power feeding portion and the resonance conductor and the radio wave reflection efficiency between the non-feed portion and the ground conductor are optimal. The power feeding portion and the resonance conductor can be efficiently resonated, and the non-power feeding portion and the ground conductor can be efficiently resonated. The antenna can resonate efficiently between the power feeding part and the resonance conductor, and can efficiently obtain a plurality of resonance frequencies by efficiently resonating the parasitic part and the ground conductor. Since the resonance frequencies are adjacent to each other in one direction and a part of the resonance frequencies overlap, the frequency band used in the antenna can be greatly expanded. This antenna can transmit or receive radio waves in all of the frequency bands in which it can be used, and can be used in a wide band.

  The power supply part of the unbalanced power supply material is formed from the first conductor and the first insulator, and the non-power supply part of the unbalanced power supply material is at least the first of the first and second conductors and the first and second insulators. In the antenna formed of the first and second conductors and the first insulator, the power feeding part and the resonance conductor parallel to the power feeding part reliably resonate, and the power feeding part and the ground conductor parallel to the power feeding part reliably resonate. By doing so, it is possible to obtain a plurality of resonance frequencies, and since the obtained plurality of resonance frequencies are adjacent to each other continuously in one direction and a part of the resonance frequencies overlap, the frequency band used in the antenna is expanded. And can transmit or receive radio waves in all of the frequency bands in which it can be used.

  The antenna in which the first conductor is exposed for a predetermined length outward in the axial direction from the first insulator in the power supply unit of the unbalanced power supply material can move the resonance point between the power supply unit and the resonance conductor to the higher side. As a result, the operating frequency band of the antenna can be moved higher. The antenna can finely adjust the level of the used frequency band freely by changing the exposed length of the first conductor in the power feeding unit. In the antenna, it is possible to obtain a plurality of resonance frequencies by surely resonating the power feeding part and the resonance conductor parallel to the power supply part and reliably resonating the parasitic part and the ground conductor parallel thereto. Because the obtained multiple resonance frequencies are adjacent to each other in one direction and some of the resonance frequencies overlap, the usable frequency band in the antenna can be expanded, and all of the usable frequency bands Radio waves can be transmitted or received in the band.

  An antenna in which a third insulator of a predetermined length extending in the axial direction is fixed to the extension part of the power supply part of the unbalanced power supply material, optimizes the VSWR (voltage standing wave ratio) at a low frequency within the use frequency band. In addition, it is possible to increase the resonance wavelength of the power supply unit and the resonance conductor, thereby moving the used frequency band to the lower side. The antenna can finely adjust the level of the used frequency band freely by changing the length of the third insulator fixed to the first conductor. In the antenna, it is possible to obtain a plurality of resonance frequencies by surely resonating the power feeding part and the resonance conductor parallel to the power supply part and reliably resonating the parasitic part and the ground conductor parallel thereto. Because the obtained multiple resonance frequencies are adjacent to each other in one direction and some of the resonance frequencies overlap, the usable frequency band in the antenna can be expanded, and all of the usable frequency bands Radio waves can be transmitted or received in the band.

  A radio wave reflector disposed behind the antenna and extending in a direction around the antenna, the axis of the unbalanced power supply is aligned with the center line of the radio wave reflector, and the first free portions of the resonance conductor are located with respect to the center line; Antennas that are arranged symmetrically and whose second free parts of the ground conductor are arranged symmetrically with respect to the center line can of course widen the frequency band used in the antenna, By being reflected by the reflecting material, all of the radio waves transmitted from the antenna can be transmitted in a predetermined direction, and radio waves entering from the predetermined direction can be received by the entire antenna, and a wide operating frequency band can be obtained. The antenna having the directivity in a specific direction can be given.

  An antenna that forms a circular arc around the antenna so that the radio wave reflector surrounds the rear of the antenna. The radio wave transmitted to the rear of the antenna is reliably reflected by the radio wave reflector, and the radio wave is transmitted to the front of the antenna. Therefore, all the radio waves transmitted from the antenna can be transmitted to the front of the antenna, and the radio waves entering from the front can be received by the entire antenna, and the antenna having a wide use frequency band is directed in a specific direction. Can have sex.

