JP6311512B2 - Integrated antenna device - Google Patents

Description

  The present invention relates to an integrated antenna device in which a plurality of antennas are integrated, and more particularly to a technique for downsizing the integrated antenna device.

  2. Description of the Related Art A miniaturized antenna device that includes antennas that operate at a plurality of different frequencies is known. For example, in Patent Document 1, the antenna device is downsized by using the inside of the loop of the coil antenna and arranging the patch antenna inside the loop of the coil antenna.

Japanese Patent No. 4142523

  In order to increase the gain of the patch antenna, the patch antenna ground should be large. However, in the technique of Patent Document 1 in which the patch antenna is disposed inside the loop of the coil antenna, the patch antenna ground must be smaller than the coil antenna. Therefore, in the configuration of Patent Document 1, it is difficult to increase the gain of the patch antenna while reducing the size.

  The present invention has been made based on this situation, and an object thereof is to provide an integrated antenna device that includes a patch antenna and other antennas, can be downsized, and can increase the gain of the patch antenna. There is to do.

  The above object is achieved by a combination of the features described in the independent claims, and the subclaims define further advantageous embodiments of the invention. Reference numerals in parentheses described in the claims indicate a correspondence relationship with specific means described in the embodiments described later as one aspect, and do not limit the technical scope of the present invention. .

  In order to achieve the above object, the present invention provides a first antenna (10) comprising a flat plate-like first antenna element (12) and a ground pattern (11) arranged opposite to the first antenna element, A second antenna element (21, 22) disposed outside the ground pattern, connected to the second antenna (20) having a different frequency from the first antenna, the ground pattern and the second antenna element, An integrated antenna apparatus comprising a filter (16, 116, 216) having a low impedance at a frequency used by one antenna.

  The first antenna is a patch antenna because it includes a flat plate-like first antenna element and a ground pattern disposed to face the first antenna element.

  A second antenna element is disposed outside the ground pattern, and the ground pattern and the second antenna element are connected by a filter. Since this filter has low impedance at the operating frequency of the first antenna, in addition to the ground pattern, the second antenna element also functions as the ground of the first antenna.

  Since the second antenna element functions as the ground of the first antenna in addition to the ground pattern, the gain of the first antenna that is a patch antenna is improved. Further, since the second antenna element serves as the ground of the first antenna and the element of the second antenna, the integrated antenna device can be reduced in size.

1 is a plan view of an integrated antenna device 1 according to an embodiment of the present invention. It is an II arrow directional view of FIG. 2 is a diagram illustrating a configuration of a filter 16. FIG. FIG. 3 is a diagram illustrating a configuration of a second antenna 20. 4 is a conceptual diagram for explaining the operation of the second antenna 20. FIG. 4 is a conceptual diagram for explaining the operation of the second antenna 20. FIG. 4 is a conceptual diagram for explaining the operation of the second antenna 20. FIG. 4 is a conceptual diagram for explaining the operation of the second antenna 20. FIG. It is a directivity analysis result of the first antenna 10. It is a directivity analysis result of the patch antenna in the comparative configuration in which the filter 16 is removed from the integrated antenna device 1. It is a figure which shows the structure of the filter 116a of the modification 1. It is a figure which shows the structure of the filter 216 of the modification 2.

<Embodiment>
Hereinafter, embodiments of the present invention will be described with reference to the drawings. The integrated antenna device 1 shown in FIG. 1 is an antenna device in which a first antenna 10 and a second antenna 20 are integrated.

  The integrated antenna device 1 of this embodiment is used in, for example, a vehicle, and transmits / receives circularly polarized waves having two different frequencies, or performs either one of transmission and reception. In the following, the integrated antenna device 1 transmits and receives radio waves in a frequency band used in DSRC (Dedicated Short Range Communication), and is transmitted from a satellite used in GPS (Global Positioning System) which is one of satellite positioning systems. It will be described as receiving radio waves. The integrated antenna device 1 is attached to, for example, an upper part of a vehicle windshield.

