CN110600842B - Four-frequency-band microstrip band-pass filter with notch characteristic and design method thereof - Google Patents
Four-frequency-band microstrip band-pass filter with notch characteristic and design method thereof Download PDFInfo
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- CN110600842B CN110600842B CN201910998521.3A CN201910998521A CN110600842B CN 110600842 B CN110600842 B CN 110600842B CN 201910998521 A CN201910998521 A CN 201910998521A CN 110600842 B CN110600842 B CN 110600842B
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01P—WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE
- H01P1/00—Auxiliary devices
- H01P1/20—Frequency-selective devices, e.g. filters
- H01P1/201—Filters for transverse electromagnetic waves
- H01P1/203—Strip line filters
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01P—WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE
- H01P11/00—Apparatus or processes specially adapted for manufacturing waveguides or resonators, lines, or other devices of the waveguide type
- H01P11/007—Manufacturing frequency-selective devices
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Abstract
The invention discloses a four-frequency-band microstrip bandpass filter with a notch characteristic and a design method thereof, wherein the four-frequency-band microstrip bandpass filter with the notch characteristic comprises a circuit board comprising a conductor band, a dielectric substrate and a grounding plate, wherein a short circuit perforation is arranged on the circuit board; the conductor strip comprises an input port, an output port, a feeder line, two first ladder impedance resonators, two second ladder impedance resonators and two F-shaped open-circuit branches; the feeder is connected between an input port and an output port, two first ladder impedance resonators are connected to the upper end of the feeder, two second ladder impedance resonators are connected to the lower end of the feeder, two F-shaped open-circuit branches are connected to the upper end of the feeder, and the first ladder impedance resonators are located between the two F-shaped open-circuit branches. The invention has the characteristics of notch, can realize band-pass filtering of four frequency bands simultaneously, and has the advantages of simple structure, small volume, high integration level, excellent performance and strong compatibility.
Description
Technical Field
The invention relates to a four-frequency-band microstrip band-pass filter with a notch characteristic and a design method thereof.
Background
In a mobile communication system, a filter is a radio frequency front-end device for selecting an operating frequency band and filtering out-of-band interference. A filter is a two-port network having the property of providing signal transmission in the passband frequency and attenuation in the stopband to control the frequency response in a communication system. With the rapid development of modern mobile communication, the filter gradually moves towards miniaturization, high performance, low cost and multi-band trend, and the microstrip band-pass filter is widely focused by researchers in industry because of being easy to meet the requirements, and is applied to various fields of the mobile communication industry.
Currently, the fifth generation mobile communication (5G) is one of the most popular subjects in the global information industry, and has raised a new technological revolution in the global mobile communication field. The development of the 5G technology in China has been greatly advanced, the industrial and communication department has formally issued the low-frequency experimental frequencies in the 5G mobile communication to three major operators such as China Mobile, china telecom, china Unicom and the like, and the experimental frequencies are respectively: 2515 MHz-2675 MHz, 3400 MHz-3500 MHz MHz, 3500 MHz-3600 MHz and 4800 MHz-4900 MHz, the conventional filter can not well realize band-pass filtering of four frequency bands, and can not construct notches between adjacent narrow bands while realizing band-pass filtering of four frequency bands, so that the conventional filter can not meet the use requirements of 5G technology.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provide a four-frequency-band microstrip bandpass filter with notch characteristics, which can realize bandpass filtering of four frequency bands simultaneously, and has the advantages of simple structure, small volume, high integration level, excellent performance and strong compatibility.
In order to solve the technical problems, the technical scheme of the invention is as follows: a four-frequency band microstrip bandpass filter with notch characteristics comprises a circuit board comprising a conductor band, a dielectric substrate and a grounding plate which are sequentially arranged;
The circuit board is provided with a short circuit perforation penetrating through the conductor belt, the dielectric substrate and the grounding plate so that the conductor belt penetrates through the dielectric substrate to be connected with the grounding plate; wherein the conductor strip comprises:
An input port and an output port;
A feeder line connected between the input port and the output port by means of a stepped feed, the short-circuit perforation passing through the feeder line;
Two first ladder impedance resonators which are connected to the upper end of the feeder line and are bilaterally symmetrical with respect to the center line of the circuit board;
two second ladder impedance resonators connected to the lower end of the feeder line and bilaterally symmetrical with respect to the center line of the circuit board;
And the two F-shaped open-circuit branches are connected to the upper end part of the feeder line and are bilaterally symmetrical relative to the central line of the circuit board, and the first ladder impedance resonator is positioned between the two F-shaped open-circuit branches.
