CN203690458U - Ultra wide band wave limiting filter - Google Patents

Abstract

An ultra-wideband wave-limiting filter, comprising an upper metal layer on the upper part, on which a first input-output microstrip line and a second input-output microstrip line are etched, and a lower layer located on the lower part The metal layer has a coplanar waveguide structure and a T-shaped defect ground structure etched on the lower metal layer. The first input-output microstrip line and the second input-output microstrip line are metal structures, and the coplanar waveguide structure and T-shaped defect ground structure are etched. The defective structure is a metal gap structure. This provides a high-performance, low-cost, miniaturized ultra-wideband bandpass filter.

Description

An Ultra-Wideband Limiting Filter

technical field

The invention belongs to the technical field of filter devices, and in particular relates to an ultra-wideband wave-limiting filter.

Background technique

Since the U.S. Federal Communications Commission (FCC) decided to open the unlicensed frequency bands from 3.1GHz to 10.6GHz, UWB wireless communication technology has received great attention. UWB systems have many advantages, such as higher data transfer rates and lower transmit power. Among them, the ultra-wideband filter is one of the important components of the ultra-wideband system.

Contents of the invention

The object of the present invention is to provide an ultra-wideband wave-limiting filter, including an upper metal layer on the upper part, and a first input-output microstrip line and a second input-output microstrip line are etched on the upper layer metal layer, and in addition Including the lower metal layer located at the lower layer, the coplanar waveguide structure and the T-shaped defect ground structure are etched on the lower metal layer, and the first input-output microstrip line and the second input-output microstrip line are metal structures, coplanar The waveguide structure and the T-shaped defect structure are metal slot structures. This provides a high-performance, low-cost, miniaturized ultra-wideband bandpass filter.

In order to overcome the deficiencies in the prior art, the present invention provides a solution for ultra-wideband wave-limiting filters, specifically as follows:

An ultra-wideband filter with T-shaped defects, including an upper metal layer on the upper part, on which a first input-output microstrip line 1 and a second input-output microstrip line 2 are etched, and also includes The lower metal layer located at the lower layer has a coplanar waveguide structure 3 and a T-shaped defect ground structure 4 etched on the lower metal layer, and the first input-output microstrip line 1 and the second input-output microstrip line 2 are metal structures , the coplanar waveguide structure 3 and the T-shaped defect ground structure 4 are metal slot structures.

Applying the above-mentioned scheme of the present invention, the remarkable advantage of the ultra-wideband filter of the T-shaped defect of the present invention is: (1) the relative bandwidth is large, and the 3dB passband range is 2.8GHz to 10.6GHz, and the 3dB relative bandwidth is about 116%, which satisfies the Requirements for ultra-wideband bandpass filters; (2) It can be manufactured through PCB board technology, with a total size of 10mm×20mm, small size and light weight, easy to manufacture and low cost.

Description of drawings

FIG. 1 is a structural schematic diagram of the first input-output microstrip line and the second input-output microstrip line of the present invention.

FIG. 2 is a structural schematic diagram of the coplanar waveguide structure and the T-shaped defect ground structure of the present invention.

Fig. 3 is a graph showing the S-parameter electromagnetic simulation results of the ultra-wideband filter with T-shaped defects of the present invention.

Detailed ways

Below in conjunction with accompanying drawing, content of the invention will be further described:

Referring to Figures 1 and 2, the UWB filter with T-shaped defects: includes an upper metal layer on the upper part, on which the first input-output microstrip line 1 and the second input-output microstrip line 1 and the second input-output microstrip line are etched. The stripline 2 also includes a lower metal layer located at the lower part, a coplanar waveguide structure 3 and a T-shaped defect ground structure 4 are etched on the lower metal layer, and the first input-output microstrip line 1 and the second input-output microstrip line 1 and the second input-output The microstrip line 2 is a metal structure, and the coplanar waveguide structure 3 and the T-shaped defect ground structure 4 are metal slot structures.

The etching method in which the first input-output microstrip line 1 and the second input-output microstrip line 2 are etched on the upper metal layer is a circuit board etching method; in addition, the lower metal layer is etched with a coplanar waveguide structure 3 The etching method of the structure 4 and the T-shaped defect is a circuit board etching method.

The first input-output microstrip line 1 is a plate-shaped body as a whole, and is formed by connecting the first T-shaped coupling microstrip line 1-2 with the first matching line 1-1. The first input-output microstrip line 1 and the second input-output microstrip line 2 have a mirror-symmetrical structure.

The characteristic impedance of the first matching line 1-1 is 50 ohms.

The coplanar waveguide structure 3 includes a connection slot 3-1, two U-shaped slots 3-2 and two L-shaped slots 3-3; the T-shaped defect ground structure 4 includes two square slots 4- 1. An inverted T-shaped slit 4-2, one end of two mirror-symmetrically arranged U-shaped slits 3-2 is connected by a connecting slit 3-1, and the other end of each U-shaped slit 3-2 corresponds to an L-shaped The gaps 3-3 are connected, the inverted T-shaped gap 4-2 is composed of a horizontal gap and a vertical gap, the square gap 4-1 is connected with the horizontal gap of the inverted T-shaped gap 4-2, and the vertical gap of the inverted T-shaped gap 4-2 is connected. The slit is located in the middle of the two L-shaped slits 3-3.

