JP2018117258A - Planar antenna and radio equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a planar antenna and radio equipment capable of achieving miniaturization of radio equipment.SOLUTION: The planar antenna includes: a radiation conductor part 11 posing a rectangle; a feeding part 12 and a ground part 13 disposed at one short side part 11a of the radiation conductor part 11; and a stationary part 14 disposed at the other edge short side 11b of the radiation conductor part 11. Any of the feeding part 12, the ground part 13 and the stationary part 14 are extended from the radiation conductor part 11 toward a circuit board which is a part to be mounted, and a width B of the stationary part 14 is formed to be smaller than a width A of the short side of the radiator conductor part 11.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a plate antenna and a radio using the same.

  FIG. 5 discloses a conventional plate antenna 100. The plate antenna 100 is connected to the ground plate 101 by bending an element 102 arranged so as to be parallel to the ground plate 101 on the substrate 106 at a predetermined interval, and a vicinity of one side of the element 102 being bent. Power is supplied from a grounding portion 103 and a power supply portion 104 provided in an open portion of the element 102, and an insulating spacer 105 is inserted and fixed between the ground plate 101 and the other of the element 102. The distance between the element 102 and the ground plate 101 is kept constant (see, for example, Patent Document 1).

  In addition, in order to keep the ground plate and the element parallel to each other, there is disclosed a configuration in which a fixing portion is provided on one side opposite to the power feeding portion to be connected and fixed to the substrate (for example, see Patent Document 2). .

JP-A-9-252214 JP 2012-129582 A

  However, in the conventional configuration described in Patent Document 1, it is necessary to provide the spacer 105 as a separate member, and a double-sided pressure-sensitive adhesive tape or the like for fixing is required, and there is a problem that workability is poor.

  In addition, in the configuration of the method described in Patent Document 2, although the configuration for fixing the side opposite to the power feeding unit is disclosed, the influence on the transmission frequency by the fixing plate is not considered, and the size thereof is not considered. Not disclosed.

  The present invention solves the above-described conventional problems, and an object thereof is to provide a plate-like antenna capable of efficiently transmitting a transmission frequency while reducing the size of the plate-like antenna, and a radio using the plate-like antenna.

  In order to solve the above-described conventional problems, a plate-shaped antenna according to the present invention includes a rectangular plate-shaped radiating conductor portion, a feeding portion and a grounding portion disposed on one edge of the radiating conductor portion, and the radiation. A fixing portion disposed on the short side of the other edge of the conductor portion, and the power feeding portion, the grounding portion, and the fixing portion are all directed from the radiation conductor portion to a circuit board that is a mounting portion. The fixed portion has a width that is smaller than the width of the short side of the radiation conductor portion.

  This allows the fixed portion to function as a part of the antenna, thereby reducing the resonant frequency and reducing the size of the antenna element. In addition, the antenna can be held securely by engaging the fixed portion with the circuit board. Is something that can be done.

  The wireless device of the present invention includes a circuit board having a power feeding circuit and a ground plate, and a plate-like antenna mounted on the circuit board, and the plate-like antenna includes a plate-like radiation conductor portion that forms a rectangle. A power supply part electrically connected to the power supply circuit disposed on one edge of the radiation conductor part, a ground part electrically connected to the ground plate, and a short of the other edge of the radiation conductor part A fixing portion that is fixed to the circuit board disposed on a side, and the power feeding portion, the grounding portion, and the fixing portion are all extended from the radiation conductor portion toward the circuit board. The width of the fixed portion is smaller than the width of the short side of the radiation conductor portion.

  According to the plate antenna of the present invention and a radio using the plate antenna, it is possible to provide a plate antenna capable of efficiently transmitting a transmission frequency while miniaturizing the plate antenna and a radio using the plate antenna. .

A perspective view showing an example of a configuration of a plate antenna according to the first exemplary embodiment. (1), (2) The perspective view which shows an example of a structure of the other plate-shaped antenna concerning Embodiment 1. FIG. The perspective view which shows the mounting state to the circuit board of the plate-shaped antenna concerning Embodiment 1. FIG. Schematic configuration diagram showing an example of a radio device according to the second exemplary embodiment Schematic showing a conventional plate antenna

  1st invention arrange | positions the rectangular plate-shaped radiation conductor part, the electric power feeding part and grounding part which were arrange | positioned at one edge of the said radiation conductor part, and the short side of the other edge of the said radiation conductor part Each of the power feeding unit, the grounding unit, and the fixing unit is extended from the radiating conductor unit toward a circuit board that is a mounting unit, and the width of the fixing unit Is a plate-like antenna formed smaller than the width of the short side of the radiation conductor.

