JP2007135186A - Impedance matching method and array antenna utilizing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stably match impedance even if the interval of antenna elements is made narrow. <P>SOLUTION: An array antenna shown in Fig1 includes a linear first array element 11, second array element 12, first conductor 21, second conductor 22, third conductor 23, and fourth conductor 24. Furthermore, it is illustrated that the conductors are disposed around each of the array elements while spaced away by a predetermined interval. In such a case, an RF signal from a transmitter that is not shown is applied to an array element, thereby also calling it power feeding element. An RF signal is not applied to a conductor, on the other hand, thereby also calling it parasitic element. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to antenna technology, and more particularly to an impedance matching method in a wireless terminal and an array antenna using the same.

  In recent years, with the development of wireless communication technology, mobile terminals capable of high-speed data communication have been realized. Also, as a technique for performing high-speed data communication, an array antenna having directivity using a plurality of antenna elements is known. On the other hand, a portable terminal is desired to be smaller than its intended use. Then, in an array antenna used for a portable terminal, it is inevitably necessary to install the antenna elements inside the portable terminal with a small interval between antenna elements. Since a small array antenna having a small antenna element interval is affected by mutual coupling between elements, impedance matching between the array feeding element and the transmission line is shifted from a design value when there is no coupling between elements. At this time, a loss occurs in the radiated power of the array feed element, leading to a decrease in signal-to-noise ratio and a deterioration in communication channel capacity. Therefore, it is necessary to readjust impedance matching in a state including mutual coupling between elements by a matching circuit for each array feeding element.

As a conventional technique for impedance matching of an array antenna, a method of placing a parasitic element in the vicinity of an antenna as well as loading a matching circuit has been reported (for example, see Patent Document 1). When impedance matching is performed with an array antenna having inter-element coupling, the radiation pattern of each array element has directivity, and the beams of each antenna element are formed in directions that do not affect each other. That is, the beam pattern is formed so that the supplied signal power is radiated efficiently. Therefore, in the case of a three-dimensional array such as a circular array or a rectangular array, it is relatively easy to form an efficient beam pattern by impedance matching. Further, in the case of a linear array, it can be formed on a printed circuit board and is easy to manufacture and adjust, so that it is suitable for incorporation into a wireless terminal device.
JP 2001-189620 A

  However, in the case of a linear array that is two-dimensionally arranged in a plane, it is difficult to achieve sufficient matching only with the matching circuit of each array element because other array elements are arranged close to both sides of the array element. Become.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an impedance matching method capable of stably matching impedance even when the interval between antenna elements is narrowed, an array antenna manufacturing method using the same, and an array antenna And providing a wireless terminal device.

  In order to solve the above problems, an array antenna according to an aspect of the present invention includes a plurality of antenna elements and a plurality of conductors arranged around each of the plurality of antenna elements by a predetermined distance, A reactance element is connected to each conductor.

  Here, the “conductor” includes a medium that can be energized, and includes, for example, metals and semiconductors. The “reactance element” includes a passive element, and is an element having inductance or capacitance depending on a reactance value set in the reactance element.

  According to this aspect, the electromagnetic coupling in the array antenna can be reduced by the reactance element connected to the conductor.

  The plurality of antenna elements may include a matching unit that performs impedance matching. The reactance value of the reactance element may be set to a value that changes mutual coupling between the elements of the plurality of array antenna elements, thereby assisting impedance matching by the matching unit.

  Here, “inter-element mutual coupling” includes dielectric phenomena such as electrostatic coupling and electromagnetic coupling. Further, “set” includes setting in advance, may be set at the time of manufacture and shipment in a factory, and includes setting externally at the time of use. The external setting includes setting by a switch, that is, setting by a user's direct action on hardware or software including an array antenna.

  According to this aspect, the impedance of the array antenna can be more effectively matched by both the matching portion and the reactance element.

  The plurality of antenna elements are arranged at intervals that are narrower than the wavelength of the signal input to the array antenna, and at least one of the plurality of conductors is spaced at intervals that are narrower than the interval between the antenna elements. May be arranged around at least one of the antenna elements. According to this aspect, the array antenna can be configured in a narrow space.

  The reactance value of the reactance element may be set according to the frequency of the signal input to the array antenna. According to this aspect, the optimum impedance can be matched according to the frequency of the input signal.

  A reactance element connected to at least one conductor among the plurality of conductors is set with a different reactance value, and a conductor connected to a corresponding reactance element is connected to each of the plurality of antenna elements. On the other hand, it may operate as a director or a reflector.

  Here, “reactance elements that are respectively connected to at least one of the plurality of conductors are set to different reactance values” means that the reactance values of the reactance elements are changed to change the reactance values. It is intended to provide a function as a reflector or reflector. For example, the reactance elements connected to the plurality of conductors may have different reactance values, or there may be two or more reactance elements having the same reactance value. According to this aspect, the directivity of each of the plurality of antenna elements can be set flexibly. In addition, the directivity of the array antenna can be set flexibly.

  A conductor to which a reactance element having inductance is connected, and a conductor whose electrical length is longer than the antenna element is disposed between at least two antenna elements among the plurality of antenna elements, It may be operated as a reflector. A conductor to which a reactance element having a capacitance property is connected, and the conductor has an electrical length shorter than that of the antenna element, is disposed around the plurality of antenna elements, and operates as a waveguide.

  Here, “arranged between at least two or more antenna elements” includes arranging them on a straight line when at least two or more antenna elements are connected by a straight line. However, it does not have to be arranged on the straight line. For example, the position of the conductor is projected on the straight line, and the projected position exists on the straight line. In addition, “arranged around a plurality of antenna elements” includes being arranged outside a planar space formed by a plurality of antenna elements, or a three-dimensional space, etc., and “arranged between antenna elements” Including unfinished conductors.

  According to this aspect, an array antenna having sharp directivity can be configured.

  The plurality of antenna elements may be arranged substantially in parallel on the substrate. According to this aspect, the array antenna can be configured in a narrow space. Further, the plurality of antenna elements may be arranged on any one of the plurality of faces constituting the terminal device, and each antenna element may have a different polarization plane and be arranged close to each other. In this case, since impedance matching is realized by the conductors and reactance elements arranged around the antenna element, it is possible to further reduce the mutual interference of radio waves. Further, at least one of the plurality of antenna elements may be an inverted F-type antenna. Further, instead of the inverted F-type antenna, a low attitude antenna such as an inverted L-type antenna or a T-type antenna may be used. In this case, the array antenna can be configured in a narrower space.

  The conductor may be disposed on a substrate on which a plurality of antenna elements are disposed, or may be disposed at a predetermined distance from the substrate on which the plurality of antenna elements are disposed. According to this aspect, when the array antenna is configured in a narrow space, a waveguide or a reflector can be installed in the vertical direction of the substrate plane, and impedance matching can be facilitated. Moreover, since impedance matching is realized by selecting a reactance value, the circuit configuration is simplified and the design time can be reduced.

  The conductor and the reactance element may be disposed on a surface of the substrate opposite to the surface on which the plurality of antenna elements are disposed.

  It may further comprise at least two dielectric layers stacked. A plurality of antenna elements are arranged substantially in parallel on a first layer of at least two dielectric layers, and a plurality of conductors and reactance elements are arranged on a second layer of at least two dielectric layers. May be arranged.

  A plurality of antenna elements are arranged on the upper surface of the first layer of at least two dielectric layers, and the second layer of the at least two dielectric layers is stacked above the upper surface of the first layer. However, a plurality of conductors and reactance elements may be disposed on the top surface of the second layer, and a plurality of conductors and reactance elements may be disposed on the bottom surface of the first layer.