Further provided is a specific construction scheme of the F-shaped open-circuit branch, the F-shaped open-circuit branch comprising:
an inverted-L open stub connected to the feed line;
rectangular open-circuit branches connected to the inverted-L-shaped open-circuit branches and parallel to the feeder line.
Further, the width of the rectangular open-circuit branch is greater than the width of the inverted-L open-circuit branch.
Further provided is a specific structure of the first ladder impedance resonator including a first high impedance branch line and a first low impedance branch line; wherein,
The lower end part of the first high-impedance branch line is connected to the feed line;
An end of the first low-impedance branch line is connected to an upper end of the first high-impedance branch line;
A coupling gap is formed between the other end portion of the first low-impedance branch line and the first low-impedance branch line in the other first stepped-impedance resonator.
Further provided is a specific structure of the second stepped impedance resonator including a second high impedance branch line and a second low impedance branch line; wherein,
The upper end part of the second high-impedance branch line is connected to the feed line;
One end of the second low-impedance branch line is connected with the lower end of the second high-impedance branch line;
the other end portion of the second low-impedance branch line is connected to a second low-impedance branch line in another second ladder impedance resonator.
Further, the short-circuit perforation is located at the center of the circuit board and/or the diameter of the short-circuit perforation is 0.5mm.
Further, the input port and the output port are symmetrically disposed about a centerline of the circuit board, and/or lengths of the first stepped impedance resonator and the second stepped impedance resonator are each one quarter of an operating wavelength.
Further, the dielectric substrate has a dielectric constant of 2.2; and/or the thickness of the dielectric substrate is 0.707mm; and/or the material of the medium substrate is Rogowski 5880; and/or the dielectric substrate has a length of 35.8mm and a width of 30.7mm.
The invention also provides a design method of the four-frequency band microstrip band-pass filter with the notch characteristic, which comprises the following steps:
S1: on the basis that an input port and an output port are connected to a feeder line in a stepped feed connection mode and the input port and the output port share a short circuit perforation, a pair of first stepped impedance resonators, a pair of second stepped impedance resonators and a pair of F-shaped open circuit branches are arranged in parallel on a dielectric substrate;
s2: the sizes and the positions of the first ladder impedance resonator and the second ladder impedance resonator are adjusted so as to adjust the working ranges of the highest frequency band and the lowest frequency band in the four frequency bands; the size and the position of the F-shaped open circuit branch knot are adjusted to adjust the working range and the notch point frequency of the other two frequency bands in the four frequency bands, so that the four-frequency band microstrip band-pass filter with the notch characteristic meeting the requirements is obtained.
Further, the specific steps of step S2 are as follows:
M1: inverting the sizes of the first ladder impedance resonator and the second ladder impedance resonator according to the working ranges of the highest frequency band and the lowest frequency band in the four frequency bands, and inverting the sizes of the F-shaped open-circuit branches according to the working ranges and the notch point frequencies of the other two frequency bands in the four frequency bands;
M2: and adjusting the positions of the first ladder impedance resonator, the second ladder impedance resonator and the F-shaped open circuit branch knot so as to reduce coupling interference among the first ladder impedance resonator, the second ladder impedance resonator and the F-shaped open circuit branch knot on the same side and obtain the four-frequency-band microstrip band-pass filter with notch characteristics which meets the requirements.