  In DSRC, a radio wave of 5.8 GHz band is used, and in GPS, a 1.5 GHz band is used. The polarization of both DSRC and GPS is circular polarization. That is, the integrated antenna device 1 transmits and receives circularly polarized radio waves in the 5.8 GHz band and receives circularly polarized radio waves in the 1.5 GHz band. In the following description, the 5.8 GHz band is the first frequency, and the 1.5 GHz band is the second frequency. The first frequency is a use frequency of the first antenna 10, and the second frequency is a use frequency of the second antenna 20.

(overall structure)
The board | substrate 2 is comprised with dielectric materials, such as a glass epoxy board | substrate, and a shape is a substantially square rectangular flat plate shape. A ground pattern 11, a powered element 21, a parasitic element 22, and filters 16 a to 16 d are arranged on one surface (referred to as a front surface) 2 a of the substrate 2. Therefore, the ground pattern 11, the fed element 21 and the parasitic element 22 are arranged on the same plane.

  The size and shape of the substrate 2 only have to be sufficient size and shape to dispose the ground pattern 11, the fed element 21, the parasitic element 22, and the filters 16a to 16d. The shape of the substrate 2 of this embodiment is a square, but may be a rectangle or a circle (including an ellipse). Further, the size of the substrate 2 of the present embodiment is about 28 mm on a side.

The ground pattern 11 is a plate made of a conductor such as copper or a foil shape. The shape of the ground pattern 11 is such that the electrical length of one side is less than a quarter of the wavelength of the radio wave used by the second antenna 20 (hereinafter, the second wavelength λ ₂ ), and the first antenna 10 uses it. A square having a predetermined length larger than the half wavelength of the wavelength of the radio wave (hereinafter, the first wavelength λ ₁ ) is used.

  The ground pattern 11 is electrically connected to the parasitic element 22 at one point on one side 11a of the four sides corresponding to the outer peripheral portion. Moreover, it is connected with the 2nd electric power feeding part 23 in one point on the edge | side 11b orthogonal to the edge | side 11a to which the parasitic element 22 is connected. The second power supply unit 23 is also connected to the power-supplied element 21.

  In the ground pattern 11, a point connected to the second power feeding unit 23 is a fed-side connection point 25, and a point connected to the parasitic element 22 is a parasitic side connection point 26.

  The patch antenna element 12 as the first antenna element is a plate-like member made of a conductor. The shape of the patch antenna element 12 is a shape in which a cutout portion 13 is provided in a pair of diagonal portions of a square. The notch 13 has a structure for radiating circularly polarized waves, and corresponds to a so-called degenerate separation element or perturbation element. The area of the portion cut from the original square by the notch 13 may be an area determined by a well-known degenerate separation method.

The electrical length of one side of the patch antenna element 12 is the length of the first wavelength lambda ₁ of about half. Here, the electrical length of one side is a shape when the cutout portion 13 is ignored, that is, one side in a square.

  The patch antenna element 12 is disposed to face the ground pattern 11 in a posture substantially parallel to the ground pattern 11 at a predetermined interval. The position of the patch antenna element 12 passes through the center of the patch antenna element 12, and the axis perpendicular to the plane including the patch antenna element 12 passes through the approximate center of the ground pattern 11.

  As shown in FIG. 2, the patch antenna element 12 is disposed away from the ground pattern 11 by a resin spacer 14. The spacer 14 has a columnar shape, and one end is in contact with the patch antenna element 12 and the other end is in contact with the ground pattern 11. Here, the number of the spacers 14 is four.

  The first power supply unit 15 supplies the patch antenna element 12 with a high-frequency current corresponding to the first frequency. For example, the first feeding portion 15 may be a columnar member in which conductive pins that electrically connect the patch antenna element 12 and the inner conductor of the coaxial cable are covered with an electrically insulating material such as resin. The first feeding portion 15 is provided at the center of the side 12 a facing the longitudinal portion 21 b of the power-supplied element 21 among the four sides included in the outer peripheral portion of the patch antenna element 12.

  The fed element 21 is a linear element. Specifically, the fed element 21 is a so-called inverted L-type monopole conductor element obtained by bending a substantially linear monopole conductor element at a right angle in the middle thereof. The fed element 21 and the parasitic element 22 described below correspond to an antenna element included in the second antenna 20, that is, a second antenna element in claims.