  An antenna having a separation distance of λ / 4 between the center of the power supply unit of the unbalanced power supply material and the radio wave reflection material is transmitted from the antenna by setting the separation distance of the center of the power supply unit and the radio wave reflection material to λ / 4. The transmitted radio wave efficiently reaches the radio wave reflecting material, and the radio wave is reflected by the reflecting material, so that all the radio waves transmitted from the antenna can be transmitted in a predetermined direction. In addition, the radio wave that enters from a predetermined direction and is reflected by the radio wave reflecting material efficiently reaches the antenna, and the antenna can efficiently receive the radio wave.

The perspective view of the antenna shown as an example. FIG. 2 is a sectional view taken along line 2-2 in FIG. 1. The elements on larger scale of an antenna. The figure which shows the correlation with a separation distance and a use frequency band. The perspective view of the electric power feeding part shown as an example. The figure which shows the correlation with VSWR (voltage standing wave ratio) and a use zone | band. Smith chart showing antenna impedance. The figure which shows the field intensity measured in the surroundings direction of an antenna. The figure which shows the field intensity measured in the surroundings direction of an antenna. The perspective view which shows an example of use of an antenna. The front view of FIG. FIG. 11 is a top view of FIG. 10. The perspective view of the electric power feeding part shown as another example.

  The details of the antenna according to the present invention will be described with reference to the accompanying drawings such as FIG. 1 showing an example of the antenna. 2 is a cross-sectional view taken along line 2-2 in FIG. 1, and FIG. 3 is a partially enlarged view of the antenna 10. FIG. 4 is a diagram showing the correlation between the separation distance and the used frequency band. In FIG. 1, the axial direction is indicated by an arrow A, the radial direction is indicated by an arrow B, the front in the axial direction is indicated by an arrow A1, and the rear in the axial direction is indicated by an arrow A2. In FIG. 3, the axis S1 (center axis) is indicated by a dotted line. The antenna 10 is formed of an unbalanced power supply material 11 (coaxial cable or semi-rigid cable), a resonance conductor 12 and a ground conductor 13.

  As shown in FIG. 2, the unbalanced power supply 11 includes a first conductor 14 (center metal conductor), a first insulator 15 that covers the outer peripheral surface of the first conductor 14, and an outer periphery of the first insulator 15. It is made of a second conductor 16 (outer metal conductor) covering the surface and extends in the axial direction. In the unbalanced power supply member 11, the outer peripheral surface of the first conductor 14 and the inner peripheral surface of the first insulator 15 are fixed, and the outer peripheral surface of the first insulator 15 and the inner peripheral surface of the second conductor 16 are fixed. ing.

  The unbalanced power supply member 11 includes a power supply unit 17 set to a length of approximately λ / 4 and a non-power supply unit 18 having a predetermined length (approximately λ / 4 + 2) connected to the power supply unit 17. The power feeding unit 17 is formed of the first conductor 14 and the first insulator 15 and extends substantially linearly in the axial direction. The parasitic part 18 is formed of the first conductor 14, the first insulator 15, and the second conductor 16, and extends substantially linearly from the feeding part 17 to the rear in the axial direction.

  The unbalanced power supply member 11 includes a second insulator (not shown) that covers the outer peripheral surface of the second conductor 16 in addition to the first conductor 14, the first insulator 15, and the second conductor 16. May be. In this case, the outer peripheral surface of the second conductor 16 and the inner peripheral surface of the second insulator are fixed, the power feeding part 17 is formed of the first conductor 14 and the first insulator 15, and the parasitic part 18 is The first conductor 14, the first insulator 15, the second conductor 16, and the second insulator are formed. Aluminum, copper, or the like can be used for the first conductor 14 or the second conductor 16, and thermoplastic synthetic resin (especially Teflon having a plastic-based dielectric constant) is used for the first insulator 15 or the second insulator. (Registered trademark) resin) can be used.

  The resonance conductor 12 is a strip that is elongated in the axial direction with a circular cross section, is made of a conductive metal (aluminum, copper, etc.), and resonates with the power feeding portion 17 of the unbalanced power feeding material 11. The resonance conductor 12 may have a plate shape that is long in the axial direction. The resonance conductor 12 includes a first fixed portion 19 and a pair of first free portions 20 connected to the first fixed portion 19. The first fixing portion 19 is welded (soldered or the like) to the unbalanced power supply material 11 (the second conductor 16 of the power supply portion 18 located in the vicinity of the boundary between the power supply portion 17 and the power supply portion 18 in the power supply material 11) ( And is electrically connected to the unbalanced power supply member 11. The first free parts 20 are separated from the power supply part 17 radially outward of the unbalanced power supply material 11, and in parallel to the power supply part 17, forward from the first fixing part 19 in the axial direction of the unbalanced power supply material 11. It extends.