  The second layer of the at least two dielectric layers may be laminated on a portion other than the portion where the plurality of antenna elements are arranged on the upper surface of the first layer.

  A plurality of conductors and reactance elements are arranged on the upper surface of the second layer of at least two dielectric layers, and the first layer of at least two dielectric layers is formed on the upper surface of the second layer. While being stacked on the upper side, a plurality of antenna elements may be disposed on the upper surface of the first layer, and a plurality of antenna elements may also be disposed on the lower surface of the second layer.

  The first layer of at least two dielectric layers may be laminated on a portion other than the portion where the plurality of conductors and the reactance element are arranged on the upper surface of the second layer.

  It may further include at least one dielectric layer and a radome provided so as to cover the uppermost surface of the at least one dielectric layer. A plurality of antenna elements are arranged substantially parallel to at least one dielectric layer, and a plurality of conductors and reactance elements are arranged on the uppermost surface of at least one dielectric layer of the radome. May be.

  Another aspect of the present invention is also an array antenna. The array antenna includes a substrate, a plurality of antenna elements disposed substantially in parallel on the substrate, and a plurality of conductors disposed on a surface of the substrate opposite to the surface on which the plurality of antenna elements are disposed. . A reactance element is connected to each of the plurality of conductors.

  According to this aspect, since only a plurality of antenna elements, a plurality of conductors, and a reactance element are arranged on another surface of one substrate, it can be easily manufactured, and nothing is added to the antenna element, so that radiation efficiency can be improved. .

  Yet another embodiment of the present invention is also an array antenna. The array antenna includes at least two dielectric layers stacked, a plurality of antenna elements arranged substantially in parallel in a first layer of the at least two dielectric layers, and at least one of the two dielectric layers. And a plurality of conductors arranged in the second layer. A reactance element is connected to each of the plurality of conductors.

  According to this aspect, since the antenna element and the conductor are arranged on different laminated surfaces, they can be arranged apart from each other.

  The second layer of the at least two dielectric layers is stacked above the upper surface of the first layer, and the plurality of antenna elements are disposed on the upper surface of the first layer of the at least two dielectric layers. The plurality of conductors and reactance elements may be disposed on the upper surface of the second layer and the lower surface of the first layer. In this case, since the antenna element is arranged in the lower layer, the antenna element can be easily manufactured by arranging the feeding line only in the layer.

  The second layer of the at least two dielectric layers may be laminated on a portion other than the portion where the plurality of antenna elements are arranged on the upper surface of the first layer. In this case, nothing is added to the antenna element, so that the radiation efficiency can be improved.

  The first layer of at least two dielectric layers is stacked above the upper surface of the second layer, and the plurality of conductors and reactance elements are disposed on the upper surface of the second layer of at least two dielectric layers. The plurality of antenna elements may be disposed on the upper surface of the first layer and the lower surface of the second layer. In this case, nothing is added to the antenna element, so that the radiation efficiency can be improved.

  The first layer of at least two dielectric layers may be laminated on a portion other than the portion where the plurality of conductors and the reactance element are arranged on the upper surface of the second layer. In this case, nothing is added to the antenna element, so that the radiation efficiency can be improved.

  Yet another embodiment of the present invention is also an array antenna. The array antenna includes at least one dielectric layer, a plurality of antenna elements arranged substantially parallel to the at least one dielectric layer, and a radome provided so as to cover the top surface of the at least one dielectric layer. And a plurality of conductors arranged on the uppermost surface of at least one dielectric layer of the radome. A reactance element is connected to each of the plurality of conductors.

  According to this aspect, since free space exists around the antenna element, radiation efficiency can be improved.

  Another aspect of the present invention is an impedance matching method. In this method, a conductor to which a reactance element is connected is arranged around a plurality of antenna elements, and a reactance value of the reactance element connected to the conductor is changed in a predetermined manner such that the mutual coupling between the plurality of array antenna elements is changed. To match the impedance.

  According to this aspect, the reactance element connected to the conductor can reduce the electromagnetic coupling in the array antenna and can efficiently match the impedance.

  Another aspect of the present invention is a method for manufacturing an array antenna. The method includes disposing a plurality of conductors on one surface of the substrate, disposing a reactance element connected to the plurality of conductors on one surface of the substrate, and a plurality of conductors of the substrate. Disposing a plurality of antenna elements substantially parallel to a surface opposite to the disposed surface.

  Yet another embodiment of the present invention is also a method for manufacturing an array antenna. In this method, a plurality of antenna elements are arranged substantially in parallel on the upper surface of one dielectric layer, a step of arranging a plurality of conductors on the lower surface of one dielectric layer, and a lower surface of one dielectric layer. A step of disposing reactance elements respectively connected to a plurality of conductors; a step of stacking another dielectric layer on the upper surface of one dielectric layer; and a plurality of conductors on the upper surface of another dielectric layer. And disposing a reactance element respectively connected to a plurality of conductors on an upper surface of another dielectric layer.

  Yet another embodiment of the present invention is also a method for manufacturing an array antenna. The method includes arranging a plurality of antenna elements substantially parallel to the upper surface of one dielectric layer, laminating another dielectric layer above the upper surface of one dielectric layer, and another dielectric Arranging a plurality of conductors on the upper surface of the layer, arranging a reactance element connected to each of the plurality of conductors on the upper surface of another dielectric layer, and arranging a plurality of conductors on the upper surface of another dielectric layer A step of performing masking on the conductor and the reactance element, and a step of performing etching on a portion of the other dielectric layer other than the portion on which the masking is performed.

  Yet another embodiment of the present invention is also a method for manufacturing an array antenna. The method includes disposing a plurality of conductors on an upper surface of one dielectric layer, disposing reactance elements respectively connected to the plurality of conductors on an upper surface of one dielectric layer, and one dielectric Disposing a plurality of antenna elements substantially parallel to the lower surface of the layer; laminating another dielectric layer above the upper surface of one dielectric layer; and a plurality of antenna elements on the upper surface of another dielectric layer. Arranged substantially parallel to each other.

  Yet another embodiment of the present invention is also a method for manufacturing an array antenna. The method includes disposing a plurality of conductors on an upper surface of one dielectric layer, disposing reactance elements respectively connected to the plurality of conductors on an upper surface of one dielectric layer, and one dielectric Laminating another dielectric layer on the upper surface of the layer, arranging a plurality of antenna elements substantially parallel on the upper surface of the other dielectric layer, and arranging a plurality of antenna elements on the upper surface of the other dielectric layer And a step of performing etching on a portion of the other dielectric layer other than the portion subjected to the masking.

  Yet another embodiment of the present invention is also a method for manufacturing an array antenna. The method includes the steps of arranging a plurality of antenna elements substantially parallel to the upper surface of the dielectric layer, and providing a radome so as to cover the uppermost surface of the dielectric layer. Among the radomes in the step of providing the radome, a plurality of conductors are arranged on the surface on the upper surface side of the dielectric layer, and reactance elements are connected to the plurality of conductors, respectively.

  It should be noted that any combination of the above-described constituent elements and a representation of the present invention converted between a method, an apparatus, a system, etc. are also effective as an aspect of the present invention.

  According to the present invention, even when the distance between antenna elements is narrowed, impedance matching can be performed stably.

  Before the embodiments of the present invention are specifically described, an outline is first described. Embodiments described herein relate generally to an array antenna mounted on a wireless terminal device or the like. A linear array arranged two-dimensionally on an array antenna can be formed on a printed circuit board, is easy to manufacture and adjust, and is suitable for use in a wireless terminal device.

