JP2005236656A - Circular polarization antenna - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a circular polarization antenna capable of receiving a circularly polarized wave by means of a configuration of combining one monopole antenna with a wire-shaped conductor orthogonal thereto and providing a power transfer part between them. <P>SOLUTION: The circular polarization antenna 10 comprises: the monopole antenna 5 formed on a transparent dielectric film 8 and having a power feed terminal and an opening terminal; and a non-powered element 7 having a length component in the vertical direction with respect to an antenna shaft of the monopole antenna 5 and acting like the wire-shaped conductor not electrically connected to the monopole antenna 5. The non-powered element 7 is provided with the power transfer part capable of transmitting / receiving power to / from the monopole antenna 5 and arranged close to the opening terminal of the monopole antenna 5. The power transfer part is configured by folding at least either of the opening terminal of the monopole antenna 5 and one end of the non-powered element 7 and arranging the folded part nearly in parallel. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a circularly polarized antenna, and particularly to a mobile body such as an automobile, which is attached to the mobile body without impairing the design of the mobile body, and receives, transmits, or transmits / receives radio waves including circularly polarized waves. The present invention relates to a small and lightweight circularly polarized antenna that can be used.

  2. Description of the Related Art Conventionally, an antenna that enables reception of radio waves while moving is mounted on a vehicle (moving body) such as an automobile. In general, radio waves received by vehicles have been mainly AM radio wave (MW), FM radio and TV ultra-high frequency (VHF) and ultra-high frequency (UHF) for many years.

  However, in recent years, in addition to antennas that receive these radio waves, high-frequency GPS (Global Positioning System) antennas, or satellite radio waves for satellite digital broadcasting and their re-radiated waves (gap filler) An antenna that receives a radio wave) and an antenna that transmits and receives radio waves for a telephone such as a car phone or a cellular phone are becoming necessary for vehicles. Furthermore, as part of ITS (Intelligent Transport System), ETC (Automatic Tollgate System) that automatically collects tolls for highways and toll roads, and VICS (Road Traffic Information Communication System) that provides road traffic information Antennas that transmit and receive radio waves are also required for radio wave beacons. Therefore, recent vehicles have to be equipped with antennas for receiving or transmitting many types of radio waves.

  Among such radio waves to be transmitted and received by the mobile body, circularly polarized waves are used for GPS radio waves, satellite digital broadcast satellite radio waves, or ETC radio waves. Many patch antennas have been used as conventional circularly polarized antennas. As this patch antenna, a configuration is often adopted in which a planar ground conductor is installed on one surface of a dielectric substrate such as ceramic and a radiation conductor is installed on the other surface. As this type of patch antenna, a low-profile type patch antenna that has been used by being installed on the roof of a moving body such as an automobile has already been proposed (for example, see Patent Document 1).

Japanese Patent Laid-Open No. 2002-135045 (FIGS. 1 and 2)

  However, since the patch antenna disclosed in Patent Document 1 and the like uses a substrate, the thickness of the antenna becomes large, and it is difficult to reduce the thickness, which may impair the design of the vehicle. In addition, since this patch antenna needs to include a substrate having a certain area or more and a flat ground conductor, when installed on a member that requires transmission visibility such as a windshield, the patch antenna has a front view. There was also a problem to lose.

  For such problems, circularly polarized antennas composed of linear conductors, such as helical antennas and crossed dipole antennas, have been proposed as circularly polarized antennas that do not impair forward visibility. However, this proposed antenna needs to have high antenna characteristics, and the antenna pattern must be precisely placed on both sides of the dielectric, such as a dielectric film, where the antenna is installed. However, there is a problem that the transparency of the film is lowered or the manufacturing cost is increased to increase the cost.

  In response to such problems, the present inventors have already proposed a thin loop antenna for circularly polarized wave reception, but this circularly polarized loop antenna has a substantial area.

  Therefore, the present invention enables the antenna to be thinned and mounted inside the vehicle, eliminates the possibility of impairing the design of the vehicle, prevents the antenna from obstructing the field of view, has a simple structure, and is mainly circularly polarized. It is an object of the present invention to provide a circularly polarized antenna with a small antenna area that can transmit and receive the signal.

  The thin antenna of the present invention that achieves the above object can take the following first to sixteenth forms.

  The first embodiment includes a monopole antenna having a feeding point and an open end, and a linear conductor that has a length component in a direction perpendicular to the antenna axis of the monopole antenna and is not electrically connected to the monopole antenna. The parasitic element includes a power delivery unit capable of delivering power to the monopole antenna, and is disposed near the open end of the monopole antenna. It is an antenna for circular polarization.

  The second form is a circularly polarized wave antenna in which the antenna axis of the monopole antenna and the axis of the parasitic element are arranged in a direction orthogonal to each other in the circularly polarized wave antenna of the first form.

  A third mode is the circularly polarized antenna according to the first or second mode, wherein one end of a parasitic element in which the power delivery unit is disposed substantially parallel to the open end of the monopole antenna; This is a circularly polarized antenna.

  In the fourth embodiment, in the circularly polarized antenna according to the third embodiment, at least one of a portion having a predetermined length from the open end of the monopole antenna and a portion having a predetermined length from one end of the parasitic element is bent. This is a circularly polarized antenna in which this bent portion is formed as a power delivery portion.

  The fifth mode is the circularly polarized antenna according to any one of the first to fourth modes, wherein the length of the parasitic element is set to ½ wavelength of the radio wave of the transmission / reception frequency of the circularly polarized antenna. This is a circularly polarized antenna having the above length.