  The second invention is characterized in that, in the first invention, a second grounding portion is provided on a side adjacent to the side where the power feeding unit and the grounding unit are arranged.

  A third invention includes a circuit board having a power feeding circuit and a ground plate, and a plate-like antenna mounted on the circuit board, wherein the plate-like antenna has a rectangular plate-like radiation conductor portion and the radiation On the short side of the other edge of the radiation conductor part, a power supply part electrically connected to the power supply circuit arranged on one edge of the conductor part, a ground part electrically connected to the ground plate, and A fixed portion that is fixed to the arranged circuit board, and the power feeding portion, the grounding portion, and the fixed portion all extend from the radiation conductor portion toward the circuit board, and The width of the fixed portion is a wireless device characterized in that it is formed smaller than the width of the short side of the radiation conductor portion.

  According to a fourth aspect of the invention, in the third aspect of the invention, a second grounding portion for grounding the circuit board is provided on a side adjacent to the side where the power feeding unit and the grounding unit are disposed. To do.

  According to a fifth aspect of the invention, particularly in the third or fourth aspect of the invention, a claw portion that engages with an opening hole provided in the circuit board is provided at the tip of the fixing portion, and the circuit around the opening hole is within a predetermined range. The present invention is characterized in that a ground removal portion where no ground is disposed is provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a perspective view illustrating an example of a schematic configuration of the plate antenna according to the first exemplary embodiment.

  As illustrated in FIG. 1, the plate-like antenna 10 of the present embodiment includes a power feeding unit 12 that is electrically connected to a power feeding circuit on one short side portion 11 a of a rectangular radiation conductor 11. And a grounding portion 13 for being electrically connected to the ground plate, and a fixing portion 14 is formed on the other short side portion 11 b facing the power feeding portion 12 and the grounding portion 13. At the tips of the power feeding unit 12 and the grounding unit 13, claw units 12a and 13a are provided for connection with radio circuits provided on the circuit board, respectively.

  The fixed portion 14 extends from the short side portion 11b of the radiating conductor portion 11 to the circuit board side, which is the attached portion, with a width shorter than the width A of the short side of the radiating conductor portion 11, and has a claw at the tip portion. The part 15 is configured and can be engaged with a hole provided in the circuit board.

  The radiating conductor 11 is designed to resonate at ½λ when the transmission wavelength is λ. From the viewpoint of obtaining antenna matching, the fixed portion 14 is connected to the power feeding portion 12. It is necessary to arrange it in a spatially distant place so that stray capacitance does not occur. Therefore, the short side is preferably about A <1 / 16λ so that a sufficient space can be secured on the long side of the radiation conductor portion 11. Further, since a current flows through the fixed portion 14, a narrower one is preferable in order to reduce the influence of nearby surroundings and to keep the attenuation term of the antenna low, but considering the viewpoint of manufacturing (independence as a part), B A design of about 1/2 A is appropriate.

  In addition, the code | symbol was attached | subjected only in order to illustrate the corresponding | compatible relationship between this Embodiment and its Example, and the structure of the plate-shaped antenna of this Embodiment is not limited to FIG. Hereinafter, the same applies to other embodiments.

  In the following description, the side on which the feeding circuit and the ground plate are provided with respect to the plate antenna is defined as the lower side, and the direction such as up and down is specified and described. It goes without saying that the direction designation can be arbitrarily replaced by rotating.

  In the embodiment shown in FIG. 1, the feeding part 12 and the grounding part 13 are provided on the short side part 11a. However, like the plate antenna 20 shown in FIG. 2 (1), the long side part 21c of the radiation conductor part 21 is provided. Even the configuration in which the feeding portion 22 and the grounding portion 23 are provided at the end portion 21d and the fixing portion 24 is provided in the short side portion 21b far from the end portion 21d does not depart from the configuration of the plate antenna of the present invention. Further, a claw portion 25 is provided at the tip of the fixing portion 24.

