JP2000341026A - Antenna substrate and radio communication machine using same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a reflector for antenna at low cost by providing via holes as antenna reflection parts and forming an antenna radiation part at a desired position on a substrate. SOLUTION: Via holes (through holes) of a desired diameter are formed on the printed board. For example, five via holes are formed almost in a straight line and the internal surface sides of the via holes are made conductive. A radiator is formed at a specific distance nearly from the center of the array of the via holes on the substrate and the via holes which are formed almost in the straight line operate as reflectors. The intervals of the via holes are preferably narrow and >=1/10 as large as the wavelength. Further, the polarization of the antenna is preferably in parallel to the via holes so that the via holes operate as reflectors.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technology for forming an antenna using via holes formed in a substrate, and more particularly, to the size and length of via holes on the substrate.
The present invention relates to an antenna substrate having an antenna formed on a substrate by arrangement or the like and a wireless communication device using the same.

[0002]

2. Description of the Related Art FIG. 12 shows a conventional antenna. Conventional antennas are dipole antennas and reflector-equipped antennas (reflector antennas) having reflectors having directivity. In FIG. 12, a reflector is provided near the dipole antenna, and unidirectional directivity having a maximum radiation direction in the z-axis direction can be obtained. This antenna with a reflector is used as a means for concentrating radio waves in a specific direction.

Next, as a conventional antenna, there is an antenna as shown in FIG. In FIG. 13, FIG.
Is a bent structure of such a reflector, and such a reflector is called a corner reflector. By adjusting the opening angle α of this corner reflector and the distance d between the antenna and the reflector, the half-value angle of unidirectional directivity can be controlled, and the radiation direction or arrival direction of radio waves can be concentrated in a specific direction. It is valid.

Next, a Yagi antenna will be described as a conventional antenna. The Yagi antenna is an antenna in which a reflector longer than the radiator and a director shorter than the radiator are arranged in parallel near the half-wave dipole, which is the radiator (exciter). Widely used for TV reception and others.

FIG. 14 shows a schematic configuration diagram of a conventional Yagi antenna. A radiator having a feed portion, a reflector arranged in parallel with the radiator, and a waveguide arranged in parallel on the opposite side to the reflector are formed. Longer than radiators, directors are shorter than radiators. When a plurality of waveguides are provided, the shorter ones are arranged in order as the distance from the radiator increases, so that the transmission and reception accuracy for each wavelength is increased.

FIG. 15 shows a schematic configuration example of a monopole Yagi antenna as a specific example of a conventional Yagi antenna. On the ground plate, a quarter-wave monopole as a radiator, and a reflector and a director are arranged on both sides of the radiator so as to be parallel to each other. The monopole Yagi antenna includes a method of fixing a pin as a separate component on a ground plate, and a method of integrally forming the ground plate and a reflector or a waveguide by molding.

[0007]

In the above-described reflector antenna, it is necessary to hold the antenna and the reflector at a constant interval. In particular, when the wavelength becomes higher than the quasi-millimeter wave or the millimeter wave band and becomes less than several centimeters (approximately 4 cm), the antenna becomes smaller, and the distance between the fed antenna element and the reflector can be fixed accurately. It becomes difficult. In addition, when a conductive screw for fixing is used, there is a problem that the characteristics of the antenna are affected by the screw.

Further, in the above-described monopole Yagi antenna, when fixing the pin serving as the antenna element, each element becomes shorter as the operating frequency becomes higher, so that dimensional accuracy is required, and the pin itself is not fixed. There is a problem that becomes difficult. Further, in the case of integrally forming a mold, there is a problem that the mold must be manufactured and the mold itself is expensive, so that unless the mass is produced, the price is high.

In each of these prior arts, the number of necessary parts such as the ground plate, the pins of the antenna member, the power supply line, and the like is large in each case. There are problems such as difficulty in arranging parts. The present invention solves these conventional problems by using a via hole of a substrate to form a reflector (reflector) that has the same effect as a radiating portion or a reflector of an antenna. It is an object of the present invention to provide a wireless communication device using the same.

[0010]

According to a first aspect of the present invention, a substrate includes a plurality of via holes, a desired position of the substrate is used as an antenna radiating portion, and the plurality of via holes are provided. Are antenna reflectors.

According to a second aspect of the present invention, in order to solve the conventional problem, in the substrate according to the first aspect, the plurality of via holes are arranged substantially in a straight line to constitute an antenna reflecting portion. Features.

According to a third aspect of the present invention, there is provided a substrate according to the first aspect, wherein a first via hole group in which about half of the plurality of via holes are arranged substantially linearly; A second via hole group in which about half of the plurality of via holes other than the first via hole group are arranged substantially in a straight line, and the first and second via hole groups It is characterized in that a predetermined angle is formed.

