JP3518955B2 - Submicrowave band intrinsically safe explosion-proof antenna barrier device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna barrier device which satisfies intrinsically safe explosion-proof conditions in the quasi-microwave band and has a small loss.

[0002]

2. Description of the Related Art Some radios employ an intrinsically safe explosion-proof antenna that prevents an abnormally high voltage from being input to the antenna section and protects the main body of the radio from the abnormally high voltage.

In the conventional intrinsically safe explosion-proof antenna for radio equipment, as shown in FIG. 3, for example, two blocking capacitors 4 are provided in the signal line 3 connected to the radio equipment body, and the ground 5 and ground of the antenna 2 are provided. Two blocking capacitors 8 are also provided in the ground line 7 connecting between 6 and, when an abnormally high voltage is input to the antenna 2 from the outside, it is provided in the signal line 3 or the ground line 7. Blocking capacitors 4 and 8 block this,
It is designed to prevent an abnormally high voltage from entering the main body of the radio.

[0004]

However, in the above-mentioned conventional intrinsically safe explosion-proof antenna, when used in the quasi-microwave band, the ground impedance becomes high due to the two blocking capacitors 8 provided in the ground line 7. As a result, there is a problem that the loss of the signal line 3 connecting the main body connection terminal 1 and the antenna 2 increases and the antenna 2 does not function as an antenna.

The present invention has been made in order to solve the above-mentioned conventional problems, and satisfies the intrinsically safe explosion-proof condition even when used in the quasi-microwave band, and the quasi-microwave band intrinsically safe with less signal line loss. It is an object of the present invention to provide an explosion-proof antenna barrier device.

[0006]

In order to solve the above problems, a quasi-microwave band intrinsically safe explosion-proof antenna barrier device according to the present invention comprises a printed circuit board made of a BT resin glass substrate, and upper and lower surfaces of the printed circuit board. Formed in
And a ground that is connected to each other by a plurality of through holes, a ground that is galvanically insulated from the ground provided on one side surface of the printed circuit board, and that is connected to the ground side of the antenna, and the antenna and the radio unit main body. And a signal line which is connected and is provided with a plurality of blocking capacitors in the middle thereof.

In order to solve the above-mentioned problems, the quasi-microwave band intrinsically safe explosion-proof antenna part barrier device according to the present invention is arranged such that the area of the ground provided on the printed circuit board, the thickness and the dielectric constant of the printed circuit board are adjusted to the ground impedance. Is set to be low.

With the above configuration, even if an abnormally high voltage is input to the antenna, a plurality of blocking capacitors provided in the signal line block the blocking and prevent the wireless device from entering the main body. The conditions of can be satisfied.

BT with less loss in the quasi-microwave band
Since the ground impedance can be lowered sufficiently by using the resin glass substrate as the printed circuit board and selecting the area of the ground, the thickness of the printed circuit board and the dielectric constant appropriately, the antenna and the transceiver itself are connected. The loss of the signal line is reduced, which allows the antenna to function sufficiently as an antenna.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A quasi-microwave band intrinsically safe explosion-proof antenna barrier device according to claim 1 is a printed circuit board made of a BT resin glass substrate and a plurality of through-holes formed on the upper and lower surfaces of the printed circuit board. A ground connected to each other by a hole, a ground provided on one side surface of the printed circuit board in a direct current manner, and a ground connected to the ground side of the antenna, the antenna connected to the main body of the radio, and And a signal line provided with a plurality of blocking capacitors on the way.

With this structure, even if an abnormally high voltage is input to the antenna while the wireless device is in use, a plurality of blocking capacitors provided on the signal line block this and prevent the abnormally high voltage from entering the wireless device main body. Because of the prevention, the conditions for intrinsically safe explosion-proof can be satisfied, and the radio main unit can be protected against abnormally high pressure.

In the quasi-microwave band intrinsically safe explosion-proof antenna part barrier device according to claim 2, the area of the ground provided on the printed circuit board, the thickness of the printed circuit board, and the dielectric constant are set so that the ground impedance becomes low. It is a thing.

With this configuration, the ground impedance of the antenna can be sufficiently lowered, so that the loss of the signal line connecting the antenna and the main body of the radio can be reduced, and the antenna can sufficiently function as an antenna, so that the transmission / reception sensitivity is reduced. Since it can be configured easily and in a small size while being improved, it can be provided at low cost.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail with reference to the drawings shown in FIGS.

FIG. 1 is a perspective view of the antenna barrier device, and FIG. 2 shows the same circuit.

In these figures, reference numeral 10 denotes a printed circuit board made of a BT resin glass substrate which causes little loss even when used in the quasi-microwave band, and grounds 11 made of a conductive layer such as copper foil are formed on the upper and lower surfaces thereof. The grounds 11 are connected to each other by a large number of through holes 12 which are opened at regular intervals in the vertical and horizontal directions to reduce the ground impedance in the high frequency band.

