TWI764072B - Semi-anechoic chamber and floor structure thereof - Google Patents

Abstract

A floor structure of a semi-anechoic chamber includes a reflection panel and a ground frame. The reflection panel has a first metal layer, a second metal layer and an insulation layer. The first metal layer and the second metal layer, which are respectively on the upside and downside of the insulation layer, electrically connect each other by a via of the insulation layer. The ground frame is connected to the second metal layer so as to make the current on the first metal layer and the second metal layer flow to a ground.

Description

Semi-anechoic chamber and its floor structure

The present invention relates to a semi-anechoic chamber, in particular to a floor structure of the semi-anechoic chamber.

Electronic devices may be interfered by surrounding electromagnetic waves and cannot function normally. To solve the problem of electromagnetic interference, electromagnetic compatibility (ElectroMagnetic Compatibility; EMC) tests are usually carried out before products are put on the market. This test is usually performed in a laboratory that meets the requirements carried out, for example, in a semi-anechoic chamber.

FIG. 1 shows a top view of a conventional semi-anechoic chamber 100, which is a hexahedral space formed by a wall 102, a ceiling (not shown) and a floor, wherein the wall 102 and the ceiling have materials that absorb electromagnetic waves to avoid Electromagnetic waves are reflected by the wall 102 or the ceiling and affect the test results. The floor is formed by splicing multiple reflectors 104 to simulate an infinite metal ground plane. The semi-anechoic chamber 100 will have an electromagnetic wave emitting area 106 for setting the electromagnetic wave emitting device. and an electromagnetic wave receiving area 108 for setting an electromagnetic wave receiving device. When the electromagnetic wave emitted by the electromagnetic wave transmitting device (not shown in the figure) in the electromagnetic wave transmitting area 106 is emitted to the reflecting plate 104, it will be reflected by the reflecting plate 104, and at the same time the electromagnetic wave on the reflecting plate 104 will be reflected by the reflecting plate 104. A current I1 will be generated, and the current I1 will flow to the wall 102 , and then flow to the ground GND through the wall 102 . FIG. 2 shows a partial cross-sectional view of the semi-anechoic chamber 100 of FIG. 1 . Each reflector 104 includes an insulating layer 1044 and two metal layers 1042 and 1046 on two sides of the insulating layer 1044 respectively, and an upper surface is used between the reflectors 104 . The board 110, the lower board 112 and a screw 114 form a joint structure for connection. There is an L-shaped support frame 116 on the wall 102 to support the adjacent reflector 104. The reflector 104 adjacent to the wall 102 can use a metal wire 118 connects the metal layer 1042 to the wall surface 102 , and both the support frame 116 and the metal wire 118 enable the current on the reflector 104 to flow to the wall surface 102 . As shown in FIG. 2 , when a current I1 is generated on one of the reflectors 104 in FIG. 1 , the current I1 will flow through the joint structure between the reflectors 104 to the adjacent reflector 104 , and finally flow to the wall 102 , and then pass through the wall. Surface 102 flows to ground GND.

However, the conventional semi-anechoic chamber 100 allows the current I1 to flow to the surrounding wall 102, and then flows to the ground GND through the wall 102, resulting in a poor grounding effect, which in turn affects the test of low frequency (eg 30MHz~300MHz) characteristics.

One of the objectives of the present invention is to provide a floor structure of a semi-anechoic chamber.

One of the objectives of the present invention is to provide a semi-anechoic chamber with improved grounding effect.

According to the present invention, a floor structure of a semi-anechoic chamber includes a reflector having a first metal layer, a second metal layer and an insulating layer. The insulating layer is between the first metal layer and the second metal layer, and the insulating layer has a through hole through which the current on the first metal layer can flow to the second metal layer. The floor structure further includes a ground structure connected to the second metal layer, so that the current on the second metal layer flows to the ground.

According to the present invention, a floor structure of a semi-anechoic chamber includes a through hole and a ground structure, and the ground structure is electrically connected to the through hole and a ground. Current on the floor structure flows to the ground through the through hole and the ground structure.

According to the present invention, a semi-anechoic chamber includes a plurality of reflection plates and a plurality of ground structures, and the plurality of ground structures are respectively connected to the plurality of reflection plates, so that the currents on the plurality of reflection plates flow to the ground. Since each reflector can be connected to the ground through the grounding structure connected thereto, the semi-electric darkroom has a better grounding effect, which can improve the test of low frequency characteristics.

