JP4118215B2 - Radio transmitter - Google Patents

Description

  The present invention relates to a radio wave transmitter, and more particularly to improvement of directivity characteristics of an antenna.

  In recent years, wireless systems including radio transmitters and radio receivers used at a distance of several meters have been widely used, and keyless entry systems and wireless LANs for automobiles are well known. The keyless entry system is a control system for opening and closing the door of an automobile, and includes a keyless entry receiver mounted on the vehicle side and a keyless entry transmitter owned by the driver. The keyless entry transmitter transmits a transmission signal whose modulation signal is an ID code or an operation command code assigned to each transmitter. When the keyless entry receiver receives the transmission signal, the keyless entry transmitter demodulates the transmission signal, It is determined whether the transmission is from a paired keyless entry transmitter. If the determination is affirmative, a control signal corresponding to the operation command code is output to the control ECU of each part of the vehicle to open / close the door and start the engine . As such a keyless entry system, those using weak radio waves in the 300 MHz band are the mainstream.

  Generally, a keyless entry transmitter is built in a key or in a key holder that is separate from the key. In either case, the shape is small and thin, about 30 mm × 30 mm × 5 mm. As a structure of such a small radio wave transmitter, a main body housed in a housing is generally composed of only one electronic board, a transmission circuit is formed on the electronic board, and the surface of the electronic board The antenna is patterned. A loop antenna is generally used as an antenna type.

  By the way, it is desirable that the reception characteristic at the mounting position of the keyless entry receiver is omnidirectional, but it exhibits complicated characteristics depending on the reception environment. In particular, in-vehicle devices such as keyless entry receivers have a dip point problem in which the vehicle is made of metal, which greatly affects radio wave propagation and the received signal becomes weak. Also, the direction in which this dip point appears is different between the two types of polarized waves of radio waves. In the loop antenna patterned on the electronic substrate, current flows only along the plate surface of the electronic substrate, and the normal direction of the surface surrounded by the loop-shaped current path is parallel to the plate thickness direction of the electronic substrate. The direction of the magnetic field generated by the loop antenna is parallel to the thickness direction of the electronic substrate. The electric field is in a direction along the current path, that is, a direction parallel to the plate surface of the electronic substrate. In addition, the ground pattern patterned on the board surface of the electronic board also emits radio waves, but since the current flowing through the ground pattern flows only along the board surface of the electronic board, the electric field is parallel to the board surface of the electronic board. It becomes. Therefore, one type of polarized wave is radiated from the radio wave transmitter.

  For this reason, if the driver does not work well as operated, the driver must move around the dip point or change the direction of the keyless entry transmitter to change the type of polarization.

  In Patent Document 1 below, as an improvement of the type of antenna that forms a pattern on the plate surface of an electronic substrate, the pattern shape is a partially broken loop shape, and the broken portion is connected by an elongated conductive plate. Is described. In the conductive plate, both end portions connected to the conductive portion with the loop pattern are bent at right angles in the same direction, and a portion excluding both end portions is floated from the plate surface of the electronic substrate. The current path is in the direction perpendicular to the plate surface at both ends as the floats. Thereby, an electric field in a direction parallel to a plane orthogonal to the plate surface of the electronic substrate is also generated to improve the directivity.

In addition, in the following Patent Document 2, as a modification of the one in Patent Document 1, instead of the conductive plate, another pattern corresponding to the discontinuous portion is provided on the plate surface opposite to the patterned plate surface. It is formed and both patterns are connected by through holes, and the through holes are used as current paths extending in a direction perpendicular to the plate surface. In this device, the use of the thickness of the electronic substrate is intended to reduce the thickness in the thickness direction.
JP-A-7-113365 Japanese Patent No. 3159185

  By the way, the effects of the techniques of both Patent Documents 1 and 2 depend on the amount of protrusion from the plate surface of the conductive plate and the thickness of the electronic substrate that defines the depth of the through hole. The amount of protrusion from the board surface must be set in consideration of the height of the components mounted on the electronic board due to the demand for a compact radio wave transmitter, and the board thickness of the electronic board is usually around 1 mm. There is only. For this reason, in the techniques of Patent Documents 1 and 2, the length of the current path extending in the thickness direction of the electronic substrate is very small compared to the wavelength of the radio wave in the UHF band used for a keyless entry system or the like. The normal direction of the surface surrounded by the loop-shaped current path is not much different from the case where the normal direction of the surface surrounded by the loop-shaped current path is the thickness direction of the electronic substrate, as in the case of a loop antenna patterned on only one plate surface of the electronic substrate. The practicality is not always sufficient.

  The present invention has been made in view of the above circumstances, and radiates polarized light of a different kind from a conventional antenna in which the normal direction of the surface surrounded by the current path of the antenna is the thickness direction of the electronic substrate with sufficient intensity. An object of the present invention is to provide a radio wave transmitter capable of performing the above.

In the invention according to claim 1, in the radio wave transmitter having an electronic substrate on which a transmission circuit is formed, and an antenna that radiates a transmission signal from the transmission circuit.
As the antenna, a current path extends substantially parallel to the plate surface of the electronic substrate and is arranged in parallel with each other in parallel in the plate thickness direction of the electronic substrate, and the two linear portions A bridging part that bridges adjacent ends of the two linear parts so that currents flow in opposite directions, and a normal direction of a surface surrounded by the linear part and the bridging part is the electron A loop antenna is provided in a direction substantially parallel to the plate surface of the substrate. Further, the ground pattern formed on the plate surface of the electronic substrate is divided into a plurality of pieces, and the adjacent ground patterns are electrically connected by an impedance element.