  However, as described above, with the miniaturization of the wireless terminal device, in the array antenna mounted on the wireless terminal device, since a plurality of antenna elements are arranged closer to each other, only the matching circuit of each antenna element is provided. It is difficult to achieve sufficient alignment. On the other hand, as a conventional technique for matching the impedance of an array antenna, there has been reported a method of placing a parasitic element in the vicinity of an antenna as well as loading a matching circuit (see, for example, Patent Document 1). However, every time the installation environment such as the shape of the feed element or the ground plane changes, it is necessary to redesign the shape and installation position of the parasitic element, and it takes time to change the physical shape and change the installation position. It will be necessary. Also, in a printed circuit board linear array mounted on a wireless terminal device, electromagnetic coupling also occurs between the feed element or passive element and the wireless terminal housing. It was necessary to determine the layout, length, radius, and other dimensions of the parasitic elements for each degree by trial and error.

  Therefore, in the present invention, a conductor is disposed as a parasitic element around the array antenna, and a reactive element is loaded on the parasitic element. This makes it possible to optimize impedance matching efficiently and easily by adjusting the reactance value of the reactance element as well as the shape and installation position of the conductor and the matching portion of the antenna element. To do. Moreover, the array antenna in the present invention has a configuration in which conductors with reactance elements are arranged at intervals smaller than the antenna element intervals. For a linear array formed on a printed circuit board, conductors with reactance elements are arranged not only on the substrate surface but also in the broadside direction of the array, that is, in a direction parallel to the substrate surface, and an appropriate reactance value is set and guided. By operating as a reflector or reflector, it is possible to reduce the interference caused by the beams of the array elements and radiate signal power efficiently.

  That is, since impedance matching is easily achieved, sufficient impedance matching can be achieved. As a result, it is possible to avoid a reduction in communication channel capacity in an array antenna having a narrow element spacing. Even in the actual antenna design of wireless communication equipment, the mutual coupling between elements including the housing can be electrically changed by adjusting the reactance value, so that it is not necessary to design the position and dimensions of the conductor strictly. .

  Further, in order to simplify the antenna manufacturing process and reduce the cost, it is important that the antenna is designed to be easily adjusted. By arranging a conductor with a reactance element in the vicinity of an array element in an array antenna with a narrow element spacing, impedance matching, which has been difficult in the past, is caused not only by the physical shape and mechanical arrangement of the conductor but also by the electrical action of the reactance. It becomes possible to adjust flexibly. According to the present invention, the design period of a small array antenna can be greatly shortened, and the load of developing a model of a wireless communication terminal can be reduced. A specific configuration will be described below.

  Here, a configuration example of the array antenna according to the embodiment of the present invention will be described with reference to FIGS. Here, an array antenna composed of two linear array elements is assumed as a configuration example.

  FIG. 1 is a perspective view showing a configuration example of an array antenna according to an embodiment of the present invention. The array antenna shown in FIG. 1 includes a first array element 11, a second array element 12 represented by an array element 10, a first conductor 21, a second conductor 22, a third conductor 23, 4 conductors 24 are included. Further, it is indicated that the plurality of conductors 20 are arranged at predetermined intervals around each of the plurality of array elements 10. Here, since a radio signal (Radio Frequency Signal; hereinafter abbreviated as “RF signal”) from a transmitter (not shown) is applied to the array element 10, it is also called a power feeding element. On the other hand, the conductor 20 is also called a parasitic element because no RF signal is applied.

  FIG. 2 is a diagram showing a configuration example of the array element 10 of FIG. Array element 10 includes a matching unit 30, a frequency oscillation unit 32, and an antenna element 34. Matching unit 30 performs impedance matching between array element 10 and the transmission line. It is rare that the input impedance of the array element 10 matches the characteristic impedance of the transmission line, and reflection of the RF signal input at the junction occurs. Therefore, the matching unit 30 adjusts so as to reduce the reflection of the RF signal. Specifically, adjustment is performed using a coil, a capacitor, or the like in consideration of the input impedance of the antenna element 34 or the like. The frequency oscillating unit 32 generates a frequency signal and supplies it to the array element 10. The matching unit 30 is adjusted according to the frequency of the frequency signal. The antenna element 34 transmits the signal supplied from the frequency oscillating unit 32 as a radio wave.

  FIG. 3A is a diagram illustrating a first configuration example of the conductor of FIG. FIG. 3B is a diagram illustrating a second configuration example of the conductor of FIG. Both the first configuration example and the second configuration example include two conductors 20 and a reactance element 40. In the case of the first configuration example, the reactance element 40 is a reactance element 41 having a capacitance property. In the case of the second configuration example, the reactance element 40 is a reactance element 42 having inductance. Hereinafter, the reactance element 41 and the reactance element 42 will be described as the reactance element 40. The two conductors 20 are connected with the reactance element 40 interposed therebetween. The reactance element 40 has its reactance value set according to the frequency of the signal input to the array antenna, that is, the individual array elements 10. As shown in FIG. 1, since a plurality of conductors 20 are installed in the array antenna, different reactance values are set for the reactance elements 40 connected to the individual conductors.

  The reactance value of each reactance element 40 is set to a predetermined value that changes the mutual coupling between the plurality of antenna elements 34, and assists impedance matching by the matching unit 30. Specifically, a predetermined value is set using a value obtained through experiments, simulations, or an empirical rule in consideration of the shape and installation position of the conductor. As described above, in an array antenna in which a plurality of antenna elements are arranged close to each other, it is difficult to achieve sufficient matching only with the matching section 30 of each array element 10. Perform impedance matching. When the conductor 20 and the reactance element 40 cooperate to obtain impedance matching, more flexible matching can be performed.

  FIG. 4 is a plan view of the array antenna of FIG. 4, as in FIG. 1, the array antenna includes two array elements 10 and four conductors 20. The first conductor 21 and the fourth conductor 24 are arranged on a straight line when the first array element 11 and the second array element 12 are connected by a straight line. The second conductor 22 and the fourth conductor 24 are disposed between the first array element 11 and the second array element 12 or inside. “Between” or “inner side” includes disposing at least two antenna elements on a straight line when they are connected by a straight line. However, it does not have to be arranged on the straight line. For example, the respective positions of the second conductor 22 and the fourth conductor 24 are projected on a straight line when the first array element 11 and the second array element 12 are connected by a straight line, and the projected positions are on the straight line. Including being present between the first array element 11 and the second array element 12.

  Each conductor 20 operates as a director or a reflector for each of the plurality of array elements 10 depending on the reactance value of the corresponding reactance element 40. When the reactance element 40 has inductance, it operates as a director, and when it has capacitance, it operates as a reflector. Here, since directivity is required for the array antenna, a conductor to which a reactance element 40 having inductance is connected is disposed inside at least two of the plurality of antenna elements and reflected. Operate as a vessel. That is, the reactance element 40 connected to the second conductor 22 and the fourth conductor 24 is provided with inductance. By adopting such a configuration, the array antenna can have a sharp directivity.

  Further, the plurality of antenna elements are respectively arranged at an interval narrower than the wavelength of the signal input to the array antenna. Here, when the interval between the plurality of antenna elements is L1 and the wavelength is λ, λ> L1. More preferably, the interval is set so as to maximize the channel capacity obtained by experiments or the like. However, when miniaturization is required as in a wireless communication terminal, the interval cannot be widened, so L1 is desirably about 1/10 wavelength compared to λ.

  At least one conductor 20 of the plurality of conductors 20 is arranged around at least one antenna element of the plurality of antenna elements at an interval narrower than the interval between the array elements 10. That is, if the interval between the array elements 10 is L1 and the minimum interval among the intervals between the conductors and the array elements 10 is L2, L1> L2. When there are three or more array elements, the minimum interval among the intervals between the array elements 10 may be L1.

