JP4878000B2 - Antenna device - Google Patents

Description

  The present invention relates to an antenna device, and more particularly to an antenna device provided with a loop antenna.

  Conventionally, indoor antenna devices for receiving television broadcasts include a rod antenna for receiving radio waves of VHF (Very High Freguency) television broadcasts and a loop antenna for receiving radio waves of UHF (Ultra High Freguency) television broadcasts. Is provided.

The directivity of the rod antenna is adjusted by extending and contracting and rotating the rod antenna. As a method for adjusting the directivity of the loop antenna, a first method for changing the direction of the case itself in which the loop antenna is accommodated (for example, see Patent Document 1), a second method for rotating the loop antenna by a rotation mechanism, There is a third method for electrically combining radio waves received by a pair of orthogonally arranged loop antennas (see, for example, Patent Document 2).
JP 2005-31960 A JP-A-10-242736

  However, in the first conventional method, it is necessary to manually change the direction of the case. For example, when the case also serves as a photo frame, the case does not always face the front after adjusting the directivity. Convenience is bad.

  In the second method, there is a problem that the case becomes large when the rotating loop antenna is accommodated in the case. In addition, since a rotation mechanism for rotating the loop antenna is provided, the device configuration becomes complicated and the cost increases.

  In the third method, when a pair of orthogonal loop antennas are accommodated in the case, there is a problem that the case becomes large. In addition, since a synthesizing device for synthesizing the received radio waves of the pair of loop antennas is provided, the device configuration becomes complicated and the cost increases.

  Therefore, a main object of the present invention is to provide a small antenna device capable of directivity control.

  The antenna device according to the present invention includes a pair of loop antennas arranged orthogonally and formed in a bowl shape when viewed from above or below.

Each loop antenna is provided with a metal line from one side of the center point of the upper or lower side of the rectangle to the other side of the center point through the outer periphery of the rectangle, and each part corresponding to the upper and lower sides of the rectangle among the metal lines One end of each of the two is bent in one direction substantially perpendicular to the rectangle and the other end is bent in the other direction substantially perpendicular to the rectangle.

The antenna device further includes first and second feed points provided at one end and the other end of one loop antenna of the pair of loop antennas, and the other of the pair of loop antennas. Third and fourth feeding points provided at one end and the other end of the loop antenna, two output terminals for outputting received radio waves, and first to fourth directivity of the antenna device are different from each other. And switching means for switching in the direction. When the directivity is controlled in the first direction, the switching means connects the first and third feeding points to one of the two output terminals and the second and fourth feeding points. Is connected to the other output terminal and the directivity is controlled in the second direction, the third and fourth feed points are connected to the two output terminals, respectively, and the directivity is controlled in the third direction. In this case, the first and fourth feeding points are connected to one of the two output terminals, the second and third feeding points are connected to the other output terminal, and the directivity is set to the fourth. When controlling in the direction, each of the first and second feeding points is connected to two output terminals.

The antenna device further includes a rectangular parallelepiped housing that accommodates a pair of loop antennas, and portions of the pair of loop antennas that correspond to the left and right sides of the rectangle are arranged at the four corners of the housing. The means is a switch that can be switched from outside the housing.
Preferably, the switch is formed on an insulating substrate having first to fourth regions corresponding to the first to fourth cases, and is formed on the surface of the insulating substrate across the first to fourth regions, respectively. 1st to 4th wirings connected to 1st to 4th feeding points and 5th and 5th formed on the surface of the insulating substrate across the 1st to 4th regions, respectively connected to two output terminals A sixth wiring, a plurality of first electrodes distributed in the first to fourth regions, each connected to any one of the first to fourth wirings, and the first to first 4 are disposed in each of the four regions, and are slidably provided along the first to sixth wirings, and the second and third electrodes respectively connected to the fifth and sixth wirings. And a slider disposed in the first to fourth regions in the fourth case. The slider includes a first slider that short-circuits each first electrode and second electrode in a region where the slider is disposed, and each first electrode and third electrode in a region where the slider is disposed. And a second slider that short-circuits.