FIG. 3 shows the floor structure 200 of the semi-anechoic chamber of the present invention, and FIG. 4 shows a cross-sectional view along the AA' direction in FIG. 3 . 3 and 4 , the floor structure 200 includes a reflector 202 and a grounding structure 206. The reflector 202 has two metal layers 2022 and 2026 and an insulating layer 2024. The insulating layer 2024 is between the two metal layers 2022 and 2026, insulating The layer 2024 has a through hole 204. The metal layers 2022 and 2026 are connected through the through hole 204 so that the current I1 on the metal layer 2022 can flow to the metal layer 2026. The metal layers 2022 and 2026 can be, but not limited to, galvanized steel sheet. Yes but not limited to planks. The grounding structure 206 is connected to the reflector 202 so that the current I1 on the reflector 202 flows to the ground GND. In this embodiment, the grounding structure 206 is realized by a support frame, which is arranged on the ground GND and is used for supporting For the reflection plate 202 , the support frame is connected to the metal layer 2026 of the reflection plate 202 . When electromagnetic waves are emitted to the reflector 202, a current I1 is generated on the metal layer 2022 of the reflector 202. The current I1 flows to the metal layer 2026 through the through hole 204, and then flows to the ground GND through the support frame (grounding structure 206). In one embodiment, the through hole 204 may be filled with conductive material, so that the metal layer 2022 is electrically connected to the metal layer 2026 . In one embodiment, a screw can be used to fix the reflector 202 on the support frame through the through hole 204, and the metal layer 2022 can be electrically connected to the metal layer 2026 through the screw.

In the embodiment shown in FIG. 4 , the reflector 202 has a three-layer structure, but the present invention is not limited thereto. For example, more insulating layers may be added between the metal layers 2022 and 2026 , or the reflector 202 may be modified into a single-layer structure. metal plate. In addition, the numbers and positions of the vias 204 and the ground structures 206 in FIGS. 3 and 4 can also be changed as required.

FIG. 5 shows the first embodiment of the semi-anechoic chamber 300 of the present invention, which includes a plurality of reflecting plates 202 spliced to form the floor of the semi-anechoic chamber 300. The semi-anechoic chamber 300 has an electromagnetic wave emitting area 304 for installing an electromagnetic wave transmitting device and an electromagnetic wave receiving area 306 is for setting an electromagnetic wave receiving device. When electromagnetic waves are emitted to the reflector 202 , the reflector 202 will reflect the electromagnetic waves, and at the same time, a current I1 will be generated on the reflector 202 . Each reflector 202 is connected to a ground structure 206 (as shown in FIG. 4 ), so that the current I1 on each reflector 202 can flow to the ground GND through the ground structure 206 connected thereto, and the current I1 does not need to flow to the wall 302 first. , and then flows to the ground GND, so the semi-anechoic chamber 300 of the present invention has a better grounding effect and can improve the test of low frequency characteristics. In the semi-anechoic chamber 300 of FIG. 5 , the reflector 202 may be a multi-layer structure as shown in FIG. 4 , or may be a single-layer metal plate. FIG. 6 shows a cross-sectional view of a part of the area in FIG. 5 . As shown in FIG. 6 , the current I1 on the reflector 202 of the present invention can not only flow to the ground GND through the through hole 204 and the ground structure 206 , but also through the reflector 202 . The adjacent wall surface 302 flows to the ground GND. Compared with the prior art, the present invention can provide more current paths for the current I1 on the reflector 202 to flow to the ground GND, which has a better grounding effect.

As shown in FIG. 5 , each reflector 202 can allow the current I1 to flow to the ground through the grounding structure 206 connected to it. Therefore, the semi-anechoic chamber 300 of the present invention does not need to be completely spliced by the reflector 104 like the conventional semi-anechoic chamber 100 . so that the current I1 can flow to the wall 102 and then to the ground. FIG. 7 shows the second embodiment of the semi-anechoic chamber 300 of the present invention. In this embodiment, the floor of the semi-anechoic chamber 300 is not entirely composed of the reflector 202, and the reflector 202 is only disposed in the electromagnetic wave emitting area 304 and the electromagnetic wave receiving area 306 area in between. FIG. 8 shows the third embodiment of the semi-anechoic chamber 300 of the present invention. In this embodiment, the reflector 202 is only disposed in the main reflecting areas 308 , 310 , 312 and 314 . The main reflection area is clearly defined in current specifications, such as ANSI C63.4 section 5.3, and those skilled in the art can determine the location of the main reflection area in the semi-anechoic chamber 300.