  FIG. 5 is a diagram showing a first effect of the array antenna of FIG. The first effect is obtained by simulation. FIG. 5 is a graph in which the horizontal axis represents the element spacing of the array elements 10 and the vertical axis represents the channel capacity. FIG. 6 is a diagram showing the relationship between channel capacitance and element spacing when optimal impedance matching is performed only by the matching unit 30 and when optimal matching is performed by the matching unit 30 and the reactance element 40; The channel capacity includes the number of bits that can be transmitted per 1 Hz. In addition, λ in the figure indicates a wavelength.

  In FIG. 5, the case where the impedance matching is performed optimally only by the matching unit 30 is indicated by a broken line. In addition, a solid line indicates a case where optimum matching is performed by the matching unit 30 and the reactance element 40. Further, the channel capacity corresponding to the interval of the array element 10 of 0.1λ is shown as C1 and C2 in each case.

  As shown in FIG. 5, when the interval between the array elements 10 is 0.3λ, the optimum matching is performed only by the matching unit 30 and the optimum matching is performed by both the matching unit 30 and the reactance element 40. Compared with, channel capacity is almost the same. However, when the distance between the array elements 10 is 0.1λ, the channel capacity when the optimum matching is performed only by the matching unit 30 is C1, whereas when the optimum matching is performed by both the matching unit 30 and the reactance element 40, It becomes C2 and both are remarkably different. Here, when the optimum matching is performed only by the matching unit 30, only the channel capacity C1 can be obtained because the impedance matching is not taken out. Therefore, as described above, even when the array antenna is configured in a narrow space, the channel capacity can be increased by performing the optimum matching in both the matching unit 30 and the reactance element 40.

  FIG. 6 is a diagram illustrating a second effect of the array antenna of FIG. The second effect is obtained by simulation. In FIG. 6, the second effect is a graph in which the horizontal axis represents the frequency of the signal input to the array antenna and the vertical axis represents the standing wave ratio (hereinafter referred to as “VSWR”). As shown. FIG. 6 is a diagram showing the relationship between the channel capacitance and the element spacing when optimal impedance matching is performed only by the matching unit 30 and when optimal matching is performed by the matching unit 30 and the reactance element 40. .

VSWR is defined as “ratio between the maximum value and the minimum value of a wave formed by overlapping an incident wave and a reflected wave (this is called a standing wave)”. The ratio between the incident wave and the reflected wave is called a reflection coefficient, and the value expressed in decibels is called “return loss”. Normally, the radio wave or power does not consume 100% of the transmitted / input radio wave / power, but always returns or bounces at least. The relationship between “feed” and “return” is VSWR and is expressed by the following equation.
VSWR = (incident wave + reflected wave) / (incident wave-reflected wave)

  From the above equation, it can be seen that the greater the reflected wave, the greater the VSWR. That is, an increase in the reflected wave causes a large loss of radio waves or power, which adversely affects the system. In order to make this reflected wave zero, it is necessary to perfectly match the impedance. Therefore, when the impedance is perfectly matched, that is, the ideal value of VSWR is 1.

  In FIG. 6, as in FIG. 5, the case where the impedance matching is performed optimally only by the matching unit 30 is indicated by a broken line. In addition, a solid line indicates a case where optimum matching is performed by the matching unit 30 and the reactance element 40. Further, the VSWR for each case is shown as V1 and V2.

  As shown in FIG. 6, at the frequency f0, the VSWR when the optimum matching is performed only by the matching unit 30 is V1. On the other hand, when optimal matching is performed by both the matching unit 30 and the reactance element 40, the VSWR is V2 close to the ideal value of 1, and the two are significantly different. Here, it can be said that the VSWR is large when the optimum matching is performed only by the matching unit 30 because the impedance matching is not sufficiently removed. Therefore, as can be seen from this result, when an array antenna is configured in a narrow space, impedance matching can be achieved more effectively by optimally matching both the matching unit 30 and the reactance element 40. Become.

  Here, the example of arrangement | positioning at the time of arrange | positioning the array antenna of FIG. 1 on a board | substrate is shown using FIG.7 (a)-FIG.7 (c). FIG. 7A is a first plan view showing an arrangement example when the array antenna of FIG. 1 is arranged on a substrate. FIG. 7B is a second plan view showing an arrangement example when the array antenna of FIG. 1 is arranged on a substrate. FIG.7 (c) is the sectional view on the AA line of Fig.7 (a). Moreover, FIG.7 (c) is also the sectional view on the AA line of FIG.7 (b). In each figure, in order to clarify the correspondence, a semiconductor substrate 50, a substrate front surface 52, and a substrate back surface 54 are attached in the figure. 7A is a plan view of the substrate surface 52 side of FIG. 7C, and FIG. 7B is a plan view of the substrate back surface 54 side of FIG. 7C.

  As shown in FIGS. 7A and 7C, the first array element 11, the second array element 12, the first conductor 21, the second conductor 22, and the fourth conductor 24 are formed on the semiconductor substrate 50. The substrate surfaces 52 are arranged in parallel. Further, as shown in FIGS. 7B and 7C, the third conductor 23 is disposed on the substrate back surface 54 of the semiconductor substrate 50. Each is arranged in parallel. Thus, by arranging an array antenna on a board | substrate planarly, an array antenna can be mounted also in a card-like radio | wireless communication terminal. Further, as described above, optimum impedance matching can also be performed.

  In addition, the array antennas shown in FIGS. 7A to 7C can react with the reactance value of the reactance element with little redesign and re-installation even when the frequency of the input signal changes. Since the same effect as described above can be obtained simply by changing the above, it is possible to use the array antenna for general purposes. In order to change the reactance value of the reactance element, the reactance element in which a desired reactance value is set may be re-installed, or may be changed externally. “Externally changing” may be set at the time of manufacture and shipment in a factory, and includes setting at the time of use. Setting at the time of use includes setting by a switch, selection by a switch, setting by a user's direct action on hardware or software including an array antenna, and the like.

  By the above aspect, even if the space | interval of an antenna element is narrowed, impedance can be matched stably. In addition, the impedance of the array antenna can be more effectively matched by both the matching portion and the reactance element. Also, the optimum impedance can be matched according to the frequency of the input signal. A reactive element is loaded on a parasitic element (conductor). Thereby, impedance matching can be optimized efficiently and easily by adjusting the reactance value of the reactance element as well as the shape and installation position of the conductor and the impedance matching by the matching portion of the antenna element.

  In designing antennas when mounted on portable wireless communication devices, etc., by designing the reactance values optimally, it is possible to change the electromagnetic coupling including the communication device housing and easily achieve impedance matching. Further, as a result of sufficient impedance matching, it is possible to avoid a reduction in communication channel capacity in an array antenna having a narrow element spacing. Even in the actual antenna design of wireless communication equipment, the mutual coupling between elements including the housing can be electrically changed by adjusting the reactance value, so that it is not necessary to design the position and dimensions of the conductor strictly. . In addition, by arranging a conductor with a reactance element in the vicinity of an array element in an array antenna having a narrow element spacing, impedance matching, which has been difficult in the past, can be performed not only in the physical shape and mechanical arrangement of the conductor but also in the electrical resistance. It can be adjusted flexibly by the action. The effect similar to the above can be obtained when the frequency of the input signal is changed only by changing the reactance value of the reactance element, and the array antenna can be used for general purposes.