  The two linear portions arranged in parallel in the thickness direction of the electronic board are opposite to each other in the direction of current flow in one linear portion and the other linear portion, and are surrounded by the linear portion and the bridging portion. A loop current path is formed along the periphery of the surface. Since the normal direction of the surface is a direction substantially parallel to the plate surface of the electronic substrate, a magnetic field is generated in this direction. The electric field is generated in a direction along the current path, that is, in a direction substantially parallel to a plane orthogonal to the plate surface of the electronic substrate. Therefore, the radio wave radiated from the loop antenna is a loop antenna of a conventional radio wave receiver in which the normal direction of the surface surrounded by the loop current path is the thickness direction of the electronic substrate, or the electric field is the plate surface of the electronic substrate. The polarization pattern is different from the ground pattern formed in the direction parallel to the ground pattern.

Here, the radiant intensity of radio waves increases as the area of the surface surrounded by the loop current path increases. The length of the linear portion that defines the area depends on the planar shape of the electronic substrate, but the planar shape is larger than the thickness of the electronic substrate and the height of the mounted component. Therefore, the length of the linear portion can be made sufficiently long and the radiation intensity of the radio wave can be made sufficiently large. In addition, by adjusting the impedance of the impedance element, the current flowing in the ground pattern is adjusted by the transmission signal, the radiation intensity of the ground pattern that generates an electric field parallel to the plate surface of the electronic board is changed, and the directional characteristics are optimized can do.

  According to a second aspect of the present invention, in the configuration of the first aspect of the present invention, the linear portion is formed by patterning a conductive layer on the plate surface of the electronic substrate.

  Since it can be formed together with the wiring pattern of the transmission circuit, the manufacturing process can be simplified.

  According to a third aspect of the present invention, in the configuration of the first or second aspect of the invention, a U-shaped conductive member bent at both ends in the length direction is sandwiched between the both ends using the both ends as legs. The center portion thus fixed is fixed to the plate surface of the electronic substrate so as to float from the plate surface of the electronic substrate, the center portion constitutes the linear portion, and the both end portions constitute the bridging portion.

Since the distance between the two linear portions in the thickness direction of the electronic substrate is increased by the amount that the linear portion is lifted from the surface of the electronic substrate, the area of the surface surrounded by the linear portion and the bridging portion can be increased. it can.

  According to a fourth aspect of the present invention, in the configuration of the first to third aspects of the present invention, the linear portion or the linear portion and the bridging portion are formed by patterning a conductive layer on the inner surface of the housing for storing the electronic substrate. It becomes the composition which becomes.

  The area of the surface surrounded by the linear portion and the bridging portion can be increased by making maximum use of the inner space of the housing.

  According to a fifth aspect of the present invention, in the configuration of the first to fourth aspects of the present invention, the linear portion is arranged with the electronic substrate sandwiched in the thickness direction of the electronic substrate, and the electronic substrate is used as the bridging portion. Through-holes are provided in the plate thickness direction.

  The area of the surface surrounded by the linear portion and the bridging portion can be increased by utilizing the thickness of the electronic substrate.

According to a sixth aspect of the present invention, in the configuration of the first to fifth aspects, the two linear portions are arranged in parallel in the plate thickness direction of the electronic substrate, and a plurality of the linear portions are arranged in parallel in the plate surface direction of the electronic substrate. Place and
Each of the two linear parts arranged in parallel in the plate surface direction of the electronic substrate and corresponding to each other in a line thickness direction has a one-to-one correspondence with each end of the linear part arranged in the plate thickness direction of the electronic substrate. The bridging portion is provided, and one bridging portion of the bridging portions is used to bridge between the ends of one of the two linear portions, and the two linear portions Make a bridge between the ends of the other linear part,
In the two linear parts arranged in parallel in the plate surface direction of the electronic substrate, current flows in opposite directions to the two linear parts arranged in parallel in the plate thickness direction of the electronic board. Currents should flow in the same direction.

  Since the current path is in the form of a solenoid, the current flowing through the current path substantially increases, and the radio wave radiation intensity can be increased.

According to a seventh aspect of the present invention, in the configuration of the first to sixth aspects, the antenna is a loop antenna different from the loop antenna, and a normal direction of a surface surrounded by a current path is the electron. A loop antenna is provided in the thickness direction of the substrate.

  Since both of the two types of polarized waves can be radiated with sufficient intensity, the directivity can be further improved.

According to an eighth aspect of the present invention, in the configuration of the seventh aspect of the present invention, the another loop antenna forms a line so as to follow a peripheral portion of the electronic substrate and surround the transmission circuit with a current path.

  Compact use can be achieved by effectively using the box-shaped blank portion surrounding the transmission circuit as the formation area of the other loop antenna.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a key-integrated radio wave transmitter to which the present invention is applied. FIG. 2 shows an electronic substrate as the main body. This radio wave transmitter is a keyless entry transmitter used in a keyless entry system. In the radio wave transmitter, the grip portion 10 coupled to the key plate 14 serves as a housing for housing the electronic substrate 2 on which the transmission circuit 3 is formed. The grip portion 10 includes a lower housing 11 and an upper housing 12 made of synthetic resin, and a shallow concave portion in which the electronic substrate 2 is accommodated is formed on the opposing surface. The upper housing 12 is provided with a lock / unlock operation button 13.

