JP2011078037A - Wide-band plane antenna - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wide-band plane antenna which prevents reception energy reduction and a sneaking phenomenon even if a radiation element conductor is shared among a plurality of frequency bands. <P>SOLUTION: On one side of a dielectric substrate 10, an elliptical radiation element conductor 11 and a rectangular ground conductor 12 are provided in a contactless state, one-side ends of first and second transmission lines 13 and 14 in a zigzag shape are connected to lower end and obliquely lower right portions of the radiation element conductor 11, other-side ends are terminated in the vicinity of the ground conductor 12, and a linear third transmission line 15 is provided in parallel in a termination portion of the second transmission line 14. At positions of an upper-side portion of the ground conductor 12 opposed to the first and third transmission lines 13 and 15, first and second plugs 16 and 17 are provided, a core wire of the first plug 16 is connected to a termination of the first transmission line 13 by a lead wire 18, and a core wire of the second plug 17 is connected to a terminal part of the transmission line 15 at a side of the ground conductor 12, through a lead wire 19. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a planar antenna, and more particularly to a broadband planar antenna capable of sharing one radiating element conductor in a plurality of frequency bands.

  One conventional antenna is a broadband planar antenna having the configuration shown in FIG. The planar antenna 100 includes a dielectric substrate 101, an elliptical radiating element conductor 102 made of a conductor such as a copper foil provided on one surface of the dielectric substrate 101, and a predetermined amount with respect to the radiating element conductor 102. A rectangular ground conductor 103 made of a conductor such as a copper foil provided on the same plane at a distance and a dielectric substrate 101 interposed between the ground conductor 103 at a position closest to the radiating element conductor 102. And the lead wire 105 for connecting the radiating element conductor 102 and the core wire of the plug 104 so as not to contact the ground conductor 103. In addition, there exists what is shown by the nonpatent literature 1 as a broadband planar antenna similar to the broadband planar antenna of the structure shown in FIG.

  The planar antenna 100 is connected to a plug 104 by a coaxial cable connector connected to a wireless device (not shown) such as a receiver, a transmitter, and a transceiver. When the wireless device uses the planar antenna 100 as a receiving antenna, broadcast radio waves or the like are received by the radiating element conductor 102 and input to the wireless device via the lead wire 105, the plug 104, and the coaxial cable. Further, when the planar antenna 100 is used for transmission, a high frequency output from the wireless device is applied to the radiating element conductor 102 via the plug 104 and the lead wire 105, and radio waves are radiated from the radiating element conductor 102.

  By the way, although an antenna is usually prepared for each wireless device, there is a case where one antenna is desired to be shared by a plurality of wireless devices (for example, a television broadcast receiving device and a wireless LAN device). However, when the frequency used or the communication function differs between wireless devices, a plug for connecting a coaxial cable from each wireless device is generally required for each device. For this reason, when an antenna is shared by a plurality of wireless devices having different frequency bands or communication functions, a distribution circuit for distributing frequency components handled by one plug to a plurality of coaxial cables has been conventionally used.

The Institute of Image Information and Television Engineers Technical Report Vol. 32, no. 11, PP. 5-8

  However, if the flat antenna shown in FIG. 7 is provided with a plurality of plugs and is shared by a plurality of wireless devices, a distribution circuit is required, which limits the downsizing of the wireless device and reduces the manufacturing cost. difficult. In addition, since the distribution circuit distributes the energy of all received frequency components to the plurality of coaxial cables, the signal energy after distribution is reduced and reception quality is deteriorated. Furthermore, when a phenomenon occurs in which transmission energy from one wireless device wraps around to another receiving device via a distributor, transmission energy is not efficiently transmitted to the radiating element conductor, so communication quality deteriorates due to a decrease in transmission energy. There is a problem.

  Therefore, an object of the present invention is to provide a configuration in which a distributor is not provided, so that even if a radiating element conductor is shared by a plurality of frequency bands, a decrease in reception energy and a wraparound phenomenon caused by the use of the distributor are avoided. It is an object of the present invention to provide a broadband planar antenna that does not occur.

