JP2010021618A - Antenna - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antenna which has a high degree of freedom for wiring in lines of a distribution circuit and can also be miniaturized. <P>SOLUTION: On a first substrate 2 located inside of a cylinder, a first antenna pattern 21 is arranged in a spiral pattern and a first distribution circuit 22 for supplying a signal to the first antenna pattern 21 is arranged. On a second substrate 3 located outside of the cylinder, a second antenna pattern 31 is arranged in a spiral pattern and separated from the first antenna pattern 21 with a spacing, and a second distribution circuit 32 for supplying a signal to the second antenna pattern 31 is arranged. Between the first distribution circuit 22 and the second distribution circuit 32, a ground layer 4 is arranged. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an antenna having a distribution circuit, such as a helical antenna used as a terminal antenna for mobile communication using a satellite.

  For example, a helical antenna is an antenna in which antenna elements, which are radiating elements, are arranged in a spiral shape, and a plurality of antenna elements are arranged, and a signal is fed with each antenna element having a phase difference. (For example, refer to Patent Document 1). In this helical antenna, antenna elements having a length corresponding to 3/4 wavelength of transmitted / received waves are spirally arranged on the outer peripheral surface of a dielectric cylindrical member at intervals. A circuit board on which a distribution circuit for supplying a high-frequency signal with a phase difference of 90 degrees is provided for each antenna element is disposed below the cylindrical member. At the time of transmission, signals having the same amplitude and different phases by 90 degrees are distributed and fed from the distribution circuit to each antenna element, and each signal resonates at each antenna element and is converted into an electromagnetic wave. Sent to. At the time of reception, signals transmitted from satellites or the like are received by each antenna element as signals having the same amplitude and different phases by 90 degrees, and these signals are sent to a distribution circuit and synthesized. is there. Note that such a helical antenna radiates strong circularly polarized waves in the axial direction.

In addition, there is known a device in which a helical antenna is miniaturized by integrating an antenna element and a distribution circuit (see, for example, Patent Document 2). That is, since the helical antenna is attached to a portable terminal or the like, its accommodation volume is limited, and it is desired to make it as small as possible. However, in the helical antenna of Patent Document 1, since the cylindrical member on which the antenna element is disposed and the circuit board on which the distribution circuit is mounted are separate, the helical antenna is increased in size. For this reason, a plurality of antenna elements are disposed on one surface of the substrate, that is, a surface located outside when formed in a cylindrical shape, and a distribution circuit pattern is disposed on the same surface below the antenna element. Is.
JP 2001-053531 A Japanese translation of PCT publication No. 2002-500457

  By the way, the distribution circuit needs to be configured according to the frequency of transmission / reception waves used for communication. In other words, it is necessary to adjust the impedance and the like according to the frequency of the transmitted / received wave and configure an appropriate distribution circuit with low passage loss. On the other hand, in the helical antenna of Patent Document 2, since the distribution circuit is disposed on the same plane as the antenna element, the area of the distribution circuit is limited, and the wiring flexibility of the lines of the distribution circuit is low. For this reason, depending on the frequency of the transmission / reception wave, it may be difficult to arrange an appropriate distribution circuit. For example, a long line length is required at a frequency as low as about 1.0 GHz, and a wide line is desirable to reduce the passage loss. However, since the arrangement area is limited, the distribution circuit for such a line is used. It becomes difficult to arrange. Alternatively, in order to arrange an appropriate distribution circuit, it is necessary to increase the distribution area of the distribution circuit, and the entire helical antenna becomes large.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an antenna that has a high degree of freedom in wiring of a line of a distribution circuit and can be further downsized.

  In order to achieve the above object, the invention described in claim 1 includes a first antenna element and a second antenna element disposed on a substrate, and a first distribution for feeding a signal to the first antenna element. A circuit, a second distribution circuit disposed on a surface opposite to the surface on which the first distribution circuit is disposed, and supplying a signal to the second antenna element; the first distribution circuit; And an earth layer disposed between the two distribution circuits.

  According to the present invention, the first distribution circuit and the second distribution circuit are disposed to face each other, and the ground layer is disposed between the first distribution circuit and the second distribution circuit. It has a three-layer structure.

  According to a second aspect of the present invention, in the antenna according to the first aspect, the first antenna element and the first distribution circuit are disposed on one surface of the substrate, and the other surface of the substrate. In addition, the second antenna element and the second distribution circuit are disposed, and the substrate is formed in a cylindrical shape.