  The electronic substrate 2 is generally rectangular, and a ground pattern 51 is formed by etching except for an elongated region on one short side and a peripheral portion. The following patterns other than the ground pattern 51 are similarly formed. The electronic component 301 for the transmission circuit 3 and the like are mounted in a range substantially covered by the ground pattern 51. The transmission circuit 3 includes a code generation circuit unit 31 and a high frequency circuit 32, and the high frequency circuit unit 32 is located on the side of the elongated region where the ground pattern 51 is not formed. The code generation circuit 31 includes a code generation IC 301, a switch 303, and the like. When the switch 303 is turned on, the code generation circuit 31 outputs a code signal including an ID code of the radio wave transmitter and a predetermined operation code to the high frequency circuit unit 32. The switch 303 is disposed immediately below the operation button 13 and is turned on when the driver presses the operation button 13. The high frequency circuit unit 32 includes a modulation IC 302 and the like. The high frequency circuit unit 32 modulates a carrier signal in the 300 MHz band using the code signal from the code generation circuit unit 31 as a modulation signal, and transmits a transmission signal as a transmission signal from the final stage output unit. Output to the antenna 4.

  Transmission is performed to a plate surface (hereinafter referred to as a back surface) 2b opposite to a plate surface (hereinafter referred to as a front surface) 2a on which electronic components such as the ICs 301 and 302 and the switch 303 are mounted. A button type battery 304 serving as a power source for the circuit 3 is attached in a replaceable manner.

  An antenna 4 is provided in the elongated region where the ground pattern 51 is not formed. The antenna 4 has a ground line pattern 52, a conductive plate 71, and a through hole 62, which form a current path. The ground line pattern 52 is formed by etching on the back surface 2b of the electronic substrate, extends linearly in parallel with the transmission circuit 3 in the length direction of the elongated region, and near the corner on the near side of the electronic substrate 2 in the drawing. At 90 degrees and reaches a position directly below the ground pattern 51. From there, it is electrically connected to the ground pattern 51 through a through hole 61 penetrating the electronic substrate 2 in the thickness direction.

  The conductive plate 71 is a conductive belt-like flat plate such as aluminum or copper bent at a right angle at both ends in the length direction into a U-shape, and both ends are formed as leg portions 712 and 713 as bridging portions. A beam portion 711 which is a central portion sandwiched between the leg portions 712 and 713 is fixed to the electronic substrate surface 2a so as to float from the electronic substrate surface 2a. The length of the conductive plate beam portion 711 is approximately the same as the straight line portion 521 that is a linear portion extending in parallel with the transmission circuit 3 of the ground line pattern 52, and the conductive plate 71 has the ground line pattern straight line portion 521. And the beam portion 711 are arranged at a position immediately above the linear portion 521 so as to be parallel to each other.

  A land pattern 541 is patterned by etching on the surface 2a of the electronic substrate at the position of one leg 712 of the conductive plate 71. Further, a signal line pattern 53 reaching the final output portion of the high frequency circuit portion 32 from the position of the other leg portion 713 of the conductive plate 71 is patterned by etching. The leg 712 of the conductive plate 71 is soldered on the land pattern 712, and the leg 713 of the conductive plate 71 is soldered on the signal line pattern 53. The land pattern 541 is electrically connected to the ground line pattern 52 at the end thereof through a through hole 62 that is a bridging portion. Therefore, the end of the conductive plate beam portion 711 connected to the one leg portion 712 and the end of the ground line pattern straight line portion 521 adjacent thereto are bridged by the leg portion 712 and the through hole 62.

  FIG. 3 shows a current that flows through the radio wave transmitter and contributes to radio wave radiation, and an electric field and a magnetic field generated thereby, and some of the mounting parts are omitted for convenience of explanation.

  Since the current IH flowing through the ground pattern 51 by the transmission signal output from the final output unit of the high-frequency circuit unit 32 flows along the electronic substrate surface 2a as described above, the plate surface of the electronic substrate 2 is generated by the current IH. An electric field EH is generated in a direction parallel to. Therefore, the radio wave radiated from the ground pattern 51 is a loop of a conventional radio wave receiver in which a normal direction of a surface surrounded by a loop-shaped current path (hereinafter referred to as a loop surface as appropriate) is the thickness direction of the electronic substrate. It becomes the same type of polarization as the antenna (hereinafter, this polarization is referred to as horizontal polarization as appropriate).

  On the other hand, the current IV output from the final stage output portion of the high-frequency circuit 32 and flowing through the antenna 4 is a ground line pattern straight line from the conductive plate 71 (the leg portion 713 to the beam portion 711 to the leg portion 712) through the through hole 62. Flows to portion 521. Here, since the conductive plate beam portion 711 and the ground line pattern straight line portion 521 are parallel to each other and arranged in parallel in the thickness direction of the electronic substrate 2, the conductive plate beam portion 711 and the ground line pattern straight line portion 521 are The direction in which the current flows is the opposite direction. A current path is formed in a loop shape along the periphery of the loop surface surrounded by the conductive plate 71, the through hole 62, and the ground line pattern straight line portion 521. In addition, since the conductive plate beam portion 711 and the ground line pattern straight line portion 521 are arranged in parallel in the thickness direction of the electronic substrate 2, the normal direction of the loop surface is on the plate surfaces 2 a and 2 b of the electronic substrate 2. It is a substantially parallel direction. Therefore, the current IV causes a magnetic field in a direction substantially parallel to the plate surfaces 2a and 2b of the electronic substrate 2 which is the normal direction of the loop surface surrounded by the conductive plate 71, the through hole 62, and the ground line pattern straight line portion 521. HV is generated. The electric field EV is generated in a direction substantially parallel to the loop surface.