After the technical scheme is adopted, the four-frequency-band microstrip band-pass filter with the notch characteristic has the advantages of simple structure, small volume, high integration level and excellent performance, has the notch characteristic, realizes band-pass filtering of four working frequency bands, namely a first passband, a second passband, a third passband and a fourth passband, and can adjust the working range of the first passband and the fourth passband by adjusting the lengths and the widths of the first high-impedance branch line, the first low-impedance branch line, the second high-impedance branch line and the second low-impedance branch line and the distances between the first high-impedance branch line, the second low-impedance branch line, the input port and the output port; the working ranges of the second passband and the third passband and the notch point frequency can be adjusted by adjusting the lengths of the inverted L-shaped open-circuit branches and the rectangular open-circuit branches, adjusting the distances between the inverted L-shaped open-circuit branches and the input port and the output port and the distances between the rectangular open-circuit branches and the feeder line, so that the frequency ranges of four working frequency ranges can be flexibly adjusted according to design requirements, the frequency ranges can be adapted to the use requirements of 5G technology, and more working frequency ranges can be expanded by adding proper structures such as a ladder impedance resonator.
Drawings
FIG. 1 is a schematic diagram of a circuit board used in the present invention;
FIG. 2 is a schematic diagram of a four-band microstrip bandpass filter with notch characteristics according to the present invention;
FIG. 3 is a signal path diagram of a four-band microstrip bandpass filter with notch characteristics according to the invention;
Fig. 4 is a graph showing the insertion loss and return loss of the four-band microstrip bandpass filter with notch characteristics according to the invention.
Detailed Description
In order that the invention may be more readily understood, a more particular description of the invention will be rendered by reference to specific embodiments that are illustrated in the appended drawings.
Example 1
As shown in fig. 1 and 2, a four-band microstrip bandpass filter with notch characteristics includes a circuit board including a conductor strip 1, a dielectric substrate 2 and a ground plate 3, which may be a printed circuit board;
the circuit board is provided with a short circuit perforation 4 penetrating through the conductor strip 1, the dielectric substrate 2 and the grounding plate 3 so that the conductor strip 1 penetrates through the dielectric substrate 2 to be connected with the grounding plate 3; wherein the conductor strip 1 comprises:
an input port 5 and an output port 6;
a feeder 7 connected between the input port 5 and the output port 6 by way of a stepped feed, the short-circuit perforation 4 passing through the feeder 7; specifically, the short-circuit perforation 4 divides the feeder 7 into two sections;
Two first ladder impedance resonators connected to the upper end of the feeder 7 and bilaterally symmetrical about the center line 8 of the circuit board;
two second ladder impedance resonators connected to the lower end of the feeder 7 and bilaterally symmetrical about the center line 8 of the circuit board;
Two F-shaped open-circuit branches which are connected to the upper end part of the feeder 7 and are bilaterally symmetrical with respect to a central line 8 of the circuit board, wherein the first ladder impedance resonator is positioned between the two F-shaped open-circuit branches; specifically, the conductor strip 1 is connected with the grounding plate 3 through a wire positioned in the short-circuit perforation 4; the step feeding means that in the direction perpendicular to the feeder 7, the upper end face and the lower end face of the feeder 7 are located between the upper end face and the lower end face of the input port 5 so as to form a step at the junction of the input port 5 and the feeder 7; the upper end face and the lower end face of the feeder 7 are also positioned between the upper end face and the lower end face of the output port 6 so as to form a step at the joint of the output port 6 and the feeder 7; the input port 5 and the output port 6 share one of the shorting perforations 4.
Specifically, the four-frequency band microstrip band-pass filter with the notch characteristic has four working frequency bands, namely a first passband, a second passband, a third passband and a fourth passband, in this embodiment, the first passband is 2515 MHz-2675 MHz, the second passband is 3400 MHz-3500 MHz, the third passband is 3500 MHz-3600 MHz, the fourth passband is 4800 MHz-4900 MHz, the notch point frequency is 3.5GHz, and the working range of the second passband and the third passband and the notch point frequency can be adjusted by adjusting the position and the size of an F-shaped open circuit branch.
Further specifically, the first ladder impedance resonator is easy to couple with the F-shaped open circuit branch on the same side, and the isolation degree between the first ladder impedance resonator and the F-shaped open circuit branch can be improved by reasonably controlling the relative position between the first ladder impedance resonator and the F-shaped open circuit branch; the input port 5 and the output port 6 can be welded by common SMA connectors in a side-feed manner to be connected to test equipment or other devices. The dielectric substrate 2 and the conductor strip 1 together form a microstrip line, in this embodiment, the resistance of the microstrip line is 50Ω, and the input port 5 and the output port 6 are located on the same microstrip line.