  Further, the electromagnetic coupling in the array antenna can be reduced by the reactance element connected to the conductor. Further, by setting different reactance values in the reactance elements connected to the plurality of conductors, it is possible to operate each of the plurality of antenna elements as a director or a reflector. This also allows flexible setting of the directivity of the array antenna. Further, it is possible to reduce the interference caused by the beams of the array elements and radiate the signal power efficiently. In addition, an array antenna having a sharp directivity can be configured. By arranging the plurality of antenna elements in parallel on the substrate, the array antenna can be configured in a narrow space.

  In addition, the antenna manufacturing process can be simplified and the cost can be reduced. Also, the antenna can be designed to be easy to adjust. According to the present invention, the design period of a small array antenna can be greatly shortened, and the load of developing a model of a wireless communication terminal can be reduced. The array antenna does not require rigorous redesign of the conductor shape and installation position even when the impedance matching of the array antenna is readjusted as a result of new development or design change of the communication equipment housing. Flexible adjustment is possible, and the design period of the small array antenna can be greatly shortened.

  Hereinafter, modifications of the array antenna will be described. Note that the following modifications also include the characteristics of the array antenna described so far. That is, a conductor is disposed in the vicinity of the array element, and a reactance element is connected to the conductor. Further, impedance matching of the array antenna is realized by adjusting the reactance of the reactance element. Therefore, in the following description, the description regarding the above features is omitted, and the description will focus on the configuration of the array antenna.

(First modification)
FIG. 8 shows a first modification of the array antenna. The array antenna includes a first dielectric layer 60a, a second dielectric layer 60b, collectively referred to as a dielectric layer 60, a first antenna element 62a, a second antenna element 62b, and a third antenna element 62c, collectively referred to as an antenna element 62. , Fourth antenna element 62d, first conductor 64a, second conductor 64b, third conductor 64c, fourth conductor 64d, fifth conductor 64e, sixth conductor 64f, seventh conductor 64g, eighth The first reactance element 66a, the second reactance element 66b, the third reactance element 66c, the fourth reactance element 66d, the fifth reactance element 66e, the sixth reactance element 66f, and the seventh reactance element, collectively referred to as the conductor 64h and the reactance element 66 66g, a first matching portion 68a, a second matching portion 68b, a third matching portion 68c, which are collectively referred to as a matching portion 68, a fourth matching portion Including 68d, first frequency oscillating portion 70a which are generically referred to as frequency oscillating unit 70, a second frequency oscillating unit 70b, a third frequency oscillator unit 70c, a fourth frequency oscillating unit 70d.

  The antenna element 62, the matching unit 68, and the frequency oscillating unit 70 correspond to the antenna element 34, the matching unit 30, and the frequency oscillating unit 32 of FIG. 2, respectively, and the conductor 64 is the conductor 20 of FIGS. 3 (a)-(b). It corresponds to. The reactance element 66 corresponds to the reactance element 41 in FIG. 3A and the reactance element 42 in FIG. Therefore, description of these configurations is omitted.

  The first dielectric layer 60a and the second dielectric layer 60b are arranged so as to be separated by a predetermined distance. Here, a support element (not shown) is provided between the first dielectric layer 60a and the second dielectric layer 60b, and the distance between the two is maintained by the support element. A plurality of antenna elements 62 are arranged in parallel on the upper surface of the first dielectric layer 60a and the lower surface of the second dielectric layer 60b. That is, the antenna element 62 disposed on the first dielectric layer 60a and the antenna element 62 disposed on the second dielectric layer 60b are configured to face each other. Here, the plurality of antenna elements 62 may be arranged to the extent that the characteristics as an array can be realized even if they are not parallel. On the other hand, a plurality of conductors 64 are disposed on the lower surface of the first dielectric layer 60a and the upper surface of the second dielectric layer 60b, that is, the surface opposite to the surface on which the plurality of antenna elements 62 are disposed. Reactance elements 66 are connected to the plurality of conductors 64, respectively. Further, a matching unit 68 and a frequency oscillating unit 70 are connected to the antenna element 62.

  FIGS. 9A to 9C show the manufacturing process of the first modification. FIG. 9A shows a first stage, in which a plurality of conductors 64 and reactance elements 66 respectively connected to the plurality of conductors 64 are arranged on the upper surface of the second dielectric layer 60b. FIG. 9B shows a second stage, in which a plurality of antenna elements 62 are arranged substantially in parallel on the lower surface of the second dielectric layer 60b. FIG. 9C shows a third stage, in which the matching unit 68 and the frequency oscillation unit 70 are connected to the antenna element 62.

  According to this modification, since the distance between the first dielectric layer and the second dielectric layer can be set to a predetermined value, the space between the two can be designed to have a sufficient value. Further, the manufacturing can be facilitated. In addition, radiation from the array element can be facilitated.

(Second modification)
FIG. 10 shows a second modification of the array antenna. The components included in FIG. 10 are the same as the components included in FIG. A second dielectric layer 60b is stacked on the top surface of the first dielectric layer 60a. The plurality of antenna elements 62 are arranged substantially in parallel on the upper surface of the first dielectric layer 60a. A matching unit 68 and a frequency oscillation unit 70 are connected to the antenna element 62. The plurality of conductors 64 are disposed on the upper surface of the second dielectric layer 60b. The reactance element 66 is disposed on the upper surface of the second dielectric layer 60b while being connected to each of the plurality of conductors 64. Similarly, the conductor 64 and the dielectric layer 60 are also disposed on the lower surface of the first dielectric layer 60a.

  FIGS. 11A to 11D show a manufacturing process of the second modification of the array antenna. FIG. 11A shows a first stage, in which a plurality of antenna elements 62 are arranged substantially in parallel on the upper surface of the first dielectric layer 60a. Although not shown, a plurality of conductors 64 are disposed on the lower surface of the first dielectric layer 60a, and reactance elements 66 respectively connected to the plurality of conductors are disposed on the lower surface of the first dielectric layer 60a. . FIG. 11B shows a second stage, in which the second dielectric layer 60b is laminated on the upper surface of the first dielectric layer 60a. FIG. 11C shows a third stage, in which a plurality of conductors 64 are arranged on the upper surface of the second dielectric layer 60b. Although not shown, reactance elements 66 respectively connected to the plurality of conductors 64 are disposed on the upper surface of the second dielectric layer 60b. FIG. 11D shows the fourth stage, in which the matching unit 68 and the frequency oscillation unit 70 are connected to the antenna element 62.

  According to this modification, since the feeder line from the matching portion is arranged on the same plane, that is, on the upper surface of the first dielectric layer, wiring can be facilitated. Further, the manufacturing can be facilitated.

(Third Modification)
FIG. 12 shows a third modification of the array antenna. The components included in FIG. 12 are the same as the components included in FIG. The plurality of antenna elements 62 are arranged substantially in parallel on the upper surface of the first dielectric layer 60a. A matching unit 68 and a frequency oscillation unit 70 are connected to the antenna element 62. The second dielectric layer 60b is laminated on a portion other than the portion where the plurality of antenna elements 62 are disposed on the upper surface of the first dielectric layer 60a. The plurality of conductors 64 are disposed on the upper surface of the second dielectric layer 60b. The reactance element 66 is disposed on the upper surface of the second dielectric layer 60b while being connected to each of the plurality of conductors 64. Similarly, the conductor 64 and the dielectric layer 60 are also disposed on the lower surface of the first dielectric layer 60a.