  Therefore, the radio wave radiated from the antenna 4 becomes a different type of polarized wave from the loop antenna of the conventional radio wave receiver in which the normal direction of the loop surface is the thickness direction of the electronic substrate and the ground pattern 51 (hereinafter referred to as the following). , Where appropriate, this polarization is called vertical polarization).

  The loop surface of the antenna 4 has a dimension in a direction parallel to the plate surfaces 2a and 2b of the electronic substrate 2 defined by the length of the beam portion 711 of the conductive plate 71. It is defined by the length of the legs 712 and 713 of the conductive plate 71 and the length of the through hole 62, that is, the thickness of the electronic substrate 2. Here, the lengths of the conductive plate beam portion 711 and the ground line pattern straight line portion 521 depend on the planar shape of the electronic substrate 2, here, the length of the short side. It is larger than the height of the electronic component 301 to be mounted. Therefore, the area of the loop surface can be increased, and the intensity of the vertically polarized wave radiated from the antenna 4 can be made sufficiently high.

  Thus, according to this radio wave transmitter, two types of polarized waves can be radiated with sufficient intensity.

  In addition, since the ground line pattern 52 that is a part of the current path of the antenna 4 can be formed together with the wiring pattern of the transmission circuit 3, the manufacturing process can be simplified.

  Further, by using the U-shaped conductive plate 71, the conductive plate beam portion 711 and the ground line pattern linear portion 521 are connected to the electronic substrate 2 by the amount that the conductive plate beam portion 711 is floated from the electronic substrate surface 2a. Since the interval in the plate thickness direction is widened, the area of the loop surface can be increased.

  Further, by forming the ground line pattern 52 on the back surface 2b opposite to the electronic substrate surface 2a to which the conductive plate 71 is attached, the loop area is equal to the length of the through hole 62, that is, the plate thickness of the electronic substrate 2. Can be widened.

  The conductive plate may be arcuate rather than U-shaped with straight beam portions. The both ends become bridging parts.

(Second Embodiment)
FIG. 4 shows a radio wave transmitter according to the second embodiment of the present invention. In the radio wave transmitter according to the first embodiment, the antenna is a different antenna, and parts that operate substantially the same as those in the first embodiment are denoted by the same reference numerals and are different from the first embodiment. The explanation will be focused on.

  As a part of the current path of the antenna 4A, in addition to the conductive plate 71 disposed on the front surface 2a side of the electronic substrate 2, a conductive plate 72 is provided on the back surface 2b of the electronic substrate 2. The conductive plate 72 is a member having the same shape as the conductive plate 71 having the beam portion 721 and the leg portions 722 and 723. The conductive plate 71 and the conductive plate 72 are arranged at symmetrical positions with the electronic substrate 2 interposed therebetween, and the two conductive plate beam portions 711 and 721 are parallel and arranged in parallel in the plate thickness direction of the electronic substrate 2. (Hereinafter, the conductive plate 71 will be referred to as the front side conductive plate 71 and the conductive plate 72 will be referred to as the back side conductive plate 72 as appropriate).

  A land pattern 542 is formed at a position symmetrical to the land pattern 541 on the front surface 2 a on the back surface 2 b of the electronic substrate on which the back side conductive plate 72 is disposed, and is electrically connected by the through hole 62. In addition, a ground line pattern 55 is formed on the back surface 2b of the electronic substrate so as to reach the position immediately below the ground pattern 51 from the position of the leg portion 723 of the back side conductive plate 72. The ground line pattern 55 has substantially the same shape as the signal line pattern 53 except that the length reaches the position immediately below the ground pattern 51. Leg portions 722 and 723 of the back side conductive plate 72 are soldered to the land pattern 542 and the ground line pattern 55 in a one-to-one correspondence. The ends connected to the leg portions 712 of the front side conductive plate beam portion 711 and the ends connected to the leg portions 722 of the back side conductive plate beam portion 721 adjacent thereto are the leg portions 712, the through holes 62, and the leg portions 722. Bridged by

  The antenna 4A is a loop antenna in which the surface surrounded by the two conductive plates 71 and 72 and the through hole 62 is a loop surface, and the normal direction of the loop surface is parallel to the plate surface of the electronic substrate 2. Radiates vertically polarized waves. In the present embodiment, in addition to the front conductive plate 71, the beam portion 721 of the back conductive plate 72 is also lifted from the back surface 2b of the electronic substrate 2, so that the dimension of the loop surface in the thickness direction of the electronic substrate 2 is the first implementation. It becomes longer than that of the form, and the area of the loop surface can be increased.

  It should be noted that a battery 304 is usually arranged on the back surface 2b side of the electronic substrate 2 on which the electronic components such as the ICs 301 and 302 constituting the transmission circuit 3 are not mounted. Even if the conductive plate 72 is arranged, the radio wave transmitter does not increase in size in the thickness direction of the electronic substrate 2.

  Moreover, although the same thing as the front side conductive plate 71 is used for the back side conductive plate 72, the kind of component is reduced, However, It is not necessarily limited to this. The length of the leg portions 722 and 723 of the back side conductive plate 72 is preferably as long as possible within the range of the height of the battery 304 to increase the area of the loop surface of the antenna 4A.