The powered element 21 has a base side end connected to the second power feeding unit 23 and the other end being an open end. The distance between the power supply side end of the power supplied element 21 and the power supplied side connection point 25 that is the point where the second power supply unit 23 is connected to the ground pattern 11 is compared with the second wavelength λ _2. Small enough. Therefore, in the following description, it is assumed that the end of the power supplied element 21 on the ground pattern 11 side is the power supplied side connection point 25.

  The power-supplied element 21 has a relatively long length from the right-angled portion to the open end relative to the length from the end on the power-supplied side connection point 25 side to the portion bent at right angles (hereinafter, the right-angled portion). Hereinafter, the short side portion 21a is defined from the end on the power supply side connection point 25 side to the right angle portion, and the long portion 21b is defined from the right angle portion to the open end.

  The power-supplied element 21 is disposed on the substrate 2 such that the longitudinal portion 21 b faces the outer periphery of the ground pattern 11. The longitudinal portion 21b corresponds to a power-supplied side facing portion in the claims.

  More specifically, the power-supplied element 21 has a predetermined interval with respect to the side 11b on which the power-supplied connection point 25 is provided, among the four sides where the longitudinal portion 21b forms the outer periphery of the ground pattern 11. Parallel to each other. Moreover, it arrange | positions so that the to-be-powered side connection point 25 may be located in the parasitic element 22 side rather than an open end.

  The electrical length of the power-supplied element 21 only needs to be a length that induces an image current having a desired magnitude in the ground pattern 11 when a current is passed through the power-supplied element 21.

  The length of the longitudinal portion 21 b is shorter than the length of one side of the ground pattern 11. Therefore, it is not necessary to increase the length of the substrate 2 in the direction along the longitudinal portion 21b in order to arrange the longitudinal portion 21b. The open end of the longitudinal portion 21 b is on an extension line of one side of the ground pattern 11. As will be described in detail later, the power-supplied element 21 also functions as the ground of the first antenna 10, so that the substrate 2 need not be enlarged in order to dispose the power-supplied element 21. This is to make the ground as large as possible.

  The parasitic element 22 is an inverted L-type monopole conductor element, like the powered element 21, and includes a short portion 22 a on the relatively short side and a long portion 22 b on the relatively long side. . The short part 22a is from the non-feed side connection point 26 to a right angle part that is bent at a right angle, and the long part 22b is from the right angle part to the open end.

  The parasitic element 22 is disposed on the substrate 2 so that the longitudinal portion 22 b of the parasitic element 22 faces the outer periphery of the ground pattern 11. Therefore, the longitudinal portion 22b corresponds to the non-feeding side facing portion of the claims.

  More specifically, the parasitic element 22 has a longitudinal portion 22b parallel to the side 11a of the ground pattern 11, and the parasitic connection point 26 is positioned closer to the fed element 21 than the open end. To be arranged. The electrical length of the parasitic element 22 is the same as that of the powered element 21. The lengths of the short portion 22a and the long portion 22b are also the same as the lengths of the short portion 21a and the long portion 21b of the power-supplied element 21, respectively.

  Therefore, the length of the longitudinal portion 22b is also shorter than the length of one side of the ground pattern 11. Therefore, it is not necessary to increase the length of the substrate 2 in the direction along the longitudinal portion 22b in order to arrange the longitudinal portion 22b. The open end of the longitudinal portion 22b is also on the extension line of one side of the ground pattern 11.

  Since the fed element 21 and the parasitic element 22 are conductor patterns, they can be formed simultaneously when the ground pattern 11 is formed on the substrate 2.

  In the second power feeding unit 23, the short part 21a of the power-supplied element 21 is electrically connected to the inner conductor of the coaxial cable, and the power-feeding side connection point 25 of the ground pattern 11 is electrically connected to the outer conductor of the coaxial cable. It is the structure connected to.

  The filters 16 a and 16 b connect the ground pattern 11 and the longitudinal portion 21 b of the power supplied element 21. Specifically, the filter 16 a connects the longitudinal portion 21 b and the ground pattern 11 at the distal end portion of the longitudinal portion 21 b of the power supplied element 21. The filter 16b connects the longitudinal portion 21b and the ground pattern 11 at the base portion of the longitudinal portion 21b of the power-supplied element 21, that is, in the vicinity of the right-angle portion.