  In the antenna device according to the present invention, a pair of loop antennas are arranged orthogonally and formed in a bowl shape when viewed from above or below, so that the received radio waves of each loop antenna can be used independently or a pair of loop antennas. The directivity of the antenna device can be switched in four directions depending on whether the received radio waves are synthesized and used. In addition, since the pair of loop antennas is formed in a bowl shape, the size of the apparatus can be reduced. Further, the cost can be reduced by switching the directivity with a switch.

  FIG. 1 is a perspective view showing a main part of an indoor antenna apparatus for receiving a television broadcast according to an embodiment of the present invention. In FIG. 1, the indoor antenna apparatus includes a pair of loop antennas 1 and 2 arranged orthogonally. The loop antennas 1 and 2 are provided for receiving UHF broadcasting.

  The loop antennas 1 and 2 are formed in a bowl shape when viewed from above. That is, as shown in FIG. 2, the loop antenna 1 is centered from one side of the center point of the lower side of the rectangle 3 having a width of about 140 mm, a height of about 160 mm, and a peripheral length of about 600 mm through the outer periphery of the rectangle 3. A metal line ML extending to the other side of the point is provided, and a portion of about 35 mm from one end corresponding to the upper side and the lower side of the rectangle 3 of the metal line ML is bent in one direction substantially perpendicular to the rectangle 3. In addition, a portion of about 35 mm from the other end is bent in the other direction substantially perpendicular to the rectangle 3. The space | interval of the part corresponding to the left side and the right side of the rectangle 3 among the metal lines ML is about 99 mm. The loop antenna 2 also has the same shape and dimensions as the loop antenna 1.

  If the perimeter of each of the loop antennas 1 and 2 is about 600 mm, the perimeter of the 470 MHz radio wave of the 470 to 770 MHz UHF band is 0.94 wavelength, and the perimeter of the 770 MHz radio wave The peripheral length is 1.5 wavelengths, and the amplitude of the current standing wave can be increased to obtain a high gain over the entire UHF band.

  FIG. 3 is a view of a portion of the loop antennas 1 and 2 corresponding to the lower side of the rectangle 3 as viewed from above. In FIG. 3, the centers of the loop antennas 1 and 2 are arranged at the origin O on the horizontal plane, the direction perpendicular to the center of the loop antenna 1 is 0 degree, and the direction perpendicular to the center of the loop antenna 2 is 90 degrees. To do.

  The loop antenna 1 includes two L-shaped antenna pieces 1a and 1b. The antenna pieces 1a and 1b are arranged on the left and right of the origin O. One side of the antenna piece 1a extends in the 270 degree direction, and the other side extends in the 180 degree direction. One side of the antenna piece 1b extends in the 90 degree direction, and the other side extends in the 0 degree direction. Feed points P1 and P2 are provided at the ends on the origin O side of the antenna pieces 1a and 1b, respectively.

  The loop antenna 2 includes two L-shaped antenna pieces 2a and 2b. The antenna pieces 2a and 2b are arranged before and after the origin O. One side of the antenna piece 2a extends in the 0 degree direction, and the other side extends in the 270 degree direction. One side of the antenna piece 2b extends in the direction of 180 degrees, and the other side extends in the direction of 90 degrees. Feed points P3 and P4 are provided at the ends on the origin O side of the antenna pieces 2a and 2b, respectively.

  In addition, as shown in FIG. 4, the indoor antenna apparatus includes output terminals T1 and T2 for supplying radio waves received by the loop antennas 1 and 2 to a television receiver, feed points P1 to P4, and an output terminal T1. And a switch 4 provided between T2 and T2. The switch 4 is used to switch the directivity of the indoor antenna device in four directions.

  FIGS. 5A to 5H are diagrams illustrating a directivity control method of the indoor antenna device. As shown in FIGS. 5 (a) and 5 (b), when the 8-shaped directivity of the indoor antenna device is directed to the 0 degree direction (front) and the 180 degree direction (rear), the feeding points P1 and P3 are output by the switch 4. In addition to being connected to the terminal T1, the feeding points P2 and P4 are connected to the output terminal T2. The radio waves transmitted from the 0 degree direction and the 180 degree direction are received by the portion A of the loop antennas 1 and 2 facing the 0 degree direction and the 180 degree direction and supplied to the output terminals T1 and T2. Therefore, the directivity of the indoor antenna device is an 8-character directivity that maximizes the reception sensitivity in the 0 degree direction and the 180 degree direction, as shown in FIG. 5B.

