JP2729307B2 - Wireless transmission unit - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a wireless transmission unit in which a plate antenna is integrated into a high-frequency circuit.

[Prior Art] In recent years, in a non-contact ID card system or the like, a plate antenna has been used to reduce the size and thickness of a wireless transmitter and a receiver. For example,
FIG. 5 shows a conventional non-contact ID card system that opens and closes a door by wirelessly transmitting and receiving identification data. The system includes an ID card 102, a receiver 100, and a signal processing unit 103. And a door gate 104 and the like. The receiver 100 includes an antenna 101, a receiving circuit 105, a power supply unit, and the like. The antenna 101 is shown in FIGS. 6 (a) and (b) and FIGS. A rectangular patch antenna whose structure and characteristics are shown is used.

In this antenna 200, as shown in FIGS. 6A and 6B, a radiation conductor 202 smaller than the ground conductor 201 is laminated and disposed above the ground conductor 201 via a dielectric 203. A feed line 205 is connected to a feed point 204 of the radiation conductor 202, and a connector 206 is provided on the back surface of the ground conductor 201.

To explain the operation of this system, as shown in FIG. 8, the normal door gate (door) 104 is in a closed state,
To open the door gate 104, stand near the door gate 104 and press the push switch of the ID card 102, and the ID card 102 transmits identification data. The data is received by the receiver 100 installed near the door gate 104, the data content is read by the signal processing unit 103, and the door gate 104 is unlocked. In the figure, the arrow indicates the moving direction of the door gate 104.

By the way, in such a conventional method, only the check at the time of entering the room is performed, so the directivity of the receiving antenna is
A unidirectional radiation pattern facing the outside of the room was sufficient.

However, when checking the exit using this system, the reception cannot be sufficiently performed due to the problem of the directivity of the antenna, and the limitation is obvious.

In view of such circumstances, the present applicant has proposed an antenna structure in which the directional characteristics of the antenna are made closer to non-directional in Japanese Patent Application No. 63-73684 (Japanese Patent Application Laid-Open No. 01-245721). The present invention proposes a wireless transmission unit in which such an antenna structure is integrated into a high-frequency circuit.

[Problem to be Solved by the Invention] Therefore, the problem to be solved by the present invention is disclosed in Japanese Patent Application No. 63-73684.
In the case where the antenna structure proposed in Japanese Patent Application Laid-Open No. Hei 01-245721 is applied to an actual wireless transmission / reception device, the object is to facilitate assembly of the device.

[Means for Solving the Problems] A wireless transmission unit according to the present invention proposed to achieve the above object is provided with a power supply pin above a ground conductor plate provided with a cut-and-raised piece for a spacer at each opening edge. A circuit board on which a high-frequency circuit portion having a circuit board is mounted is mounted, and a frame-shaped radiating conductor plate having an opening window formed in the center and a short-circuiting plate is provided above the circuit board. An antenna unit having a layered structure, the radiation conductor plate is connected to the ground conductor plate through the circuit board by the short-circuit plate, and is connected to the high-frequency circuit unit of the circuit board by the feed pin, In addition, the ground pattern of the circuit board is connected to the ground conductor plate, and the high-frequency circuit section is fixed at a position separated from the periphery of the opening window of the radiation conductor plate. It is characterized by.

First, the circuit board on which the high-frequency circuit section is mounted is arranged in a state of being floated at an appropriate height by a cut-and-raised piece for a spacer provided at a side end of the opening formed on the ground conductor plate side. In addition, the ground conductor plate and the circuit board are connected only to the ground side wiring portion of the circuit board. The second radiation conductor plate is connected to the ground conductor plate through the circuit board by the short-circuit plate, and is connected to a power supply pin of the high-frequency circuit unit so that a high-frequency current is supplied.

Thirdly, the radiation conductor plate is provided with an opening window to provide a sufficient separation distance from the high-frequency circuit section.