  The first free portions 20 of the resonance conductor 12 are connected to the first fixed portion 19 and extend in a direction intersecting the axial direction, and are connected to the first intersecting portion 21 and unbalanced from the power feeding portion 17. And a first separating portion 22 that is spaced outward in the radial direction of the power supply member 11. In FIG. 1 to FIG. 3, the first intersecting portion 21 extends from the first fixed portion 19 and inclines toward the front in the axial direction with respect to the axis S <b> 1 (see FIG. 3) of the unbalanced power supply 11. Tilted). The first separation portion 22 extends in parallel to (in parallel with) the power feeding unit 17 from the intersecting portion 21 in the axial direction. Note that the first separation portion 22 may extend so as to incline toward the front in the axial direction with respect to the power feeding portion 17. The feeding portion 17 of the unbalanced feeding material 11 includes a parallel portion 23 extending in parallel with the first free portion 20 of the resonance conductor 12, and an axis line from the first free portion 20 of the resonance conductor 12 connected to the parallel portion 23. And an extending portion 24 extending forward in the direction.

The first free portions 20 of the resonance conductor 12 are in a plane-symmetrical relationship with respect to the axis S1 of the unbalanced power supply member 11. Accordingly, the cross-sectional shapes of the first free portions 20 are the same, and the length L3 in the axial direction described later of the first free portions 20 is the same. The inclination angle α1 of the first intersection 21 of them the first free portion 20 with respect to the axis S1 of the unbalanced feed material 11 are identical, the center of the feeding portion 17 of the unbalanced feed material 11 (the center of the first conductor 14 ) And the first separation portion 22 of the first free portion 20 are the same.

  The ground conductor 13 is a strip that is elongated in the axial direction with a circular cross section, is made of a conductive metal (such as aluminum or copper), and resonates with the parasitic portion 18 of the unbalanced power supply member 10. The ground conductor 13 may have a plate shape that is long in the axial direction. The ground conductor tube 13 includes a second fixed portion 25 and a pair of second free portions 26 connected to the second fixed portion 25. The second fixing portion 25 is welded (soldered or the like) to the unbalanced power supply material 11 (the second conductor 16 of the power supply portion 18 located in the vicinity of the boundary between the power supply portion 17 and the power supply portion 18 in the power supply material 11) ( And is electrically connected to the unbalanced power supply member 11. The second free portions 26 are spaced radially outward of the unbalanced power supply member 11 from the non-feeding portion 18, and in parallel to the non-feeding portion 18, the second fixing portion 25 extends in the axial direction of the unbalanced feeding member 11. It extends backward.

  The second free parts 26 of the ground conductor 13 are connected to the second fixed part and extend in a direction intersecting the axial direction, and are connected to the second crossed part 27 and unbalanced from the parasitic part 18. And a second separating portion 28 that is spaced outward in the radial direction of the power supply member 11. In FIG. 1 to FIG. 3, the second intersecting portion 27 extends from the second fixed portion 25 and inclines toward the end with respect to the axis S <b> 1 of the unbalanced power supply material 11 (inclined rearward in the axial direction). ). The second separation portion 28 extends in the axial direction rearward from the intersecting portion 27 in parallel with the parasitic portion 18, and inclines so as to extend rearward in the axial direction with respect to the parasitic portion 18.

  The parasitic portion 18 of the unbalanced power supply member 11 is connected to the parallel portion 29 extending in parallel with the second free portion 26 of the ground conductor 13 and from the second free portion 26 of the ground conductor 13 connected to the parallel portion 29. And an extending portion 30 extending rearward in the axial direction. A connector 31 is attached to the rear end of the extended portion 30 of the non-feed portion 18.

  These second free portions 26 of the ground conductor 13 are in a plane-symmetrical relationship with respect to the axis S1 of the unbalanced power supply member 11. Therefore, the cross-sectional shape of these 2nd free parts 26 is the same, and the length L4 of the axial direction mentioned later of these 2nd free parts 26 is the same. Further, the inclination angle α2 of the second intersecting portion 27 of the second free portion 26 with respect to the axis S1 of the unbalanced power supply member 11 is the same, and the outer peripheral surface (second conductor 16) of the non-feeding portion 18 of the unbalanced power supply member 11. Of the second free portion 26 and the second separation portion 28 of the second free portion 26 have the same separation distance.