  The filters 16 c and 16 d connect the ground pattern 11 and the longitudinal portion 22 b of the parasitic element 22. Specifically, the filter 16 c connects the longitudinal portion 22 b and the ground pattern 11 in the vicinity of the open end of the longitudinal portion 22 b of the parasitic element 22. The filter 16b connects the longitudinal portion 22b and the ground pattern 11 in the vicinity of a right angle portion of the longitudinal portion 22b of the parasitic element 22.

  These filters 16 a to 16 d are elements constituting the first antenna 10, and the connection here means that there is electrical continuity at the first frequency, and spatial connection with the ground pattern 11. There may be a gap.

  All of the four filters 16a to 16d of the present embodiment have the same configuration. Hereinafter, when the four filters 16a to 16d are not distinguished, they are simply referred to as a filter 16. As shown in FIG. 3, the configuration of the filter 16 of the present embodiment includes a capacitor C having one end connected to the ground pattern 11, one end connected to the capacitor C, and the other end to the power-supplied element 21 (or no power supply). It is an LC series resonant circuit comprising a coil L connected to the element 22).

  The characteristic of the filter 16 is a characteristic that has a low impedance at the first frequency and a high impedance at the second frequency. Specifically, the characteristic of the filter 16 is a characteristic in which the resonance frequency is at or near the first frequency.

  The low impedance here is a value at which the ground pattern 11, the fed element 21 and the parasitic element 22 can be regarded as being conductive at the first frequency. On the other hand, the high impedance is a value that can be considered that the ground pattern 11, the fed element 21 and the parasitic element 22 are electrically disconnected at the second frequency. Of course, the impedance at the first frequency is lower than the impedance at the second frequency.

(Operation of the first antenna 10)
Among the above configurations, the ground pattern 11, the patch antenna element 12, the notch portion 13, the spacer 14, the first feeding unit 15, the filter 16, the fed element 21, and the parasitic element 22 constitute the first antenna 10. Next, the operation of the first antenna 10 will be described.

Since the patch antenna element 12 is about half of the first wavelength λ ₁ and is provided with a set of notches 13, the patch antenna element 12 radiates a circularly polarized wave having the first frequency. Since the filter 16 is set to have a low impedance at the first few wave numbers, the ground pattern 11, the fed element 21, and the parasitic element 22 are electrically connected by the filter 16 at the first frequency. Connected. That is, for the first antenna 10, at the first frequency, in addition to the ground pattern 11, the fed element 21 and the parasitic element 22 also function as the ground.

(Operation of the second antenna 20)
The second antenna 20 includes a ground pattern 11, a fed element 21, a parasitic element 22, and a second feeding unit 23. The operation of the second antenna 20 will be described with reference to FIGS.

  The fed element 21 and the parasitic element 22 are arranged along the sides 11 b and 11 a of the ground pattern 11 which are orthogonal to each other. In other words, the longitudinal directions of the fed element 21 and the parasitic element 22 are orthogonal to each other. In addition, the powered element 21 and the parasitic element 22 are arranged so that the powered side connection point 25 and the parasitic side connection point 26 that are the ends on the ground pattern 11 side are close to each other and the open ends are separated from each other. The

  Therefore, the half line extending from the right-angled portion of the fed element 21 toward the open end does not intersect with the straight line passing through the longitudinal portion 22b of the parasitic element 22 and from the right-angled portion of the parasitic element 22 toward the open end. The extending half straight line does not intersect with the straight line passing through the longitudinal portion 21b of the fed element 21.

  For convenience of explanation, as shown in FIG. 4, in the ground pattern 11, vertices corresponding to both ends of the side 11 b where the power-supplied side connection point 25 is provided are A and B, respectively, and sides where the non-feed side connection point 26 is provided. Let vertices corresponding to both ends of 11a be B and C. Side 11a and side 11b share vertex B. The symbols A, B, and C in FIGS. 5 to 8 have the same meaning.