  In order to achieve the above object, the present invention according to claim 1 is directed to a dielectric substrate, a ground conductor disposed on a surface of the dielectric substrate, a non-contact with the ground conductor, and a predetermined distance. A radiating element conductor disposed on the same plane as the ground conductor of the dielectric substrate with a gap therebetween and wired in a predetermined shape from a predetermined position on the periphery of the radiating element conductor toward a predetermined position of the ground conductor A transmission line or a transmission line formed by two or more wirings close to each other in a non-contact manner, the shape, length or line width of the transmission line being changed, or two or more wirings close to each other without contact By changing the distance or length, the frequency band of the signal passing through the transmission line is changed, and thereby the end on the side opposite to the side connected to the radiating element conductor is changed to the frequency. A plurality of transmission lines serving as transmission / reception power supply units for wireless devices using a band signal; and a plurality of plugs provided on the ground conductor and connected to the power supply units at ends of the plurality of transmission lines, respectively. A wideband planar antenna is provided.

  In order to achieve the above object, according to a second aspect of the present invention, in the wideband planar antenna according to the first aspect, the radiating element conductor has an elliptical shape and the ground conductor has a rectangular shape. It is characterized by.

  In order to achieve the above object, according to a third aspect of the present invention, there is provided the broadband planar antenna according to the first or second aspect, wherein a plurality of the plugs are a plurality of the transmissions wired on the dielectric substrate. They are connected from the track by lead wires.

  In order to achieve the above object, according to a fourth aspect of the present invention, there is provided a broadband planar antenna according to any one of the first to third aspects, wherein the plurality of transmission lines are wired on the dielectric substrate. In addition, the transmission line connected to the radiating element conductor can receive radio waves in a predetermined frequency band with high sensitivity, is connected to a position where the frequency band is widened, and the current at the transmission / reception frequency is strong. It is characterized by being connected to distributed positions.

  In order to achieve the above object, according to a fifth aspect of the present invention, in the wideband planar antenna according to any one of the second to fourth aspects, one of the plurality of transmission lines has one end. Is connected to the lower end long axis end of the radiating element conductor, and the other end is formed of a zigzag wiring pattern reaching the vicinity of the ground conductor side.

  In order to achieve the above object, according to a sixth aspect of the present invention, in the broadband planar antenna according to any one of the first to fourth aspects, one of the plurality of transmission lines has one end. Is connected to the peripheral edge on the short axis side of the radiating element conductor, and has a zigzag wiring pattern having a linear portion of a predetermined length on the other end side, provided in non-contact with the linear portion and in parallel And a linear wiring pattern formed.

  In order to achieve the above object, the present invention according to claim 7 is the broadband planar antenna according to claim 5 or 6, wherein one of the plurality of transmission lines is directed to digital terrestrial television broadcasting, One of the other transmission lines is characterized by a wireless LAN.

  According to the wideband planar antenna of the present invention, even if a radiating element conductor is shared by a plurality of frequency bands, it is possible to prevent a reduction in reception energy and a wraparound phenomenon, thereby reducing the size of the antenna. Degradation of communication quality can be prevented.

It is a front view which shows the wideband planar antenna which concerns on the 1st Embodiment of this invention. It is a reverse view of the broadband planar antenna shown in FIG. It is a figure which shows the equivalent circuit of the wideband planar antenna of FIG. It is a front view which shows the wideband planar antenna which concerns on the 2nd Embodiment of this invention. It is a front view which shows the wideband planar antenna which concerns on the 3rd Embodiment of this invention. FIG. 6 is a back view of the broadband planar antenna of FIG. 5. It is a front view which shows the conventional broadband planar antenna.