Also, as shown in FIGS. 5C and 5D, when the directivity of the indoor antenna device is directed to the 45 degree direction (right diagonally forward) and the 225 degree direction (left diagonally backward), the feeding point is switched by the switch 4. P3 and P4 are connected to output terminals T 1 and T 2 , respectively. The radio waves transmitted from the 45 degree direction and the 225 degree direction are received by the portion B of the loop antennas 1 and 2 facing the 45 degree direction and the 225 degree direction and supplied to the output terminals T1 and T2. Therefore, the directivity of the indoor antenna device is 8-character directivity that maximizes the reception sensitivity in the 45-degree direction and the 225-degree direction, as shown in FIG.

  Also, as shown in FIGS. 5 (e) and 5 (f), when the 8-shaped directivity of the indoor antenna device is directed in the 90 degree direction (right lateral direction) and 270 degree direction (left lateral direction), the feeding point is switched by the switch 4. P1 and P4 are connected to the output terminal T1, and feed points P2 and P3 are connected to the output terminal T2. The radio waves transmitted from the 90 degree direction and the 270 degree direction are received by the portion C of the loop antennas 1 and 2 facing the 90 degree direction and the 270 degree direction and supplied to the output terminals T1 and T2. Therefore, the directivity of the indoor antenna device is an 8-character directivity that maximizes the reception sensitivity in the 90-degree direction and the 270-degree direction, as shown in FIG.

  As shown in FIGS. 5 (g) and 5 (h), when the 8-shaped directivity of the indoor antenna device is directed to the 135 degree direction (right diagonally rearward) and the 315 degree direction (left diagonally forward), the feeding point is switched by the switch 4. P1 and P2 are connected to output terminals T1 and T2, respectively. The radio waves transmitted from the 135 degree direction and the 315 degree direction are received by the portion D of the loop antennas 1 and 2 facing the 135 degree direction and the 315 degree direction and supplied to the output terminals T1 and T2. Therefore, the directivity of the indoor antenna device is 8-character directivity that maximizes the reception sensitivity in the 135 degree direction and the 315 degree direction, as shown in FIG.

  FIG. 6 is a diagram illustrating a main part of the switch 4. In FIG. 6, the switch 4 includes an insulating substrate 10. On the surface of the insulating substrate 10, four input terminals 11 to 14, a plurality of electrodes 15, and two output terminals 16 and 17 are formed. Input terminals 11-14 are connected to feed points P1-P4, respectively. The output terminals 16 and 17 are connected to the output terminals T1 and T2, respectively.

  The central portion of the insulating substrate 10 is divided into four regions 10a to 10d, and each of the four regions 10a to 10d is divided into sub-regions of 5 rows and 2 columns. The four areas 10a to 10d correspond to the four switching states shown in FIGS. The two sub-regions in each region correspond to the output terminals T1 and T2, respectively.

  In the right column in the drawing of the region 10a, the electrodes 15 are formed in the subregions in the first, third and fourth rows, and in the left column, the electrodes 15 are formed in the subregions in the second, third and fifth rows. Yes. In the right column in the drawing of the region 10b, the electrodes 15 are formed in the subregions of the third and fourth rows, and in the left column, the electrodes 15 are formed in the subregions of the third and fifth rows. In the right column in the drawing of the region 10c, the electrodes 15 are formed in the subregions in the first, third and fifth rows, and in the left column, the electrodes 15 are formed in the subregions in the second, third and fourth rows. Yes. In the right column in the drawing of the region 10d, electrodes 15 are formed in the first and third row subregions, and in the left column, the electrodes 15 are formed in the second and third row subregions.

  The three electrodes 15 in the first row are all connected to the input terminal 11. The three electrodes 15 in the second row are all connected to the input terminal 12. Of the eight electrodes 15 in the third row, four electrodes in the right column are connected to the output terminal 16, and four electrodes in the left column are connected to the output terminal 17. The three electrodes 15 in the fourth row are all connected to the input terminal 13. The three electrodes 15 in the fifth row are all connected to the input terminal 14.