  In the sixth aspect, in the circularly polarized antenna according to any one of the first to fourth aspects, the length of the parasitic element is an integer of a half wavelength of the radio wave wavelength of the transmission / reception frequency of the circularly polarized antenna. It is a circularly polarized antenna characterized by having a double length.

  A seventh aspect is a circularly polarized wave antenna according to any one of the first to sixth aspects, wherein the monopole antenna and the parasitic element are arranged on the same plane. It is an antenna.

  An eighth aspect is the circularly polarized wave antenna according to the seventh aspect, wherein the antenna element and parasitic element of the monopole antenna are configured on a flexible sheet-like dielectric. It is an antenna.

  The ninth form is a circularly polarized antenna according to the eighth form, wherein the sheet-like dielectric is made of a transparent insulator film, and this film is installed on an exterior member made of automobile glass or insulator. This is a circularly polarized antenna.

  In a tenth aspect, in the circularly polarized antenna according to the eighth aspect, the monopole antenna and the first parasitic element are installed on the surface or inside of an exterior member made of glass of an automobile or an insulator. This is a circularly polarized antenna.

  The eleventh aspect is the circularly polarized antenna according to any one of the first to tenth aspects, wherein the second antenna comprises a linear conductor that is not electrically connected to at least one of the monopole antenna and the parasitic element. A circularly polarized wave antenna characterized in that a parasitic element is provided so as to function as a director or a reflector.

  In a twelfth aspect, in the circularly polarized antenna according to the eleventh aspect, the second parasitic element is configured by a monopole antenna and a parasitic element, and a virtual line orthogonal to the second parasitic element at a substantially central position thereof. The circularly polarized antenna is provided so as to pass through substantially the center of the circularly polarized antenna.

  In a thirteenth embodiment, in the circularly polarized antenna of the eleventh or twelfth embodiment, the length of the second parasitic element is set to a monopole antenna so that the second parasitic element functions as a reflector. It is a thin antenna characterized in that it is longer than half the wavelength of the radio wave of the transmission / reception frequency of a circularly polarized antenna composed of a parasitic element.

  In the fourteenth embodiment, in the circularly polarized antenna according to the eleventh or twelfth embodiment, the length of the second parasitic element is set to a monopole antenna so that the second parasitic element functions as a director. A thin antenna characterized in that it is shorter than half the wavelength of a radio wave of a transmission / reception frequency of a circularly polarized antenna composed of a parasitic element.

  A fifteenth aspect is a circularly polarized antenna according to any one of the eleventh to fourteenth antennas, wherein the second parasitic element is a part of another antenna.

  A sixteenth aspect is a circularly polarized antenna according to the fifteenth aspect, wherein the other antenna is a part of an antenna for receiving a radio wave on the same plane as the monopole antenna. This is a polarization antenna.

  According to the present invention, there is provided a small circularly polarized wave antenna having a simple feeding structure and capable of receiving circularly polarized waves. In addition, various antennas can be installed on thin dielectrics, and can also be installed on vehicle dielectrics, so there is no risk of damaging the vehicle design, and the antennas are damaged or stolen. There is no fear of it. Furthermore, there is no possibility of obstructing the driver's view by forming a thin dielectric on the transparent film.

  Embodiments according to the present invention will be described below in detail based on specific examples with reference to the accompanying drawings. In general, an antenna can perform both transmission and reception of radio waves. However, in the following embodiment, only the case where the antenna receives radio waves will be described for the sake of simplicity. Description of the case of transmitting radio waves is omitted.

  FIG. 1A shows a basic configuration of a circularly polarized antenna 1L according to an embodiment of the present invention for receiving left-handed circularly polarized waves. The circularly polarized wave antenna 1L of this embodiment includes a monopole antenna 2, a ground plate 3, and a parasitic conductor 4. The feed point of the monopole antenna 2 is connected to the core wire 25 of the coaxial cable 24, and the ground plate 3 is connected to the ground wire 27 of the coaxial cable 24. The parasitic conductor 4 is not electrically connected to the monopole antenna 2 and is disposed in the vicinity of the tip of the monopole antenna 2 in a direction orthogonal to the monopole antenna 2.

  In this embodiment, the front end portion 2A, which is the open end of the monopole antenna 2, is bent obliquely, and the one end portion 4A of the parasitic conductor 4 is also bent obliquely, and both are arranged close to each other in parallel. ing. In other words, the one end portion 4A of the parasitic conductor 4 and the tip portion 2A of the monopole antenna 2 form a power delivery section, and the parasitic conductor 4 can deliver power to the monopole antenna 2. ing. When the current delivery portion is formed obliquely, current loss is reduced. In this embodiment, the length D of the parasitic conductor 4 (including the end portion 4A) D is a length equal to or longer than ½ wavelength of the radio wave wavelength of the reception frequency of the circularly polarized antenna 1L, or 1 / The length is an integral multiple of two wavelengths.

  FIG. 1B shows a basic configuration of a right-hand circularly polarized antenna 1R according to an embodiment of the present invention for receiving right-hand circularly polarized waves. The right-handed circularly polarized wave antenna 1R of this embodiment is composed of a monopole antenna 2, a ground plate 3, and a parasitic conductor 4, like the left-handed circularly polarized wave antenna 1L. Similarly, the feeding point of the monopole antenna 2 is connected to the core wire 25 of the coaxial cable 24, and the ground plate 3 is connected to the ground wire 27 of the coaxial cable 24. The parasitic conductor 4 is disposed on the right side of the monopole antenna 2 in the left-hand circularly polarized antenna 1L, but is not shown in the figure with respect to the monopole antenna 2 in the right-hand circularly polarized antenna 1R. It is arranged on the left side.

