CN204375891U - Plane lower passband leads to double frequency filter - Google Patents
Plane lower passband leads to double frequency filter Download PDFInfo
- Publication number
- CN204375891U CN204375891U CN201420826344.3U CN201420826344U CN204375891U CN 204375891 U CN204375891 U CN 204375891U CN 201420826344 U CN201420826344 U CN 201420826344U CN 204375891 U CN204375891 U CN 204375891U
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- Prior art keywords
- transmission line
- line
- double frequency
- frequency filter
- lower passband
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Abstract
The utility model discloses a kind of plane lower passband and lead to double frequency filter, be produced in the manner of a printed circuit board on medium substrate, the same face of medium substrate is manufactured with respectively the input feeder line head port1 for inputting electromagnetic wave signal, for exporting output feeder line head port2, the first transmission line (1), the second transmission line (2), the 3rd transmission line (3), the 4th transmission line (4), the 5th transmission line (5), the 6th transmission line (6), the 7th transmission line (7) of electromagnetic wave signal, medium substrate another side is ground plate.Plane lower passband disclosed in the utility model leads to double frequency filter and is ensureing under the prerequisite that low-pass characteristic is constant, the logical centre frequency of band can regulate on a large scale, this filter is made up of open circuited transmission line and high impedance line, by adjusting electrical length and the characteristic impedance of transmission line, make band lead to centre frequency can in very wide scope independent regulation, have that frequency-adjustable, selectivity are good, low-loss, the simple advantage of structure.
Description
Technical field
The utility model relates to the technical field of plane microstrip filter, and particularly a kind of plane lower passband leads to double frequency filter.
Background technology
Along with the high speed development of radio communication skill, be no matter the burning hot or arrival of 4G of universal, the Internet of Things of 3G technology, all indicate that wireless technology will welcome a flourish peak period again.In recent years, the RF/Microwave communication system that simultaneously can be operated in two frequency ranges becomes study hotspot, and microwave double frequency filter is also more and more concerned as the Primary Component of these communication systems, traditional double frequency filter passband is generally fixing, sometimes the demand of wireless communications application system to high performance microwave double frequency filter cannot be met, therefore, the logical variable high performance microwave double frequency filter of research band has very important significance.
The simplest method for designing of double frequency filter is combined by the band pass filter of two different frequencies, but the size of this filter is comparatively large and need extra interconnection network, in addition, by a band pass filter and a band stop filter series connection, also can realize the design of double frequency filter, but this method can make the size of filter comparatively large and increase the design cost of filter equally.
2011, the people such as Ming-Lin Chuang deliver the paper being entitled as " Microstrip Diplexer Design Using Common T-Shaped Resonator " on " IEEE MICROWAVE AND WIRELESS COMPONENTS LETTERS ", structure disclosed in this paper adopts T connector, two band pass filters are connected, form a duplexer, this structure is concrete as shown in Figure 1.
2013, the people such as Pu-Hua Deng deliver the paper being entitled as " Design of Microstrip Lowpass-Bandpass Diplexer " on " IEEE MICROWAVE AND WIRELESS COMPONENTS LETTERS ", structure disclosed in this paper is also adopt T connector, a low pass filter is connected with band pass filter, form a duplexer, this structure is concrete as shown in Figure 2.
2013, the people such as K.Tanii deliver the paper being entitled as " Frequency diplexer using multimode bandpass filters with high stopband attenuation level " on " IEEE ELECTRON DEVICE LETTERS ", disclosed in this paper, structure remains employing T connector, two multi-mode bandpass filters are connected, form a duplexer, this structure is concrete as shown in Figure 3.
Above achievement method for designing is all combined by the band pass filter of two different frequencies, but the size of this filter is comparatively large and need extra interconnection network, and structure is comparatively complicated and add the design cost of filter.
Utility model content
The purpose of this utility model is that the shortcoming overcoming prior art is with not enough, a kind of plane lower passband is provided to lead to double frequency filter, this double frequency filter combination property is better, by changing characteristic impedance and the electrical length of transmission line, make filter can under the constant prerequisite of low-pass characteristic, realize band all with independence control, the centre frequency of two passbands of the micro-band double frequency filter utilizing the program to design can independent regulation on a large scale, has the advantages that He Ne laser performance is high, passband independently controls, cost is low, performance is excellent, size is little.