(Third embodiment)
5 and 6 show a radio wave transmitter according to a third embodiment of the present invention. In the radio wave transmitter according to the first embodiment, the antenna is a different antenna, and parts that operate substantially the same as those in the first embodiment are denoted by the same reference numerals and are different from the first embodiment. The explanation will be focused on.

The antenna 4B is provided on the surface 2a of the electronic substrate 2 with a plurality of (2 in the illustrated example) conductive plates 73 and 74 extending in the length direction of the transmission circuit 3 non-formation region (direction parallel to the short side of the electronic substrate 2). have. The conductive plates 73 and 74 are U-shaped members composed of beam portions 731 and 741 and leg portions 732, 733, 742, and 743 like the conductive plates of the respective embodiments. Then, they are arranged in parallel in a direction parallel to the plate surfaces 2 a and 2 b of the electronic substrate 2 in parallel with each other at intervals sufficiently shorter than the lengths of the beam portions 731 and 741.

  In the first conductive plate 73 on the front side in FIG. 5, both leg portions 732 and 733 are soldered to the land patterns 543 and 544 formed on the electronic substrate surface 2a in a one-to-one correspondence. . The land pattern 543 coupled to one leg 732 on the front side in FIG. 6 is electrically connected to the ground line pattern 52B formed on the back surface 2b of the electronic substrate through the through hole 63. The ground line pattern 52B extends in a straight line from the position directly below the land pattern 543 toward the opposite side of the second conductive plate 74 and extends in a straight line, and slightly near the other leg portion 732 of the first conductive plate 73. The direction is changed by approximately 90 degrees at a position that has passed, and has reached a position directly below the ground pattern 51. Therefore, it is electrically connected to the ground pattern 51 through the through hole 61.

  Further, a linear line pattern 56 is formed on the electronic substrate back surface 2b so as to be inclined toward the second conductive plate 74 side from a position immediately below the other leg portion 733 of the first conductive plate 73. The one leg portion 742 of the second conductive plate 74 extends toward a position directly below the land pattern 545 to be soldered. The line pattern 56 is electrically connected to the land pattern 544 to which the other leg portion 733 of the first conductive plate 73 is soldered by the through hole 64, and one leg portion 742 of the second conductive plate 74 is soldered. The land pattern 545 and the through hole 65 are electrically connected. The other leg portion 743 of the second conductive plate 74 is soldered to the signal line pattern 53 </ b> B leading to the final stage output portion of the high frequency circuit portion 32.

  Here, each of the line pattern 56 and the ground line pattern straight line portion 521B is a pattern extending in a one-to-one correspondence from the positions corresponding to the leg portions 732 and 733 of the same conductive plate 73, and is substantially parallel. It has become. It is easy to set them to be parallel. That is, the line pattern 56 and the ground line pattern straight line portion 521B are arranged in parallel in a direction parallel to the plate surfaces 2a and 2b of the electronic substrate 2 in the same manner as the conductive plate beam portions 731 and 741. .

  Now, the first conductive plate beam portion 731 is in a relationship in which the first conductive plate beam portion 731 is arranged in the thickness direction of the electronic substrate 2 with the ground line pattern straight line portion 521B. They are in a relationship in which they are arranged in the thickness direction of the electronic substrate 2. The first conductive plate beam portion 731 has an end on the through hole 63 side between the leg portion 732 and the through hole 63 between the adjacent ground line pattern straight line portion 521B and the end on the through hole 63 side. Bridged by hole 63. On the other hand, the end on the through hole 64 side of the first conductive plate beam portion 731 is between the end on the through hole 64 side of the adjacent line pattern 56 by the other leg portion 733 and the through hole 64. It is being bridged.

  Further, the line pattern 56 is in a relationship in which the line pattern 56 and the beam portion 731 of the first conductive plate 73 are arranged in the thickness direction of the electronic substrate 2, but the beam of the second conductive plate 74. Also with the part 741, there is a relationship in which each other is arranged in the thickness direction of the electronic substrate 2. As described above, the line pattern 56 has a through hole 64 and a leg portion between the end on the through hole 64 side and the end on the through hole 64 side of the first conductive plate beam portion 731 adjacent thereto. Bridged by 733. On the other hand, the end of the line pattern 56 on the through hole 65 side is bridged by the through hole 65 and the leg portion 742 between the end of the second conductive plate beam portion 741 adjacent to the end of the line pattern 56 on the through hole 65 side. Yes.

  As a result, current flows in the opposite directions to the ground line pattern straight line portion 521B and the conductive plate beam portion 731 arranged in parallel in the plate thickness direction of the electronic substrate 2. Similarly, current also flows in the conductive plate beam portion 731 and the line pattern 56 in directions opposite to each other. Similarly, currents flow in opposite directions to the line pattern 56 and the second conductive plate beam portion 741. Then, currents flow in the same direction in the first conductive plate beam portion 731 and the second conductive plate beam portion 741 that are arranged in parallel in the direction of the plate surfaces 2 a and 2 b of the electronic substrate 2. Similarly, current flows in the same direction in the ground line pattern straight line portion 521B and the line pattern 56 as well.

  Since the antenna 4B has a current path formed in a two-turn solenoid shape to increase the current, the radiation intensity can be further increased. In addition, it is good also as a solenoid with a larger number of turns by increasing the number of conductive plates and the number of line patterns.