  Also in this embodiment, the front end portion 2A, which is the open end of the monopole antenna 2, is bent obliquely, and the one end portion 4A of the parasitic conductor 4 is also bent obliquely, and both are arranged close to each other in parallel. . That is, in the right-handed circularly polarized antenna 1R, the one end 4A of the parasitic conductor 4 and the tip 2A of the monopole antenna 2 form a power delivery unit. The length of the parasitic conductor 4 in the right-hand circularly polarized antenna 1R (including the end portion 4A) may be the same as that of the left-hand circularly polarized antenna 1L. It has a length of ½ wavelength or more of the wavelength of the radio wave, or a length that is an integral multiple of ½ wavelength.

  FIG. 2A shows a basic configuration of an embodiment of the left-handed circularly polarized antenna 10L of the present invention for receiving the left-handed circularly polarized wave formed on the dielectric film 8. The left-handed circularly polarized wave antenna 10L of this embodiment is configured by forming a monopole antenna 5, a ground pattern 6, and a parasitic element 7 on a dielectric film 8 by patterns. The feeding point of the monopole antenna 5 is connected to the core wire 25 of the coaxial cable 24, and the ground pattern 6 is connected to the ground wire 27 of the coaxial cable 24. The parasitic element 7 is not electrically connected to the monopole antenna 5, and is formed in the direction orthogonal to the monopole antenna 5 in the vicinity of the tip portion that is the open end of the monopole antenna 5.

  In this embodiment, the front end portion 5A of the pattern of the monopole antenna 5 is bent obliquely, and the end portion 7A of the pattern of the parasitic element 7 is also bent obliquely, and both are close and parallel. Is arranged. That is, the one end portion 7A of the parasitic element 7 and the tip portion 5A of the monopole antenna 5 form a power delivery section, and the parasitic element 7 can deliver power to the monopole antenna 5. ing. The length D of the parasitic element 7 in this embodiment (including the one end portion 7A) D is a length equal to or longer than ½ wavelength of the radio wave of the reception frequency of the left-handed circularly polarized antenna 10L, or 1 The length is an integral multiple of / 2 wavelengths.

  FIG. 2B shows a basic configuration of an embodiment of the left-hand circularly polarized antenna 10R of the present invention for receiving the right-hand circularly polarized wave formed on the dielectric film 8. In the right-hand circularly polarized antenna 10R of this embodiment, the monopole antenna 5, the ground pattern 6, and the parasitic element 7 are formed on the dielectric film 8 according to the pattern, similarly to the left-hand circularly polarized antenna 10L. Formed and configured. Similarly, the feeding point of the monopole antenna 5 is connected to the core wire 25 of the coaxial cable 24, and the ground pattern 6 is connected to the ground wire 27 of the coaxial cable 24. The parasitic element 7 is disposed on the right side of the monopole antenna 5 in the left-hand circularly polarized antenna 10L, but is not shown in the figure with respect to the monopole antenna 5 in the right-hand circularly polarized antenna 10R. It is arranged on the left side.

  Also in this embodiment, the front end portion 5A which is the open end of the monopole antenna 5 is bent obliquely, and the one end portion 7A of the parasitic element 7 is also bent obliquely, and both are arranged close to each other in parallel. . That is, in the right-hand circularly polarized antenna 10R, the one end portion 7A of the parasitic element 7 and the tip portion 5A of the monopole antenna 5 form a power delivery portion. The length of the parasitic element 7 in the right-handed circularly polarized wave antenna 10R (including the end portion 7A) may be the same as that of the left-handed circularly polarized wave antenna 10L. It has a length of ½ wavelength or more of the wavelength of the radio wave, or a length that is an integral multiple of ½ wavelength.

  Hereinafter, a modified embodiment of the circularly polarized antenna of the present invention formed on the dielectric film 8 will be described, particularly, an embodiment for receiving a left-handed circularly polarized wave.

  FIGS. 3A to 3H are explanatory views showing various shapes of embodiments of the power delivery unit of the left-handed circularly polarized antenna 10L of the present invention described in FIG. Circles in these drawings indicate power supply terminals. (A) is an embodiment in which the end portion 5A which is the open end of the monopole antenna 5 is not bent, and the one end portion 7A of the parasitic element 7 is bent at a right angle and close to the left side of the end portion 5A. It is. (B) is an embodiment in which the tip portion 5A of the monopole antenna 5 is not bent, and the one end portion 7A of the parasitic element 7 is bent at a right angle and is close to the right side of the tip portion 5A. (C) is an embodiment in which the end portion 5A of the monopole antenna 5 is bent to the right at a right angle, and the one end portion 7A of the parasitic element 7 is not bent and is close to the upper side of the end portion 5A. It is. (D) is an embodiment in which the front end portion 5A of the monopole antenna 5 is bent to the right at a right angle, and the one end portion 7A of the parasitic element 7 is not bent and is close to the lower side of the front end portion 5A. It is an example. (E) is an embodiment in which the front end portion 5A of the monopole antenna 5 is bent obliquely to the lower right side, and the one end portion 7A of the parasitic element 7 is also bent to the lower right side, and both are arranged in parallel. It is an example. (F) is an embodiment in which the front end portion 5A of the monopole antenna 5 is bent obliquely to the upper left side, and the one end portion 7A of the parasitic element 7 is bent to the lower right side and both are arranged in parallel. It is. (G), the tip 5A of the monopole antenna 5 is bent and bent to the upper right side, and the one end 7A of the parasitic element 7 is bent and bent to the lower left and is outside the tip 5A. It is an Example arrange | positioned in parallel. In (h), the tip portion 5A of the monopole antenna 5 is bent and bent to the upper right side, and the one end portion 7A of the parasitic element 7 is bent and bent to the lower left side, and inside the tip portion 5A. It is an Example arrange | positioned in parallel.