  FIG. 5 is a conceptual diagram for explaining the positional relationship between the power supply side connection point 25 and the non-power supply side connection point 26 on the side 11 a and the side 11 b of the ground pattern 11. As can be seen by comparing FIG. 4 and FIG. 5, among the line segments from the vertex A to the vertex C in FIG. 5, the section from the vertex A to the vertex B represents the side 11 b, and the section from the vertex B to the vertex C Represents the side 11a. The section representing the side 11a and the section representing the side 11b are actually perpendicular.

The feed-side connection point 25, the distance from the vertex C on the outer periphery of the ground pattern 11 is electrically provided in a position where the second wavelength lambda ₂ of the quarter wave. In other words, it provided one and a position of the quarter the sum of the length and the apex B to the power supply side connection point 25 a length of electrically second wavelength lambda ₂ of the sides 11a. Note that λ _{2 in} FIG. 5 represents the wavelength of the second frequency radio wave (so-called waveguide wavelength) in the ground pattern 11 shortened by the wavelength shortening effect by the substrate 2.

The non-feed side connection point 26 is provided at a position where the distance from the apex A on the outer periphery of the ground pattern 11 is electrically a quarter of the second wavelength λ ₂ . That is, the position of the passive side connection point 26, in 1 a position of a quarter the sum of the length and the apex B to the passive side connection point 26 a length of electrically second wavelength lambda ₂ sides 11b Provide.

  When the waveguide wavelength of the second frequency in the ground pattern 11 is about 117 mm, the length of one side of the ground pattern 11 is shorter than the length corresponding to a quarter of the waveguide wavelength (about 29 mm). A value, for example, 25 mm may be used. In that case, the distance from the vertex B to the power-supplied side connection point 25 may be 4 to 5 mm.

  The operation of the second antenna 20 will be described with reference to FIG. 5 and FIGS. 6 to 8 in which a current flow is added to FIG. Since the antenna has reversible transmission / reception, only the operation during transmission will be described below.

  Since the filter 16 has a high impedance at the second frequency, it can be considered that the fed element 21 and the parasitic element 22 are not electrically connected to the ground pattern 11 for the second antenna 20. Therefore, in FIG. 5 to FIG. 8, the fed element 21 and the parasitic element 22 and the sides 11 a and 11 b of the ground pattern 11 are separated from each other.

  At the time of transmitting the radio wave of the second frequency, as shown in FIG. 6, a high-frequency current corresponding to the second frequency is supplied from the second power supply unit 23 to the power-supplied element 21 and the current on the power-supplied element 21 is directed toward the open end. I1 flows. An image current I2 is induced near the edge of the ground pattern 11, that is, near the outer periphery, by the current I1 flowing through the powered element 21. The image current I2 is induced in a direction from the vertex A toward the non-feed side connection point 26 along the side 11b.

Note that the image current can also be induced by the current I1 in the outer peripheral portion of the ground pattern 11 other than the sides 11b and 11a, for example, the opposite side of the side 11a of the ground pattern 11. However, since the electrical length from the vertex A to the non-feed side connection point 26 is a quarter wavelength of the second wavelength λ ₂ , the image current I2 is supplied to the non-feed side connection point 26 and It is easy to form a standing wave with each vertex A as a node (or an antinode). Therefore, the image current I2 induced by the current I1 is mainly generated between the apex A and the non-feed side connection point 26. For the above reason, the vertex A can be regarded as the starting point of the image current I2.

The image current I <b> 2 that flows from the vertex A toward the parasitic connection point 26 flows into the parasitic element 22 from the parasitic connection point 26. The component is referred to as current I3 for convenience. Note that the phase of the current I3 flowing through the parasitic element 22 is such that the electrical length from the apex A to the parasitic connection point 26 is ¼ of the second wavelength λ ₂ , so that the current I3 flows with respect to the image current I2. Will be delayed by 90 degrees.

  Then, when the current I3 is generated on the parasitic element 22, an image current I4 is induced around the side 11a as shown in FIG. The direction of the image current I4 is the direction from the vertex C toward the power supply side connection point 25. Further, the phase of the image current I4 is delayed by 90 degrees with respect to the image current I2.