Further, such a wireless transmission unit of the present invention can be used as a wireless receiver if the high-frequency circuit unit mounted on the circuit board is a high-frequency reception circuit unit that processes a radio signal captured from an antenna unit. If the high-frequency circuit unit mounted on the circuit board is a high-frequency transmission circuit unit that outputs a radio signal radiated from the antenna unit, it can be used as a wireless transmitter.

[Operation] The wireless transmission unit of the present invention has the following operation.

The width of the ground conductor plate is made equal to the width of the radiation conductor plate, and the length of the ground conductor plate is made longer than that of the radiation conductor plate. As a result, antenna directivity close to non-directionality can be obtained as compared with a conventional rectangular patch antenna.

Embodiment An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is an assembly structure diagram of the wireless transmission unit A of the present invention, and FIG. 2 is an exploded perspective view.

With reference to these figures, reference numeral 1 denotes a rectangular grounding conductor plate, and at its four corners, fixing portions 1a... For screwing to a main body case of the receiver are formed, and Two openings 11, 11 are formed at a constant interval while the conductive portion 13 is left, and cut-and-raised pieces 11a, 11a are formed at corresponding one ends of the openings 11, 11, respectively. Provided. The cut-and-raised pieces 11a, 11a serve as spacers when the circuit board 3 described later is arranged, and the solder portions formed on the back surface of the circuit board 3 by careless floating contact with the ground conductor plate 1 Is prevented from doing so.

In the present invention, since the conductive portion 13 is left in the center of the ground conductor plate 1 having the highest current density of the antenna, there is no problem in lowering the antenna efficiency.

The cut-and-raised pieces 11a, 11a are provided with positioning claws 11b and connecting small pieces 11c.
The circuit board 3 is fixed to an appropriate position on the ground conductor plate 1 by fitting into a hole (not shown) provided on the side, and the other connection piece 11c
Is a soldering allowance for applying and connecting solder to make the ground wiring portion provided on the back surface of the circuit board 3 the same ground level as the ground conductor plate 1.

A cut-and-raised piece 12 is also formed at the rear end of the ground conductor plate 1, and the same connection small piece 12a,
・ Is formed.

Further, locking recesses 1b are provided on both sides of the ground conductor plate 1 to prevent accidental contact when the ground conductor plate 1 is incorporated in the main body case (see FIG. 4).

FIG. 3 is a view of the grounding conductor plate 1 as viewed from the back, and the circuit board 3 has two openings 11 and 11 of the grounding conductor plate 1.
, 12a... Provided on the side of the ground conductor plate 1 are connected to conductive lands formed on a ground pattern portion formed on the back surface of the circuit board 3.
3a are connected by soldering.

Reference numeral 2 denotes a radiation conductor plate disposed above the ground conductor plate. A large rectangular opening window 20 is formed at the center, and a short-circuit plate 4 for connecting the radiation conductor plate 2 to the ground conductor plate 1 is provided. Stop piece extending to one end and screwed to the body case
2a... Are provided at four corners.

A locking piece 4a is formed at the tip of the short-circuit plate 4, and the locking piece 4a is fitted into a slit (not shown) provided at a corresponding portion of the circuit board 3 to penetrate the circuit board 3. Thereby, the mounting position of the radiation conductor plate 2 to the circuit board 3 is defined.

The rectangular opening window 20 formed in the center of the radiation conductor plate 2
When the circuit board 3 is mounted and arranged on the ground conductor plate 1,
It is formed to prevent contact with the circuit unit mounted on the circuit board 3 and to separate the high-frequency circuit unit 31 from the radiation conductor plate 2 with a sufficient distance.

On the other hand, the circuit board 3 is provided with a power supply pin 32, an electronic component 33 constituting a signal processing unit, and an output terminal 34 for outputting a processed signal to the outside, in addition to a metal shield case incorporating the high-frequency circuit unit 31. In addition, various control devices to be controlled by the wireless system are connected to the output terminal 34.

The output terminal 34 is omitted when the wireless unit is configured as a transmitter.