(Fourth embodiment)
FIG. 7 shows a radio wave transmitter according to a fourth embodiment of the present invention. In the radio wave transmitter according to the first embodiment, the antenna is a different antenna, and parts that operate substantially the same as those in the first embodiment are denoted by the same reference numerals and are different from the first embodiment. The explanation will be focused on.

  A line pattern 57 is formed on the electronic substrate surface 2a. The line pattern 57 is a pattern symmetrical to the ground line pattern 52 formed on the back surface 2b of the electronic substrate and communicates with the final output section of the high-frequency circuit section 32. The straight line portion 571 of the line pattern 57 is a pattern that is parallel to the straight line portion 521 of the ground line pattern 52 and arranged in parallel in the thickness direction of the electronic substrate 2. The end portion of the line pattern 57 opposite to the final output portion side and the end portion of the ground line pattern 52 opposite to the ground pattern 51 side are electrically connected by a through hole 66. The antenna 4 </ b> C is a loop antenna whose surface is surrounded by the line pattern straight line portion 571, the ground line pattern straight line portion 521, and the through hole 66.

  Even in the present embodiment, the direction of current flow is opposite between the line pattern straight line portion 571 and the ground line pattern straight line portion 521, and the line pattern straight line portion 571 and the ground line pattern straight line portion 521 are in the thickness direction of the electronic substrate 2. Therefore, the normal direction of the loop surface is parallel to the plate surfaces 2 a and 2 b of the electronic substrate 2. Thereby, vertical polarization different from the horizontal polarization radiated from the ground pattern 51 can be radiated. The lengths of the line pattern straight line portion 571 and the ground line pattern straight line portion 521 that define the shape of the loop surface in the plate surface directions 2a and 2b of the electronic substrate 2 are sufficiently long by taking full advantage of the planar shape of the electronic substrate 2. It can take enough. The shape of the loop surface in the thickness direction of the electronic substrate 2 can be ensured by the length of the through hole 66, that is, the thickness of the electronic substrate 2. Thereby, the radiation intensity is sufficient.

  Further, since only pattern formation is required, the manufacturing is simple.

  In each of the above embodiments, the linear portions are provided on both sides of the electronic substrate so that the linear portions are arranged in parallel in the thickness direction of the electronic substrate. However, the present invention is not limited to this. The two linear portions may be disposed only on the front side or the back side of the electronic substrate. For example, it can be constituted by a linear line pattern formed on one plate surface of an electronic substrate and a conductive plate fixed on the one plate surface. To explain in accordance with each of the above embodiments, the conductive plate shown in each of the above embodiments is arranged so that one leg thereof is positioned on one end of the line pattern and substantially parallel to the line pattern. To do. It fixes to one leg part of an electroconductive plate, and the one end part of a line pattern by soldering. Here, the length of the line pattern is slightly shorter than the length of the beam portion of the conductive plate so that the other leg portion of the conductive plate does not come into contact with the line pattern. Alternatively, the conductive plate may be slightly inclined from the direction parallel to the line pattern so that the other leg of the conductive plate passes in the vicinity of the line pattern. Alternatively, the line pattern is wide at one side edge side at one end portion coupled to one leg portion of the conductive plate, and the protruding portion is soldered to the leg portion.

(Fifth embodiment)
FIG. 8 shows a radio wave transmitter according to a fifth embodiment of the present invention. In the radio wave transmitter according to the first embodiment, the antenna is a different antenna, and parts that operate substantially the same as those in the first embodiment are denoted by the same reference numerals and are different from the first embodiment. The explanation will be focused on.

  A band-shaped ground pattern non-formation portion is provided at the boundary position between the code generation circuit unit 31 and the high frequency circuit unit 32, and the ground pattern is referred to as a ground pattern of the code generation circuit unit 31 (hereinafter referred to as a first ground pattern as appropriate). 511 and the ground pattern of the high-frequency circuit unit 32 (hereinafter, referred to as a second ground pattern as appropriate) 512. In the ground pattern non-forming portion, inductors 305 and 306 as impedance elements are interposed between the ground patterns 511 and 512.

  Of course, the antenna 4 is connected to the ground pattern 512 of the high-frequency circuit unit 32 among the ground patterns 511 and 512.

  FIG. 9 shows currents contributing to radio wave radiation in the electronic substrate 2. The first and second ground patterns 511 and 512 and the inductors 305 and 306 are connected to the high-frequency circuit section 32 from the final stage output section. Since the output transmission signal forms a current path from the second ground pattern 512 to the inductors 305 and 306 to the first ground pattern 511 and flows through I′Ha and I′Hb, it emits horizontally polarized waves. Since the inductors 305 and 306 have high impedances Za and Zb with respect to the high-frequency signal, the I′Ha and I′Hb can be adjusted by adjusting the inductance of the inductors 305 and 306. Thereby, the balance between the vertically polarized waves radiated from the antenna 4 and the horizontally polarized waves radiated from the ground patterns 511 and 512 can be adjusted for the transmission radio wave.

  If the width of the ground pattern non-forming portion between the first and second ground patterns 511 and 512 is too narrow, the ground pattern is short-circuited via a parasitic capacitance for a high-frequency signal, and the inductor is not connected. Since the meaning of provision is reduced, the width should be set in consideration of parasitic capacitance.

  In addition, an impedance element can be used as well as an inductor. However, since the impedance of the inductor can be suppressed to a very low level for low frequency signals, problems such as fluctuations in the power supply voltage between the code generation circuit section and the high frequency circuit section. Is less likely to occur.