  FIG. 4A shows a configuration of a modified example of the circularly polarized wave antenna 10 of the present invention. In the embodiment described above, the parasitic element 7 is arranged in a direction orthogonal to the monopole antenna 5. However, the parasitic element 7 in the present invention only needs to have a component orthogonal to the monopole antenna 5, and is not necessarily arranged in a direction orthogonal to the monopole antenna 5.

  That is, in the embodiment shown in FIG. 4A, the leading end portion 5A of the monopole antenna 5 is formed to be bent in the upper right direction, and the parasitic element 7 in which the one end portion 7A and the main body portion are in a straight line is formed. These are formed parallel to the tip 5A. In this case, even if the parasitic element 7 is inclined with respect to the monopole antenna 5, the parasitic element 7 has an antenna component 7V indicated by a two-dot chain line in a direction orthogonal to the axis CL of the monopole antenna 5. (Axis VL), the circularly polarized antenna 10 having this configuration can receive circularly polarized waves (left-handed circularly polarized waves).

  FIG. 4B shows the configuration of another modification of the circularly polarized antenna 10 of the present invention. In the above embodiment, the monopole antenna 5 and the parasitic element 7 are linear. However, the monopole antenna 5 and the parasitic element 7 of this embodiment are curved with respect to the axis line CL and the axis line VL orthogonal thereto. However, in the circularly polarized wave antenna 10 of this embodiment, the monopole antenna 5 has a component in the direction of the axis CL, and the parasitic element 7 has a component of the axis VL in the direction orthogonal to the axis CL. The circularly polarized wave antenna 10 can receive circularly polarized waves (left-handed circularly polarized waves). As described above, the monopole antenna 5 and the parasitic element 7 used in the circularly polarized antenna 10 of the present invention are not necessarily linear.

  FIG. 5A shows the configuration of another modification of the monopole antenna 5 and the parasitic element 7 of the circularly polarized antenna of the present invention, and FIG. 5B shows the main part of FIG. The cross section of is shown. In the embodiments described so far, the monopole antenna 5 and the parasitic element 7 are on the same plane, but in this embodiment, the monopole antenna 5 is formed on the front side of the dielectric film 8, and the parasitic element 7 is formed on the back side of the dielectric film 8. When the monopole antenna 5 and the parasitic element 7 are formed on the same plane, as shown in FIG. 3C or 3D, the tip 5A of the monopole antenna 5 and one end of the parasitic element 7 are used. 7A had to be placed in parallel. On the other hand, in this embodiment, one end portion 7A of the parasitic element 7 is arranged on the back surface immediately below the front end portion 5A of the bent monopole antenna 5 to form a power delivery portion. Thus, the monopole antenna 5 and the parasitic element 7 do not have to be on the same plane.

  6A shows a configuration of a modified example of the left-handed circularly polarized antenna 10L in FIG. 2A, and FIG. 6B shows a right-handed circularly polarized antenna 10R in FIG. 2B. The structure of this modification is shown. Therefore, the same components are denoted by the same reference numerals, and the description thereof is omitted. In these modified examples, a second parasitic element 9 that is not electrically connected to the monopole antenna 5 and the parasitic element 7 is disposed on the side of the parasitic element 7 far from the monopole antenna 5. . The second parasitic element 9 is formed in parallel with the parasitic element 7. As will be described in detail later, the second parasitic element 9 is provided so as to function as a director or a reflector.

  FIG. 7A illustrates an example of the positional relationship with the circularly polarized antenna 10 when the second parasitic element 9 is provided in the circularly polarized antenna 10 of the present invention. In the second parasitic element 9, an imaginary line IM that is orthogonal to the center of the second parasitic element 9 passes through the center point CP of the circularly polarized antenna 10 composed of the monopole antenna 5 and the parasitic element 7. It is provided as follows. When the second parasitic element 9 is located at the central point CP of the circularly polarized antenna 10 or in the vicinity thereof, the second parasitic element 9 effectively functions as a director or a reflector.

  FIG. 7B shows an embodiment in which another parasitic element 19 (hereinafter referred to as a third parasitic element 19) is provided in the circularly polarized antenna 10 having the configuration of FIG. In the third parasitic element 19, an imaginary line KM that is orthogonal to the substantially central position passes through the center point CP of the circularly polarized antenna 10 composed of the monopole antenna 5 and the parasitic element 7. It is provided as follows. When the third parasitic element 19 is at or near the center point CP of the circularly polarized antenna 10, the third parasitic element 19 effectively functions as a director or a reflector.

  8A and 8B show the directivity of the circularly polarized antenna 10 when the length of the second parasitic element 9 shown in FIG. 7A is increased or decreased. It explains the change of. First, FIG. 8A shows a case where the second parasitic element 9 having a length of ½ or more of the wavelength of the transmission / reception frequency of the circularly polarized antenna 10 is installed in the vicinity of the parasitic element 7. The directivity of the circularly polarized antenna 10 is shown. In this case, the second parasitic element 9 functions as a reflector. As a result, the reception directivity of the circularly polarized antenna 10 is obliquely above the second parasitic element 9 with respect to the vertical axis Y standing at the center point CP of the circularly polarized antenna 10. The direction of the pointing axis Z is the direction.