The purpose of this utility model is achieved through the following technical solutions:
A kind of plane lower passband leads to double frequency filter, be produced in the manner of a printed circuit board on medium substrate, the same face of described medium substrate is manufactured with respectively the input feeder line head port1 for inputting electromagnetic wave signal, for exporting output feeder line head port2, the first transmission line 1, second transmission line 2, the 3rd transmission line 3, the 4th transmission line 4, the 5th transmission line 5, the 6th transmission line 6, the 7th transmission line 7 of electromagnetic wave signal, the another side of this medium substrate is ground plate;
Described input feeder line head port1 is connected with the first end of described second transmission line 2, and described output feeder line head port2 is connected with the second end of described second transmission line 2, and three is located along the same line;
The first end of described first transmission line 1, the first end of the 5th transmission line 5 are connected with described input feeder line head port1 is vertical with the first end of described second transmission line 2 respectively, and towards the opposite;
The first end of described 3rd transmission line 3, the first end of the 6th transmission line 6 are connected with described output feeder line head port2 is vertical with the second end of described second transmission line 2 respectively, and towards the opposite;
The first end of described 4th transmission line 4 is connected with the second end of described 3rd transmission line 3, the first end of described 7th transmission line 7 is connected with the second end of described 6th transmission line 6, and four are located along the same line, the straight line parallel that this straight line and described first transmission line 1 and the 5th transmission line 5 connect into.
Further, the characteristic impedance of described first transmission line 1, the 3rd transmission line 3, the 4th transmission line 4 is identical with electrical length with the characteristic impedance of the 5th transmission line 5, the 6th transmission line 6, the 7th transmission line 7 respectively with electrical length, and is formed symmetric relation centered by the straight line connected into by described input feeder line head port1, output feeder line head port2 and the second transmission line 2.
Further, described second transmission line 2 is high-impedance transmission line.
Further, described 4th transmission line 4 is not identical with the characteristic impedance of described 3rd transmission line 3, is connected to each other rear formation Stepped Impedance open circuited transmission line;
Described 6th transmission line 6 is not identical with the characteristic impedance of described 7th transmission line 7, is connected to each other rear formation Stepped Impedance open circuited transmission line.
Further, described first transmission line 1 is open circuited transmission line with described 5th transmission line 5.
Further, described transmission line all adopts microstrip transmission line or parallel double conducting wire or parallel many wires or coaxial line or strip line or works in the microstrip line of accurate TEM mould.
The utility model has following advantage and effect relative to prior art:
1, filter construction disclosed in the utility model is ensureing that under the prerequisite that low pass filter cutoff frequency is constant, the centre frequency realizing band pass filter is adjustable on a large scale.By changing the length of transmission line, filter bandpass characteristics is changed, then change the characteristic impedance of microstrip line by the width changing microstrip line, thus ensure that low-pass characteristic is constant, bandpass characteristics can control on a large scale.
2, disclosed in the utility model, the double frequency filter of filter construction has comparatively low insertion loss, is with outer selectivity good, the feature that filtering characteristic is good.
Accompanying drawing explanation
Fig. 1 is the structural representation of a kind of duplexer disclosed in prior art 1;
Fig. 2 is the structural representation of a kind of duplexer disclosed in prior art 2;
Fig. 3 is the structural representation of a kind of duplexer disclosed in prior art 3;
Fig. 4 is that in the utility model, lower passband leads to double frequency filter Ideal Transmission Line model schematic;
Fig. 5 utilizes AWR Microwave office to design to lead to the scattering parameter ideal waveform figure of double frequency filter for the lower passband of parameter before adjustment in the present embodiment;
Fig. 6 utilizes AWR Microwave office to design to lead to the scattering parameter ideal waveform figure of double frequency filter for the lower passband of parameter after adjustment in the present embodiment;
Fig. 7 utilizes full-wave simulation software I E3D to lead to the scattering parameter simulation result figure of double frequency filter to the lower passband of parameter before adjustment in the present embodiment;
Fig. 8 utilizes full-wave simulation software I E3D to lead to the scattering parameter simulation result figure of double frequency filter to the lower passband of parameter after adjustment in the present embodiment.
Embodiment
The technological means realized for making the utility model, creation characteristic, reaching object and effect is easy to understand, referring to the accompanying drawing embodiment that develops simultaneously, the utility model being further described.Should be appreciated that specific embodiment described herein only in order to explain the utility model, and be not used in restriction the utility model.
Embodiment
In the utility model as shown in Figure 4, lower passband leads to double frequency filter Ideal Transmission Line model schematic, present embodiment discloses a kind of plane lower passband and lead to double frequency filter, be produced in the manner of a printed circuit board on medium substrate, the same face of described medium substrate is manufactured with respectively the input feeder line head port1 for inputting electromagnetic wave signal, for exporting the output feeder line head port2 of electromagnetic wave signal, first transmission line 1, second transmission line 2, 3rd transmission line 3, 4th transmission line 4, 5th transmission line 5, 6th transmission line 6, 7th transmission line 7, the another side of this medium substrate is ground plate.
In the present embodiment, medium substrate adopts the micro-band plate of two-sided shoe copper, and transmission line adopts microstrip line, but except microstrip line, parallel double conducting wire, parallel many wires, coaxial line, strip line, and the microstrip line etc. working in accurate TEM mould all can realize this structure.