According to a fourth aspect of the present invention, in order to solve the conventional problem, in the substrate according to the first or second or third aspect, the antenna radiating portion has a structure in which a via hole is provided in the substrate. This via hole serves as a feed portion and can be used as an antenna radiating portion.

In order to solve the conventional problem, the invention according to claim 5 is characterized in that a plurality of via holes are provided in a substrate, and these via holes operate as a reflector, a radiator, or a director of a Yagi antenna. I have.

According to a sixth aspect of the present invention, there is provided a substrate as set forth in the fifth aspect, wherein one of the plurality of via holes is an antenna radiator, and another one of the plurality of via holes is different from the antenna radiator. One of the via holes is an antenna reflector, and the via hole having a shorter hole length than the antenna reflector is an antenna director.

According to a seventh aspect of the present invention, to solve the conventional problem, in the substrate according to the fourth to sixth aspects, the power supply portion forms a power supply element by a coplanar line formed on the same substrate. It is characterized by.

In order to solve the conventional problem, the invention according to claim 8 is the substrate according to claims 4 to 6, wherein the power supply portion forms a power supply element by a microstrip line formed on the same substrate. It is characterized by:

According to a ninth aspect of the present invention, in order to solve the conventional problem, in the substrate according to the fourth to eighth aspects, high frequency components are arranged and connected on the same substrate as the substrate.

According to a tenth aspect of the present invention, in order to solve the conventional problem, in a wireless communication apparatus, a transmitter, a receiver, or a transceiver is provided by using the substrate according to the first to ninth aspects. And

[0020]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a first embodiment of the present invention, in which a plurality of via holes (through holes) having a predetermined diameter are formed on a printed circuit board. In this embodiment, five via holes are formed so as to be arranged substantially on a straight line, and the inner side surfaces of the via holes are made of a conductor. The radiator is arranged at a predetermined distance from the vicinity of the center with respect to the arrangement of the via holes on the substrate, and the via holes formed in a substantially straight line function as a reflector. This means that each via hole acts as a plane as shown in the (explanatory diagram) of the drawing. The radiator itself has a configuration using a connector or a configuration using the center conductor of a power supply cable as it is. Here, it is desirable that the interval between the via holes is narrow, and that the interval is desirably at least 1/10 or less of the wavelength. Further, it is desirable that the polarization of the antenna be parallel to the via hole so that the via hole acts as a reflector.

FIGS. 2 (a) and 2 (b) show a second embodiment of the present invention. A part different from the above-described embodiment of FIG. 1 is that a plurality of via holes arranged substantially linearly form two sides. And acts as a corner reflector. The radiator is disposed at a predetermined distance from the corner of the corner reflector. In FIG. 2A, the same number of via holes are arranged on two sides starting from the via hole arranged at the corner, and in FIG. 2B, a gap is formed without disposing the via hole at the corner. The same number of via holes are arranged on two sides starting from the position, and the two sides function as a corner reflector. Further, in this embodiment, the number of via holes on each side is the same, but one may be increased (or decreased) instead of the same in order to adjust the direction of radio waves.

FIG. 3 shows a third embodiment of the present invention. Connecting the via holes with conductive patterns formed on both sides of the substrate is effective even if the via hole interval is wider than that of the embodiment of FIG. In FIG. 3, the conductive patterns are arranged on both sides of the substrate, but it is effective to use only one side.

FIG. 4 shows a fourth embodiment of the present invention. This drawing is a cross-sectional side view. In this embodiment, when a multilayer substrate is used, a denser reflector can be formed by connecting via holes by a conductive pattern in each layer.
Connecting each via hole with a conductive pattern as shown in the above-described third and fourth embodiments,
This is because the potential of each via hole can be equalized, and the same effect as that of the ground plate can be easily obtained.

FIG. 5 shows a fifth embodiment of the present invention. In this embodiment, two long via holes are formed in the substrate to have the function and effect as a corner reflector.
In this embodiment, the corner reflector is formed by a long hole on two sides. However, as in the first embodiment, a reflector having one side may be used. The third embodiment shown in FIG. 3 and the fourth embodiment shown in FIG.
In the case where each via hole is connected in a conductive pattern as in the embodiment of the present invention or when the via hole is a long hole as in the fifth embodiment shown in FIG. 5, even when the polarization of the antenna and the via hole are not parallel, It has an effect as a reflector.