As shown in fig. 2, the F-type open circuit dendrite includes, for example but not limited to, the following structure:
an inverted-L open stub 9 connected to the feeder 7;
Rectangular open-circuit stubs 10 connected to the inverted-L open-circuit stubs 9 and parallel to the feed line 7; the F-shaped open branch can improve the stability of the working frequency band and the stability of the notch frequency of the four-frequency-band microstrip band-pass filter with the notch characteristic. Specifically, by adjusting the lengths of the inverted-L open-circuit branch 9 and the rectangular open-circuit branch 10, adjusting the distances between the inverted-L open-circuit branch 9 and the input port 5 and the output port 6, and adjusting the distances between the rectangular open-circuit branch 10 and the feeder 7, the operating ranges of the second passband and the third passband and the notch point frequency can be adjusted.
As shown in fig. 2, the width of the rectangular open-circuit branch 10 is larger than the width of the inverted-L open-circuit branch 9.
As shown in fig. 2, the first stepped impedance resonator is, for example and without limitation, a structure including a first high impedance branch line 11 and a first low impedance branch line 12; wherein,
The lower end of the first high-impedance branch line 11 is connected to the feeder line 7;
one end of the first low-impedance branch line 12 is connected to an upper end of the first high-impedance branch line 11;
A coupling gap 13 is formed between the other end portion of the first low-impedance branch line 12 and the first low-impedance branch line 12 in the other first stepped-impedance resonator; specifically, in the frequency range of the first passband, signals are transmitted by coupling between the two first low impedance branch lines 12.
As shown in fig. 2, the second stepped impedance resonator is, for example and without limitation, of a structure including a second high impedance branch line 14 and a second low impedance branch line 15; wherein,
The upper end of the second high-impedance branch line 14 is connected to the feeder line 7;
One end of the second low-impedance branch line 15 is connected to a lower end of the second high-impedance branch line 14;
The other end portion of the second low-impedance branch line 15 is connected to a second low-impedance branch line 15 in another second-step impedance resonator; specifically, in the frequency range of the fourth passband, the signal is transmitted through the direct connection of the two second low-impedance branch lines 15; by adjusting the length, width and distance of the first high impedance branch line 11, the first low impedance branch line 12, the second high impedance branch line 14 and the second low impedance branch line 15 from the input port 5, the output port 6, the operating ranges of the first passband and the fourth passband can be adjusted. In the present embodiment, the first high-impedance branch line 11 and the second high-impedance branch line 14 are bent, which is advantageous in downsizing.
As shown in fig. 1 and 2, the short-circuit perforation 4 may be located at the center of the circuit board, and the short-circuit perforation 4 may have a diameter of 0.5mm.
As shown in fig. 2, the input port 5 and the output port 6 may be symmetrically disposed about a center line 8 of the circuit board, and the lengths of the first stepped impedance resonator and the second stepped impedance resonator may each be a quarter of an operating wavelength.
In this embodiment, the dielectric constant of the dielectric substrate 2 may be 2.2, the thickness of the dielectric substrate 2 may be 0.707mm, the material of the dielectric substrate 2 may be rogers 5880, the length of the dielectric substrate 2 may be 35.8mm, and the width may be 30.7mm; the dielectric substrate 2 may also use dielectric materials with the same properties.
Specifically, the first step impedance resonator and the second step impedance resonator are removed, and the F-shaped open branch is singly connected in parallel to the feeder line 7 containing the short circuit perforation 4, so that a notch effect still exists.
As shown in fig. 3, the signal propagates along the first signal path 16 and the second signal path 17, respectively, after entering through the input port 5.
FIG. 4 is a graph showing the insertion loss S21 and the return loss S11 of the four-band microstrip bandpass filter with notch characteristics, wherein the insertion loss S21 is above-2.5 dB, and the return loss S11 is below-12.5 dB in four frequency bands of 2515 MHz-2675 MHz,3400 MHz-3500 MHz,3500 MHz-3600 MHz,4800 MHz-4900 MHz, so as to meet the requirements.