The reason why the image current I4 is mainly generated between the vertex C and the power-supplied connection point 25 is that the electrical length from the vertex C to the power-supplied connection point 25 is ¼ of the second wavelength λ _2. It is because it has become. That is, the image current I4 is generated between the vertex C and the power-supplied side connection point 25 due to the stability in the resonance state. Here, the stability of the resonance state refers to the ease of forming a standing wave node.

  In the section from the non-feed side connection point 26 to the fed side connection point 25, the image current I2 and the image current I4 overlap. Since the image current I2 and the image current I4 are currents in opposite directions, they behave so as to cancel each other.

  FIG. 8 summarizes the operation of the second antenna 20 described above. Between the vertex A of the ground pattern 11 and the power-supplied side connection point 25, an image current I2a caused by the current I1 flowing through the power-supplied element 21 flows. Further, an image current I4a whose phase is delayed by 90 degrees with respect to the image current I2a flows between the vertex C of the ground pattern 11 and the non-power-supply side connection point 26. Further, the side 11b and the side 11a where the image currents I2a and I4a are generated are at right angles as shown in FIG.

  That is, the image currents I2a and I4a are orthogonal to each other and are 90 degrees out of phase. In addition, since the amplitude of the current is approximately the same, circular polarization of the second frequency is transmitted by these image currents I2a and I4a. The circularly polarized wave having the second frequency is radiated to the side where the patch antenna element 12 is disposed in the direction perpendicular to the ground pattern 11.

(Effect of embodiment)
In the integrated antenna device 1 of this embodiment, a fed element 21 and a parasitic element 22 are arranged outside the ground pattern 11 in the same plane as the ground pattern 11. Further, the ground pattern 11 and the fed element 21 and the parasitic element 22 are connected by a filter 16. Since the filter 16 has a low impedance at the first frequency, the fed element 21 and the parasitic element 22 function as the ground of the patch antenna element 12 in addition to the ground pattern 11 for the first antenna 10.

  In addition to the ground pattern 11, the fed element 21 and the parasitic element 22 also function as the ground of the patch antenna element 12, so that the gain of the first antenna 10 is improved. FIG. 9 shows the directivity analysis result of the first antenna 10 in the integrated antenna device 1 of the present embodiment. FIG. 10 shows a directivity analysis result of the patch antenna in the comparative configuration in which the filter 16 is removed from the integrated antenna device 1 of the present embodiment.

  9 and 10, the direction from the center toward the top of the figure is the direction from the ground pattern 11 toward the patch antenna element 12. FIG. 9 shows that the gain in the upper direction is better. 9 and 10 also show that the gain of the integrated antenna device 1 of this embodiment is improved.

  In addition, since the integrated antenna device 1 of the present embodiment also includes the second antenna 20 that operates at a second frequency different from the first frequency, the integrated antenna device 1 operates at two frequencies.

  In addition, the fed element 21 and the parasitic element 22 that are elements of the second antenna 20 also function as the ground of the first antenna 10. That is, since the element of the second antenna 20 also functions as the element of the first antenna 10, the integrated antenna device 1 can be downsized.

Further, the second antenna 20 radiates circularly polarized waves by the image currents I2a and I4a flowing through the ground pattern 11 that is an element of the first antenna 10. That is, the element of the first antenna 10 also functions as the element of the second antenna 20. In addition, the lengths of the fed element 21 and the parasitic element 22 can be shorter than a quarter wavelength of the second wavelength λ ₂ . Therefore, the integrated antenna device 1 that radiates circularly polarized waves having two different frequencies can be made smaller.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to the above-mentioned embodiment, The following modification is also contained in the technical scope of this invention, Furthermore, the summary other than the following is also included. Various modifications can be made without departing from the scope. In the following description, elements having the same reference numerals as those used so far are the same as the elements having the same reference numerals in the previous embodiments unless otherwise specified. Further, when only a part of the configuration is described, the above-described embodiment can be applied to the other parts of the configuration.

<Modification 1>
The filter 16a of the above-described embodiment is a direct resonance circuit including a capacitor C and a coil L, one end of which is connected to the side 11a of the ground pattern 11. In the first modification, instead of the filter 16a, as shown in FIG. 11, a filter 116a composed of parallel lines 117 and a meander pattern 118 is provided.