[First Embodiment]
(Configuration of wideband planar antenna)
FIG. 1 is a front view showing a broadband planar antenna according to the first embodiment of the present invention, and FIG. 2 is a back view of the broadband planar antenna of FIG. The planar antenna 1 includes a 470-710 MHz band terrestrial digital television (hereinafter referred to as “terrestrial digital TV”) broadcast and a 2.4 GHz band (2.4-2.497 GHz) wireless LAN (Local Area Network). However, the present invention is not limited to this combination. The wireless LAN includes a 2.4 GHz band that conforms to the IEEE 802.11b and IEEE 802.11g standards and a 5.2 GHz band (5.15 to 5.25 GHz) that conforms to the IEEE 802.11a standard.

  The planar antenna 1 includes a dielectric substrate 10 made of epoxy resin, glass, and the like, an elliptical radiating element conductor 11 provided on one surface of the dielectric substrate 10, and a non-contact with the radiating element conductor 11, and a predetermined amount. A rectangular ground conductor 12 provided on the same plane as the radiating element conductor 11 at a distance of 1 mm and the dielectric substrate 10 in a state where one end is connected to one end (the lower end in FIG. 1) of the radiating element conductor 11. The copper provided on the dielectric substrate 10 with one end connected to the first transmission line 13 by a wiring pattern such as a copper foil pattern provided on the lower side of the radiating element conductor 11. A second transmission line 14 by a foil pattern or the like, and a third by a copper foil pattern or the like provided on the dielectric substrate 10 in parallel with the other end (the lower end of FIG. 1) of the second transmission line 14. A transmission line 15, a first plug 16 provided on the dielectric substrate 10 positioned on the ground conductor 12 in the vicinity of the other end (lower end in FIG. 1) of the first transmission line 13, and a second transmission A second plug 17 provided on the dielectric substrate 10 on the ground conductor 12 in the vicinity of the other end of the line 14 (lower end in FIG. 1), and the other end (lower end) of the first transmission line 13. The first lead wire 18 that connects the core wire of the first plug 16 so as not to contact the ground conductor 12, the lower end of the third transmission line 15, and the core wire of the second plug 17 are connected to the ground conductor. And a second lead wire 19 that is connected so as not to come into contact therewith.

  The radiating element conductor 11 is made of, for example, a copper foil pattern (wiring pattern) made of printed wiring or the like. The radiating element conductor 11 has a frequency band (first frequency band) of terrestrial digital television and a frequency band of wireless LAN of 2.4 GHz band (second band). The major axis and the minor axis of the ellipse are set so that radio waves can be efficiently emitted and received in both frequency bands. The eccentricity e when the length of the major axis is D1 and the length of the minor axis is D2 is obtained by Equation 1. For example, the eccentricity e when D1 is 16 mm and D2 is 12.8 mm is 0. .6. By changing (D2 / D1) in Equation 1, the frequency characteristics can be changed. The radiating element conductor 11 is not limited to an elliptical shape, but according to the study by the present inventors, good results were obtained by making the radiating element conductor 11 an elliptical shape.

[Equation 1]

e = {1- (D2 / D1)} ^1/2

  The ground conductor 12 has, for example, a size of width (w) 30.5 mm × height (h) 16 mm, and is formed of a copper foil pattern or the like in the same manner as the radiating element conductor 11. Broadband characteristics can be obtained by setting.

  The first to third transmission lines 13 to 15 are all provided on the dielectric substrate 10 by printed wiring, and the ends of the first transmission line 13 and the third transmission line 15 on the ground conductor 12 side are grounded. A predetermined distance from the conductor 12 is provided. By setting the length, line width, and shape of the first transmission line 13, the first transmission line 13 can have frequency characteristics for efficiently transmitting terrestrial digital television broadcast radio waves to the plug 16. The second and third transmission lines 14 and 15 have frequency characteristics for efficiently transmitting 2.4 GHz band wireless LAN radio waves to the plug 17 by setting the length, line width, and shape thereof. It is set to have.

  The first transmission line 13 is provided in a zigzag shape toward the ground conductor 12, and the lower end thereof is terminated at a position close to the first plug 16 to serve as a power feeding unit for the wireless device. 1 lead wire 18 is connected. The connection position of the first transmission line 13 to the radiating element conductor 11 is a place where the terrestrial digital television broadcast wave can be received with high sensitivity and the frequency band is widened.