  Moreover, the switch 4 includes a slider 20 and two sliders 21 and 22 as shown in FIGS. The slider 20 is provided so as to be movable in the row direction (left-right direction in the figure) above the insulating substrate 10 shown in FIG. Each of the sliders 21 and 22 is formed of an elastic metal plate and is fixed to the lower surface of the slider 20. The slider 21 is provided to short-circuit the electrodes 15 in the right column of each region, and the slider 22 is provided to short-circuit the electrodes 15 in the left column of each region. Therefore, the slider 21 is provided with five contact points 21a corresponding to five rows, and the slider 22 is provided with five contact points 22a corresponding to five rows.

  7A and 7B show a state where the slider 20 is positioned above the region 10a. In FIG. 7A, the contacts 21a and 22a of the sliders 21 and 22 are in contact with the two electrodes 15 in the third row. In FIG. 7B, the three contact points 21 a of the slider 21 are in contact with the electrodes 15 in the first, third, and fifth rows, respectively, and these electrodes 15 are short-circuited by the slider 21.

  FIGS. 8A to 8D are diagrams illustrating the operation of the switch 4. Note that the electrode 15 is omitted as appropriate for simplification of the drawing. In the case where the 8-shaped directivity of the indoor antenna device is oriented in the 0 degree direction and the 180 degree direction, the slider 20 is set above the region 10a. As a result, as shown in FIG. 8A, the electrodes 15 in the first, third, and fourth rows in the right column of the region 10a are short-circuited by the slider 21, and the feeding points P1, P3 and the output terminal T1 are connected. Is done. Further, the electrodes 15 in the second, third and fifth rows in the left column of the region 10a are short-circuited by the slider 22, and the feeding points P2 and P4 and the output terminal T2 are connected.

  In addition, when the 8-shaped directivity of the indoor antenna device is directed to the 45 ° direction and the 225 ° direction, the slider 20 is set above the region 10b. As a result, as shown in FIG. 8B, the electrodes 15 in the third and fourth rows in the right column of the region 10b are short-circuited by the slider 21, and the feeding point P3 and the output terminal T1 are connected. Further, the electrodes 15 in the third and fifth rows in the left column of the region 10b are short-circuited by the slider 22, and the feeding point P4 and the output terminal T2 are connected.

  In addition, when the 8-shaped directivity of the indoor antenna device is directed to the 90 ° direction and the 270 ° direction, the slider 20 is set above the region 10c. As a result, as shown in FIG. 8C, the electrodes 15 in the first, third and fifth rows in the right column of the region 10c are short-circuited by the slider 21, and the feeding points P1 and P4 and the output terminal T1 are connected. Is done. Further, the electrodes 15 in the second, third and fourth rows in the left column of the region 10c are short-circuited by the slider 22, and the feeding points P2 and P3 and the output terminal T2 are connected.

  Further, when the eight-character directivity of the indoor antenna device is directed to the 135 degree direction and the 315 degree direction, the slider 20 is set above the region 10d. As a result, as shown in FIG. 8D, the electrodes 15 in the first and third rows in the right column of the region 10d are short-circuited by the slider 21, and the feeding point P1 and the output terminal T1 are connected. Further, the electrodes 15 in the second and third rows in the left column of the region 10d are short-circuited by the slider 22, and the feeding point P2 and the output terminal T2 are connected. Therefore, in this embodiment, directivity can be switched in four directions with a simple configuration.

  FIG. 9 is a perspective view showing the overall configuration of the indoor antenna device 30. In FIG. 9, the indoor antenna device 30 includes a plastic rectangular parallelepiped case 31. The case 31 includes a right cover part 31a, a central part 31b, a left cover part 31c, and a pedestal 31d, and is designed to be seen as a speaker as a whole. The slider 20 of the switch 4 is provided on the front surface of the central portion 31b of the case 31 so that the directivity can be switched from the outside. On the upper surface of the case 31, the tip portions of rod antennas 32 and 33 for receiving VHF broadcasts protrude.