  In addition, in the plate-like antenna 20 ′ shown in FIG. 2 (2), the plate-like antenna 20 shown in FIG. 2 (1) is further improved, and the second grounding portion is connected to the short side portion 21a adjacent to the end portion 21d. By providing 26, the self-supporting property to the circuit board is improved, and even when automatic soldering is performed, it is possible to prevent a problem that the plate-shaped antenna 20 'is inclined.

  As a result, in the conventional inverted-F antenna, in order to support the component before mounting, another component such as a resin spacer is generally used. However, in this plate antenna, the component itself is stable and self-supported. There is no need for supporting parts, and there is a merit in terms of cost.

Further, by providing the second grounding portion 26, the inductor (L) component adjusted by the antenna perimeter can be adjusted at the position of the second grounding portion 26, and the floating generated between the power feeding portion 22 and the inductor (L) component can be adjusted. The capacitance capacitor (C) component can be adjusted at the position of the ground portion 23. As a result, the L component and the C component can be adjusted independently, and antenna matching can be realized more easily. In addition, since the antenna element itself will become large if the space | interval of the 2nd grounding part 26 and the grounding part 23 is large, it is preferable to keep a space | interval within 1/16 (lambda).

  FIG. 3 is a diagram showing a state in which the plate antenna 10 shown in FIG. 1 is attached to the circuit board 30, and the multilayer circuit board 30 functions as a ground plate 31, and as shown in FIG. A ground removal portion 32 that is not provided with a ground at a certain distance from the periphery is provided, and the fixing portion 14 is not connected to the ground plate.

  Further, the claw portion 15 is inserted and fixed in an opening hole 33 provided in the circuit board 30.

  Note that the circuit ground of the circuit board 30 is also one of the major factors affecting the fixing, and the fixing portion 14 needs to be separated from the opening by a certain distance from the opening so as not to be affected by the circuit ground. The larger the distances C and D away from 31 are, the smaller the influence is. However, in this embodiment, the distances C and D are set to 1 / 32λ or more as the size of the ground removal portion 32.

  The plate-like antenna 10 configured as described above allows the fixing portion 14 to function as a part of the antenna, and the size of the antenna, in particular, the length in the longitudinal direction when a rectangular radiation conductor portion is used. By shortening, the area occupied when mounted on the circuit board 30 can be reduced, and the wireless device can be miniaturized.

(Embodiment 2)
FIG. 4 is a schematic view showing a state in which a circuit board on which a radio circuit using the plate antenna of the present application is mounted is mounted on an ultrasonic gas meter as a radio device.

  In the figure, in the gas meter 40, a gas passage 44 is formed in a U-shape in a housing 41 between a gas inflow portion 42 and an outflow portion 43, and ultrasonic waves are used in a lower flow path 45 of the gas passage. The flow rate measuring unit 46 is disposed. Further, a shutoff valve 54 is disposed between the inflow portion 42 and the lower flow path 45 for shutting off the gas when an abnormality occurs.

  In the following description, for the sake of convenience, the positional relationship will be described with reference to FIG. 4, such as upper, lower, left, and right, and the longitudinal direction of the rectangular plate antenna will be described as the horizontal direction.

  The circuit board 47 is located in the central space of the gas passage 44, and a measurement circuit unit that calculates a flow rate based on a flow rate signal from the radio circuit unit 52 and a flow rate measurement unit 46 as a radio that communicates with the outside. 53 is partitioned and mounted. Further, a liquid crystal display unit 48 that displays a flow rate value and an integrated value calculated by the measurement circuit unit 53 and communication conditions of the wireless circuit unit 52 is mounted. In addition, a battery 49 as a circuit power source is disposed on the back of the circuit board 47.

  The liquid crystal display unit 48 is arranged at the center of the circuit board 47, and a first antenna 50 that is horizontally oriented on the upper side of the liquid crystal display unit 48 and a second antenna 51 that is vertically oriented on the left side constitute diversity. Further, connectors 55a, 55b, and 55c for connecting the circuit board 47 to the battery 49, the shutoff valve 54, and the flow rate measuring unit 46 are arranged on the right side of the circuit board 47, and lead wires 56a, 56b, and 56c, respectively. Connected with.