  According to a third aspect of the present invention, in the antenna according to the first or second aspect, the substrate includes a first substrate on which the first antenna element and a first distribution circuit are disposed, and the first substrate. And a second substrate on which two antenna elements and a second distribution circuit are arranged.

  According to a fourth aspect of the present invention, in the antenna according to the first or second aspect, the substrate is composed of a single substrate.

  According to the first aspect of the present invention, the distribution circuit is divided into two opposing surfaces, and the ground layer is provided between the two distribution circuits. Therefore, the distribution can be performed without reducing the area of the ground layer. A wide circuit area can be secured. In other words, when the distribution circuit is arranged using the end portion of the substrate as the arrangement portion, both sides of the arrangement portion can be used as the distribution surface of the distribution circuit. Get higher. As a result, the arrangement area of the same size is ensured about twice as much as the arrangement area only on one side, so that a long line corresponding to the frequency of the transmission / reception wave, It is possible to easily arrange a distribution circuit for the line. Further, compared with the case where the distribution circuit is provided only on one side, the present invention only requires about half of the arrangement portion, so that the antenna can be reduced in size. In addition, since the ground layer is sandwiched between the two distribution circuits, the strength and rigidity are increased. As a result, even if a thin substrate material or a low-strength substrate material is used as the substrate, it is possible to ensure predetermined strength and rigidity.

  According to the second aspect of the present invention, it is possible to easily manufacture a helical antenna, a whip antenna, or the like by forming the substrate into a cylindrical shape and inserting the substrate into a cylindrical cover.

  According to the third aspect of the present invention, since it is composed of two substrates, it is possible to ensure predetermined strength and rigidity even if a thin substrate material or a low strength substrate material is used. Moreover, an antenna can be easily manufactured only by superimposing the board | substrate with which the antenna element and the distribution circuit were each arrange | positioned.

  According to the fourth aspect of the present invention, since the substrate is composed of a single substrate, the antenna can be made thinner, more lightweight and smaller.

  The present invention will be described below based on the illustrated embodiments.

(Embodiment 1)
FIGS. 1-6 is a figure which shows the helical antenna (antenna) 1 which concerns on this embodiment. This helical antenna 1 is an antenna in which antenna elements are spirally arranged on a cylindrical substrate, and mainly includes a first substrate 2, a second substrate 3, and a ground layer (ground layer) 4. I have.

  FIG. 2 is a development view of the first substrate 2. The first substrate 2 is a sheet shape made of a material that can be easily bent and formed into a cylindrical shape such as polyimide, and is provided with substantially parallelogram elements. The portion 2A and a substantially rectangular distribution circuit arrangement portion 2B located below the element arrangement portion 2A are integrally formed. The inclination angle θ of the element placement portion 2A, that is, the angle and the length L formed by the base and side of the parallelogram are predetermined when the first substrate 2 is spirally wound and formed into a cylindrical shape. The number of turns and the cylinder length are set. Further, two first antenna patterns (first antenna elements) 21 are arranged in parallel on the surface of the element arrangement portion 2A at a predetermined interval as will be described later.

  The first antenna pattern 21 is composed of a conductive member, for example, copper foil, and includes a substantially linear first transmission pattern 21A and a first reception pattern 21B, which are arranged on the distribution circuit arrangement part 2B side. Connected at some lower end. For example, the length of the first transmission pattern 21A is set to correspond to 3/4 wavelength of the transmission wave so as to resonate at the frequency of the transmission band, and the length of the first reception pattern 21B is the frequency of the reception band. For example, it is set to be equivalent to 3/4 wavelength of the received wave. Here, in this embodiment, the frequency of the transmission band is set lower than the frequency of the reception band, and the first transmission pattern 21A is set longer than the first reception pattern 21B.

  The distribution circuit arrangement portion 2B is an area shown in FIG. 3, and the first distribution circuit 22 is arranged on the surface thereof. The first distribution circuit 22 is a circuit that is connected to two first antenna patterns 21 and transmits / receives signals to / from each first antenna pattern 21 as described later. It is composed of foil. Further, a connection hole 2C is formed in the distribution circuit arrangement portion 2B, and the ground layer 4 faces the connection hole 2C when it is overlapped with the ground layer 4 as will be described later.

  FIG. 4 is a development view of the second substrate 3, and the second substrate 3 has a shape symmetrical to the first substrate 2 and has the same configuration as the first substrate 2. Yes. That is, two second antenna patterns (second antenna elements) 31 are arranged on the surface of the element arrangement portion 3A, and the second distribution circuit 32 is arranged on the surface of the distribution circuit arrangement portion 3B. Has been. Here, the second antenna pattern 31 includes a second transmission pattern 31A corresponding to the first transmission pattern 21A and a second reception pattern 31B corresponding to the first reception pattern 21B. In addition, when the first substrate 2 and the first substrate 3 are overlapped, the first antenna patterns 21 and the second antenna patterns 31 are alternately positioned with a predetermined interval therebetween. As described above, the first antenna pattern 21 and the second antenna pattern 31 are provided.