Example two
A method for designing a four-band microstrip bandpass filter with notch characteristics according to embodiment one, the method comprising the steps of:
S1: on the basis that an input port 5 and an output port 6 are connected to a feeder 7 in a stepped feed connection mode and the input port 5 and the output port 6 share a short circuit perforation 4, a pair of first stepped impedance resonators, a pair of second stepped impedance resonators and a pair of F-shaped open circuit branches are arranged in parallel on a medium substrate 2;
s2: the sizes and the positions of the first ladder impedance resonator and the second ladder impedance resonator are adjusted so as to adjust the working ranges of the highest frequency band and the lowest frequency band in the four frequency bands; the size and the position of the F-shaped open circuit branch knot are adjusted to adjust the working range and the notch point frequency of the other two frequency bands in the four frequency bands, so that the four-frequency band microstrip band-pass filter with the notch characteristic meeting the requirements is obtained.
The specific steps of step S2 are as follows:
M1: inverting the sizes of the first ladder impedance resonator and the second ladder impedance resonator according to the working ranges of the highest frequency band and the lowest frequency band in the four frequency bands, and inverting the sizes of the F-shaped open-circuit branches according to the working ranges and the notch point frequencies of the other two frequency bands in the four frequency bands;
M2: and adjusting the positions of the first ladder impedance resonator, the second ladder impedance resonator and the F-shaped open circuit branch knot so as to reduce coupling interference among the first ladder impedance resonator, the second ladder impedance resonator and the F-shaped open circuit branch knot on the same side and obtain the four-frequency-band microstrip band-pass filter with notch characteristics which meets the requirements.
In this embodiment, the four working frequency bands of the four-band microstrip bandpass filter with notch characteristics are four frequency bands of 5G mobile communication in China, namely 2515 MHz to 2675MHz, 3400 MHz to 3500MHz, 3500MHz to 3600MHz, and 4800MHz to 4900MHz.
The working principle of the invention is as follows:
The four-frequency band microstrip band-pass filter with the notch characteristic has the advantages of simple structure, small volume, high integration level and excellent performance, has the notch characteristic, simultaneously realizes band-pass filtering of four working frequency bands, namely a first passband, a second passband, a third passband and a fourth passband, and can adjust the working ranges of the first passband and the fourth passband by adjusting the lengths and the widths of the first high-impedance branch line 11, the first low-impedance branch line 12, the second high-impedance branch line 14 and the second low-impedance branch line 15 and the distances between the first high-impedance branch line and the second low-impedance branch line 15 and between the first high-impedance branch line and the input port 5 and the output port 6; the working ranges of the second passband and the third passband and the notch point frequency can be adjusted by adjusting the lengths of the inverted-L-shaped open-circuit branch 9 and the rectangular open-circuit branch 10, adjusting the distances between the inverted-L-shaped open-circuit branch 9 and the input port 5 and the output port 6 and the distances between the rectangular open-circuit branch 10 and the feeder 7, so that the frequency ranges of four working frequency ranges can be flexibly adjusted according to design requirements, the frequency ranges can be adapted to the use requirements of 5G technology, and a plurality of working frequency ranges can be expanded by adding proper structures such as a ladder impedance resonator.
The technical problems, technical solutions and advantageous effects solved by the present invention have been further described in detail in the above-described embodiments, and it should be understood that the above-described embodiments are only illustrative of the present invention and are not intended to limit the present invention, and any modifications, equivalent substitutions, improvements, etc. within the spirit and principle of the present invention should be included in the scope of protection of the present invention.
In the description of the present invention, it should be understood that the terms "orientation" or "positional relationship" are based on the orientation or positional relationship shown in the drawings, and are merely for convenience of description and to simplify the description, rather than to indicate or imply that the apparatus or elements referred to must have a particular orientation, be constructed and operate in a particular orientation, and therefore should not be construed as limiting the invention.
In the present invention, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.
In the description of the present invention, it should be noted that, directions or positional relationships indicated by terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., are directions or positional relationships based on those shown in the drawings, or are directions or positional relationships conventionally put in use of the inventive product, are merely for convenience of describing the present invention and simplifying the description, and are not indicative or implying that the apparatus or element to be referred to must have a specific direction, be constructed and operated in a specific direction, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and the like are used merely to distinguish between descriptions and should not be construed as indicating or implying relative importance.