  Moreover, the characteristic part of this embodiment which divides | segments a ground pattern into several and connects between adjacent ground patterns with an impedance element is applicable also to the said 2nd Embodiment-5th Embodiment.

(Sixth embodiment)
FIG. 10 shows a radio wave transmitter according to a sixth embodiment of the present invention. In the radio wave transmitter according to the fifth embodiment, another antenna is provided as an antenna. The parts that operate substantially the same as those of the fifth embodiment are denoted by the same reference numerals, and the fifth embodiment is different from the fifth embodiment. The difference will be mainly described.

  Another antenna 4D has a U-shaped line pattern formed on the surface 2a of the electronic substrate so as to border the peripheral edge of the electronic substrate 2 at the outer periphery of the transmission circuit 3. One end of the antenna 4 </ b> D is connected to the final output unit of the high-frequency circuit unit 32, and the other end is connected to the ground pattern 512 of the high-frequency circuit unit 32. Another antenna 4D differs from the antenna 4 in that the normal direction of the loop surface is parallel to the plate thickness direction of the electronic substrate 2, and therefore the horizontal polarization is different from that of the antenna 4.

  By radiating strong horizontal polarized waves from another antenna 4D, the dip point can be eliminated more satisfactorily.

(Seventh embodiment)
FIG. 11 shows a radio wave transmitter according to a seventh embodiment of the present invention. In the radio wave transmitter according to the sixth embodiment, the antenna is a different antenna, and parts that operate substantially the same as in the sixth embodiment are denoted by the same reference numerals, and are different from the sixth embodiment. The explanation will be focused on.

  In the antenna 4E, a linear ground line pattern 52E is formed in the longitudinal direction on the back surface 2b of the electronic substrate 2 in the elongated region where the transmission circuit is not formed, and the antenna 4E curves 90 degrees near the corner of the electronic substrate 2. Then, it reaches a position directly below the ground pattern 512, where it is electrically connected to the ground pattern 512 through the through hole 61.

  On the surface 2a of the electronic substrate 2, a land pattern 546 is formed at a position immediately above one end of the ground line pattern straight line portion 521E, and is electrically connected to the ground line pattern straight line portion 521E through the through hole 67. Further, a signal line pattern 58 is formed from a position immediately above the other end of the ground line pattern straight line portion 521E at which the ground line pattern 52E starts to curve, and is connected to the final output section.

  Leaf springs 82 and 83 having a V-shaped cross section are soldered to one end portions of the land pattern 546 and the signal line pattern 58.

  On the other hand, as shown in FIG. 12, the inner surface 12a of the upper housing 12E has flat portions 12a1 and 12a2 parallel to the electronic substrate surface 2a at positions facing the leaf springs 82 and 83, and from there, a reverse-facing bathtub A concave shape is formed. On the inner surface 12a, a band-like line pattern 81 is formed from one flat portion 12a1 to the other flat portion 12a2 following the position of the ground line pattern linear portion 521E facing the electronic substrate 2 in the plate thickness direction. The line pattern 81 is a conductive layer formed by metal deposition. A central portion 811 excluding both ends 812 and 813 of the line pattern 81 is substantially straight and substantially parallel to the plate surfaces 2a and 2b of the electronic substrate 2, and both ends 812 and 813 are gently curved from the central portion 811. It extends in the thickness direction of the electronic substrate 2 and reaches the flat portions 12a1 and 12a2.

  When the electronic board 2 is stored in the lower housing 11 and then closed by the upper housing 12E, the flat portions 12a1 and 12a2 of the upper housing 12E are brought into elastic contact with the leaf springs 82 and 83, and the line pattern 81 is formed therebetween. One end portion 812 is electrically connected to the land pattern 546 and the other end portion 813 is electrically connected to the line pattern 58. As a result, when a transmission signal is output, a current flows through a current path from the line pattern 81 to the through hole 67 to the ground line pattern straight line portion 521E, and the current direction is opposite between the line pattern 81 and the line pattern straight line portion 521E. Therefore, the antenna 4E is a loop antenna whose loop surface is a surface surrounded by the line pattern 81, the through hole 67, and the ground line pattern straight line portion 521E. Since the line pattern central portion 811 and the line pattern linear portion 521E are formed in a direction substantially parallel to the plate surfaces 2a and 2b of the electronic substrate 2 and are arranged in parallel in the plate thickness direction of the electronic substrate 2, the loop plane method is used. The lines are parallel to the plate surfaces 2a and 2b of the electronic substrate 2, and the antenna 4E emits vertically polarized waves.

  By forming the antenna 4E on the inner surface 12a of the upper housing 12E, the linear portion of the antenna current path can be separated from the plate surfaces 2a and 2b of the electronic substrate 2, and the area of the loop surface can be increased.

  In the present embodiment, the line pattern 81 is formed on the inner surface 12a of the upper housing 12E facing the surface 2a of the electronic substrate 2. However, the line pattern 81 may be formed on the inner surface of the lower housing 11. Or you may form in both an upper housing and a lower housing. In this case, the loop area can be increased by making maximum use of the space in the housing.

  The line pattern 81 has a shape that reaches the leaf springs 82 and 83 on the surface 2a of the electronic substrate 2a by drawing a gentle curve at both ends. Coil springs project from the positions immediately below both ends of the line pattern to make elastic contact with the line pattern, and the coil spring bridges the end of the line pattern and the end of the ground line pattern on the through hole 67 side. But you can.