  In the antenna 10, the maximum separation distance L <b> 1 between the center of the feeding portion 17 (the center of the first conductor 13) of the unbalanced feeding material 11 and the first separation portion 22 of the first free portion 20 of the resonance conductor 12 ( 3) is in the range of 2-8 mm, preferably in the range of 2-3 mm. When the maximum separation distance L1 is less than 2 mm, the resonance between the power feeding portion 17 of the unbalanced power supply member 11 and the resonance conductor 12 becomes insufficient, and a plurality of resonance frequencies cannot be obtained, and frequencies that can be used in the antenna 10. The band cannot be expanded. When the maximum separation distance L1 exceeds 8 mm, the usable frequency band in the antenna 10 is saturated in the widest state, and not only the frequency band of the antenna 10 cannot be further expanded, but the maximum separation distance L1 is excessively increased. In some cases, the power feeding portion 17 of the unbalanced power feeding material 11 and the resonance conductor 12 cannot resonate.

  As shown in FIG. 4, the antenna 10 is used at a maximum separation distance L <b> 1 of about 8 mm (point b) as the maximum separation distance L <b> 1 increases from about 0.2 mm (point a). Even if the frequency band becomes the widest state and the maximum separation distance L1 becomes larger than that, the use frequency band of the antenna 10 becomes substantially constant. The antenna 10 has a maximum separation distance L1 in the range of 2 to 8 mm, preferably in the range of 2 to 3 mm, so that the reflection efficiency of radio waves between the resonance conductor 12 and the power feeding unit 17 is optimized, and the resonance conductor 11 and The power feeding unit 17 can be efficiently resonated.

  In the antenna 10, when the inclination angle α1 (see FIG. 3) of the first intersecting portion 21 with respect to the axis S1 of the unbalanced power supply member 11 is in the range of 30 to 90 degrees, the inclination angle α1 is less than 30 degrees or exceeds 90 degrees. The resonance between the feeding portion 17 of the unbalanced feeding material 11 and the resonance conductor 12 becomes insufficient, so that a plurality of resonance frequencies cannot be obtained, and the frequency band usable in the antenna 10 cannot be expanded. The antenna 10 has an inclination angle α1 in the range of 30 to 90 degrees, so that the radio wave reflection efficiency between the resonance conductor 11 and the power supply unit 17 is optimal, and the resonance conductor 11 and the power supply unit 17 are efficiently resonated. Can be made.

  In the antenna 10, the maximum separation between the outer peripheral surface of the parasitic portion 18 (the outer peripheral surface of the second conductor 16) of the unbalanced power supply member 11 and the second separation portion 28 of the second free portion 26 of the ground conductor 13. The distance L2 (see FIG. 3) is in the range of 3.5 to 10 mm. The most preferable maximum separation distance L2 is 4 mm. In the antenna 10, the maximum separation distance L2 is larger than the maximum separation distance L1.

  When the maximum separation distance L2 is less than 3.5 mm, resonance between the parasitic portion 18 of the unbalanced power supply member 11 and the ground conductor 13 becomes insufficient, and a plurality of resonance frequencies cannot be obtained, and the antenna 10 is used. The possible frequency band cannot be expanded. When the maximum separation distance L2 exceeds 10 mm, the usable frequency band in the antenna 10 is saturated in the widest state, and not only the frequency band of the antenna 10 cannot be further expanded, but the maximum separation distance L2 is excessively increased. In some cases, the non-feeding portion 18 of the unbalanced feeding member 11 and the ground conductor 13 cannot be resonated.

  As shown in FIG. 4, the antenna 10 has a use frequency band that steeply spreads as the separation distance L2 increases from approximately 0.2 mm (point a), and the use frequency band when the separation distance L2 is approximately 10 mm (point b). Becomes the widest state, and even if the separation distance L2 becomes larger than that, the frequency band used for the antenna 10 is substantially constant. The antenna 10 has an optimum radio wave reflection efficiency between the ground conductor 13 and the parasitic portion 18 by setting the maximum separation distance L2 in the range of 3.5 to 10 mm, and most preferably 4 mm. The parasitic part 18 can be resonated efficiently.