  FIG. 8B shows a circle when the second parasitic element 9 having a length less than ½ of the wavelength of the radio wave of the transmission / reception frequency of the circularly polarized antenna 10 is installed in the vicinity of the parasitic element 7. The directivity of the polarization antenna 10 is shown. In this case, the second parasitic element 9 functions as a director. As a result, the directivity of reception of the circularly polarized antenna 10 is obliquely above the same side as the second parasitic element 9 with respect to the vertical axis Y standing at the center point CP of the circularly polarized antenna 10. The direction of the directivity axis X is facing.

  FIGS. 9A and 9B show the directivity of the circularly polarized antenna 10 when the length of the third parasitic element 19 shown in FIG. 7B is increased or decreased. It explains the change of. First, FIG. 9A shows a case where the third parasitic element 19 having a length of 1/2 or more of the wavelength of the radio wave of the transmission / reception frequency of the circularly polarized antenna 10 is installed in the vicinity of the monopole antenna 5. The directivity of the circularly polarized antenna 10 is shown. In this case, the third parasitic element 19 functions as a reflector. As a result, the directivity of reception of the circularly polarized antenna 10 is obliquely above the third parasitic element 19 with respect to the vertical axis Y standing at the center point CP of the circularly polarized antenna 10. The direction of the pointing axis P is the direction.

  FIG. 9B shows a circle in the case where the third parasitic element 19 having a length less than ½ of the wavelength of the transmission / reception frequency of the circularly polarized antenna 10 is installed in the vicinity of the monopole antenna 5. The directivity of the polarization antenna 10 is shown. In this case, the third parasitic element 19 functions as a director. As a result, the reception directivity of the circularly polarized antenna 10 is obliquely above the same side as the third parasitic element 19 with respect to the vertical axis Y standing at the center point CP of the circularly polarized antenna 10. The direction of the pointing axis Q is facing.

  FIG. 10 shows a specific example of the circularly polarized antenna 10 of the present invention, and shows an example of the integrated antenna 20 combined with the TV antenna 13. In the integrated antenna 20 of this embodiment, both a cable 24 connected to the circularly polarized antenna 10 and a cable 33 connected to the TV antenna 13 are shown. The integrated antenna 20 of this embodiment includes a circularly polarized antenna 10 for transmitting and receiving circularly polarized waves and a TV antenna 13 for receiving television radio waves on a transparent film 11. The circularly polarized wave antenna 10 in this example is the right-handed circularly polarized wave antenna 10 </ b> R described with reference to FIG. 2B, and includes the monopole antenna 5 and the parasitic element 7.

  FIG. 10 shows the integrated antenna 20 as seen from the direction opposite to the direction of arrival of radio waves. That is, when the integrated antenna 20 is attached to, for example, the inside of a windshield of an automobile, this is viewed from the interior side of the automobile. The circularly polarized wave antenna 10 viewed from the vehicle interior side is disposed on the left side of the transparent film 11 and receives right-handed circularly polarized wave with high sensitivity.

  The TV antenna 13 is provided along the periphery of the transparent film 11, and the tip is bent. An antenna connection terminal 18 is provided at one end of the linear conductor constituting the TV antenna 13. In this embodiment, the transparent film 11 where the circularly polarized antenna 10 and the TV antenna 13 are not provided is cut to form a hole 15. The hole 15 is provided so as to surround a portion of the transparent film 11A on which the circularly polarized antenna 10 is disposed, and the portion of the transparent film 11A on which the circularly polarized antenna 10 is disposed has a tongue-like shape. It has become. Hereinafter, this portion is referred to as a tongue portion 11A of the transparent film.

  Further, the end portion on the power feeding side of the monopole antenna 5 constituting the circularly polarized antenna 10 is formed in a land shape and serves as a power feeding terminal 16. A ground pattern 6 is formed in the vicinity of the power supply terminal 16. The ground pattern 6 has a terminal connection portion 17 to which a connection terminal 23 of a connector 21 described later is connected. In addition, a part of the TV antenna 13 located outside the parasitic element 7 of the circularly polarized antenna 10 functions as a second parasitic element.

  The radio wave received by the circularly polarized antenna 10 can be guided to a predetermined receiver such as a GPS receiver via the connector 21 and the cable 24. The connector 21 has a connection terminal 22 connected to the power supply terminal 16 of the monopole antenna 5 and a connection terminal 23 connected to the terminal connection portion 17 of the earth pattern 6. The two connection terminals 22 and 23 have springiness in this embodiment. The connector 21 may be adhered to the transparent film 11 with, for example, a double-sided adhesive tape. A position indicated by a two-dot chain line on the transparent film 11 in FIG. In addition, an amplifier to be described later can be mounted inside the connector 21. In this case, the connection terminal 23 is connected to the ground of the amplifier. The cable 24 connected to the connector 21 is a coaxial cable.

  A cable 33 can be connected to the antenna connection terminal 18 of the TV antenna 13, and a signal obtained from the radio wave received by the TV antenna 13 is sent to a TV tuner (not shown) by the cable 33 and a cable 49 connected thereto. Led. A connector 31 is connected to the tip of the cable 33 on the integrated antenna 20 side, and a connection terminal 32 provided on the connector 31 is connected to the antenna connection terminal 18 of the TV antenna 13. For example, the connector 31 may be bonded to the transparent film 11 with a double-sided adhesive tape. The cable 33 is a single-core cable, and is connected to the core wire 41 of the coaxial cable 49 in this embodiment. The ground wire 42 of the coaxial cable 49 is guided to a part of the body 44 of the automobile by another single-core cable 43 and is connected to a metal foil 45 attached to the body 44 by a connector 46. That is, the ground wire 42 of the coaxial cable 49 is AC-grounded to the body 44 of the automobile.