  FIGS. 13A to 13E show the manufacturing process of the third modified example. FIG. 13A shows the first stage, in which a plurality of antenna elements 62 are arranged substantially in parallel on the upper surface of the first dielectric layer 60a. FIG. 13B shows a second stage, in which the second dielectric layer 60b is laminated on the upper surface of the first dielectric layer 60a. FIG. 13C shows a third stage, in which a plurality of conductors 64 are arranged on the upper surface of the second dielectric layer 60b. Although not shown, reactance elements 66 respectively connected to the plurality of conductors 64 are disposed on the upper surface of the second dielectric layer 60b. FIG. 13D shows a fourth stage, in which masking is performed on a plurality of conductors 64 and reactance elements 66 arranged on the upper surface of the second dielectric layer 60b, and a masking unit 72 is added. FIG. 13E shows a fifth stage, in which etching is performed on portions of the second dielectric layer 60b other than the masking portion 72. FIG.

  According to this modification, the radiation efficiency from the antenna element can be improved. Further, the manufacturing can be facilitated.

(Fourth modification)
FIG. 14 shows a fourth modification of the array antenna. The constituent elements included in FIG. 14 are the same as the constituent elements included in FIG. The first dielectric layer 60a is stacked on the upper surface of the second dielectric layer 60b. The plurality of conductors 64 are disposed on the upper surface of the second dielectric layer 60b. The reactance element 66 is disposed on the upper surface of the second dielectric layer 60b while being connected to each of the plurality of conductors 64. The plurality of antenna elements 62 are arranged substantially in parallel on the upper surface of the first dielectric layer 60a. Similarly, the antenna element 62 is also disposed on the lower surface of the second dielectric layer 60b. Further, a matching unit 68 and a frequency oscillating unit 70 are connected to the antenna element 62.

  As a further modification of the fourth modification, the first dielectric layer 60a is laminated on a portion other than the portion where the plurality of conductors 64 and the reactance element 66 are disposed on the upper surface of the second dielectric layer 60b. It may be. That is, FIG. 14 may be modified as shown in FIG.

  FIGS. 15A to 15D show the manufacturing process of the fourth modified example. FIG. 15A shows the first stage, in which a plurality of conductors 64 are arranged on the upper surface of the second dielectric layer 60b. In addition, reactance elements 66 respectively connected to the plurality of conductors 64 are disposed on the upper surface of the second dielectric layer 60b. Although not shown, a plurality of antenna elements 62 are arranged substantially in parallel on the lower surface of the second dielectric layer 60b. FIG. 15B shows a second stage, in which the first dielectric layer 60a is laminated on the upper surface of the second dielectric layer 60b. FIG. 15C shows a third stage, in which a plurality of antenna elements 62 are arranged substantially in parallel on the upper surface of the first dielectric layer 60a. FIG. 15D shows the fourth stage, in which the matching unit 68 and the frequency oscillation unit 70 are connected to the antenna element 62.

  Moreover, the manufacturing process of the further modification of a 4th modification is shown as follows. In the first stage, a plurality of conductors 64 are disposed on the upper surface of the second dielectric layer 60b. In addition, reactance elements 66 respectively connected to the plurality of conductors 64 are disposed on the upper surface of the second dielectric layer 60b. In the second stage, the first dielectric layer 60a is stacked on the upper surface of the second dielectric layer 60b. In the third stage, a plurality of antenna elements 62 are arranged substantially in parallel on the upper surface of the first dielectric layer 60a. In the fourth stage, masking is performed on the plurality of reactance elements 66 arranged on the upper surface of the first dielectric layer 60a, and a masking unit 72 is added. In the fifth stage, etching is performed on portions of the first dielectric layer 60a other than the masking portion 72.

  According to this modification, since the antenna element is arranged on the uppermost surface, the radiation efficiency can be improved.

(Fifth modification)
FIGS. 16A and 16B show a fifth modification of the array antenna. Components included in FIGS. 16A to 16B are obtained by adding a radome 74 to the components included in FIG. FIG. 16A shows a perspective view of a fifth modification. The plurality of antenna elements 62 are disposed substantially parallel to the first dielectric layer 60a. The radome 74 is provided so as to cover the upper surface of the first dielectric layer 60a. The plurality of conductors 64 are arranged on the upper surface of the first dielectric layer 60 a in the radome 74. A reactance element 66 is connected to each of the plurality of conductors 64. Further, the lower surface of the first dielectric layer 60a is similarly configured. FIG. 16B is a cross-sectional view along the AA ′ plane of the fifth modification.

  The manufacturing process of the fifth modification is shown as follows. In the first stage, a plurality of antenna elements 62 are arranged substantially in parallel on the upper surface of the first dielectric layer 60a. In the second stage, the radome 74 is provided so as to cover the upper surface of the first dielectric layer 60a. Of the radome 74 in the second stage, a plurality of conductors 64 are arranged on the upper surface of the first dielectric layer 60a, and a reactance element 66 is connected to each of the plurality of conductors 64. Has been.

  According to this modification, since the antenna element is surrounded by the free space, the radiation efficiency of the antenna element can be improved.

  FIG. 17 shows a simulation model for the array antenna. FIG. 17 is shown similarly to FIG. FIG. 17 shows the first antenna element 62a to the fourth antenna element 62d, and the first conductor 64a to the eighth conductor 64h. For the sake of clarity, the reactance element 66 and the like are omitted. As shown in the figure, it is assumed that each interval is determined. The reactance value of the matching unit 68 connected to the first antenna element 62a and the fourth antenna element 62d is set to “15.2Ω”, and the matching unit connected to the second antenna element 62b and the third antenna element 62c. It is assumed that the reactance value of 68 is set to “−8.5Ω”. Here, the matching unit 68 is not shown. Further, it is assumed that the first conductor 64a and the fifth conductor 64e are set to “20Ω”, and other reactance values are set to “−90Ω”. It is assumed that the carrier frequency is “2.5 GHz”.

  FIGS. 18A to 18D show simulation results for the simulation model. FIG. 18A shows a radiation pattern by the first antenna element 62a. FIG. 18B shows a radiation pattern by the second antenna element 62b. FIG. 18C shows a radiation pattern by the third antenna element 62c. Further, FIG. 18D shows a radiation pattern by the fourth antenna element 62d. As shown in the drawing, by adjusting the reactance value, a radiation pattern is formed such that there is less overlap between adjacent antenna elements 62.

(Sixth Modification)
The sixth modification shows a case where the array element 10, the conductor 20, and the reactance element 40 described above are mounted on a portable terminal device. FIG. 19 shows a configuration example of a terminal device 80 according to the sixth modification. The terminal device 80 includes an oscillator 82, a first transmission / reception unit 84, a second power amplification unit 86, a first transmission bandpass filter 88, a first matching unit 90, a first antenna element 92, and a first reception. A bandpass filter 94, a second transmission / reception unit 96, a second power amplification unit 98, a second transmission bandpass filter 100, a second matching unit 102, a second antenna element 104, and a second reception bandpass filter 105, a first conductor 106a to a fourth conductor 106d represented by a conductor 106, and a first reactance element 108a to a fourth reactance element 108d represented by a reactance element 108. The first antenna element 92 and the second antenna element 104 correspond to the array element 10 described above. The conductor 106 and the reactance element 108 correspond to the conductor 20 and the reactance element 40, respectively. The first matching unit 90 and the second matching unit 102 correspond to the matching unit 30 described above.

  The first transmission / reception unit 84 performs modulation processing and the like on the signal to be transmitted. Further, the first transmission / reception unit 84 generates a transmission signal by superimposing the signal oscillated by the oscillator 82 and the signal subjected to the modulation process or the like. The second power amplifier 86 amplifies the power of the transmission signal generated by the first transmitter / receiver 84. The first transmission band-pass filter 88 performs band-pass filter processing on the signal whose power has been amplified by the second power amplification unit 86. The first matching unit 90 performs an impedance matching process on the signal that has been subjected to the bandpass filter process by the first transmission bandpass filter 88. The adjustment related to the impedance matching process is set when the antenna element is mounted on the terminal device 80. Thereby, flexible setting is possible. The first antenna element 92 transmits a signal whose impedance is matched by the first matching unit 90. The first antenna element 92 receives a radio signal and sends it to the first transmission / reception unit 84 via the first reception bandpass filter 94 and the like.

