阅读说明：本技术 一种基于dgs的紧凑型多陷波超宽带滤波器 (DGS-based compact multi-notch ultra-wideband filter ) 是由 高明明 徐克达 南敬昌 杜冲 王丽 程力 李春晨 于 2019-12-16 设计创作，主要内容包括：本发明公开了一种基于DGS的紧凑型多陷波超宽带滤波器,包括介质基板、位于介质基板上表面中心处的半波长短路枝节微带线、加载在所述半波长短路枝节微带线两侧的开路枝节微带线、加载在所述半波长短路枝节微带线正上方的圆形缺陷微带线、加载在开路枝节微带线上方的宽枝节微带线、开路枝节微带线和宽枝节微带线之间形成有直线型插入耦合微带线、50Ω输入馈线和50Ω输出馈线和位于接地板上的开环型枝节缺陷地结构。本发明采用多模谐振器耦合开路枝节和开环型枝节缺陷地结构,不仅能实现四个陷波,还可以通过调节开路枝节尺寸来改变各个陷波的中心频率,整个通带内插入损耗较低,带外特性良好,结构紧凑,成本低廉,加工方便,易于与其他电路集成。(The invention discloses a DGS (defected ground structure) -based compact multi-notch ultra-wideband filter, which comprises a dielectric substrate, a half-wavelength short-circuit stub microstrip line positioned at the center of the upper surface of the dielectric substrate, an open-circuit stub microstrip line loaded on two sides of the half-wavelength short-circuit stub microstrip line, a circular defect microstrip line loaded right above the half-wavelength short-circuit stub microstrip line, a wide stub microstrip line loaded above the open-circuit stub microstrip line, and linear insertion coupling microstrip lines, 50 omega input feed lines, 50 omega output feed lines and an open-loop stub defect ground structure positioned on a ground plate, wherein the linear insertion coupling microstrip lines, the open-circuit stub microstrip lines and the wide stub microstrip lines are formed between the open-circuit stub microstrip line. The invention adopts a multi-mode resonator to couple the open-circuit branch and the open-loop branch defected ground structure, not only can realize four trapped waves, but also can change the central frequency of each trapped wave by adjusting the size of the open-circuit branch, and has the advantages of lower insertion loss in the whole passband, good out-of-band characteristic, compact structure, low cost, convenient processing and easy integration with other circuits.)

1. A DGS-based compact multi-notch ultra-wideband filter is characterized in that: the microstrip line structure comprises a dielectric substrate (11), a half-wavelength short-circuit stub microstrip line (2) located at the center of the upper surface (10) of the dielectric substrate (11), a circular defect microstrip line (5) loaded right above the half-wavelength short-circuit stub microstrip line (2), open-circuit stub microstrip lines (3) loaded on two sides of the half-wavelength short-circuit stub microstrip line (2), and a wide stub microstrip line (6) loaded above the open-circuit stub microstrip line (3);

a linear insertion coupling microstrip line (4) is formed between the open-circuit branch microstrip line (3) and the wide branch microstrip line (6);

and an input end feeder (1) and an output end feeder (7) which are respectively positioned on two sides of the upper surface (10) of the dielectric substrate (11) are arranged at the bottom of the linear insertion coupling microstrip line (4).

2. The DGS-based compact multi-notch ultra-wideband filter according to claim 1, wherein the straight insertion coupling microstrip line (4) has equal coupling distance with the upper and lower wide stub microstrip lines (6) and the open stub microstrip line (3).

3. The DGS-based compact multi-notch ultra-wideband filter of claim 1, wherein: a metal grounding plate (8) is formed on the lower surface (12) of the dielectric substrate (11), an open-loop branch defective ground structure (9) is arranged on the metal grounding plate (8), and a copper-plated layer on the upper surface (10) of the dielectric substrate has a filter circuit structure.