  FIG. 10 is a view showing a state in which the rod antennas 32 and 33 are drawn out of the case 31 and extended. The rod antenna 32 includes a plurality of stages of cylindrical antenna elements having different thicknesses, and the second and subsequent stages can be accommodated in the first stage of the cylindrical antenna element. The first stage cylindrical antenna element of the rod antenna 32 is fixed vertically in the case 31. A rotating member 32a is provided at the base end of the second-stage cylindrical antenna element, and the rotating member 32a is provided so as to be slidable in the first-stage cylindrical antenna element together with the second-stage cylindrical antenna element. ing.

  In a state where the second-stage cylindrical antenna element is pulled out from the first-stage cylindrical antenna element, the rotating member 32a includes a distal end portion of the first-stage cylindrical antenna element and a proximal end portion of the second-stage cylindrical antenna element. And the second-stage cylindrical antenna element is rotatably supported. The rod antenna 33 has the same configuration as the rod antenna 32, and a rotating member 33a is provided between the first-stage cylindrical antenna element and the second-stage cylindrical antenna element, and the second-stage cylindrical antenna is provided. The element is rotatably supported by a rotation member 33a.

  FIG. 11 is a diagram illustrating a state where the right cover portion 31a of the case 31 is removed. In FIG. 11, a case 31 contains loop antennas 1 and 2, a switch 4, rod antennas 32 and 33, and an amplifier 34 for amplifying the received radio wave and supplying it to a television receiver. .

  FIG. 12 is a diagram illustrating only the loop antennas 1 and 2, the rod antennas 32 and 33, the left cover portion 31 c, and the pedestal 31 d of the indoor antenna device 30. FIG. 13 illustrates the loop antennas 1 and 2, the rod antenna. It is a figure which shows only 32 and 33 and the base 31d. 12 and 13, portions of the loop antennas 1 and 2 corresponding to the left and right sides of the rectangle 3 in FIG. 2 (portions extending in the vertical direction) are arranged at the four corners of the case 31. Each of the rod antennas 32 and 33 is disposed between the loop antennas 1 and 2. Thereby, size reduction of the case 31 is achieved.

  The indoor antenna device 30 can be used as an outdoor antenna device by performing a waterproof treatment. Further, instead of the slide-type switch 4, a rotary switch or a mechanical switch may be used.

  Fig.14 (a) is a figure which shows the comparative example 1 of this embodiment. In FIG. 14A, the width of the loop antenna 40 is about 140 mm, its height is about 160 mm, and its peripheral length is about 600 mm. That is, the loop antenna 40 has the same dimensions as the rectangle 3 shown in FIG. 2, and the bent portion of the loop antenna 1 is linear. As shown in FIG. 15, the center frequency of the gain of the loop antenna 40 is 620 MHz, and a high gain is obtained in the entire HF band of 470 to 770 MHz. However, as shown in FIG. 14B, when the two loop antennas 40 are arranged orthogonally, the volume of the case that accommodates them is at least about 99 mm × 99 mm × 160 mm.

  On the other hand, in the present invention, the volume of the case that accommodates the loop antennas 1 and 2 shown in FIGS. 1 and 2 is about 70 mm × 70 mm × 160 mm. (99 × 99) ≈0.5 times. Further, as shown in FIG. 15, the center frequency of the gain of the loop antenna 1 is 650 MHz, and the difference from the center frequency of the gain of the loop antenna 40 is only 30 MHz.

  FIG.14 (c) is a figure which shows the comparative example 2 of this embodiment. In FIG. 14C, the loop antenna 41 has a width of about 99 mm and a height of about 160 mm. As shown in FIG. 14D, when the two loop antennas 41 are arranged orthogonally, the volume of the case that accommodates them is about 70 mm × 70 mm × 160 mm, which is the same as the present invention. However, since the circumference of the loop antenna 41 is shorter than 600 mm, the center frequency of the gain of the loop antenna 41 is 710 MHz as shown in FIG. 15, and the difference from the center frequency of the gain of the loop antenna 40 is 90 MHz. Became. Therefore, according to the present invention, it is possible to reduce the size of the apparatus while maintaining a relatively high gain.