In the current specification, the normalized site attenuation (NSA) error of the semi-anechoic chamber must be within +/-4dB, while the NSA error of the traditional semi-anechoic chamber 100 is about +/-3.5dB However, the NSA error of the semi-anechoic chamber 300 of the present invention can be reduced to +/-2.5dB, so compared with the conventional semi-anechoic chamber 100, the semi-anechoic chamber 300 of the present invention has better efficacy.

The above description of the preferred embodiments of the present invention is for illustrative purposes, and is not intended to limit the present invention to the exact form disclosed. Modifications or changes are possible based on the above teachings or learning from the embodiments of the present invention. The embodiments are selected and described in order to illustrate the principle of the present invention and to allow those familiar with the technology to use the present invention in practical applications with various embodiments. Decide.

100: Semi-anechoic chamber 102: Walls 104: Reflector 1042: Metal Layer 1044: Insulation layer 1046: Metal Layer 106: Electromagnetic wave emission area 108: Electromagnetic wave receiving area 110: Upper board 112: Lower board 114: Screws 116: Support frame 118: Metal Wire 200: Floor Structure 202: Reflector 2022: Metal Layers 2024: Insulation 2026: Metal Layers 204: Through hole 206: Grounding Architecture 300: Semi-anechoic chamber 302: Wall 304: Electromagnetic wave emission area 306: Electromagnetic wave receiving area 308: Main reflection area 310: Main reflection area 312: Main reflection area 314: Main reflection area

Figure 1 shows a top view of a conventional semi-anechoic chamber. Figure 2 shows a partial cross-sectional view of a conventional semi-anechoic chamber. Figure 3 shows the floor structure of the present invention. Fig. 4 shows a cross-sectional view in the direction AA' of Fig. 3 . Fig. 5 shows the first embodiment of the semi-anechoic chamber of the present invention. FIG. 6 shows a cross-sectional view of a portion of the area in FIG. 5 . Figure 7 shows a second embodiment of the semi-anechoic chamber of the present invention. FIG. 8 shows a third embodiment of the semi-anechoic chamber of the present invention.

200: Floor Structure

202: Reflector

2022: Metal Layers

2024: Insulation

2026: Metal Layers

204: Through hole

206: Grounding Architecture

Claims (13)

A floor structure of a semi-anechoic chamber, comprising: a reflector, including: a first metal layer; a second metal layer; and an insulating layer with a through hole between the first metal layer and the second metal layer; Wherein, the current on the first metal layer flows to the second metal layer through the through hole. The floor structure of claim 1, further comprising a grounding structure connected to the second metal layer, so that the current on the second metal layer flows to the ground. The floor structure of claim 2, wherein the grounding structure comprises a support frame disposed on the ground and connected to the second metal layer to support the reflector, wherein the current on the second metal layer flows to the ground through the support frame . A floor structure of a semi-anechoic chamber, comprising: a through hole; and a grounding structure electrically connecting the through hole and a ground; Wherein, the current on the floor structure flows to the ground through the through hole and the ground structure. The floor structure of claim 4 further includes a reflector for reflecting electromagnetic waves, the reflector has the through hole and is connected to the grounding structure. According to the floor structure of claim 5, the reflector is a single-layer metal plate. The floor structure of claim 5, wherein the grounding structure includes a support frame disposed on the ground for supporting the reflector, wherein the current on the floor structure flows to the ground through the through hole and the support frame. A semi-anechoic chamber, comprising: a plurality of reflectors for reflecting electromagnetic waves; and A plurality of grounding structures are respectively connected to the plurality of reflection plates, so that the currents on the plurality of reflection plates flow to the ground. The semi-anechoic chamber of claim 8, wherein each of the plurality of reflectors comprises: a first metal layer for reflecting electromagnetic waves; a second metal layer connected to one of the plurality of ground structures; and an insulating layer with a through hole between the first metal layer and the second metal layer; Wherein, the current on the first metal layer flows to the second metal layer through the through hole. The semi-anechoic chamber of claim 8, wherein the plurality of reflecting plates are single-layer metal plates. The semi-anechoic chamber of claim 8, wherein each of the plurality of grounded structures includes a support frame disposed on the ground and connected to one of the plurality of reflectors for supporting the connected reflector, wherein the support frame is The current of the connected reflector flows to the ground through the support frame. If the semi-anechoic chamber of claim 8, it also includes: an electromagnetic wave emitting area for arranging the electromagnetic wave emitting device; and an electromagnetic wave receiving area, used to set the electromagnetic wave receiving device; Wherein, the plurality of reflectors are between the electromagnetic wave emitting area and the electromagnetic wave receiving area. The semi-anechoic chamber as claimed in claim 8, wherein the plurality of reflecting plates are disposed in the main reflection area of the semi-anechoic chamber.

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