4. The DGS-based compact multi-notch ultra-wideband filter of claim 3, wherein: the filter circuit structure comprises an input end feeder line (1), a half-wavelength short-circuit branch microstrip line (2), an open-circuit branch microstrip line (3), a linear insertion coupling microstrip line (4), a circular defect microstrip line (5), a wide branch microstrip line (6) and an output end feeder line (7).

5. The DGS-based compact multi-notch ultra-wideband filter of claim 1, wherein: the open-circuit branch microstrip line (3) and the wide branch microstrip line (6) are loaded on two sides of the half-wavelength short-circuit branch microstrip line (2) in a bilateral symmetry manner.

6. The DGS-based compact multi-notch ultra-wideband filter of claim 3, wherein: the open-loop branch knot defect ground structure (9) is printed on the metal grounding plate (8) on the lower surface (12) of the medium substrate in a slotting mode.

7. The DGS-based compact multi-notch ultra-wideband filter of claim 3, wherein: the dielectric substrate (11) has a relative dielectric constant of 10.2, a thickness of 1.27mm and a tangent loss of 0.001; the thickness of copper plating layer and metal grounding plate (8) is 35 um.

Technical Field

The invention belongs to the technical field of microwave communication, and particularly relates to a DGS-based compact multi-notch ultra-wideband filter.

Background

Ultra-wideband technology has emerged in the fifties of the 20 th century but has been used primarily in the military until the 90 s of the 20 th century. In 2002, the Federal communications Commission in the United states mandates that the 3.1-10.6GHz band be available for commercial communications. This approach opens a new door to the commercialization of ultra-wideband technology products, and has rapidly accelerated the application of ultra-wideband technology in various fields, such as: the ultra-wideband technology in the intelligent transportation field can quickly search and accurately position the target; the imaging ultra-wideband technology has good barrier penetration capability; the military field ultra-wideband technology has a good signal hiding function; the low power consumption and low cost of the ultra-wideband can be used for the sensor network.

The ultra-wideband technology has a wide application prospect due to the advantages of high transmission speed, simple system, strong confidentiality and the like, but signal interference generated by a plurality of communication systems working in the same frequency band is also a problem which needs to be solved. Such as a 3.7-4.2GHz C-band satellite communication band, a 5.725-5.825GHz wlan and a 7.9-8.4GHz X-band satellite communication band, these radio signals may cause severe interference to the ultra-wideband system, so that the ultra-wideband filter with notch characteristics is particularly important in the ultra-wideband communication system.

The ultra-wideband filter designed by the prior art has the following problems: (1) the trapped wave bandwidth is too large, and part of useful information is filtered; (2) the depth of trapped wave is insufficient, and interference signals cannot be completely filtered; (3) the out-of-band rejection effect is poor, the frequency mixing phenomenon at the output end of the filter is serious (4), the number of trapped waves is small, only one interference signal can be filtered, and the interference signals cannot be completely filtered.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a DGS-based compact multi-notch ultra-wideband filter with high integration level and low cost, which can shield frequency bands of 5.76-6.14GHz, 7.82-8.45GHz, 3.8-4.4GHz and 10-10.6GHz and effectively eliminate the interference of C-band satellite communication, WLAN and X-band satellite communication signals on signals in a pass band.

In order to solve the technical problems, the invention is realized by the following technical scheme: the invention provides a DGS (defected ground structure) -based compact multi-notch ultra-wideband filter, which comprises a dielectric substrate, a half-wavelength short-circuit stub microstrip line positioned at the center of the upper surface of the dielectric substrate, a circular defect microstrip line loaded right above the half-wavelength short-circuit stub microstrip line, open-circuit stub microstrip lines loaded on two sides of the half-wavelength short-circuit stub microstrip line, and a wide stub microstrip line loaded above the open-circuit stub microstrip line, wherein the half-wavelength short-circuit stub microstrip line is positioned at the center of the upper surface of the dielectric substrate;

the open-circuit branch microstrip line) and the wide branch microstrip line are formed with a linear insertion coupling microstrip line;

and an input end feeder line and an output end feeder line which are respectively positioned on two sides of the upper surface of the dielectric substrate are arranged at the bottom of the linear insertion coupling microstrip line.