  FIG. 16 is a diagram showing a modified example of this embodiment, and is compared with FIG. Referring to FIG. 16, this indoor antenna device is different from the indoor antenna device of FIG. 3 in that each of loop antennas 1 and 2 is bent in the opposite direction to FIG. That is, one side of the L-shaped antenna piece 1a of the loop antenna 1 extends in the 270 degree direction, and the other side extends in the 0 degree direction. One side of the antenna piece 1b extends in the direction of 90 degrees, and the other side extends in the direction of 180 degrees. One side of the L-shaped antenna piece 2a of the loop antenna 2 extends in the 0 degree direction, and the other side extends in the 90 degree direction. One side of the antenna piece 2b extends in the direction of 180 degrees, and the other side extends in the direction of 270 degrees. Note that the loop antennas 1 and 2 of this modified example have a bowl shape when viewed from below. Even in this modified example, the same effect as the embodiment can be obtained.

  It goes without saying that the same effect can be obtained even if the loop antennas 1 and 2 of FIG.

  FIG. 17 is a diagram showing another modification of this embodiment, and is a diagram contrasted with FIG. Referring to FIG. 17, this indoor antenna device is different from the indoor antenna device of FIG. 3 in that the lengths in the directions of 0 degrees and 180 degrees are longer than the lengths in the directions of 90 degrees and 270 degrees.

  18A to 18H are diagrams showing the directivity of the modified example shown in FIG. 17, and are diagrams for comparison with FIG. As shown in FIGS. 18A and 18B, when the feed points P1 and P3 are connected to the output terminal T1, and the feed points P2 and P4 are connected to the output terminal T2, the directivity of the indoor antenna device is as shown in FIG. As shown in (b), the 8-character directivity that maximizes the reception sensitivity in the 0 degree direction and the 180 degree direction is obtained.

  Also, as shown in FIGS. 18C and 18D, when the feed points P3 and P4 are connected to the output terminals T2 and T1, respectively, the directivity of the indoor antenna device is 45 degrees as shown in FIG. In the direction shifted 90 degrees and 270 degrees from the direction and the 225 degrees direction, the reception sensitivity becomes the maximum eight-character directivity. The direction of the 8-character directivity at this time is determined by the ratio of the vertical and horizontal lengths of the loop antennas 1 and 2 in FIG.

  As shown in FIGS. 18E and 18F, when the feeding points P1 and P4 are connected to the output terminal T1, and the feeding points P2 and P3 are connected to the output terminal T2, the directivity of the indoor antenna device is as shown in FIG. As shown in FIG. 18 (f), the 8-character directivity that maximizes the reception sensitivity is obtained in the 90-degree direction and the 270-degree direction.

  Further, as shown in FIGS. 18 (g) and (h), when the feeding points P1 and P2 are connected to the output terminals T1 and T2, respectively, the directivity of the indoor antenna device is 135 degrees as shown in FIG. 18 (h). In the direction shifted by 90 degrees and 270 degrees from the direction and 315 degrees, the 8-character directivity is maximized. The direction of the 8-character directivity at this time is determined by the ratio of the vertical and horizontal lengths of the loop antennas 1 and 2 in FIG. Even in this modified example, the same effect as the embodiment can be obtained. In this modified example, as shown in FIG. 17, the lengths of the loop antennas 1 and 2 in the directions of 0 degrees and 180 degrees are longer than the lengths in the directions of 90 degrees and 270 degrees. It goes without saying that the same effect can be obtained even if the lengths in the 90 ° and 270 ° directions of 1, 2 are made longer than the lengths in the 0 ° and 180 ° directions.