On the upper surface of the printed circuit board 10, a substantially keyhole-shaped exposed portion 13 is formed by removing the conductive layer of the ground 11 by means such as etching. The exposed portion 13 has a circular portion. Ground 1 at almost the center
1 and a square-shaped ground 14 that is galvanically isolated.

The net 14 side of the coaxial cable 15 whose other end is connected to the antenna 16 described later is fixed to the ground 14 by means such as soldering.

On the other hand, a signal line 18 is formed along the longitudinal direction substantially at the center of the straight line portion of the exposed portion 13, and the core wire 19 of the coaxial cable 15 is formed at the end of the signal line 18 on the ground 14 side. Is fixed by means such as soldering, and the distance between terminals is 8/3 in the middle of the signal line 18.
Two blocking capacitors 20 to be + 3mm
Is provided. Further, between the other end side of the signal line 18 and the ground 11, a main body connection terminal 21 for connecting the signal line 18 and the ground 11 to the radio main body (not shown) side is provided, and the coaxial cable 15 is provided. The core wire 19 on the other end side of the antenna 16 is connected to the antenna 16, and the mesh wire 17 is connected to the antenna 16
Is connected to the ground 16a.

To describe the operation, the antenna barrier device configured as described above is used by connecting the main body connection terminal 21 to the main body of the radio, but when an abnormal high voltage is input to the antenna 16 during use. Also, since the blocking capacitor 20 provided in the signal line 18 blocks this and prevents the abnormally high voltage from entering the main body of the wireless device, it is possible to satisfy the conditions for intrinsically safe explosion-proof and also to have the abnormally high voltage. Can protect the radio itself.

The ground impedance C of the antenna 16 can be expressed by the following equation.

C = ε0 × εr × A / d where ε0: Dielectric constant in vacuum εr: Dielectric constant of printed circuit board A: Area of ground 11 d: Thickness of printed circuit board Therefore, from the above equation, the area of ground 11 By properly selecting A, the thickness d of the printed circuit board 10 and the dielectric constant εr of the printed circuit board 10, the ground impedance of the antenna 16 can be sufficiently lowered even when the radio device is used in the quasi-microwave band. Therefore, the loss of the signal line 18 can be significantly reduced.

Two or more blocking capacitors 20 for the signal line 18 may be provided.

[0024]

As described in detail above, according to the antenna part barrier device for quasi-microwave band intrinsically safe explosion protection according to claim 1, a printed circuit board made of a BT resin glass substrate,
A ground formed on the upper and lower surfaces of the printed circuit board and connected to each other by a plurality of through holes, and a ground provided on one side surface of the printed circuit board are galvanically insulated and connected to the ground side of the antenna. Even if an abnormally high voltage is input to the antenna while using the wireless device, the signal line that connects the antenna and the wireless device main body with the ground and the signal line with multiple blocking capacitors provided in the middle Since a plurality of blocking capacitors provided on the line block this and prevent the abnormal high voltage from entering the main body of the radio, it is possible to satisfy the conditions for intrinsically safe explosion-proof, It has the effect of protecting the body.

In the quasi-microwave band intrinsically safe explosion-proof antenna part barrier device according to claim 2, the area of the ground provided on the printed circuit board, the thickness of the printed circuit board, and the dielectric constant are set so that the ground impedance becomes low. Since the ground impedance of the antenna can be sufficiently lowered, the loss of the signal line connecting the antenna and the radio main body can be reduced, which allows the antenna to sufficiently function as an antenna even in the quasi-microwave band.
Since the transmission / reception sensitivity is improved and the configuration can be made simple and small, it can be provided at a low cost.

[Brief description of drawings]

FIG. 1 is a perspective view of a quasi-microwave band intrinsically safe explosion-proof antenna barrier device according to an embodiment of the present invention.

FIG. 2 is a circuit diagram of the same.

FIG. 3 is a circuit diagram of a conventional intrinsically safe explosion-proof antenna section barrier device.

[Explanation of symbols]

10 printed circuit boards 11 grand 12 through holes 14 Grand 15 coaxial cable 16 antenna 16a Antenna side ground 17 mesh line 18 signal lines 19 core wire 20 blocking capacitors

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01Q 1/50

Claims (2)

(57) [Claims] 1. A printed circuit board made of a BT resin glass substrate, and a ground formed on the upper and lower surfaces of the printed circuit board and connected to each other by a plurality of through holes.
The ground provided on one side of the printed circuit board is galvanically insulated, and the ground connected to the ground side of the antenna is connected to the antenna and the wireless device main body, and a plurality of blocking capacitors are provided in the middle. Antenna device for quasi-microwave band intrinsically safe explosion-proof antenna, comprising: 2. The quasi-microwave band intrinsically safe explosion-proof antenna barrier according to claim 1, wherein the area of the ground provided on the printed circuit board, the thickness of the printed circuit board, and the dielectric constant are set so that the ground impedance becomes low. apparatus.