  The parallel lines 117 are linear conductor patterns that are spaced apart from the side 11b of the ground pattern 11 and are parallel to the side 11b. The meander pattern 118 has one end connected to the parallel line 117 and the other end connected to the power-supplied element 21.

  The parallel line 117 functions as a capacitor by facing the side 11b of the ground pattern 11 in parallel with a gap. The meander pattern 118 functions as a coil. Therefore, this filter 116a is also an LC series resonance circuit.

  The distance between the parallel line 117 and the side 11b of the ground pattern 11, the length of the parallel line 117, the shape and size of the meander pattern 118 are determined so that the resonance frequency of the filter 116a becomes the first frequency.

  11 shows the filter 116a used in place of the filter 16a in FIG. 1. Of course, this filter 116a can be used instead of the filters 16b to 16d.

  Both the parallel line 117 and the meander pattern 118 are formed of a conductor pattern. Therefore, in the configuration of the first modification, when forming the ground pattern 11, the fed element 21, and the parasitic element 22 on the substrate 2, the filter 116 a can be formed at the same time.

<Modification 2>
A filter 216 shown in FIG. 12 can also be used. A filter 216 shown in FIG. 12 includes parallel lines 217 and two coils 218. The length of the parallel line 217 is close to the length of the side 11 b of the ground pattern 11, and is parallel to the side 11 b of the ground pattern 11 and the longitudinal portion 21 b of the fed element 21. One of the two coils 218 connects one end of the parallel line 217 and the longitudinal portion 21 b of the fed element 21. The other coil 218 connects the other end of the parallel line 217 and the longitudinal portion 21 b of the fed element 21.

<Modification 3>
Further, as shown in FIG. 12 described above, the second antenna 200 may include only the fed element 21 and may not include the parasitic element 22. The second antenna 200 radiates linearly polarized waves.

<Modification 4>
In the above-described embodiment, the electrical length from the vertex C to the fed-side connection point 25 and the electrical length from the vertex A to the non-feeding side connection point 26 are each equal to a quarter of the second wavelength λ ₂ . However, the present invention is not limited to this. As another aspect, the electrical length from the vertex C to the fed-side connection point 25 and the electrical length from the vertex A to the non-feed-side connection point 26 are ¼ of the second wavelength λ ₂ . For example, it may be a length corresponding to a half or a third of the second wavelength λ ₂ .

<Modification 5-10>
In the embodiments and modifications described so far, the fed element 21 and the parasitic element 22 that are the antenna elements of the second antenna 20 are parallel to the sides of the ground pattern 11. Need not be parallel to the sides of the ground pattern 11. For example, the antenna element of the second antenna is a linear element having a linear shape, and an arrangement in which the distance from the ground pattern 11 increases as it goes from one end to the other end, and conversely, an arrangement in which the distance decreases. (Modification 5).

  The antenna element of the second antenna may be a linear element having a plurality of bending points (Modification 6).

  The ground pattern does not need to be square, and may be a ground pattern having a shape other than a square, a polygon other than a rectangle, a perfect circle, an ellipse, or the like (Modification 7).

  Also, a filter other than the LC series resonance circuit can be used as the filter. Since it is only necessary that the first antenna has a low impedance at the frequency used, a high-pass filter that has a low impedance at the first frequency when the first frequency is higher than the second frequency is the same as in the above-described embodiment. You may comprise a parallel resonant circuit etc. (modification 8).

  The first frequency may be lower than the second frequency (Modification 9). In that case, even if only the coil is used, a filter having a low impedance at the first frequency and a high impedance at the second frequency can be configured (Modification 10). Further, the first antenna 10 may be a patch antenna that does not include the cutout portion 13 and radiates linearly polarized waves (Modification 11).

<Modification 12>
Further, as in the above-described embodiment, the filters 16a and 16b that connect the power-supplied element 21 and the ground pattern 11 and the filters 16c and 16d that connect the parasitic element 22 and the ground pattern 11 are provided. It is preferable. However, only one of the elements between the fed element 21 and the ground pattern 11 and between the parasitic element 22 and the ground pattern 11 may be connected by the filter 16. Even in this case, the effect of making the area functioning as the ground larger than that of the ground pattern 11 can be obtained.