As a preferred implementation manner of the foregoing technical solution, the DGS-based compact multi-notch ultra-wideband filter provided by the embodiment of the present invention further includes some or all of the following technical features:

optionally, the linear insertion coupling microstrip line has a coupling distance equal to that of the upper and lower wide stub microstrip lines and the open stub microstrip line.

Optionally, a metal ground plate is formed on the lower surface of the dielectric substrate, the metal ground plate has an open-loop branch-knot defected ground structure, and the copper-plated layer on the upper surface of the dielectric substrate has a filter circuit structure.

Furthermore, the input end feeder line, the half-wavelength short-circuit stub microstrip line, the open-circuit stub microstrip line, the linear insertion coupling microstrip line, the circular defect microstrip line, the wide stub microstrip line and the output end feeder line form the filter circuit structure.

Preferably, the open-circuit stub microstrip line and the wide stub microstrip line are loaded on two sides of the half-wavelength short-circuit stub microstrip line in a bilateral symmetry manner.

In addition, in the embodiment of the invention, the open-loop branch-knot defected ground structure (9) is printed on the metal grounding plate on the lower surface of the dielectric substrate in a slotting mode.

Optionally, the dielectric substrate has a relative dielectric constant of 10.2, a thickness of 1.27mm, and a tangent loss of 0.001; the thickness of copper plate and metal ground plate is 35 um.

Therefore, the DGS-based compact multi-notch ultra-wideband filter can effectively inhibit C-band satellite communication signals, Wireless Local Area Network (WLAN) signals and X-band satellite communication signals in a passband, not only can realize four notches, but also has good transmission characteristics in a non-notch band by adopting a multi-mode resonator to couple an open-loop branch and an open-loop branch with a defected ground structure; the size of the circuit design can be strictly controlled by selecting the dielectric substrate with high dielectric constant, the insertion loss in the whole pass band is low, the filter has good out-of-band characteristics, the notch depth of the filter is large enough, and the requirement of narrow-band notch is met.

The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical means of the present invention more clearly understood, the present invention may be implemented in accordance with the content of the description, and in order to make the above and other objects, features, and advantages of the present invention more clearly understood, the following detailed description is given in conjunction with the preferred embodiments, together with the accompanying drawings.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings of the embodiments will be briefly described below.

FIG. 1 is a schematic diagram of the structure of the upper surface of a DGS-based compact multi-notch UWB filter of the present invention;

FIG. 2 is a schematic diagram of the lower surface of the DGS-based compact multi-notch UWB filter of the present invention;

FIG. 3 is a side view of the DGS based compact multi-notch UWB filter of the present invention;

FIG. 4 is a simulation diagram of a DGS-based compact multi-notch UWB filter of the present invention.

Detailed Description

Other aspects, features and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which form a part of this specification, and which illustrate, by way of example, the principles of the invention. In the referenced drawings, the same or similar components in different drawings are denoted by the same reference numerals.

As shown in fig. 1-3, the DGS-based compact multi-notch ultra-wideband filter of the present invention comprises a dielectric substrate 11, a metallic ground plate 8 located on a lower surface 12 of the dielectric substrate 11, and a filter circuit structure of a copper-plated layer located on an upper surface 10 of the dielectric substrate. An open-loop branch-knot defected ground structure 9 is formed on the metal grounding plate 8 in a groove mode. The filter circuit structure comprises an input end feeder line 1, a half-wavelength short-circuit stub microstrip line 2, an open-circuit stub microstrip line 3, a linear type plug-in coupling microstrip line 4, a circular defect microstrip line 5, a wide stub microstrip line 6 and an output end feeder line 7.