  In the antenna 10, the inclination angle α2 (see FIG. 3) of the second intersecting portion 27 with respect to the axis S1 of the unbalanced power supply member 11 is in the range of 30 to 60 degrees. If the inclination angle α2 is less than 30 degrees or exceeds 60 degrees, resonance between the parasitic portion 18 of the unbalanced power supply member 11 and the ground conductor 13 becomes insufficient, and a plurality of resonance frequencies cannot be obtained, and the antenna 10, the usable frequency band cannot be expanded. The antenna 10 has an inclination angle α2 in the range of 30 to 60 degrees, so that the radio wave reflection efficiency between the ground conductor 13 and the parasitic part 18 is optimized, and the ground conductor 13 and the parasitic part 18 are made efficient. It can resonate well.

  The antenna 10 has the maximum separation distances L1 and L2 in the above range, and the power feeding portion 17 and the resonance conductor 12 parallel thereto are surely resonated, and the power feeding portion 18 and the ground conductor 13 parallel thereto are reliable. It is possible to obtain a plurality of resonance frequencies by resonating with each other. As a result, a plurality of resonance frequencies are continuously adjacent to each other in one direction and a part of the resonance frequencies overlaps. Can be greatly expanded. The antenna 10 can transmit or receive radio waves in all the frequency bands in which it can be used, and can be used in a wide band.

  The antenna 10 includes a length L3 (see FIG. 2) of the first free portion 20 of the resonance conductor 12 with respect to the power supply portion 17 of the unbalanced power supply member 11 and a ground with respect to the parasitic portion 18 of the unbalanced power supply member 11. The axial length L4 (see FIG. 2) of the second free portions 26 of the conductor 13 can be freely set. In the antenna 10, it is possible to change only the length L <b> 3 of the first free part 20 with respect to the power feeding part 17, and it is possible to change only the length L <b> 4 of the second free part 26 with respect to the parasitic part 18. Both of these lengths L3 and L4 can be changed.

  In order to change the length L3 of the first free part 20 with respect to the power supply part 17, when the length of the first free part 20 of the resonance conductor 12 is changed, the first of the resonance conductor 12 with respect to the unbalanced power supply member 11 is changed. In some cases, the fixing position of the fixing portion 19 is moved forward or backward in the axial direction, or both of them are used in combination. In order to change the length L4 of the second free portion 26 with respect to the non-feeding portion 18, when the length of the second free portion 26 of the ground conductor 13 is changed, the second length of the ground conductor 13 with respect to the unbalanced feed member 11 is changed. 2 When the fixing position of the fixing part 25 is moved forward or backward in the axial direction, or both of them may be used in combination.

  The antenna 10 changes the lengths L3 and L4 of at least one of the length L3 of the first free parts 20 with respect to the power feeding part 17 and the length L4 of the second free parts 26 with respect to the parasitic part 18. Thus, the use frequency band can be freely moved to a higher side and a lower side. For example, when the length L3 is made longer than that shown in the drawing, the resonance point between the power feeding portion 17 and the resonance conductor 12 moves to the higher side, thereby moving the use frequency band of the antenna 10 to the higher side. . Conversely, if the length dimension L3 is shorter than that shown in the drawing, the wavelength of resonance between the power feeding unit 17 and the resonance conductor 12 becomes longer, and the use frequency band of the antenna 10 can be moved to the lower side. Further, if the length L4 is longer than that shown in the figure, the resonance wavelength of the parasitic portion 18 and the ground conductor 13 becomes longer, and the use frequency band of the antenna 10 can be moved to the lower side. Conversely, if the length L4 is shorter than that shown in the figure, the resonance point of the parasitic part 18 and the ground conductor 13 moves to the higher side, thereby moving the operating frequency band of the antenna 10 to the higher side. it can.

  FIG. 5 is a perspective view of the power feeding unit 17 shown as an example. In FIG. 5, only a part of the power feeding unit 17 and the resonance conductor 12 is shown, and the other illustrations are omitted. An extending portion 24 that extends forward in the axial direction from the resonance conductor 12 in the power feeding portion 17 includes a front portion 32 that is formed only from the first conductor 14, and the first conductor 14 and the first insulator 15. Formed and has a rear portion 33. Therefore, the first conductor 14 is exposed from the first insulator 15 to the front in the axial direction by a predetermined length in the extended portion 24 of the power feeding unit 17. Since the other configuration of the antenna 10 having the power feeding unit 17 is the same as that of the antenna 10 of FIG. 1, the description of the other configuration of the antenna 10 is provided by using the description of the antenna 10 of FIG. Is omitted.