<Modification 13>
In the above-described embodiment, the patch antenna element 12 is disposed on the same side of the substrate 2 as the ground pattern 11, the powered element 21, the parasitic element 22, and the like. However, the present invention is not limited to this, and the patch antenna element 12 may be disposed on one surface of the substrate 2, and the ground pattern 11, the fed element 21, the parasitic element 22, and the like may be disposed on the other surface.

<Modification 14>
If the powered element 21 and the parasitic element 22 that are the second antenna elements are arranged outside the ground pattern 11, the effect of increasing the ground can be obtained. Therefore, the ground pattern 11, the fed element 21 and the parasitic element 22 are not necessarily arranged on the same plane. For example, the powered element 21 and the parasitic element 22 may be disposed on the surface of the substrate 2 opposite to the side on which the ground pattern 11 is disposed.

DESCRIPTION OF SYMBOLS 1: Integrated antenna apparatus 2: Board | substrate 10: 1st antenna 11: Ground pattern 12: Patch antenna element 13: Notch part 14: Spacer 15: 1st electric power feeding part 16: Filter 20: 2nd antenna, 21: Power-fed element, 21a: Short part, 21b: Long part, 22: Parasitic element, 22a: Short part, 22b: Long part, 23: Second feeding part, 25: Powered side Connection point, 26: non-feed side connection point, 116a: filter, 117: parallel line, 118: meander pattern, 200: second antenna, 216: filter, 217: parallel line, 218: coil

Claims (8)

A first antenna (10) comprising a flat plate-like first antenna element (12) and a ground pattern (11) disposed opposite to the first antenna element;
A second antenna element (21, 22) disposed outside the ground pattern, and a second antenna (20) having a different operating frequency from the first antenna;
An integrated antenna apparatus comprising: a filter (16, 116, 216) that connects the ground pattern and the second antenna element and has a low impedance at a use frequency of the first antenna. In claim 1,
The use frequency of the first antenna is higher than the use frequency of the second antenna,
The integrated antenna device according to claim 1, wherein the filter has a characteristic of having a low impedance at a use frequency of the first antenna and a high impedance at a use frequency of the second antenna. In claim 2,
The integrated antenna device according to claim 1, wherein the filter is an LC series resonance circuit having a use frequency of the first antenna as a resonance frequency. In any one of Claims 1-3,
The second antenna element is a linear element,
An integrated antenna device comprising a plurality of the filters for connecting the ground pattern and the second antenna element at a base portion and a tip portion of the second antenna element, respectively. In claim 3,
The filters (116, 216)
Conductor patterns (117, 217) parallel to the sides of the ground pattern at intervals,
An integrated antenna apparatus comprising: a coil (118, 218) having one end connected to the conductor pattern and the other end connected to the second antenna element. In claim 5,
An integrated antenna comprising two coils (218), wherein one of the coils is connected to one end of the conductor pattern, and the other coil is connected to the other end of the conductor pattern. apparatus. In claim 5,
The integrated antenna device according to claim 1, wherein the coil is formed of a meander pattern (118). In any one of Claims 1-7,
The second antenna element is a linear element that is fed at one end and has an open end at the other end, and a fed element (21) that is a linear element and has one end connected to the ground pattern. And a parasitic element (22) whose other end is an open end,
The second antenna further includes a feeding part (23) provided between the fed element and the ground pattern,
The power-supplied element is provided with a power-supplied side facing portion (21b) that faces the ground pattern and moves away from the power-feeding portion toward the open end.
The parasitic element is provided with a parasitic side facing portion (22b) that faces the ground pattern and moves away from the feeding portion toward the open end,
The position of the parasitic element connected to the ground pattern is such that the phase of the image current that flows to the edge of the ground pattern by flowing current from the power feeding unit to the powered element is from the start point of the image current. It is a position shifted by an integer multiple of 90 degrees,
One or a plurality of the filters are provided, and at least one of the fed-side facing portion and the ground pattern and at least one of the non-feeding-side facing portion and the ground pattern are connected. Antenna device.

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