JPH1013130A - Intrinsic safely barrier device of antenna part for quasi-microwave band - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the intrinsic safety barrier device of an antenna part for a quasi-microwave band small in size that satisfies conditions of the intrinsically safe, even for use at the quasi-microwave band with small loss. SOLUTION: The barrier is provided with a printed circuit board 10 made of a BT resin glass board, ground plates 11 each formed to the upper and lower sides of the printed circuit board 10 and interconnected by a plurality of through-holes, a ground 14 isolated from the ground 11 provided on one side face of the printed circuit board 10 in terms of DC and connecting to a ground 16a of an antenna 16, and a signal wire 18 connecting the antenna 16 and the radio equipment body and a plurality of blocking capacitors 20 on the way. Thus, the small-sized antenna barrier with a small loss of signal wire interconnecting the radio equipment body and the antenna, while satisfying conditions of intrinsic safety are satisfied, even in the case of use at a quasi- microwave band.

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 a quasi-microwave band and has a small loss.

[0002]

2. Description of the Related Art Some radios employ an intrinsically safe explosion-proof antenna for preventing an abnormally high voltage from being input to an antenna unit and protecting the radio unit from abnormally high pressure.

[0003] Further, as shown in FIG. 3, for example, a conventional radio for intrinsically safe explosion protection of a radio device has two blocking capacitors 4 on a signal line 3 connected to the radio device main body, and a ground 5 and a ground 5 of the antenna 2. Also, two blocking capacitors 8 are provided on a ground line 7 connecting between the antennas 6. When an abnormally high voltage is input to the antenna 2 from the outside, the ground line 7 is provided on the signal line 3 or the ground line 7. Blocking capacitors 4 and 8 block this,
Abnormal high pressure is prevented from intruding into the wireless device main body.

[0004]

However, when the conventional intrinsically safe explosion-proof antenna is used in the quasi-microwave band, the ground impedance is increased by the two blocking capacitors 8 provided on 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.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems. Even when used in the quasi-microwave band, the quasi-microwave band intrinsically safe condition satisfies the intrinsically safe explosion-proof condition and the signal line loss is small. An object of the present invention is 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 unit 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 connected to each other by a plurality of through holes, a ground provided on one side of the printed circuit board, DC-insulated, and a ground connected to the ground side of the antenna; And a signal line provided with a plurality of blocking capacitors on the way.

In order to solve the above-mentioned problems, a quasi-microwave band intrinsically safe explosion-proof antenna section barrier device according to the present invention comprises a ground area provided on a printed board, a thickness and a dielectric constant of the printed board, and a ground impedance. Is set to be low.

With the above arrangement, even if an abnormally high voltage is input to the antenna, a plurality of blocking capacitors provided on the signal line block the same and prevent the intrusion into the radio unit itself. Condition can be satisfied.

BT which has a small loss in the quasi-microwave band
By using a resin glass substrate for the printed circuit board and properly selecting the area of the ground, the thickness of the printed circuit board, and the permittivity, the ground impedance can be sufficiently reduced. The loss of the signal line can be reduced, so that the antenna sufficiently functions as an antenna.

[0010]

The quasi-microwave band intrinsically safe explosion-proof antenna unit barrier device according to the first aspect of the present invention includes 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, and DC-insulated, and a ground connected to the ground side of the antenna, connecting the antenna to the wireless device main body, and And a signal line provided with a plurality of blocking capacitors on the way.

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

In the quasi-microwave band intrinsically safe explosion-proof antenna section 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 permittivity are set so that the ground impedance is reduced. Things.

[0013] With this configuration, the ground impedance of the antenna can be sufficiently reduced, so that the loss of the signal line connecting the antenna and the radio unit can be reduced, whereby the antenna sufficiently functions as an antenna. And can be configured simply and compactly, so that it can be provided at low cost.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One 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 an antenna unit 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 a ground 11 made of a conductive layer such as copper foil is formed on the upper and lower surfaces. The grounds 11 in the high frequency band are reduced by connecting the grounds 11 with each other through a large number of through holes 12 opened at regular intervals in the vertical and horizontal directions.

A substantially keyhole-shaped exposed portion 13 is formed on the upper surface of the printed circuit board 10 by removing the conductive layer of the ground 11 by means of etching or the like. Near the center, ground 1
A square ground 14 which is insulated in a DC manner from the ground 1 is formed.

The other end of the coaxial cable 15 whose other end is connected to an antenna 16 to be described later is fixed to the ground 14 by means of soldering or the like.

On the other hand, a signal line 18 is formed substantially in the center of the linear portion of the exposed portion 13 along the longitudinal direction, and a core wire 19 of the coaxial cable 15 is connected to an 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.
2 blocking capacitors 20 so as to be +3 mm
Is provided. Between the other end of the signal line 18 and the ground 11, there is provided a main body connection terminal 21 for connecting the signal line 18 and the ground 11 to the side of the radio main unit (not shown). The core wire 19 at the other end of the antenna 16 is connected to the antenna 16 and the wire 17 is connected to the antenna 16.
To the ground 16a.

Next, the operation of the antenna barrier device configured as described above will be described. The antenna unit barrier device is used by connecting the main body connection terminal 21 to the radio device main body. In addition, since the blocking capacitor 20 provided on the signal line 18 blocks this to prevent the abnormally high voltage from entering the wireless device main body, the condition for intrinsically safe explosion protection can be satisfied, and the abnormally high voltage can be satisfied. From the wireless device 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 A, the thickness d of the printed circuit board 10 and the dielectric constant εr of the printed circuit board 10 are appropriately selected so that the ground impedance of the antenna 16 can be sufficiently reduced even when a radio is used in the quasi-microwave band. As a result, the loss of the signal line 18 can be greatly reduced.

Note that two or more blocking capacitors 20 for the signal line 18 may be provided.

[0024]

As described above in detail, according to the quasi-microwave band intrinsically safe explosion-proof antenna barrier device of the first aspect, 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 is insulated DC from a ground provided on one side surface of the printed circuit board, and is connected to the ground side of the antenna. By providing a ground and a signal line connecting the antenna to the radio body and providing a plurality of blocking capacitors on the way, even if an abnormally high voltage is input to the antenna during use of the radio, the signal A plurality of blocking capacitors provided on the line block this to prevent extraordinary high voltage from entering the radio unit. There is an effect that the main body can be protected.

In the quasi-microwave band intrinsically safe explosion-proof antenna unit barrier device according to claim 2, the area of the ground provided on the printed board, the thickness and the permittivity of the printed board are set so that the ground impedance is reduced. Because the ground impedance of the antenna can be sufficiently reduced, the loss of the signal line connecting the antenna and the radio unit can be reduced, and the antenna functions sufficiently as an antenna even in the quasi-microwave band.
Since the transmission / reception sensitivity is improved and the configuration can be simplified and reduced in size, there is an effect that it can be provided at low cost.

[Brief description of the drawings]

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

FIG. 2 is the same circuit diagram.

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Printed circuit board 11 Ground 12 Through hole 14 Ground 15 Coaxial cable 16 Antenna 16a Antenna side ground 17 Mesh wire 18 Signal wire 19 Core wire 20 Blocking capacitor

Claims (2)

[Claims] 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.
A ground insulated from the ground provided on one side of the printed circuit board, and a ground connected to the ground side of the antenna, the antenna connected to the wireless device main body, and a plurality of blocking capacitors provided midway. A semi-microwave band intrinsically safe explosion-proof antenna unit barrier device comprising: 2. The quasi-microwave band intrinsically safe explosion-proof antenna unit 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 permittivity are set so as to reduce the ground impedance. apparatus.