FIG. 6 shows a sixth embodiment of the present invention.
(A) shows a perspective view, and FIG. 6 (b) shows a side view sectional view. In this embodiment, a corner reflector is formed on a substrate by a via hole, and the via hole in the radiator portion is used as an antenna feed portion. One side of the substrate has a solid (GND) effect, and the antenna element arranged in the via hole is fed by a connector connected to a semi-rigid cable. The inner surface of the via hole into which the antenna element is inserted and arranged may not be a conductor, but the antenna element itself connected to the connector may be arranged and used as a feed element. The direction of the radio wave according to this embodiment is determined by a corner reflector having a plurality of via holes as shown in FIG.
It becomes the direction of the arrow z in the middle. The semi-rigid cable is connected to a transmitting / receiving circuit (not shown) for supplying power to the antenna element, and the antenna board and the transmitting / receiving circuit constitute a wireless communication device. Of course, if the circuit connected to the semi-rigid cable is only for transmission or only for reception, it can be configured as a transmission-only or reception-only wireless communication device.

FIG. 7 shows a seventh embodiment of the present invention.
7A is a perspective view, and FIG. 7B is a bottom view of the substrate viewed from below. In this embodiment, not only a via hole serving as a reflector, but also an antenna element itself acting as a radiator is formed of a via hole to form a monopole antenna. The via hole serving as a radiator is formed with a predetermined diameter, and the inner surface is made of a conductor. Also, as shown in FIG. 7B, one surface is a solid surface (GND), and power is supplied to the radiator via hole by a coplanar line.

FIG. 8 shows an eighth embodiment of the present invention.
8A is a perspective view, FIG. 8B is a cross-sectional view in a horizontal direction, and FIG. 8C is a diagram of an upper surface, an intermediate layer, and a lower surface showing each layer of the substrate. In this embodiment, as in the seventh embodiment described above, not only the via hole serving as a reflector but also the antenna element itself is formed of a via hole to form a monopole antenna, and the lower surface is a solid surface (GND). A microstrip line is formed in the intermediate layer to supply power to the radiator via hole. In this embodiment, the antenna is fed by a microstrip line using a three-layer substrate. However, even when a multi-layer substrate having more layers is used, a layer forming the microstrip line for feeding the antenna and a solid layer are formed. An antenna substrate having the same function can be formed as long as the antenna substrate has a layer forming a surface (GND).

FIG. 9 shows a ninth embodiment of the present invention. The printed circuit board 4 is provided with three via holes, of which the via hole 1 is a radiator (exciter), the via hole 2 is a reflector, and the via hole 3 is a waveguide. The inner diameter surfaces of the via holes 2 and 3 are conductor surfaces, and therefore, these via holes have a circular cylindrical shape. Also, the via holes are arranged substantially linearly and at substantially equal intervals. Further, a plurality of via holes 3 serving as waveguides may be provided. According to this embodiment, an antenna substrate having the function of a Yagi antenna is provided.

Here, the impedance of the antenna element depends on the element length and the element diameter. Therefore, it is possible to change the impedance of each element by changing the diameter of the via hole. Specifically, the reflector has a larger via hole diameter than the director, and (inversely, the director has a smaller via hole diameter than the reflector). By forming via holes having different thicknesses in thickness, it is possible to use a reflector, a director, and a radiator separately. When a plurality of directors are provided, the plurality of via holes serving as directors may have the same diameter. However, the farther from the radiator, the shorter the element length may be. The farther the waveguide, the smaller the via hole diameter).

FIG. 10 shows a tenth embodiment of the present invention.
This drawing is a cross-sectional side view. In the ninth embodiment described above, the via hole 1 serving as a radiator may or may not have a conductive inner diameter surface. Shown in In the embodiment of FIG. 10, the inner diameter of the director via hole 3 is smaller than the inner diameter of the reflector via hole 2. Therefore, an antenna equivalent to a conventional Yagi antenna having different pin lengths can be constituted by the via holes of the substrate.

Further, in the tenth embodiment, the state of power supply to the radiator via hole when the antenna substrate is mounted on a wireless communication device is shown. A connector 5 is connected to the radiator via hole 1 to supply power or a power supply cable 6.
Is inserted into the via hole 1 as it is to radiate from the radiator via hole 1. When the inner diameter portion is made of a conductor other than the tenth embodiment, the via hole for power supply may be formed so as to separate the pattern so as not to short-circuit with the ground plane.