  Thus, by arranging the connectors 55a, 55b, and 55c at the right end of the circuit board 47, the distance between the second antenna 51 arranged at the left end and the lead wires 56a, 56b, and 56c is separated as much as possible. ing.

With the configuration described above, the flow rate signal detected by the flow rate measurement unit 46 is transmitted to the measurement circuit unit 53 of the circuit board 47 via the lead wire 56c. Then, the flow rate calculated by the measurement circuit unit 53 is wirelessly transmitted to the outside by the first antenna 50 and the second antenna 51 via the wireless circuit unit 52.

  According to the present embodiment, it is possible to effectively use the space of the circuit board 47 by mounting the first antenna 50 and the second antenna 51 so as to surround the liquid crystal display unit 48.

  In addition, the antenna radiation efficiency is deteriorated due to the influence of objects close to the first antenna 50 and the second antenna 51, but the liquid crystal display unit 48 is particularly affected, and the radiation characteristics are significantly deteriorated when close to each other. Therefore, it is necessary to realize a narrower, smaller, and higher performance antenna in order to keep the distance from the liquid crystal display unit 48 as small as possible. However, according to the plate antenna of the present application, the antenna is reduced in size, and as a result, In addition to the liquid crystal display unit 48, the distance from surrounding mounting components and lead wires can be increased, so that the attenuation term of the antenna can be reduced and the antenna radiation efficiency can be improved.

  Moreover, although the diversity structure is taken using the 1st antenna 50 and the 2nd antenna 51, if the antennas are close to each other, the antennas are spatially coupled, and the antenna radiation efficiency is deteriorated. However, even in this problem, by reducing the size of the antenna, there is an effect of securing a larger interval and minimizing the deterioration of the antenna radiation efficiency.

  Furthermore, the radio circuit unit 52 and the measurement circuit unit 53 are separated by arranging the radio circuit unit 52 on the left side of the liquid crystal display unit 48 shared by the radio circuit unit 52 and the measurement circuit unit 53 and the measurement circuit unit 53 on the right side. And implemented.

  As described above, even when diversity is configured using a plurality of the same antennas, it is possible to reduce the size of the substrate, and this is particularly effective when a wireless substrate for meter reading is mounted in a narrow space such as the inside of a meter.

  The plate-like antenna of the present invention enables miniaturization of a wireless device, and is useful in various applications as a communication antenna.

10, 20, 20 ′ Plate antenna 11, 21 Radiation conductor portion 12, 22 Power feeding portion 13, 23 Ground portion 14, 24 Fixing portion 15, 25 Claw portion 26 Second ground portion 30, 47 Circuit board 31 Ground plate 32 Ground removal part 33 Opening hole

Claims (5)

A rectangular plate-shaped radiation conductor,
A power feeding part and a grounding part arranged at one edge of the radiation conductor part;
A fixing portion disposed on the short side of the other edge of the radiation conductor portion, and
The power feeding part, the grounding part, and the fixing part are all extended from the radiation conductor part toward the circuit board that is the attached part,
A width of the fixed portion is a plate-like antenna formed smaller than a width of a short side of the radiation conductor portion. The plate antenna according to claim 1, wherein a second grounding portion is provided on a side adjacent to the side where the power feeding unit and the grounding unit are disposed. A circuit board having a power feeding circuit and a ground plate, and a plate antenna mounted on the circuit board,
The plate antenna is
A rectangular radiating conductor portion that forms a rectangle, a feeding portion that is electrically connected to the feeding circuit disposed on one edge of the radiating conductor portion, and a grounding portion that is electrically connected to the ground plate, A fixing part fixed to the circuit board disposed on the short side of the other edge of the radiation conductor part,
The feeding part, the grounding part, and the fixing part are all extended from the radiation conductor part toward the circuit board, and the width of the fixing part is larger than the width of the short side of the radiation conductor part. A radio characterized by being made small. 4. The wireless device according to claim 3, wherein a second grounding portion for grounding to the circuit board is provided on a side adjacent to the side on which the power feeding unit and the grounding unit are disposed. A claw portion that engages with an opening hole provided in the circuit board is provided at a tip of the fixing portion, and a ground removal portion that does not place a circuit ground within a predetermined range is provided around the opening hole. The wireless device according to claim 3 or 4.

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