  In this embodiment, the case where the present invention is applied to an indoor antenna apparatus that receives UHF broadcasting has been described. However, the present invention can also be applied to an antenna apparatus that receives radio waves of frequencies other than UHF.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a figure which shows the principal part of the indoor antenna apparatus by one embodiment of this invention. It is a figure which shows the shape and dimension of the loop antenna shown in FIG. It is a figure which shows the lower end part of a pair of loop antenna shown in FIG. It is a figure which shows the switch contained in the indoor antenna apparatus demonstrated in FIG. It is a figure which shows the method of controlling the directivity of the indoor antenna apparatus demonstrated in FIG. It is a figure which shows the principal part of the switch shown in FIG. It is another figure which shows the principal part of the switch shown in FIG. It is a figure which shows operation | movement of the switch shown in FIG. 6 and FIG. It is a perspective view which shows the whole structure of the indoor antenna apparatus shown in FIGS. It is a figure which shows the state which extended the rod antenna shown in FIG. FIG. 10 is a diagram illustrating a state where a right cover portion of the case illustrated in FIG. 9 is removed. It is a figure which shows the state which removed the center part etc. of the case shown in FIG. It is a figure which shows the state which removed the left side cover part etc. of the case shown in FIG. It is a figure which shows the comparative example of this embodiment. It is a figure which compares the comparative example shown in FIG. 14, and the gain of this invention. It is a figure which shows the example of a change of this embodiment. It is a figure which shows the other example of a change of this embodiment. It is a figure which shows the method of controlling the directivity of the example of a change shown in FIG.

Explanation of symbols

  1, 2, 40, 41 Loop antenna, 1a, 1b, 2a, 2b Antenna piece, 3 rectangle, P1-P4 feed point, ML metal wire, 4 switch, T1, T2 output terminal, 10 insulating substrate, 11-14 input Terminals, 15 electrodes, 16 and 17 output terminals, 20 sliders, 21 and 22 sliders, contacts 21a and 22a, 30 indoor antenna devices, 31 case, 31a right side cover part, 31b center part, 31c left side cover part, 31d base 32, 33 Rod antenna, 32a, 33a Rotating member, 34 Amplifier.

Claims (2)

A pair of loop antennas arranged orthogonally and formed in a bowl shape when viewed from above or below ,
Each loop antenna is provided with a metal line extending from one side of the center point of the upper side or the lower side of the rectangle to the other side of the center point through the outer periphery of the rectangle, and on the upper side and the lower side of the rectangle of the metal line A shape in which one end of each corresponding part is bent in one direction substantially perpendicular to the rectangle and the other end is bent in the other direction substantially perpendicular to the rectangle;
And a first feeding point and a second feeding point respectively provided at one end and the other end of one of the pair of loop antennas;
A third feeding point and a fourth feeding point respectively provided at one end and the other end of the other loop antenna of the pair of loop antennas;
Two output terminals for outputting received radio waves,
Switching means for switching the directivity of the antenna device to different first to fourth directions;
The switching means is
In the first case where the directivity is controlled in the first direction, the first and third feeding points are connected to one of the two output terminals, and the second and fourth points are connected. Is connected to the other output terminal,
In the second case of controlling the directivity in the second direction, the third and fourth feeding points are respectively connected to the two output terminals,
In the third case where the directivity is controlled in the third direction, the first and fourth feeding points are connected to one output terminal of the two output terminals, and the second and third points are connected. Is connected to the other output terminal,
In the fourth case where the directivity is controlled in the fourth direction, the first and second feeding points are respectively connected to the two output terminals,
Furthermore, a rectangular parallelepiped housing containing the pair of loop antennas is provided,
Of the pair of loop antennas, portions corresponding to the left and right sides of the rectangle are arranged at the four corners of the casing,
It said switching means Ru switchable switch der from the outside of the housing, the antenna device. The switch is
An insulating substrate having first to fourth regions respectively corresponding to the first to fourth cases;
First to fourth wirings formed on the surface of the insulating substrate over the first to fourth regions, respectively connected to the first to fourth feeding points;
Fifth and sixth wirings formed on the surface of the insulating substrate across the first to fourth regions, each connected to the two output terminals;
A plurality of first electrodes distributed in the first to fourth regions, each connected to any one of the first to fourth wires;
Second and third electrodes disposed in each of the first to fourth regions and respectively connected to the fifth and sixth wirings;
A slider provided slidably along the first to sixth wirings, and arranged in the first to fourth regions in the first to fourth cases, respectively.
The slider is
A first slider for short-circuiting each first electrode and the second electrode in a region where the slider is disposed;
The antenna device according to claim 1, further comprising: a second slider that short-circuits each first electrode and the third electrode in a region where the slider is disposed .

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