  The first distribution circuit 22 and the second distribution circuit 32 are signals having the same amplitude and sequentially different phases by 90 degrees with respect to the antenna patterns 21 and 31, that is, 0 degrees, 90 degrees, 180 degrees, and 270 degrees. It is configured to input and output signals. That is, at the time of transmission, the transmission wave signal is output and supplied to the transmission patterns 21A and 31A of the antenna patterns 21 and 31 as signals having the same amplitude and different phases by 90 degrees sequentially. For example, a signal having a phase of 0 degree is output to the first transmission pattern 21A of the first antenna pattern 21 on one side (left side in FIG. 2), and the second antenna pattern 31 on one side (right side in FIG. 4). A signal having a phase of 90 degrees is output to the second transmission pattern 31A, and a signal having a phase of 180 degrees is output to the first transmission pattern 21A of the first antenna pattern 21 of the other (right side in FIG. 2). And a signal having a phase of 270 degrees is output to the second transmission pattern 31A of the second antenna pattern 31 on the other side (left side in FIG. 4). Further, at the time of reception, signals received by the reception patterns 21B and 31B of the antenna patterns 21 and 31 having the same amplitude and different phases by 90 degrees are combined to generate a reception wave signal. In this manner, signals are input / output to / from the four antenna patterns 21 and 31 by the two distribution circuits 22 and 32. In other words, the distribution circuits for the four antenna patterns 21 and 31 are two distribution circuits. 22 and 32.

  Further, as shown in FIGS. 3 and 5, the first distribution circuit 22 and the second distribution circuit 32 are respectively formed with a first through hole 22a and a second through hole 32a. The first through hole 22a and the second through hole 32a have the same diameter, and are formed so as to be concentric when the first substrate 2 and the first substrate 3 are overlapped.

  The ground layer 4 is made of a conductive member such as copper foil, and is positioned concentrically with the first through hole 22a and the second through hole 32a in a state sandwiched between the distribution circuit arrangement portions 2B and 3B. A through hole is formed. The through hole has a larger diameter than the first through hole 22a, and a core wire 102 to be described later does not come into contact with the ground layer 4.

  The helical antenna 1 is configured by overlapping the first substrate 2, the second substrate 3, and the ground layer 4. That is, the back surface of the first substrate 2 and the back surface of the second substrate 3 are combined, and the first substrate 2 and the second substrate 3 are placed with the ground layer 4 sandwiched between the distribution circuit arrangement portions 2B and 3B. Are superimposed. Then, such a stacked substrate is spirally wound so that the first substrate 2 is positioned inside, and is formed into a cylindrical shape, and both ends thereof are fixed to form the helical antenna 1. In such a state, two first antenna patterns 21 are spirally arranged on the inner surface of the cylindrical overlapping substrate, and the first distribution circuit 22 is cylindrically arranged. Similarly, two second antenna patterns 31 are arranged in a spiral shape on the outer surface of the overlapping substrate, and a second distribution circuit 32 is arranged in a cylindrical shape. Furthermore, the first antenna pattern 21 and the second antenna pattern 31 are alternately positioned, and the first antenna pattern 21 and the second antenna pattern 31 are arranged at a predetermined constant interval. Yes. Further, the ground layer 4 is disposed between the first substrate 2 and the second substrate 3 so that the first distribution circuit 22 and the second distribution circuit 32 face each other and are sandwiched between the two distribution circuits 22 and 32. Is arranged.

  Here, FIG. 6 shows a stacked state of the first substrate 2, the second substrate 3, and the ground layer 4. As shown in this figure, in the distribution circuit arrangement portions 2B and 3B, the first distribution circuit 22, the adhesive layer, the first substrate 2, the adhesive layer, the ground layer 4, in order from the inner surface side of the helical antenna 1, The adhesive layer, the second substrate 3, the adhesive layer, and the second distribution circuit 32 are provided. In the element arrangement portions 2A and 3A, the first antenna pattern 21, the adhesive layer, the first substrate 2, the adhesive film, the second substrate 3, the adhesive layer, and the second antenna pattern are sequentially arranged from the inner surface side. 31.