The microstrip line structure on the upper surface 10 of the dielectric substrate is symmetrical as a whole, and the input end feeder 1 and the output end feeder 7 are respectively located on two sides of the upper surface 10 of the dielectric substrate. The half-wavelength short-circuit stub microstrip line 2 is located in the center of the upper surface 10 of the dielectric substrate, the circular defect microstrip line 5 is loaded right above the half-wavelength short-circuit stub microstrip line 2, the open-circuit stub microstrip line 3 is respectively loaded below two sides of the half-wavelength short-circuit stub microstrip line 2, and the ultra-wideband of 3.4-11.6GHz can be generated by adjusting the structural size of the open-circuit stub microstrip line 3. The open-loop branch defect ground structure 9 is imprinted at the central position of the metal grounding plate 8, and the notch position can be adjusted by adjusting the size of the open loop of the open-loop branch defect ground structure 9.

The linear type insertion coupling microstrip line 4 is loaded on the input end feeder line 1 and the output end feeder line 7, and is directly inserted between the open-circuit stub microstrip line 3 and the wide stub microstrip line 6 to form interdigital coupling, and the coupling distance between the linear type insertion coupling microstrip line 4 and the upper and lower microstrip lines (the wide stub microstrip line 6 and the open-circuit stub microstrip line 3) is equal.

The circular defect microstrip line 5 is loaded above the half-wavelength short-circuit stub microstrip line 2, the density of the current of the circular defect can be changed, and the adjustable trapped wave is realized by adjusting the sizes of the open ring and the wide stub microstrip line 6 of the open-ring stub defect ground structure 9.

Further, the dielectric substrate 11 of the present invention has a relative dielectric constant of 10.2, a size of 9mm 18.4mm, a thickness of 1.27mm, an insertion loss of 0.001, and a thickness of a circuit copper plating layer of 35 um.

The ultra-wideband band-pass filter of the invention is designed as follows: the half-wavelength short-circuit stub microstrip line 2 is located in the center of the upper surface 10 of the dielectric substrate, the open-circuit stub microstrip line 3 is loaded below the two sides, then the linear microstrip line is coupled on the open-circuit stub microstrip line, and the input and output feeder lines are introduced into the two sides of the dielectric substrate 11 at the same time, so that the ultra-wideband band-pass filter is formed.

Designing a trapped wave structure: the wide stub microstrip line 6 is loaded above two sides of the half-wavelength short-circuit stub microstrip line 2 to form an open-circuit resonator, then the circular defect microstrip line 5 is loaded above the wide stub microstrip line, the annular stub defect ground structure 9 is imprinted on the metal ground plate 8, and four trapped waves can be generated in the pass band of the filter by the above structure.

The DGS-based compact multi-notch ultra-wideband filter can realize the notch characteristics, simulation calculation is carried out on the structure by adopting simulation software HFSS, and the obtained simulation result is shown in figure 4. As can be seen from the figure, the notch center frequencies of the filter are respectively positioned at 4.1GHz, 5.7GHz, 7.9GHz and 10.3GHz, the multi-notch characteristic is met, two transmission zeros are arranged outside the band, and the good out-of-band rejection characteristic is effectively ensured. The whole size of the ultra-wideband filter is 18.4mm 9mm, the structure is very compact, and the integration is facilitated.

According to the invention, the wide stub microstrip line 6 is directly loaded on two sides of the half-wavelength short-circuit stub microstrip line 2 to form an open-circuit resonator, so that the design size of the filter is greatly reduced and a trapped wave at 7.9GHz is formed; a circular defect microstrip line 5 is loaded above the half-wavelength short-circuit stub microstrip line 2 to form a trapped wave of 5.7 GHz; the open-loop branch-knot defected ground structure 9 arranged on the metal grounding plate 8 can form two trapped waves at the positions of 4.1GHz and 10.3GHz, so that the ultra-wideband band-pass filter with four trapped waves is formed.

While the foregoing is directed to the preferred embodiment of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.