  The second transmission line 14 is provided in a zigzag shape toward the lower right direction of the radiating element conductor 11, and ends at a position close to the second plug 17. The connection position of the second transmission line 14 to the radiating element conductor 11 is set to a position where a 2.4 GHz band current is strongly distributed based on a current distribution analysis result by simulation.

  The third transmission line 15 is linearly provided with a short length so as to be parallel to the lower end portion of the second transmission line 14, and the lower end (end portion on the ground conductor 12 side) serves as a transmission / reception power supply portion. The second lead wire 19 is connected to the power supply unit. The frequency of the transmission system is changed by changing the length of the third transmission line 15 and the distance from the second transmission line 14.

  The first and second plugs 16 and 17 are commercially available connectors according to standards such as BNC type, N type, and SMA type, for example. The first connector 16 is a coaxial connector capable of transmitting a high-frequency signal in the digital terrestrial television broadcasting band, that is, a high-frequency signal in the 470 to 710 MHz band, and is provided on the back side of the dielectric substrate 10 shown in FIG. A coaxial cable plug connected to the receiver is connected. The second transmission line 14 is a coaxial connector capable of transmitting a signal in the frequency band of the wireless LAN, that is, a high-frequency signal up to 2.497 GHz. The wireless LAN device is provided on the back side of the dielectric substrate 10 shown in FIG. A plug (not shown) of a coaxial cable connected to is connected.

(Broadband planar antenna operation)
FIG. 3 is a diagram showing an equivalent circuit of the broadband planar antenna of FIG. As shown in FIG. 3, a frequency that allows only a desired frequency band to pass through the capacitance 20 generated between the first transmission line 13 and the feeding point and the inductance L _{1 of} the first transmission line 13. A filter, here, a first filter 30 that passes only the frequency band of digital terrestrial television broadcasting is formed.

Further, the capacitance 21 mainly generated between the second transmission line 14 and the third transmission line 15, and the inductances L ₂ and L ₃ of the second transmission line 14 and the third transmission line 15 are connected in series. A frequency filter that passes only a desired frequency band, here, a second filter 40 having a characteristic of passing only a signal having a frequency of a wireless LAN (2.4 GHz band) is formed. The first, second, and third transmission lines 13, 14, and 15 themselves have floating capacitance and resistance, but are not shown here.

  By forming the first filter 30 and the second 40 as shown in FIG. 3 by the first transmission line 13 and the second and third transmission lines 14 and 15, radio waves in the frequency band of digital terrestrial television broadcasting. And radio waves in the frequency band of the wireless LAN propagate as follows. First, a reception signal of digital terrestrial television broadcast received by the radiating element conductor 11 passes through the first filter 30 and the first lead wire 18 and is transmitted to the first plug 16, but the second filter. Since it is blocked at 40, it is not transmitted to the second plug 17. On the other hand, the received signal in the frequency band of the wireless LAN passes through the second filter 40 and is transmitted to the second plug 17 but is blocked by the first filter 30. Is not transmitted.

  The transmission output from the wireless LAN device is applied to the second filter 40 via the second plug 17 and the lead wire 19. The transmission signal having the frequency of the wireless LAN passes through the second filter 40 and is supplied to the radiating element conductor 11, and the radio wave of the wireless LAN is radiated from the radiating element conductor 11 into the air. At this time, the signal of the wireless LAN is almost blocked by the first transmission line 13 of the first filter 30 to the first plug 16.