  Such a helical antenna 1 is attached to a portable terminal with a cylindrical cover mounted outside the cylinder. Also, a fixing hole 1A that penetrates the distribution circuit arrangement portions 2B and 3B and the ground layer 4 is formed, and the fixing portion of the cover is fitted into the fixing hole 1A, so that the helical antenna 1 is formed into a cylindrical shape. Fixed. The input / output port of the first distribution circuit 22 is connected to the transmission / reception circuit in the portable terminal, and the second distribution circuit 32 is connected to the transmission / reception circuit via the first distribution circuit 22. That is, as shown in FIG. 3, the net wire 101 of the cable 100 from the transmission / reception circuit is connected by solder to the ground layer 4 facing the connection hole 2C, and the core wire 102 of the cable 100 passes through the through holes 22a and 32a. It is connected to a conductive member around the street, such as a copper foil, by soldering.

  Next, the operation of the thus configured helical antenna 1 will be described.

  First, at the time of transmission, when a transmission wave signal is transmitted from the transmission / reception circuit in the portable terminal to the distribution circuits 22 and 32, the distribution circuits 22 and 32, as described above, have the same amplitude and phases of 90 degrees sequentially. Different signals are output to the transmission patterns 21A and 31A of the antenna patterns 21 and 31, respectively. Thereby, each signal resonates in the respective transmission patterns 21A and 31A, is converted into an electromagnetic wave, and is radiated. The electromagnetic waves radiated from the four transmission patterns 21A and 31A are combined in space and transmitted as a predetermined high-frequency signal. At the time of reception, a high-frequency signal transmitted from a satellite or the like is received by the reception patterns 21B and 31B of the antenna patterns 21 and 31, respectively. At this time, the signals received by the four reception patterns 21B and 31B are signals having the same amplitude and different phases by 90 degrees as described above, and these signals are synthesized by the distribution circuits 22 and 32, The received wave signal is transmitted to a transmission / reception circuit in the portable terminal.

  As described above, according to the helical antenna 1, the distribution circuit for the four antenna patterns 21 and 31 is divided into the two distribution circuits 22 and 32, and these are arranged to be overlapped. It becomes possible to reduce the size. That is, when the two distribution circuits 22 and 32 are arranged on one surface, an arrangement portion corresponding to the two distribution circuit arrangement portions 2B and 3B is required. On the other hand, according to this embodiment, since it is only necessary to have the distribution circuit arrangement portions 2B and 3B having an area about half the area required for the arrangement of the two distribution circuits 22 and 32, the helical antenna 1 Can be miniaturized. On the other hand, even when the size of the helical antenna 1 is defined and the size of the arrangement portion where the distribution circuit is arranged is limited, the distribution circuits 22 and 32 are arranged on the both surfaces as distribution circuit arrangement portions 2B and 3B, respectively. Therefore, the degree of freedom of wiring of the distribution circuit line is increased. That is, the area where each of the distribution circuits 22 and 32 can be disposed is about twice as large as that of the conventional one, and the wiring flexibility is increased. As a result, it is possible to easily arrange the distribution circuit flexibly according to the frequency of the transmission / reception wave, the required communication quality, and the like. For example, even if the transmission / reception wave has a low frequency of about 1.0 GHz, it is possible to easily arrange an appropriate distribution circuit without increasing the helical antenna 1, and the coupling between the lines. It is possible to easily eliminate or reduce the passage loss by widening the line. In addition, it is possible to increase the bandwidth by providing the distribution circuits 22 and 32 in multiple stages.

  Further, since the distribution circuit arrangement portions 2B and 3B have a three-layer structure with the ground layer 4 interposed therebetween, the strength and rigidity are increased. As a result, even if a low-strength, low-rigidity substrate material such as a thin substrate material or polyimide is used as the first substrate 2 and the second substrate 3, predetermined strength and rigidity can be ensured.

(Embodiment 2)
This embodiment is different from the first embodiment in that the substrate on which the antenna element is disposed is composed of a single substrate. Here, about the structure equivalent to Embodiment 1, the description is abbreviate | omitted by attaching | subjecting the same code | symbol, and it is the same also in the following embodiments.

  That is, as shown in FIG. 7, in the distribution circuit arrangement portions 2B and 3B, in order from the inner surface side of the helical antenna 1, the first distribution circuit 22, the first substrate 2, the adhesive layer, the ground layer 4, and the adhesive The layer, the second substrate 3 and the second distribution circuit 32 are formed. In addition, in the element arrangement portions 2A and 3A, the first antenna pattern 21, the first substrate 2, and the second antenna pattern 31 are sequentially formed from the inner surface side. According to such a configuration, since the antenna patterns 21 and 31 are disposed on both surfaces of the single substrate 2, the helical antenna 1 can be made thinner, lighter and smaller.