  FIG. 11A shows the configuration of a thin TV antenna 50 used with the integrated antenna 20 of FIG. The TV antenna 50 includes two TV antennas 51 and 52 for receiving TV radio waves on the transparent film 14. FIG. 11A shows the television antenna 50 viewed from the interior side of the automobile when the television antenna 50 is installed inside the automobile windshield. The two TV antennas 51 and 52 viewed from the vehicle interior side are provided along the periphery of the transparent film 14. In this embodiment, the transparent film 14 in a portion where the two TV antennas 51 and 52 are not provided. Is cut out to form a hole 55. Furthermore, antenna connection terminals 53 and 54 are provided at one end portions of the linear conductors constituting the TV antennas 51 and 52, respectively. A cable similar to the cable 33 described with reference to FIG. 10 is connected to the antenna connection terminals 53 and 54 via a connector, and a signal obtained from the received radio wave is similarly guided to the TV tuner through the cable.

  FIG. 11B shows the connection of the automobile with the receiver 80 when the integrated antenna 20 of FIG. 10 and the thin TV antenna 50 of FIG. 11A are installed on the left and right upper parts of the windshield 61 of the automobile. FIG. 12 is a circuit diagram showing the connection between the integrated antenna 20, the thin TV antenna 50, and the receiver 80 shown in FIG.

  First, the connection of the integrated antenna 20 and the thin TV antenna 50 to the receiver 80 will be described with reference to FIG. The circularly polarized antenna 10 provided in the integrated antenna 20 is connected to the GPS receiver 81 built in the receiver 80 using the connector 21 and the coaxial cable 24 as described above. In this embodiment, an amplifier 26 is built in the connector 21. The radio wave received by the circularly polarized antenna 10 is amplified by the amplifier 26 and output.

  The TV antenna 13 provided in the integrated antenna 20 is connected to the selector 47 of the selector / amplifier 40 by a connector 31, a cable (not shown), and a coaxial cable 49. The two TV antennas 51 and 52 provided on the thin television antenna 50 are connected to the selector 47 of the selector / amplifier 40 by the connector 31, the cable 2 (not shown), and the coaxial cable 49, respectively. The selector 47 selects a TV antenna (any one of the TV antennas 13, 51, 52) having high reception sensitivity and switches the TV antenna so that the output is output to the amplifier 48. As a result, any one of the TV antennas 13, 51, 52 is connected to the TV tuner 82 built in the receiver 8 through the selector / amplifier 40 and the coaxial cable 5.

  Returning to FIG. 11B, in this embodiment, the receiver 80 is built in the center console of the automobile, and the selector / amplifier 40 is built in the foot on the passenger seat side. The cables 24 and 49 from the integrated antenna 20 and the flat-screen TV antenna 50 are attached along the A-pillar of the automobile and directly connected to the receiver 80 or the receiver 80 through the selector / amplifier 40 and the cables 24 and 56. Connected to. And since the integrated antenna 20 and the thin television antenna 50 are comprised using the transparent film as mentioned above, even when these are attached to the upper part of the windshield 61, the integrated antenna 10 and the thin television antenna 50 are included. And will not interfere with the field of view of the driver of the car, in particular, the field of vision V in the left front.

  Note that the circularly polarized antenna 10, the TV antennas 13, 51, 52 and a protective film for protecting the ground pattern 6 are provided on both surfaces of the transparent film 11 on which the integrated antenna 20 shown in FIG. 10 is formed. It is done. The integrated antenna 20 can be affixed to the back surface (vehicle interior side) of the windshield 61 of the automobile shown in FIG. 11B by a double-sided adhesive tape affixed on the protective film. Furthermore, as another embodiment, the integrated antenna 20 and the thin TV antenna 50 can be incorporated in a windshield 61 of an automobile.

  FIG. 13A shows an example of the mounting position of the integrated antenna 20 of the embodiment described in FIG. 10 or the integrated antenna 20 of another configuration to the automobile 100. As shown in FIG. 10, the integrated antenna 20 of the present invention is formed on the dielectric film 8, particularly the transparent dielectric film 8, and the front window FW, the rear window RW, or the side of the automobile 100. It can be attached to the window SW or the like from the back side. When an automobile body in which the integrated antenna 20 is made of a dielectric member is used instead of the dielectric film 8, it is integrated into a rear spoiler SP made of synthetic resin or a roof window RF made of synthetic resin or glass. The antenna 20 can be formed.

  Therefore, the circularly polarized wave in which the length of the second parasitic element 9 as shown in FIG. 8A is a length of ½ or more of the radio wave wavelength of the reception frequency of the circularly polarized antenna 10. When the antenna 10 is attached to the inclined windshield 61 of the automobile 100 as shown in FIG. 13B, the direction of the receiving directional axis of the circularly polarized antenna 10 is directed to the zenith direction indicated by the arrow Z. be able to. As a result, the reception performance of the circularly polarized antenna 10 in the zenith direction is improved. On the other hand, the circularly polarized wave in which the length of the second parasitic element 9 as shown in FIG. 8B is less than half the wavelength of the radio wave of the reception frequency of the circularly polarized antenna 10 is used. When the antenna 10 is attached to the inclined windshield 61 of the automobile 100 as shown in FIG. 13B, the direction of the receiving directional axis of the circular polarization antenna 10 is close to the horizontal direction indicated by the arrow X. Can be directed. As a result, the reception performance of the circularly polarized antenna 10 in the direction close to the horizontal is improved.