  The antenna 10 having the power feeding unit 17 in FIG. 5 has a resonance point between the power feeding unit 17 and the resonance conductor 12 as compared with the case where the entire power feeding unit 17 is formed of the first conductor 14 and the first insulator 15. Move higher. If the exposed length L5 of the first conductor 14 in the power feeding unit 17 is increased, the movement of the resonance point to a higher position can be increased, and if the exposed length L5 of the first conductor 14 in the power feeding unit 17 is shortened, The movement of the resonance point to a higher position can be reduced.

  The antenna 10 having the power feeding unit 17 has the following effects in addition to the effects of the antenna 10 shown in FIG. The antenna 10 can move the resonance point to a finer side by exposing the first conductor 14 from the first insulator 15 by a predetermined length in the power feeding unit 17, thereby reducing the operating frequency band of the antenna 10. It can be moved higher. The antenna 10 can freely finely adjust the level of the used frequency band by changing the exposed length L5 of the first conductor 14 in the power feeding unit 17.

  FIG. 6 is a diagram showing the correlation between the VSWR (voltage standing wave ratio) and the band used, and FIG. 7 is a Smith chart showing the impedance of the antenna. 8 and 9 are diagrams showing the radio wave intensity measured in the directions around the three planes (XY plane, YZ plane, and ZX plane) of the antenna. FIG. 8 shows the measurement results of the radio field intensity around the XY plane antenna characteristics (0 ° to 360 °), and FIG. 9 shows the radio waves around the YZ plane or ZX plane antenna characteristics (0 ° to 360 °). The measurement result of intensity is shown.

  As shown in FIG. 6, the antenna 10 has a reflection coefficient VSWR (voltage standing wave ratio) of 2 or less and a low VSWR (voltage standing wave ratio) when the operating frequency is about 2.0 GHz to about 4.0 GHz. It can be seen that it has a wide operating frequency band in the maintained state. Also, as shown in FIG. 7, the impedance of the antenna 10 is 50Ω, and as shown in FIG. 8, the radio field intensity in the direction around the XY plane antenna characteristics (0 ° to 360 °) draws a substantially perfect circle. As shown in FIG. 9, the radio field intensity in the direction around the YZ plane or ZX plane antenna characteristics (0 ° to 360 °) shows a butterfly shape, and it can be seen that the antenna 10 has good omnidirectionality. .

  FIG. 10 is a perspective view showing an example of use of the antenna, and FIG. 11 is a front view of FIG. FIG. 12 is a top view of FIG. 11 and 12, the vertical direction is indicated by an arrow C (FIG. 11 only), the surrounding direction is indicated by an arrow D (only FIG. 12), and the front-rear direction E is indicated by an arrow (only FIG. 12). 10 and 12, the front in the front-rear direction is indicated by an arrow E1, and the rear in the front-rear direction is indicated by an arrow E2 (only in FIG. 12). In FIG. 11, the center line S2 is indicated by a one-dot chain line.

  The antenna 10 includes a radio wave reflecting material 34 as an example of its use. The radio wave reflector 34 is disposed behind the antenna 10. The radio wave reflector 34 is made of a conductive metal (aluminum, copper, plating, etc.) and reflects radio waves transmitted from the antenna 10. As shown in FIGS. 10 and 12, the radio wave reflecting material 34 is formed in a semicircular shape and forms an arc (a perfect circle) in the direction around the antenna 10. In the antenna 10, the separation distance L5 between the center of the power feeding portion 17 of the unbalanced power feeding material 11 and the radio wave reflecting material 34 is set to λ / 4.

  The radio wave reflecting material 34 has a length in the vertical direction substantially the same as the length in the axial direction of the unbalanced power supply material 11 (not including the connector 31) of the antenna 10, and surrounds the entire area on the rear surface side of the antenna 10. . The radio wave reflecting material 34 is not limited to a semicircular shape, and the length of the circumference thereof can be freely set. Moreover, it should just extend in the surrounding direction so that the antenna 10 may be surrounded, and does not necessarily need to draw a perfect circle, A semi-ellipse shape or V shape may be sufficient.

  In this usage example of the antenna 10, the axis S <b> 1 (see FIG. 3) of the unbalanced power supply material 11 coincides with the center line S <b> 2 of the reflection material 34 that bisects the radio wave reflection material 34 in the circumferential direction. The antenna 10 is disposed with respect to the radio wave reflector 34 so that S1 is positioned at the center point when the reflector 34 is a perfect circle. The first free portions 20 of the resonance conductor 12 are arranged symmetrically with respect to the center line S2, and the second free portions 26 of the ground conductor 12 are arranged symmetrically with respect to the center line S2. Yes. As indicated by arrows E1 and E2 in FIG. 12, the antenna 10 reflects the reflected radio wave and the radio wave transmitted from the front side thereof by the radio wave reflected from the rear surface side to the rear in the front-rear direction. Is sent forward in the front-rear direction.