FIG. 11 shows an eleventh embodiment of the present invention.
In this embodiment, an embodiment is shown in which high-frequency components are arranged and connected on an antenna substrate, whereby a transmitting unit and a receiving unit in wireless communication can be formed on the same substrate. FIG. 11A shows the front surface of the substrate, FIG. 11B shows the back surface of the substrate, and via holes are formed in the substrate to serve as radiators, reflectors, and waveguides. Is defined as a GND pattern, and a GND pattern is formed on the back surface of the substrate at a position substantially opposite to the front surface of the substrate.
The reflector portion of the GND pattern on the back surface of the substrate is connected to a coplanar line and connected to a high-frequency circuit. No GND pattern is formed around the high-frequency circuit, and the coplanar line becomes a microstrip line and is connected to the high-frequency circuit. In the case of a multilayer substrate,
By forming a microstrip line for power supply in an arbitrary layer and connecting the microstrip line to the radiator via hole, a connection to a high-frequency circuit can be made. Note that FIG.
(B) On the back surface of the substrate, it is shown that the coplanar line can be converted into a microstrip line on the way.

In general, in a radio communication system, the lower the frequency, the smaller the loss in the transmission line.
It is often converted to F) once. In particular, since transmission loss is large in a quasi-millimeter wave band or a millimeter wave band, it is advantageous to convert to an intermediate frequency as close to the antenna as possible. Also,
In the case of a sector antenna used by switching a plurality of antennas, a sector switch is required near the antenna.
Antenna elements and these circuits are generally connected using a semi-rigid cable or the like. By making the connection, it is possible to reduce the loss generated at the connection point of the cable or the connector.

[0034]

According to the present invention, there is no need for a component or the like for holding the antenna element to be fed and the ground plate at a constant interval, and an antenna substrate for forming a reflector for an antenna at low cost can be obtained. Further, according to the present invention, a substrate having an antenna feeding portion can be provided. Further, according to the present invention, it is possible to provide an antenna substrate having a Yagi antenna effect which is inexpensive and applicable to mass production using a printed circuit board.

Particularly, it is effective in a high frequency band of a quasi-millimeter wave band or a millimeter wave band or more, and in a case of a wireless system using a frequency of several cm or less, it is easy to substantially match the thickness of the substrate. The practical effect is extremely large.

[0036]

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention.

FIG. 2 is a diagram showing a second embodiment of the present invention.

FIG. 3 is a diagram showing a third embodiment of the present invention.

FIG. 4 is a diagram showing a fourth embodiment of the present invention.

FIG. 5 is a diagram showing a fifth embodiment of the present invention.

FIG. 6 is a diagram showing a sixth embodiment of the present invention.

FIG. 7 is a diagram showing a seventh embodiment of the present invention.

FIG. 8 is a diagram showing an eighth embodiment of the present invention.

FIG. 9 is a diagram showing a ninth embodiment of the present invention.

FIG. 10 is a diagram showing a tenth embodiment of the present invention.

FIG. 11 is a diagram showing an eleventh embodiment of the present invention.

FIG. 12 is a diagram showing a conventional antenna.

FIG. 13 is a diagram showing a conventional antenna.

FIG. 14 is a diagram showing a conventional general Yagi antenna.

FIG. 15 is a diagram showing a monopole Yagi antenna of a conventional Yagi antenna.

[Explanation of symbols]

1: radiator (exciter), 2: reflector, 3: director, 4:
Printed circuit board, 5 ... Connector, 6 ... Power supply cable

Claims (10)

[Claims] 1. An antenna substrate comprising: a substrate having a plurality of via holes; a desired position on the substrate serving as an antenna radiating portion; and the plurality of via holes serving as an antenna reflecting portion. 2. The antenna substrate according to claim 1, wherein said plurality of via holes are arranged substantially in a straight line to form an antenna reflector. 3. The substrate according to claim 1, wherein about half of the plurality of via holes are substantially straight.
And a second via hole group in which about half of the plurality of via holes other than the first via hole group are arranged substantially in a straight line. An antenna substrate, wherein a predetermined angle is formed by two via-hole groups. 4. The method according to claim 1, 2 or 3.
The antenna substrate according to claim 1, wherein the antenna radiating section has a structure in which a via hole is provided in the substrate. 5. An antenna substrate comprising a substrate having a plurality of via holes, the via holes operating as a reflector, a radiator or a director of the Yagi antenna. 6. The substrate according to claim 5, wherein one of the plurality of via holes is an antenna radiator, and one of the via holes other than the antenna radiator is an antenna reflector. An antenna substrate, wherein a via hole having a shorter hole length than the antenna reflector is used as an antenna director. 7. The antenna substrate according to claim 4, wherein the feeding portion forms a feeding element by a coplanar line formed on the same substrate. 8. The antenna substrate according to claim 4, wherein said feed portion forms a feed element by a microstrip line formed on the same substrate. 9. The antenna substrate according to claim 4, wherein a high-frequency component is arranged and connected on the same substrate as said substrate. 10. A wireless communication device, wherein the substrate according to claim 1 is used as a transmitter, a receiver, or a transceiver.