Furthermore, the terms "horizontal," "vertical," "overhang," and the like do not denote a requirement that the component be absolutely horizontal or overhang, but rather may be slightly inclined. As "horizontal" merely means that its direction is more horizontal than "vertical", and does not mean that the structure must be perfectly horizontal, but may be slightly inclined.
In the present invention, unless expressly stated or limited otherwise, a first feature may include first and second features directly contacting each other, either above or below a second feature, or through additional features contacting each other, rather than directly contacting each other. Moreover, the first feature being above, over, and on the second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is higher in level than the second feature. The first feature being below, beneath, and beneath the second feature includes the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is less level than the second feature.
Claims (7)
1. A four-frequency band microstrip bandpass filter with notch characteristics is characterized in that,
The circuit board comprises a conductor belt (1), a dielectric substrate (2) and a grounding plate (3) which are sequentially arranged;
The circuit board is provided with a short circuit through hole (4) penetrating through the conductor belt (1), the dielectric substrate (2) and the grounding plate (3), so that the conductor belt (1) penetrates through the dielectric substrate (2) to be connected with the grounding plate (3); wherein the conductor strip (1) comprises:
An input port (5) and an output port (6);
-a feed line (7) connected between the input port (5) and the output port (6) by means of a stepped feed, the short-circuit perforation (4) passing through the feed line (7);
two first ladder impedance resonators which are connected to the upper end of the feeder line (7) and are bilaterally symmetrical with respect to a center line (8) of the circuit board;
two second-step impedance resonators which are connected to the lower end of the feeder line (7) and are bilaterally symmetrical with respect to the center line (8) of the circuit board;
two F-shaped open-circuit branches which are connected to the upper end part of the feeder line (7) and are bilaterally symmetrical with respect to a central line (8) of the circuit board, wherein the first ladder impedance resonator is positioned between the two F-shaped open-circuit branches;
wherein, the open-circuit branch of F type includes:
An inverted L-shaped open branch (9) connected to the feeder (7);
Rectangular open-circuit branches (10) connected to the inverted-L-shaped open-circuit branches (9) and parallel to the feeder line (7);
wherein the first stepped impedance resonator comprises a first high impedance branch line (11) and a first low impedance branch line (12);
The lower end part of the first high-impedance branch line (11) is connected to the feeder line (7);
One end of the first low-impedance branch line (12) is connected to an upper end of the first high-impedance branch line (11);
a coupling gap (13) is formed between the other end part of the first low-impedance branch line (12) and the first low-impedance branch line (12) in the other first ladder-impedance resonator;
Wherein the second stepped impedance resonator comprises a second high impedance branch line (14) and a second low impedance branch line (15);
The upper end part of the second high-impedance branch line (14) is connected to the feeder line (7);
one end of the second low-impedance branch line (15) is connected to a lower end of the second high-impedance branch line (14);
The other end of the second low-impedance branch line (15) is connected to a second low-impedance branch line (15) in another second ladder impedance resonator;
Wherein the first high-impedance branch line (11) and the second high-impedance branch line (14) each have a bend.
2. The four-band microstrip bandpass filter with notch characteristics according to claim 1, characterized in that the width of the rectangular open-circuited stubs (10) is greater than the width of the inverted-L open-circuited stubs (9).
3. Four-band microstrip bandpass filter with notch characteristics according to claim 1, characterized in that the shorting via (4) is located at the center of the circuit board, the diameter of the shorting via (4) being 0.5mm.
4. The four-band microstrip bandpass filter with notch characteristics according to claim 1, characterized in that the input port (5) and the output port (6) are symmetrically arranged about a centerline (8) of the circuit board, the lengths of the first stepped impedance resonator and the second stepped impedance resonator being each one quarter of an operating wavelength.
5. The four-band microstrip bandpass filter with notch characteristics according to claim 1, characterized in that the dielectric substrate (2) has a dielectric constant of 2.2; the thickness of the dielectric substrate (2) is 0.707mm; the material of the medium substrate (2) is Rogowski 5880; the length of the medium substrate (2) is 35.8mm, and the width is 30.7mm.