The central symmetric points of the matching line 1-1 of the first input-output microstrip line on the upper metal layer and the matching line 2-1 of the second input-output microstrip line are connected to the two square gaps 4 on the lower metal layer The central symmetry point of -1, the line connecting the two points is perpendicular to the medium plate.

The square slit 4-1 of the T-shaped defective ground structure 4 has a side length of 0.5 mm.

The transverse slit width of the inverted T-shaped slit 4-2 of the T-shaped defective ground structure 4 is 0.1 mm, and the length is 2.2-2.4 mm.

The inverted T-shaped gap 4-2 of the T-shaped defective ground structure 4 has a vertical gap width of 0.1 mm and a length of 3.8-4.0 mm.

The ultra-wideband filter with T-shaped defects of the present invention adopts a dielectric board with a relative permittivity of 3.38 and a thickness of 0.508mm, and can be realized by microwave PCB board technology, so it has very high reliability and low cost.

Combined with the S parameter diagram of the T-shaped defect ground UWB filter in Figure 3, it includes the forward transmission coefficient S21, the input reflection coefficient S11, the 3dB passband range is 2.8GHz to 10.6GHz, and the 3dB relative bandwidth is about 116%; the total The size is 10mm×20mm.

In summary, the ultra-wideband filter with T-shaped defects of the present invention has a relatively large bandwidth and ultra-wide band, which meets the needs of an ultra-wideband bandpass filter; it can be manufactured by PCB board technology, small in size and light in weight, easy to manufacture and low in cost Low, suitable for ultra-wideband communication systems, mobile communication terminals and other wireless communication systems.

The above description is only a preferred embodiment of the present invention, and does not limit the present invention in any form. Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. Anyone familiar with this field Those skilled in the art, without departing from the scope of the technical solution of the present invention, may use the technical content disclosed above to make some changes or modify equivalent embodiments with equivalent changes, but as long as they do not depart from the technical solution of the present invention, according to the technical content of the present invention Within the spirit and principles of the present invention, any simple modifications, equivalent replacements and improvements made to the above embodiments still fall within the scope of protection of the technical solutions of the present invention.

Claims (10)

1. a ultra broadband notch filter, it is characterized in that comprising superposed upper metal layers, in described upper metal layers, be etched with the first input and output microstrip line (1) and the second input and output microstrip line (2), also comprise in addition the lower metal layer that is positioned at bottom, in lower metal layer, be etched with coplanar waveguide structure (3) and T-shaped defect ground structure (4), described the first input and output microstrip line (1) and the second input and output microstrip line (2) are metal structure, and coplanar waveguide structure (3) and T-shaped defect ground structure (4) are metal slit structure.

2. according to the ultra broadband notch filter described in claim 1, the etching mode that is etched with the first input and output microstrip line (1) and the second input and output microstrip line (2) in the upper metal layers described in it is characterized in that is circuit carving erosion mode; To be etched with the etching mode of coplanar waveguide structure (3) and T-shaped defect ground structure (4) be circuit carving erosion mode to lower metal layer in addition.

3. according to the ultra broadband notch filter described in claim 1, it is characterized in that the first described input and output microstrip line (1) entirety is plates, connect a T shape coupled microstrip line (1-2) by the matched line (1-1) of the first input and output microstrip line (1) and form, the first described input and output microstrip line (1) is mirror image with the second input and output microstrip line (2).

4. according to the ultra broadband notch filter described in claim 3, it is characterized in that the characteristic impedance of the matched line (1-1) of the first input and output microstrip line (1) is 50 ohm.

5. according to the ultra broadband notch filter described in claim 4, the Central Symmetry point in two the square gaps (4-1) in the matched line (1-1) of the first input and output microstrip line in the upper metal layers described in it is characterized in that and the Central Symmetry point of the matched line (2-1) of the second input and output microstrip line and lower metal layer, 2 lines are vertical with medium version.

6. according to the ultra broadband notch filter described in claim 1, it is characterized in that described coplanar waveguide structure (3) comprises one and connects gap (3-1), two U-shaped gaps (3-2) and two L shaped gaps (3-3); Described T-shaped defect ground structure (4) comprises two square gaps (4-1) and an inverted T-shaped gap (4-2), connected the one end in the U-shaped gap (3-2) of two mirror image symmetry arrangement by connection gap (3-1), the L shaped gap (3-3) that each U-shaped gap (3-2) other end is corresponding with it is connected, inverted T-shaped gap (4-2) is connected to form by transverse slot and vertical gap, square gap (4-1) is connected with the transverse slot of inverted T-shaped gap (4-2), and the vertical gap of inverted T-shaped gap (4-2) is positioned at middle, two L shaped gaps (3-3).

7. according to the ultra broadband notch filter described in claim 1, it is characterized in that the square gap 4-1 length of side of described T-shaped defect ground structure (4) is 0.5mm.

8. according to the ultra broadband notch filter described in claim 1, it is characterized in that the transverse slot width of the inverted T-shaped gap 4-2 of described T-shaped defect ground structure (4) is 0.1mm, length is 2.2～2.4mm.

9. according to the ultra broadband notch filter described in claim 1, it is characterized in that the vertical gap width in the inverted T-shaped gap (4-2) of described T-shaped defect ground structure (4) is 0.1mm, length is 3.8～4.0mm.

10. according to the ultra broadband notch filter described in claim 1, it is characterized in that described T-shaped defect ground ultra-wide band filter adopts the dielectric-slab that relative dielectric constant is 3.38, thickness is 0.508mm, can realize by microwave pcb board technique.

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