  By the way, the total length of the monopole antenna 5 constituting the circularly polarized antenna 10 is equal to the wavelength of the received radio wave when the monopole antenna 5 is installed on a dielectric having a relative dielectric constant of 1. The length of one side of the element is about 48 mm. On the other hand, when the monopole antenna 5 is installed on a member having a high dielectric constant such as glass, the overall length of the antenna element can be shortened according to the wavelength shortening.

For example, λ1 is a wavelength of a radio wave at a specific frequency on the dielectric, λ0 is a wavelength of a radio wave having the same frequency as the above-mentioned specific frequency in free space, and α is a wavelength shortening by a dielectric around the antenna As a percentage
λ1 = α × λ0
Therefore, the total length of the antenna elements of the monopole antenna 5 can be reduced according to the wavelength shortening rate α. Therefore, the total length L1 of the monopole antenna 5 formed on the transparent film 11 can be 38 mm in this embodiment. In addition, what is necessary is just to form the conductor which comprises the monopole antenna 10 by any of the printing by a conductive thin film, a wire, and conductive ink.

  FIG. 14 shows another specific embodiment of the configuration of the integrated antenna 20 using the circularly polarized wave antenna 10 of the present invention, from the same direction as the integrated antenna 20 of the embodiment shown in FIG. It is what I saw. 14 shows only the configuration of the cable 24 connected to the integrated antenna 20, and the illustration of the connector 31 and the cable 33 connected to the TV antenna 13 is omitted.

  The difference between the integrated antenna 20 of this embodiment and the integrated antenna 20 of the embodiment shown in FIG. 10 is that the ground pattern 6 is not provided on the transparent film 11 on which the circularly polarized antenna 10 is arranged. Only. Therefore, the same components as those in the integrated antenna 20 described with reference to FIG.

  In this embodiment, only one connection terminal 22 is provided on the connector 21 attached to the distal end portion of the coaxial cable 24. The amplifier 26 described in FIG. 12 is provided inside the connector 21, and its ground is connected to a ground wire (not shown) of the coaxial cable 24. The connector 21 may be bonded to the transparent film 11 with, for example, a double-sided adhesive tape. A single-core cable 28 is connected to the ground wire of the coaxial cable 24, and a connector 29 is attached to the tip of the single-core cable 28. In other words, the ground wire of the coaxial cable 24 is guided to a part of the body 44 of the automobile by the single-core cable 28 and connected to the metal foil 45 attached to the body 44 by the connector 29. That is, the ground wire of the coaxial cable 24 is capacitively coupled to the automobile body 44 and is grounded in an alternating manner. Therefore, in this embodiment, it is not necessary to provide a ground pattern on the transparent film 11.

  In the above-described embodiment, the integrated antenna 20 has been described in which the circularly polarized antenna 10 is formed on the transparent film 11 and attached to the back side of the front windshield 61 of the automobile. The antenna 10 can be formed on a normal printed circuit board or an opaque dielectric such as the surface of a resin case. Such a form is effectively applied to a household device having a communication function that uses a circularly polarized wave as a communication wave, for example, a wireless connection between a personal computer and its peripheral devices using a circularly polarized wave. can do.

  In the embodiment described above, the reception of the circularly polarized antenna 20 according to the present invention has been described. However, the same applies to the case where radio waves are transmitted from the integrated antenna 20 described above.

(A) is a figure which shows the basic composition of the antenna for circular polarization of this invention for receiving left-handed circularly polarized wave, (b) is the antenna for circularly polarized wave of this invention for receiving right-handed circularly polarized wave It is a figure which shows the basic composition. (A) is a figure which shows the basic composition at the time of forming the antenna for circular polarization of this invention for receiving left-handed circularly polarized wave on a dielectric film, (b) is for receiving right-handed circularly polarized wave It is a figure which shows the basic composition at the time of forming the antenna for circular polarization of this invention on a dielectric film. (A)-(h) is explanatory drawing which shows the Example of various shapes of the electric power delivery part of the antenna for circular polarization of this invention. (A) is a figure which shows the structure of the modification of the antenna for circular polarization of this invention, (b) is a figure which shows the structure of another modification of the antenna for circular polarization of this invention. (A) is a partially cutaway perspective view showing the configuration of another modified example of the circularly polarized antenna of the present invention, and (b) is a cross-sectional view of the main part of (a). (A) shows the structure of the modification of the circularly polarized antenna of the embodiment of FIG. 2 (a) in which the circularly polarized antenna of the present invention for receiving left-handed circularly polarized wave is formed on a dielectric film. FIG. 2B shows a configuration of a modification of the circularly polarized antenna of FIG. 2B in which the circularly polarized antenna of the present invention for receiving right-handed circularly polarized wave is formed on a dielectric film. FIG. (A) is a figure which shows an example of the positional relationship with the antenna for circular polarization in the case of providing the 2nd parasitic element in the antenna for circular polarization of this invention, (b) is for circular polarization of this invention It is a figure which shows another example of positional relationship with the antenna for circular polarization in the case of providing the 2nd parasitic element in an antenna. (A) is a diagram showing an embodiment in which a second parasitic element having a length of ½ or more of the wavelength of a radio wave of a transmission / reception frequency of a circular polarization antenna is installed in the vicinity of the circular polarization antenna; ) Is a diagram showing an embodiment in which a second parasitic element having a length less than ½ of the wavelength of the radio wave of the transmission / reception frequency of the circularly polarized antenna is installed in the vicinity of the circularly polarized antenna. (A) shows the Example which installed the 2nd parasitic element of the length more than 1/2 of the wavelength of the electromagnetic wave of the transmission / reception frequency of the antenna for circularly polarized waves in another position near the circularly polarized antenna. FIG. 4B shows an embodiment in which a second parasitic element having a length less than ½ of the wavelength of the radio wave of the transmission / reception frequency of the circularly polarized antenna is installed at another position in the vicinity of the circularly polarized antenna. FIG. It is a figure explaining the top view which shows an example of a structure of the integrated antenna using the antenna for circular polarization of this invention, and the cable connected to this. (A) is a top view which shows the structure of the thin television antenna used with the thin antenna of this invention, (b) is the case where the thin antenna of FIG. 1 and the thin television antenna of (a) are installed in the windshield of a motor vehicle. FIG. 4 is a perspective view of the front of the interior of the automobile showing the connection with the receiver. It is a circuit diagram which shows the connection of the thin antenna shown in FIG.2 (b), a thin television antenna, and a receiver. (A) is a perspective view of an automobile showing an example of a position where the integrated antenna shown in FIG. 10 is attached to the vehicle, and (b) shows the directivity when the integrated antenna shown in FIG. 10 is attached to the windshield of the automobile. It is a figure explaining. It is a figure explaining the top view which shows another example of a structure of the integrated antenna using the antenna for circular polarization of this invention, and the cable connected to this.