6. A method for designing a four-band microstrip bandpass filter with notch characteristics according to any one of claims 1 to 5, wherein the method comprises the steps of:
S1: on the basis that an input port (5) and an output port (6) are connected to a feeder line (7) in a stepped feed connection mode and the input port (5) and the output port (6) share a short circuit through hole (4), a pair of first stepped impedance resonators, a pair of second stepped impedance resonators and a pair of F-shaped open branches are arranged in parallel on a medium substrate (2);
s2: the sizes and the positions of the first ladder impedance resonator and the second ladder impedance resonator are adjusted so as to adjust the working ranges of the highest frequency band and the lowest frequency band in the four frequency bands; the size and the position of the F-shaped open circuit branch knot are adjusted to adjust the working range and the notch point frequency of the other two frequency bands in the four frequency bands, so that the four-frequency band microstrip band-pass filter with the notch characteristic meeting the requirements is obtained.
7. The design method according to claim 6, wherein the specific steps of step S2 are as follows:
M1: inverting the sizes of the first ladder impedance resonator and the second ladder impedance resonator according to the working ranges of the highest frequency band and the lowest frequency band in the four frequency bands, and inverting the sizes of the F-shaped open-circuit branches according to the working ranges and the notch point frequencies of the other two frequency bands in the four frequency bands;
M2: and adjusting the positions of the first ladder impedance resonator, the second ladder impedance resonator and the F-shaped open circuit branch knot so as to reduce coupling interference among the first ladder impedance resonator, the second ladder impedance resonator and the F-shaped open circuit branch knot on the same side and obtain the four-frequency-band microstrip band-pass filter with notch characteristics which meets the requirements.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910998521.3A CN110600842B (en) | 2019-10-21 | 2019-10-21 | Four-frequency-band microstrip band-pass filter with notch characteristic and design method thereof |
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| CN106876845A (en) * | 2015-12-13 | 2017-06-20 | 哈尔滨飞羽科技有限公司 | The three trap bandpass filters based on step electric impedance resonator and open circuit minor matters |
| CN107482291A (en) * | 2017-08-16 | 2017-12-15 | 电子科技大学 | A kind of new double-passband filter |
| CN210668632U (en) * | 2019-10-21 | 2020-06-02 | 合肥师范学院 | Four-frequency-band microstrip band-pass filter with trapped wave characteristic |
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| JP2009296306A (en) * | 2008-06-05 | 2009-12-17 | Toshiba Corp | Wiring substrate |
| TW201505250A (en) * | 2013-07-19 | 2015-02-01 | Cybertan Technology Inc | Bandpass filter |
| CN203932263U (en) * | 2013-11-27 | 2014-11-05 | 哈尔滨飞羽科技有限公司 | A kind of ultra-wide band filter based on T font open circuit minor matters |
| CN105789764A (en) * | 2014-12-23 | 2016-07-20 | 哈尔滨黑石科技有限公司 | Multi-mode resonator based ultra-wide-band tri-band band-pass filter |
| CN106876843A (en) * | 2015-12-13 | 2017-06-20 | 哈尔滨飞羽科技有限公司 | Double trap bandpass filters of the double open circuit minor matters of toroidal cavity resonator loading |
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| CN109713411B (en) * | 2019-02-21 | 2023-11-03 | 华南理工大学 | Microstrip dual-frequency broadband filter |
| CN110137641B (en) * | 2019-06-17 | 2024-07-05 | 辽宁工程技术大学 | Miniature double-notch ultra-wideband filter based on inverted pi-type resonator |
| CN115051126B (en) * | 2022-06-23 | 2023-11-17 | 辽宁工程技术大学 | Four-notch ultra-wideband filter based on novel double open-loop resonators |
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| CN107482291A (en) * | 2017-08-16 | 2017-12-15 | 电子科技大学 | A kind of new double-passband filter |
| CN210668632U (en) * | 2019-10-21 | 2020-06-02 | 合肥师范学院 | Four-frequency-band microstrip band-pass filter with trapped wave characteristic |
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