  Similarly, the second transmission / reception unit 96 generates a transmission signal. The generated transmission signal is transmitted via the second power amplification unit 98, the second transmission bandpass filter 100, the second matching unit 102, and the second antenna element 104. The received signal is transmitted to the second transmitting / receiving unit 96 via the second antenna element 104, the second matching unit 102, and the second receiving bandpass filter 105, and demodulation processing is executed.

  Two sets of conductors 106 and reactance elements 108 are arranged around the first antenna element 92 and the second antenna element 104, respectively. The number of sets to be arranged may be a number other than two, or the number of sets different between the first antenna element 92 and the second antenna element 104 may be used. The conductor 106 and the reactance element 108 in each set are connected to each other and grounded. Specifically, a first conductor 106 a and a second conductor 106 b are installed around the first antenna element 92 so as to be parallel to the first antenna element 92. Here, “parallel” includes that the electric field direction of the helical antenna and the electric field direction of the inverted F-type antenna are the same direction, and the directions of the helical antennas or the inverted F-type antennas are the same direction. Including being. A third conductor 106 c and a fourth conductor 106 d are installed around the second antenna element 104 so as to be parallel to the second antenna element 104. The first antenna element 92 and the second antenna element 104 may be installed so as to face different directions as shown in the figure, or may be placed so as to face the same direction. Here, the “direction” includes the electric field direction of the radio wave transmitted from the antenna element.

  FIG. 20 is a diagram schematically illustrating a first arrangement example of the first antenna element 92 and the second antenna element 104 in the terminal device 80 of FIG. The same parts as those in FIG. 19 are denoted by the same reference numerals and description thereof is omitted. As illustrated, the first antenna element 92 and the second antenna element 104 are respectively installed on the first arrangement surface 110 and the second arrangement surface 120 so as to face different directions. The first arrangement surface 110 and the second arrangement surface 120 are connected vertically. The second arrangement surface 120 indicates a surface on the back side of a surface on which a display screen and operation buttons (not shown) to be installed in the terminal device 80 are provided. Here, the first antenna element 92 represents a helical antenna, and the second antenna element 104 represents an inverted F-type antenna. The inverted F-type antenna may be an inverted L-type antenna or a T-type antenna.

  Around the first antenna element 92, two sets of conductors 106 and reactance elements 108 are installed so as to be parallel to the first antenna element 92. Here, the first conductor 106 a and the first reactance element 108 a are installed so as to protrude from the terminal device 80. Further, the second conductor 106 b and the second reactance element 108 b are installed so as to be embedded in the terminal device 80. In addition, you may install so that both sets may be embedded, and you may install so that it may jump out. Around the second antenna element 104, three sets of conductors 106 and reactance elements 108 are installed so as to be parallel to the radio wave radiation direction of the second antenna element 104.

  Here, specifically, an example in which the first antenna element 92 and the second antenna element 104 are arranged in the terminal device 80 is shown. FIG. 21 is a diagram schematically illustrating a second arrangement example of the first antenna element 92 and the second antenna element 104 in the terminal device 80 of FIG. The same parts as those in FIG. 19 are denoted by the same reference numerals and description thereof is omitted. As illustrated, the first antenna element 92 and the second antenna element 104 are respectively installed on the first arrangement surface 110 and the second arrangement surface 120 so as to face different directions. Here, both the first antenna element 92 and the second antenna element 104 are inverted F-type antennas. Around the first antenna element 92, three sets of conductors 106 and reactance elements 108 are installed so as to be parallel to the radio wave radiation direction of the second antenna element 104. Further, around the second antenna element 104, three sets of conductors 106 and reactance elements 108 are installed so as to be parallel to the radio wave radiation direction of the second antenna element 104. In addition, although each conductor 106 and the reactance element 108 are illustrated as being installed so as to protrude from the terminal device 80, they may be installed so as to be embedded.

  FIG. 22 is a diagram schematically illustrating a third arrangement example of the first antenna element 92 and the second antenna element 104 in the terminal device 80 of FIG. The same parts as those in FIG. 19 are denoted by the same reference numerals and description thereof is omitted. As illustrated, both the first antenna element 92 and the second antenna element 104 are installed on the first arrangement surface 110 so as to face the same direction. Here, both the first antenna element 92 and the second antenna element 104 are inverted F-type antennas. Around the first antenna element 92, three sets of conductors 106 and reactance elements 108 are installed so as to be parallel to the radio wave radiation direction of the second antenna element 104. In addition, around the second antenna element 104, two sets of conductors 106 and reactance elements 108 are installed so as to be parallel to the radio wave radiation direction of the second antenna element 104. In addition, although each conductor 106 and the reactance element 108 are illustrated as being installed so as to protrude from the terminal device 80, they may be installed so as to be embedded.

  FIG. 23 is a diagram schematically illustrating a fourth arrangement example of the first antenna elements 92 and the second antenna elements 104 in the terminal device 80 of FIG. The same parts as those in FIG. 19 are denoted by the same reference numerals and description thereof is omitted. As illustrated, the first antenna element 92 and the second antenna element 104 are both installed on the second arrangement surface 120 so as to face the same direction. Here, both the first antenna element 92 and the second antenna element 104 are inverted F-type antennas. The fourth arrangement example shown in FIG. 23 differs from the third arrangement example shown in FIG. 22 in the plane on which the respective antenna elements are arranged.

  In this way, the plurality of antenna elements are arranged on different surfaces of the mobile terminal device so that the directions in which radio waves should be emitted are different from each other, so that the conductors and reactance elements arranged around the antenna elements Since impedance matching is realized, radio wave interference can be further reduced.

  The present invention has been described based on the embodiments. This embodiment is an exemplification, and various modifications can be made to the combination of the embodiment and modifications, or the combination of each component and each processing process, and such modifications are also applicable to the present invention. It will be understood by those skilled in the art that it is in the range.

  The embodiment of the present invention has been described as an array antenna composed of two linear array elements. However, the present invention is not limited to this, and an array antenna including three or more array elements may be used. It can be easily understood by those skilled in the art that the same effect can be obtained even if the array antenna includes three or more array elements.

It is a perspective view which shows the structural example of the array antenna concerning embodiment of this invention. It is a figure which shows the structural example of the array element of FIG. FIG. 3A is a diagram illustrating a first configuration example of the conductor of FIG. FIG. 3B is a diagram illustrating a second configuration example of the conductor of FIG. It is a top view of the array antenna of FIG. It is a figure which shows the 1st effect of the array antenna of FIG. It is a figure which shows the 2nd effect of the array antenna of FIG. FIG. 7A is a first plan view showing an arrangement example when the array antenna of FIG. 1 is arranged on a substrate. FIG. 7B is a second plan view showing an arrangement example when the array antenna of FIG. 1 is arranged on a substrate. FIG.7 (c) is the sectional view on the AA line of Fig.7 (a). It is a figure which shows the 1st modification of the array antenna of FIG. FIGS. 9A to 9C are diagrams showing a manufacturing process of the first modified example of FIG. It is a figure which shows the 2nd modification of the array antenna of FIG. FIGS. 11A to 11D are diagrams showing manufacturing steps of the second modified example of FIG. It is a figure which shows the 3rd modification of the array antenna of FIG. FIGS. 13A to 13E are diagrams showing manufacturing steps of the third modified example of FIG. It is a figure which shows the 4th modification of the array antenna of FIG. FIGS. 15A to 15D are diagrams showing manufacturing steps of the fourth modified example of FIG. FIGS. 16A and 16B are views showing a fifth modification of the array antenna of FIG. FIG. 17 is a diagram showing a simulation model for the array antenna of FIG. 18A to 18D are diagrams showing simulation results for the simulation model of FIG. It is a figure which shows the structural example of the terminal device concerning a 6th modification. It is a figure which shows typically the 1st example of arrangement | positioning of the 1st antenna element and 2nd antenna element in the terminal device of FIG. It is a figure which shows typically the 1st example of arrangement | positioning of the 1st antenna element and 2nd antenna element in the terminal device of FIG. It is a figure which shows typically the 3rd example of arrangement | positioning of the 1st antenna element and 2nd antenna element in the terminal device of FIG. It is a figure which shows typically the 4th example of arrangement | positioning of the 1st antenna element and 2nd antenna element in the terminal device of FIG.