Explanation of symbols

1L, 10L ... Circularly polarized antennas 1R, 10R for receiving left-handed polarized waves ... Circularly polarized antennas 2, 5 ... Monopole antennas 2A, 5A for receiving right-handed polarized waves ... Tip 4 ... Parasitic conductor 4A ... One end Part 6 ... Earth pattern 7 ... Parasitic element 7A ... One end part 8 ... Dielectric film 9 ... Second parasitic element 10 ... Circularly polarized antennas 11 and 14 of the present invention ... Transparent film 11A ... Tongue piece 13 ... TV antenna 16 ... feed terminal 18 ... antenna connection terminal 19 ... third parasitic element 20 ... integrated antennas 21,31 ... connectors 22,23 ... connection terminal 40 ... selector / amplifier 50 ... TV antenna 80 ... receiver

Claims (16)

A monopole antenna having a feed point and an open end;
A length component in a direction perpendicular to the antenna axis of the monopole antenna, and a parasitic element that is a linear conductor that is not electrically connected to the monopole antenna,
The parasitic element includes a power delivery unit capable of delivering power to the monopole antenna, and is disposed in the vicinity of the open end of the monopole antenna. antenna.   The circularly polarized wave antenna according to claim 1, wherein the antenna axis of the monopole antenna and the axis of the parasitic element are arranged in a direction orthogonal to each other.   3. The circularly polarized wave antenna according to claim 1, wherein the power delivery unit is disposed at one end of the parasitic element that is disposed substantially parallel to the open end of the monopole antenna. 4. A circularly polarized antenna characterized by the above.   The thin antenna according to claim 3, wherein at least one of a portion having a predetermined length from the open end of the monopole antenna and a portion having a predetermined length from one end of the parasitic element is bent. The circularly polarized antenna, wherein the bent portion forms the power delivery portion.   5. The circularly polarized wave antenna according to claim 1, wherein a length of the parasitic element is not less than ½ wavelength of a radio wave of a transmission / reception frequency of the circularly polarized wave antenna. Circularly polarized antenna characterized by its length.   5. The circularly polarized wave antenna according to claim 1, wherein a length of the parasitic element is an integer of a half wavelength of a radio wave wavelength of a transmission / reception frequency of the circularly polarized antenna. A circularly polarized antenna characterized by being twice as long.   7. The circularly polarized wave antenna according to claim 1, wherein the monopole antenna and the parasitic element are arranged on the same plane. antenna.   The circularly polarized wave antenna according to claim 7, wherein the antenna element and the parasitic element of the monopole antenna are formed on a flexible sheet-like dielectric. Antenna.   9. The circularly polarized wave antenna according to claim 8, wherein the sheet-like dielectric is made of a transparent insulator film, and the film is installed on an exterior member made of automobile glass or insulator. An antenna for circular polarization, characterized in that:   The circularly polarized wave antenna according to claim 8, wherein the monopole antenna and the first parasitic element are installed on the surface or inside of an exterior member made of glass or an insulator of an automobile. An antenna for circularly polarized waves, characterized in that   11. The circularly polarized wave antenna according to claim 1, comprising a linear conductor not electrically connected to at least one of the monopole antenna and the parasitic element. A circularly polarized antenna, wherein the second parasitic element is provided so as to function as a director or a reflector.   12. The circularly polarized wave antenna according to claim 11, wherein the second parasitic element is configured such that a virtual line orthogonal to the second parasitic element includes the monopole antenna and the parasitic element. The circularly polarized antenna is provided so as to pass through a substantially center of the circularly polarized antenna.   The circularly polarized wave antenna according to claim 11 or 12, wherein the length of the second parasitic element is the monopole antenna so that the second parasitic element functions as the reflector. A thin antenna characterized by being longer than ½ of the wavelength of the radio wave of the transmission / reception frequency of the circularly polarized antenna comprising the parasitic element.   13. The circularly polarized wave antenna according to claim 11 or 12, wherein the length of the second parasitic element is the monopole so that the second parasitic element functions as the waveguide. A thin antenna, characterized in that it is shorter than a half of the wavelength of a radio wave of a transmission / reception frequency of a circularly polarized antenna comprising an antenna and the parasitic element.   15. The circularly polarized antenna according to claim 11, wherein the second parasitic element is a part of another antenna.   16. The circularly polarized wave antenna according to claim 15, wherein the other antenna is a part of a television radio wave receiving antenna formed on the same plane as the monopole antenna. Wave antenna.

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