(Effects of the first embodiment)
According to the first embodiment, the following effects are obtained.
(1) The first filter 30 composed of the first transmission line 13 and the second filter 40 composed of the second and third transmission lines 14 and 15 are connected to the radiating element conductor 11, respectively. When an antenna capable of sharing one radiating element conductor by a plurality of frequency bands is manufactured by connecting the first and second plugs 16 and 17 and thus eliminating the distributor which has been conventionally required, Since the installation is unnecessary, the manufacturing cost can be reduced.
(2) The first filter 30 is provided to transmit the digital terrestrial television broadcast radio wave only through the first plug 16, and the second filter 40 is provided to transmit the wireless LAN radio wave through the second plug 17 only. Since the transmission structure is adopted, even if the radiating element conductor 11 is shared by two frequency bands, it is possible to prevent a decrease in transmission / reception energy and to prevent deterioration in sensitivity due to distribution of reception energy.
(3) Since the first transmission line 13 has a filter characteristic, it is possible to prevent the transmission signal applied to the second plug 17 from wrapping around the first plug 16, so that the transmission energy of the wireless LAN can be reduced. It is possible to prevent deterioration of communication quality due to the decrease.

[Second Embodiment]
FIG. 4 is a front view showing a broadband planar antenna according to the second embodiment of the present invention. In the present embodiment, the shape of the third transmission line 14 is changed according to the frequency band in which the second plug 17 is used in the first embodiment, and the second, third transmission line 14, The frequency band of the second filter 40 constituted by 15 is changed. In the present embodiment, the frequency band is changed from the 2.4 GHz band to the 5.2 GHz band. The signal flow from the radiating element conductor 11 to the first and second plugs 16 and 17 and the signal flow from the second plug 17 to the radiating element conductor 11 are the same as those in the first embodiment. Since it is the same, description is abbreviate | omitted.

  According to the second embodiment, the pass frequency and pass frequency band of the second filter 40 can be arbitrarily changed. Other effects are the same as those of the first embodiment.

[Third Embodiment]
FIG. 5 is a front view showing a broadband planar antenna according to the third embodiment of the present invention, and FIG. 6 is a back view of the broadband planar antenna of FIG. In the present embodiment, the third filter 41 having the same configuration as the second filter 40 including the second transmission line 14 and the third transmission line 15 in the first embodiment is the fourth filter. The filter 41 is formed by a transmission line 22 and a fifth transmission line 23, and is provided at a position substantially symmetrical with respect to the second filter 40 (centering on the radiating element conductor 11). The third plug 24 and the third lead wire 25 having the same configuration and the same connection relationship as the 17 and the second lead wire 19 are connected to the second plug 17 and the second lead with the feeding point interposed therebetween. The other configuration is the same as that of the first embodiment. Thereby, for example, in addition to the 2.4 GHz band, the 5.2 GHz band can be used as the third frequency band.

  In the present embodiment, the fourth transmission line 22 and the fifth transmission line 23 are different from the second transmission line 14 and the third transmission line 15 in the target frequency band. Therefore, the lengths and shapes of the fourth transmission line 22 and the fifth transmission line 23 are set so that the fourth transmission line 22 and the fifth transmission line 23 can obtain a desired third frequency band. The frequency characteristics of the third filter 41 are adjusted, and the connection point between the fourth transmission line 22 and the radiating element conductor 11 is at a position where the current in the third frequency band is strongly distributed. Furthermore, the third plug 24 is installed on the ground conductor 12 at a position where the current in the third frequency band is strongly distributed. The signal flow from the radiating element conductor 11 to the first to third plugs 16, 17, 24 and the signal flow from the second and third plugs 17, 24 to the radiating element conductor 11 are as follows: Since it is the same as that of the first embodiment, the description thereof is omitted.

  According to the third embodiment, the broadband planar antenna 1 corresponding to three frequency bands can be constructed. Other effects are the same as those of the first and second embodiments.

  In the third embodiment, the filter and the plug can be further added as necessary.

[Other embodiments]
In each said embodiment, the 1st, 2nd, 4th transmission line 13,14,22 is not limited to the zigzag type shown in FIG.1, FIG.2, FIG.4-6, for example, , S-shaped repetitive shape, V-shaped repetitive shape, spiral shape, and the like.