Explanation of symbols

  10 array elements, 11 first array elements, 12 second array elements, 20 conductors, 21 first conductors, 22 second conductors, 23 third conductors, 24 fourth conductors, 30 matching sections, 32 frequency oscillation sections, 34 antennas Element, 40 reactance element, 50 semiconductor substrate, 52 substrate surface, 54 substrate back surface, 60 dielectric layer, 62 antenna element, 64 conductor, 66 reactance element, 68 matching section, 70 frequency oscillation section, 72 masking section, 74 radome, 80 terminal device, 92 first antenna element, 104 second antenna element, 106 conductor, 108 reactance element.

Claims (26)

A plurality of antenna elements;
A plurality of conductors arranged around a predetermined distance around each of the plurality of antenna elements;
With
An reactance element is connected to each of the plurality of conductors. The plurality of antenna elements have a matching unit for impedance matching,
The reactance value of the reactance element is set to a value that changes mutual coupling between the elements of the plurality of antenna elements, thereby assisting impedance matching by the matching unit. Array antenna. The plurality of antenna elements are respectively arranged at an interval narrower than the wavelength of a signal input to the array antenna,
The at least one conductor among the plurality of conductors is arranged around at least one antenna element of the plurality of antenna elements at a distance narrower than an interval between the antenna elements. Item 3. The array antenna according to any one of Items 1 and 2.   The array antenna according to claim 1, wherein the reactance element has a reactance value set according to a frequency of a signal input to the array antenna. Reactance elements respectively connected to at least one or more of the plurality of conductors are set with different reactance values,
The array antenna according to claim 1, wherein the conductor to which the corresponding reactance element is connected operates as a director or a reflector for each of the plurality of antenna elements.   A conductor to which a reactance element having inductance is connected, and a conductor whose electrical length is longer than the antenna element is disposed between at least two antenna elements among the plurality of antenna elements, 6. The array antenna according to claim 5, wherein the array antenna is operated as a reflector.   A conductor to which a reactance element having a capacitance property is connected, and a conductor whose electrical length is shorter than that of the antenna element is disposed around the plurality of antenna elements and operates as a director. The array antenna according to claim 5.   The array antenna according to claim 1, wherein the plurality of antenna elements are arranged substantially in parallel on a substrate.   The plurality of antenna elements are arranged on any one of a plurality of faces constituting the terminal device, and each antenna element has a different polarization plane and is arranged close to each other. The array antenna according to either 1 or 2.   The array antenna according to claim 8 or 9, wherein at least one of the plurality of antenna elements is an inverted F-type antenna.   11. The conductor according to claim 8, wherein the conductor is disposed on a substrate on which the plurality of antenna elements are disposed, or is disposed at a predetermined interval from the substrate on which the plurality of antenna elements are disposed. An array antenna according to any one of the above.   The array antenna according to any one of claims 8 to 10, wherein the conductor and the reactance element are arranged on a surface of the substrate opposite to a surface on which the plurality of antenna elements are arranged. Further comprising at least two dielectric layers stacked;
The plurality of antenna elements are arranged substantially in parallel on a first layer of the at least two dielectric layers, and the plurality of conductors are arranged on a second layer of the at least two dielectric layers. The array antenna according to claim 1, wherein the reactance element is disposed.   The plurality of antenna elements are disposed on an upper surface of a first layer of the at least two dielectric layers, and a second layer of the at least two dielectric layers is formed on an upper surface of the first layer. The plurality of conductors and the reactance element are disposed on the upper surface of the second layer while being laminated on the upper side, and the plurality of conductors and the reactance element are disposed on the lower surface of the first layer. The array antenna according to claim 13, wherein:   15. The second layer of the at least two dielectric layers is stacked on a portion other than a portion where the plurality of antenna elements are arranged on an upper surface of the first layer. Array antenna.   The plurality of conductors and the reactance element are disposed on an upper surface of a second layer of the at least two dielectric layers, and a first layer of the at least two dielectric layers is a second layer. The plurality of antenna elements are arranged on the upper surface of the first layer while being stacked on the upper side of the upper surface of the layer, and the plurality of antenna elements are also arranged on the lower surface of the second layer. The array antenna according to claim 13.   The first layer of the at least two dielectric layers is laminated on a portion other than a portion where the plurality of conductors and the reactance element are arranged on an upper surface of the second layer. Item 17. The array antenna according to Item 16. At least one dielectric layer;
A radome provided to cover an uppermost surface of the at least one dielectric layer;
The at least one dielectric layer has the plurality of antenna elements arranged substantially in parallel,
The plurality of conductors and the reactance element are disposed on the uppermost surface of the at least one dielectric layer in the radome, according to any one of claims 1 to 7. Array antenna. A substrate,
A plurality of antenna elements arranged substantially parallel on the substrate;
Of the substrate, comprising a plurality of conductors disposed on the surface opposite to the surface on which the plurality of antenna elements are disposed,
An reactance element is connected to each of the plurality of conductors. At least two dielectric layers stacked;
A plurality of antenna elements arranged substantially in parallel in a first layer of the at least two dielectric layers;
A plurality of conductors disposed in a second layer of the at least two dielectric layers;
An reactance element is connected to each of the plurality of conductors. A second layer of the at least two dielectric layers is laminated on the upper surface of the first layer;
The plurality of antenna elements are disposed on an upper surface of a first layer of the at least two dielectric layers,
The array antenna according to claim 20, wherein the plurality of conductors and the reactance element are disposed on an upper surface of a second layer and a lower surface of the first layer.   The second layer of the at least two dielectric layers is stacked on a portion other than a portion where the plurality of antenna elements are arranged on the upper surface of the first layer. Array antenna. A first layer of the at least two dielectric layers is laminated on an upper surface of the second layer;
The plurality of conductors and the reactance element are disposed on an upper surface of a second layer of the at least two dielectric layers,
21. The array antenna according to claim 20, wherein the plurality of antenna elements are disposed on an upper surface of the first layer and a lower surface of the second layer.   The first layer of the at least two dielectric layers is laminated on a portion other than a portion where the plurality of conductors and the reactance element are arranged on an upper surface of the second layer. Item 24. The array antenna according to Item 23. At least one dielectric layer;
A plurality of antenna elements disposed substantially parallel to the at least one dielectric layer;
A radome provided to cover an uppermost surface of the at least one dielectric layer;
A plurality of conductors arranged on the uppermost surface of the at least one dielectric layer of the radome;
An reactance element is connected to each of the plurality of conductors. A conductor connected to a reactance element is arranged around a plurality of antenna elements,
An impedance matching method, wherein impedance is matched by setting a reactance value of a reactance element connected to a conductor to a predetermined value that changes mutual coupling between the plurality of antenna elements.

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