  Further, the characteristic part of the present embodiment in which a part of the antenna is formed on the inner surface of the housing has a configuration in which the ground pattern is not divided, or a configuration in which the normal of the loop surface does not have another antenna whose thickness direction is the electronic substrate. Of course, it can also be applied.

It is a partial destruction perspective view of the 1st electric wave receiver to which the present invention is applied. It is a perspective view of the electronic substrate which is the principal part of the said radio wave receiver. It is a figure explaining the action | operation of the said radio wave receiver. It is a perspective view of the electronic substrate which is the principal part of the 2nd electromagnetic wave receiver to which this invention is applied. It is a perspective view of the electronic substrate which is the principal part of the 3rd electromagnetic wave receiver to which this invention is applied. It is a one part perspective view of the electronic substrate of the said radio wave receiver. It is a perspective view of the electronic board which is the principal part of the 4th electromagnetic wave receiver to which this invention is applied. It is a perspective view of the electronic board which is the principal part of the 5th electromagnetic wave receiver to which this invention is applied. It is a figure explaining the action | operation of the said radio wave receiver. It is a perspective view of the electronic board which is the principal part of the 6th electromagnetic wave receiver to which this invention is applied. It is a disassembled perspective view of the 7th electromagnetic wave receiver to which this invention is applied. 3 is a partial cross section of the radio wave receiver.

Explanation of symbols

11 Lower housing (housing)
12,12E Upper housing (housing)
12a inner surface 13 operation buttons 14 key plate 2 electronic board 2a surface (plate surface)
2b Back side (plate surface)
3 Transmission Circuit 31 Code Generation Circuit 32 High Frequency Circuit Section 305, 306 Inductor (impedance element)
4, 4A, 4B, 4C, 4E Antenna (loop antenna)
4D antenna (another loop antenna)
51, 511, 512 Ground pattern 52, 52B, 52E Ground line pattern 521, 521B, 521E Ground line pattern straight line portion (linear portion)
56 Ground line pattern (linear part)
57 Signal Line Line Pattern 571 Signal Line Line Pattern Straight Line (Linear)
62, 63, 64, 65, 66, 67 Through hole (Bridge part)
71, 72, 73, 74 Conductive plate (conductive member)
711, 721, 731, 741 Beam (Linear)
712, 722, 732, 742, 713, 723, 733, 743 Leg (Bridge)
81 Line pattern 811 Center part (linear part)
812, 813 End (Bridge part)

Claims (8)

In a radio wave transmitter having an electronic board on which a transmission circuit is formed and an antenna that radiates a transmission signal from the transmission circuit,
As the antenna, a current path extends substantially parallel to the plate surface of the electronic substrate and is arranged in parallel with each other in parallel in the plate thickness direction of the electronic substrate, and the two linear portions A bridging part that bridges adjacent ends of the two linear parts so that currents flow in opposite directions, and a normal direction of a surface surrounded by the linear part and the bridging part is the electron A loop antenna having a direction substantially parallel to the board surface of the board is provided , the ground pattern formed on the board surface of the electronic board is divided into a plurality of parts, and adjacent ground patterns are electrically connected by an impedance element. A radio transmitter.   The radio wave transmitter according to claim 1, wherein the linear portion is formed by patterning a conductive layer on a plate surface of the electronic substrate.   3. The radio wave transmitter according to claim 1, wherein a U-shaped conductive member bent at both ends in the length direction is formed with a center portion sandwiched between the both ends, with the both ends as legs. A radio wave transmitter that is fixed to a plate surface of the electronic substrate so as to float from the plate surface of the electronic substrate, wherein the central portion constitutes the linear portion, and both end portions constitute the bridging portion.   4. The radio wave transmitter according to claim 1, wherein the linear portion or the linear portion and the bridging portion are formed by patterning a conductive layer on an inner surface of a housing that houses the electronic board. 5.   5. The radio wave transmitter according to claim 1, wherein the linear portion is disposed with the electronic substrate sandwiched in a thickness direction of the electronic substrate, and the electronic substrate is disposed in the thickness direction as the bridging portion. A radio wave transmitter with a through hole. 6. The radio wave transmitter according to claim 1, wherein two of the linear portions are arranged in parallel in the plate thickness direction of the electronic substrate, and a plurality of the linear portions are arranged in parallel in the plate surface direction of the electronic substrate,
Each of the two linear parts arranged in parallel in the plate surface direction of the electronic substrate and corresponding to each other in a line thickness direction has a one-to-one correspondence with each end of the linear part arranged in the plate thickness direction of the electronic substrate. The bridging portion is provided, and one bridging portion of the bridging portions is used to bridge between the ends of one of the two linear portions, and the two linear portions Make a bridge between the ends of the other linear part,
In the two linear parts arranged in parallel in the plate surface direction of the electronic substrate, current flows in opposite directions to the two linear parts arranged in parallel in the plate thickness direction of the electronic board. Radio transmitters that allow current to flow in the same direction. 7. The radio wave transmitter according to claim 1, wherein the antenna is a loop antenna different from the loop antenna, and a normal direction of a surface surrounded by a current path is a thickness direction of the electronic substrate. A radio transmitter with a loop antenna . 8. The radio wave transmitter according to claim 7 , wherein the another loop antenna has a current path formed so as to follow a peripheral portion of the electronic substrate and surround the transmission circuit with the current path .

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