(Embodiment 3)
FIG. 8 is a plan view showing a film antenna (antenna) 10 according to this embodiment.

  In this embodiment, the first substrate 2 and the second substrate 3 are both rectangular, and the first antenna pattern 21 and the first distribution circuit 22 are disposed on the surface of the first substrate 2. A second antenna pattern 31 and a second distribution circuit 32 are disposed on the surface of the second substrate 3. Then, as shown in FIG. 9, the first back surface of the portion where the first distribution circuit 22 is disposed and the back surface of the portion where the second distribution circuit 32 are disposed are overlapped. The substrate 2 and the second substrate 3 are connected. Further, a through hole 10A that penetrates the overlapping portion of the first substrate 2 and the second substrate 3 is formed, and the core wire 102 of the cable 100 is passed through the through hole 10A as in the first embodiment, and the core wire 102 Are connected to the distribution circuits 22 and 32.

  According to the film antenna 10 having such a configuration, since the first distribution circuit 22 and the second distribution circuit 32 are disposed so as to face each other and overlap, The occupied space can be reduced and the film antenna 10 can be reduced in size.

  Although the embodiment of the present invention has been described above, the specific configuration is not limited to the above embodiment, and even if there is a design change or the like without departing from the gist of the present invention, Included in the invention. For example, in the above-described embodiment, two first antenna patterns 21 are disposed on the first substrate 2, and two second antenna patterns 31 are disposed on the second substrate 3. The number of antenna patterns 21 and 31 corresponding to the phase difference of signals to be transmitted and received and the number of phase differences may be provided. In addition, the first antenna pattern 21 and the second antenna pattern 31 are arranged alternately, but the first antenna patterns 21 are arranged adjacent to each other, and the second antenna pattern is adjacent to the second antenna pattern 21. The antenna patterns 31 may be adjacent to each other, or two second antenna patterns 31 may be disposed between the first antenna patterns 21. Further, the number of antenna patterns and distribution circuits is not limited to the above. For example, one first antenna pattern 21 is arranged on the first substrate 2, and three second antennas are arranged on the second substrate 3. The pattern 31 may be arranged, or different numbers of distribution circuits may be arranged on the first substrate 2 and the second substrate 3.

  As described above, the antenna according to the present invention can be flexibly adapted to the frequency of transmitted / received waves and is extremely useful as a device that can be further downsized.

It is a perspective view which shows the helical antenna which concerns on Embodiment 1 of this invention. FIG. 2 is a development view of a first substrate of the helical antenna of FIG. 1. It is an enlarged view of the distribution circuit arrangement | positioning part of the 1st board | substrate of FIG. FIG. 3 is a development view of a second substrate of the helical antenna of FIG. 1. It is an enlarged view of the distribution circuit arrangement | positioning part of the 2nd board | substrate of FIG. It is an expanded sectional view which shows the lamination | stacking state of the helical antenna of FIG. It is an expanded sectional view which shows the lamination | stacking state of the helical antenna which concerns on Embodiment 2 of this invention. It is a top view of the film antenna which concerns on Embodiment 3 of this invention. It is a front view of the film antenna of FIG.

Explanation of symbols

1 Helical antenna (antenna)
2 1st board | substrate 21 1st antenna pattern (1st antenna element)
22 1st distribution circuit 22a 1st through-hole 3 2nd board | substrate 31 2nd antenna pattern (2nd antenna element)
32 2nd distribution circuit 32a 2nd through-hole 2A, 3A Element arrangement | positioning part 2B, 3B Distribution circuit arrangement | positioning part 4 Ground layer (grounding layer)

Claims (4)

A first antenna element and a second antenna element disposed on the substrate;
A first distribution circuit for feeding a signal to the first antenna element;
A second distribution circuit disposed on a surface opposite to the surface on which the first distribution circuit is disposed and supplying a signal to the second antenna element;
A ground layer disposed between the first distribution circuit and the second distribution circuit;
An antenna comprising: The first antenna element and the first distribution circuit are disposed on one surface of the substrate,
The antenna according to claim 1, wherein the second antenna element and the second distribution circuit are disposed on the other surface of the substrate, and the substrate is formed in a cylindrical shape. A first substrate on which the first antenna element and a first distribution circuit are disposed; and
3. The antenna according to claim 1, comprising: a second substrate on which the second antenna element and a second distribution circuit are arranged. 4. The antenna according to claim 1, wherein the substrate is composed of a single substrate.

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