  The antenna 10 has a separation distance L5 set to λ / 4. However, as shown in FIG. 12, the antenna 10 moves on a moving line S3 connecting the axis S1 of the unbalanced power supply material 11 and the center line S2 of the radio wave reflection material 34. Can be moved. Thereby, the radiation gain and the resonance frequency of the antenna 10 can be finely adjusted freely.

  The antenna 10 can widen its frequency band of use, and of course, the radio wave transmitted to the rear of the antenna 10 is reflected by the radio wave reflector 34 and the radio wave is transmitted forward in the front-rear direction. All transmitted radio waves can be transmitted forward in the front-rear direction (predetermined direction), and radio waves entering from the front in the front-rear direction (predetermined direction) can be received by the entire antenna. The antenna 10 can be provided with directivity in the front-rear direction (specific direction).

  In the antenna 10 in which the separation distance L5 is set to λ / 4, the radio wave transmitted from the antenna 10 efficiently reaches the radio wave reflecting material 34, and the radio wave is reflected by the reflecting material 34, thereby being transmitted from the antenna 10. All of the received radio waves can be transmitted forward (predetermined direction) in the front-rear direction. In addition, the radio wave that enters from the front in the front-rear direction (predetermined direction) and is reflected by the radio wave reflecting material 34 efficiently reaches the antenna 10, and the antenna 10 can receive the radio wave efficiently.

  FIG. 13 is a perspective view of a power feeding unit 17 shown as another example. In FIG. 13, only a part of the power feeding unit 17 and the resonance conductor 12 is shown, and the other illustrations are omitted. A third insulator 35 having a predetermined length extending in the axial direction is fixed to the extending portion 24 of the power feeding portion 17 of the unbalanced power feeding material 11. As with the unbalanced power supply member 11, the third insulator 35 has a circular cross-sectional shape. However, the cross-sectional shape is not limited to a circular shape, and may be a quadrangle or a polygon. For the third insulator 35, a thermoplastic synthetic resin (particularly, a Teflon (registered trademark) resin having a plastic dielectric constant) can be used. The other configurations of the antenna 10 to which the third insulator 35 is fixed are the same as those of the antenna 10 in FIG. 1, so that the description of the antenna 10 in FIG. The description of the configuration is omitted.

  The antenna 10 in which the third insulator 35 shown in FIG. 13 is fixed to the extended portion 24 of the power feeding unit 17 has a longer resonance wavelength between the power feeding unit 17 and the resonance conductor 12 than when the antenna 10 is not attached. Become. If the length L6 of the third insulator 35 fixed to the extended portion 24 is increased, the length of the resonance wavelength can be increased, and the length of the third insulator 35 fixed to the extended portion 24 is increased. When L6 is shortened, the length of the resonance wavelength can be shortened. Conversely, when the length L6 of the third insulator 35 is increased, the length of the resonance wavelength can be increased.

  The antenna 10 to which the third insulator 35 is fixed has the following effects in addition to the effects of the antenna 10 of FIG. The antenna 10 can lengthen the resonance wavelength of the power supply unit 17 and the resonance conductor 12 by fixing the third insulator 35 to the extending portion 24 of the power supply unit 17, and thereby within the operating frequency band. The VSWR of the low frequency part can be optimized. The antenna 10 can freely fine-tune the VSWR in the used frequency band by changing the length L6 of the third insulator 35.

DESCRIPTION OF SYMBOLS 10 Antenna 11 Unbalanced feeding material 12 Resonant conductor 13 Ground conductor 14 First conductor 15 First insulator 16 Second conductor 17 Feeding portion 18 Parasitic portion 19 First fixed portion 20 First free portion 21 First intersecting portion 22 First separation portion 23 Parallel portion 24 Extension portion 25 Second fixed portion 26 Second free portion 27 Second intersection portion 28 Second separation portion 29 Parallel portion 30 Extension portion 34 Radio wave reflector 35 Third insulator L1 Maximum Separation distance L2 Maximum separation distance L3 Length L4 Length L5 Exposure length L6 Length α1 Inclination angle α2 Inclination angle

Claims (13)