The power supply pin 32 protruding from the upper surface of the circuit board 3 is inserted into a hole 2b formed in the center of the radiation conductor plate 1 on the side of the short-circuit plate 4, fixed by solder, and connected.

In the above description, the unit of the wireless receiver has been described. However, if the high-frequency circuit unit mounted on the circuit board is the transmission circuit unit, it goes without saying that the unit can be used as a transmitter.

FIG. 4 shows an example in which the wireless transmission unit A of the present invention is incorporated in a main body case to constitute a wireless receiver.

The main body of the wireless receiver is formed by combining the lid cover 6 with the base case 5. When the wireless unit A of the present invention is used, the stoppers 1 a of the ground conductor plate 1 of the wireless unit A are used. Is fixed to a screw column 5a provided in the base case 5 with a screw.
2a is a screw post that stands on the base case 5 at a fixed height
5b is fixed with screws, and if necessary, the entire unit A is covered with a protective cover plate 7, and the cover 6 is finally covered.

When the whole unit A is covered with the protective cover plate 7 as shown in FIG. 4, an intermediate user such as a wiring construction worker who attaches the receiver touches the antenna unit at the time of work or the like. Can be prevented, and the destruction of the circuit section due to static electricity can be prevented.

In addition, the base case 5 shown in FIG. 4 has a plurality of standing ribs 52 with step portions 53 formed at predetermined intervals on both sides thereof.
Are formed, and the notches 1b... Of the radiation conductor plate 1 are engaged with the respective step portions 53. By letting
The contact area between the radiation conductor plate 1 and the base case 5 is minimized so that the resonance frequency of the antenna unit does not become unstable.

[Effects of the Invention] According to the wireless transmission unit of the present invention, a wireless transmission unit in which the antenna directivity is almost non-directional can be configured by integrally incorporating a circuit board on which a high-frequency circuit unit is mounted on a plate antenna. Therefore, a wireless receiver and a transmitter can be easily configured simply by assembling them in the main body case.

[Brief description of the drawings]

1 is an assembly structure diagram of a wireless transmission unit of the present invention, FIG. 2 is a perspective view showing an exploded structure thereof, FIG. 3 is a rear view of a ground conductor plate to which a circuit board is connected, and FIG. FIG. 5 is a schematic diagram of a non-contact ID card system using a plate antenna, and FIGS. 6 (a) and (b) are diagrams of a conventional plate patch antenna. FIGS. 7 (a) to 7 (c) are explanatory diagrams of the directivity characteristics, and FIG. 8 is a diagram illustrating an example of use of an ID card system using a plate-like patch antenna. [Explanation of Symbols] A: Wireless transmission unit 1: Ground conductor plate 11: Opening 11a: Cut-and-raised piece for spacer 13: Conductive portion left at center 2: Radiating conductor plate 20 ... Opening window 3 Circuit board 31 High-frequency circuit 32 Power supply pin 4 Shorting plate

Claims (4)

(57) [Claims] 1. A circuit board on which a high-frequency circuit portion having a power supply pin is mounted is mounted above a ground conductor plate having cut-and-raised pieces for a spacer at each opening edge. Above, an opening window is formed in the center, and a frame-shaped radiating conductor plate having a short-circuiting plate is provided to form an antenna portion having a three-layer structure. The power supply pin is connected to the high-frequency circuit section of the circuit board, and the ground pattern of the circuit board is connected to the ground conductor plate and the high-frequency circuit section Is fixed at a position separated from the peripheral edge of the opening window of the radiation conductor plate. 2. The wireless transmission unit according to claim 1, wherein the ground conductor plate has a width substantially equal to that of the radiation conductor plate and a length longer than the radiation conductor plate. 3. The wireless transmission unit according to claim 1, wherein the high-frequency circuit mounted on the circuit board constitutes a high-frequency receiving circuit for receiving and processing a radio signal captured by the antenna. 4. The wireless transmission unit according to claim 1, wherein the high-frequency circuit unit mounted on the circuit board constitutes a high-frequency transmission circuit unit that emits a radio signal from the antenna unit.