  In each of the above embodiments, the length and shape of the transmission line in the second filter 40 and the third filter 41 are changed without changing the overall shape, so that the second filter 40 and the second filter 40 are changed. The frequency characteristics of the third filter 41 can be changed. Moreover, the transmission lines 14 and 22 can improve transmission efficiency by changing a connection point to the position on the radiation element conductor 11 where the current of a desired frequency is strongly distributed. Furthermore, by changing the installation location of the second plug 17 to a position on the ground conductor 12 where a current of a desired frequency is strongly distributed, the frequency transmitted by the second plug 17 can be changed. it can.

  In each of the above embodiments, the first to third plugs 16, 17, and 24 are not necessarily required. A plurality of power supply / reception positions (power supply / reception points) are set on the ground conductor 12, and the wireless device side The coaxial cable core wire may be connected to the corresponding transmission line by soldering, and the coaxial cable shield may be connected to the ground conductor 12 by soldering.

  In each of the above embodiments, the dielectric substrate 10 may be a flexible substrate, a sheet, a film, or the like in addition to a hard substrate.

DESCRIPTION OF SYMBOLS 1 Broadband planar antenna 10 Dielectric board | substrate 11 Radiation element conductor 12 Ground conductor 12 Radiation element conductor 13 1st transmission line 14 2nd transmission line 15 3rd transmission line 16 1st plug 17 2nd plug 18 First lead wire 19 Second lead wire 20 Capacitance 21 Capacitance 22 Fourth transmission line 23 Fifth transmission line 24 Third plug 25 Third lead wire 30 First filter 40 First 2 filter 41 3rd filter

Claims (7)

A dielectric substrate;
A ground conductor disposed on the surface of the dielectric substrate;
A radiating element conductor disposed in the same plane as the ground conductor of the dielectric substrate at a predetermined distance in a non-contact manner with respect to the ground conductor;
A transmission line wired in a predetermined shape from a predetermined location on the periphery of the radiating element conductor toward a predetermined location of the ground conductor, or a transmission line formed by two or more wires close to each other without contact, Change the frequency band of the signal passing through the transmission line by changing the shape, length or line width of the transmission line, or changing the distance or length between two or more wires that are close to each other without contact. A plurality of transmission lines that serve as a power transmission / reception unit for radio equipment using a signal in the frequency band at the end opposite to the side connected to the radiation element conductor,
A plurality of plugs provided on the ground conductor and respectively connected to the power feeding units at the ends of the transmission lines;
A broadband planar antenna characterized by comprising: The broadband planar antenna according to claim 1,
The broadband planar antenna according to claim 1, wherein the radiating element conductor has an elliptical shape and the ground conductor has a rectangular shape. The broadband planar antenna according to claim 1 or 2,
A plurality of said plugs are respectively connected by lead wires from a plurality of said transmission lines wired on said dielectric substrate. The broadband planar antenna according to any one of claims 1 to 3,
Of the plurality of transmission lines, the transmission line wired on the dielectric substrate and connected to the radiating element conductor can receive radio waves in a predetermined frequency band with high sensitivity, and the frequency band is wide. A broadband planar antenna characterized by being connected to a position where the current at the transmission / reception frequency is strongly distributed. The broadband planar antenna according to any one of claims 2 to 4,
One of the plurality of transmission lines has a zigzag wiring pattern in which one end is connected to the lower end side long axis end of the radiating element conductor and the other end reaches the vicinity of the ground conductor side. A broadband planar antenna characterized by that. The broadband planar antenna according to any one of claims 1 to 4,
One of the plurality of transmission lines has a zigzag wiring pattern having one end connected to the peripheral edge on the short axis side of the radiating element conductor and a linear portion having a predetermined length on the other end side. A wide-band planar antenna comprising: a linear wiring pattern provided in parallel with the linear portion in a non-contact manner. The broadband planar antenna according to claim 5 or 6,
One of the plurality of transmission lines is intended for digital terrestrial television broadcasting, and one of the other transmission lines is intended for a wireless LAN.

Images