An unbalanced power supply member having a predetermined length of power supply unit and a predetermined length of non-power supply unit connected to the power supply unit, a resonant conductor that resonates with the power supply unit of the unbalanced power supply member, and the unbalanced power supply unit Formed from a feeding conductor and a ground conductor that resonates,
The resonance conductor is electrically connected to the unbalanced power supply member via a fixing means, and is connected to the first fixing portion to be spaced radially outward of the unbalanced power supply material. And a pair of first free portions extending in the axial direction of the unbalanced power supply member in parallel with the power supply portion, and the ground conductor is electrically connected to the unbalanced power supply member via a fixing means. A second fixed portion connected to the second fixed portion, and connected to the second fixed portion so as to be separated radially outward of the unbalanced power supply member, and extending in the axial direction rearward in parallel with the non-feed portion. A parallel portion parallel to the first free portion of the resonance conductor and a first free portion of the resonance conductor connected to the parallel portion. And an extending portion extending forward in the axial direction. Antenna.   The first free parts of the resonance conductor are in a plane-symmetrical relationship with respect to the axis of the unbalanced power supply, and the second free parts of the ground conductor are with respect to the axis of the unbalanced power supply. The antenna according to claim 1, which is in a plane-symmetrical relationship.   The first free portion of the resonance conductor is connected to the first fixed portion and extends in a direction intersecting the axial direction, and is connected to the first intersection and fed to the unbalanced power supply member. A first spacing portion that is spaced outward from the radial direction and extends forward in the axial direction in parallel with the power feeding portion, and an inclination angle of the first intersecting portion with respect to the axis of the unbalanced feeding material is The antenna according to claim 1 or 2, wherein the antenna is in a range of 30 to 90 degrees.   4. The antenna according to claim 3, wherein a maximum separation distance between a center of the power feeding portion of the unbalanced power feeding material and a first separated portion of the first free portion of the resonance conductor is in a range of 2 to 8 mm.   The second free portions of the ground conductor are connected to the second fixed portion and extend in a direction intersecting the axial direction, and are connected to the second crossed portion to connect the second unbalanced power supply member. A second spaced-apart portion that is spaced radially outward from the power feeding portion and extends rearward in the axial direction in parallel with the non-feeding portion, and an inclination of the second intersecting portion with respect to the axis of the unbalanced feed material The antenna according to any one of claims 1 to 4, wherein the angle is in a range of 30 to 60 degrees.   The maximum separation distance between the outer peripheral surface of the non-feeding portion of the unbalanced feeding member and the second spacing portion of the second free portion of the ground conductor is in the range of 3.5 to 10 mm. The described antenna.   The maximum separation distance between the outer peripheral surface of the non-feeding part of the unbalanced feeding material and the second separated portion of the second free part of the ground conductor is the center of the feeding part of the unbalanced feeding material and the resonance. The antenna according to claim 6, wherein the antenna is larger than a maximum separation distance between the first separation portions of the first free portions of the conductor.   The unbalanced power supply material includes a first conductor, a first insulator that covers an outer peripheral surface of the first conductor, a second conductor that covers an outer peripheral surface of the first insulator, and the second conductor. Of the first insulator and at least the first and second conductors of the second insulator covering the outer peripheral surface of the first and second insulators, and the power supply portion of the unbalanced power supply member includes the first conductor and the first insulator. And the parasitic portion of the unbalanced power supply member is at least the first and second conductors and the first insulator of the first and second conductors and the first and second insulators. The antenna according to claim 1, wherein the antenna is formed from:   The antenna according to claim 8, wherein the first conductor is exposed for a predetermined length from the first insulator forward in the axial direction in the power supply portion of the unbalanced power supply material.   The antenna according to any one of claims 1 to 9, wherein a third insulator having a predetermined length extending in the axial direction is fixed to an extension portion of the power supply portion of the unbalanced power supply material.   The antenna includes a radio wave reflector disposed behind the antenna and extending in a direction around the antenna. In the antenna, the radio wave reflector that bisects the axis of the unbalanced feeding material and the radio wave reflector in the circumferential direction. And the first free parts of the resonance conductor are arranged in plane symmetry with respect to the center line, and the second free parts of the ground conductor are surfaces with respect to the center line. The antenna according to claim 1, which is arranged symmetrically.   The antenna according to claim 11, wherein the radio wave reflecting material forms an arc in a direction around the antenna so as to surround a rear side of the antenna.   The antenna according to claim 11 or 12, wherein a separation distance between a center of a power feeding portion of the unbalanced power feeding material and the radio wave reflecting material is λ / 4.

Images