The matched impedance of 50 ohm is for inputting the input feeder line head port1 of electromagnetic wave signal and these two ports of output feeder line head port2 for exporting electromagnetic wave signal.
The annexation of each feeder line head and each transmission line describes as follows:
Input feeder line head port1 is connected with the first end of the second transmission line 2, and output feeder line head port2 is connected with the second end of the second transmission line 2, and three is located along the same line; Wherein the second transmission line 2 is called first end near that one end of input feeder line head port1, and the second transmission line 2 is called the second end near that one end of output feeder line head port2, and the second transmission line 2 is high-impedance transmission line, Z
2and θ
2be respectively characteristic impedance and the electrical length of this high impedance line, during lower passband, be equivalent to a series inductance, when frequency is band pass filter centre frequency, be equivalent to a series resonator or impedance transformer.
The first end of the first transmission line 1, the first end of the 5th transmission line 5 are connected with described input feeder line head port1 is vertical with the first end of described second transmission line 2 respectively, and towards the opposite; Wherein the first transmission line 1 and the 5th transmission line 5 are called this transmission line first end near that one end of input feeder line head port1, that one end away from input feeder line head port1 is called this transmission line second end, and the second end of the first transmission line and the 5th transmission line is open circuit.Z
1and θ
1, Z
5and θ
5be respectively characteristic impedance and the electrical length of the first transmission line and the 5th transmission line, during lower passband, be equivalent to a shunt capacitance, when frequency is band pass filter centre frequency, be equivalent to a parallel resonator.
The first end of the 3rd transmission line 3, the first end of the 6th transmission line 6 are connected with output feeder line head port2 is vertical with the second end of the second transmission line 2 respectively, and towards the opposite;
The first end of the 4th transmission line 4 is connected with the second end of the 3rd transmission line 3, the first end of the 7th transmission line 7 is connected with the second end of the 6th transmission line 6, and four are located along the same line, this straight line and the straight line parallel connected into described first transmission line 1 and the 5th transmission line 5.
Wherein, 3rd transmission line 3 and the 6th transmission line 6 are called the first end of this transmission line near that one end of output feeder line head port2, that one end away from output feeder line head port2 is called the second end of this transmission line, simultaneously, 4th transmission line 4 and the 7th transmission line 7 are called the first end of this transmission line near that one end of output feeder line head port2, that one end away from output feeder line head port2 is called the second end of this transmission line, further, the second end of the 4th transmission line 4 and the 7th transmission line 7 is also open circuit.Z
3, θ
3, Z
4, θ
4z
6, θ
6, Z
7, θ
7be respectively characteristic impedance and the electrical length of the 3rd transmission line 3, the 4th transmission line 4, the 6th transmission line 6 and the 7th transmission line 7 four sections of transmission lines, 4th transmission line 4 is not identical with the characteristic impedance of the 3rd transmission line 3, be connected to each other rear formation Stepped Impedance open circuited transmission line, 6th transmission line 6 is not identical with the characteristic impedance of the 7th transmission line 7, forms Stepped Impedance open circuited transmission line after being connected to each other yet.When frequency is band pass filter centre frequency, they are equivalent to a parallel resonator; When low frequency, this structural equivalents is a third-order low-pass filter, and in the logical centre frequency of band, equivalence becomes three rank or two rank band pass filters.
Can be released by equivalent relation, the cut-off frequency of low pass filter is determined jointly by the characteristic impedance of transmission line and electrical length, and the centre frequency of band pass filter is determined by the electrical length of open circuited transmission line, just based on this point, the utility model proposes a kind of lower passband and lead to double frequency filter, under the prerequisite keeping low pass filter cutoff frequency constant, the centre frequency of band pass filter can regulate in a big way, specifically as shown in Figure 5 and Figure 6.Fig. 5 and Fig. 6 is the ideal waveform obtained when designing this plane lower passband bandpass filter with AWR Microwave office, and the parameter that wherein in Fig. 5, lower passband leads to double frequency filter is that before adjustment, the characteristic impedance of its transmission line is Z
1=Z
5=24.15, Z
2=131, Z
3=Z
5=64.15, Z
4=Z
7=83.3, electrical length is θ
1=θ
2=θ
3=θ
4=θ
5=θ
6=θ
7=30 °, in Fig. 6, lower passband leads to the parameter of double frequency filter is that after adjustment, the characteristic impedance of its transmission line is Z
1=Z
5=37.75, Z
2=104, Z
3=Z
5=69.15, Z
4=Z
7=89.8, electrical length is θ
1=θ
2=θ
3=θ
4=θ
5=θ
6=θ
7=36 °.Show the scattering parameter simulation result of the double frequency filter under different qualities parameter in Fig. 5 and Fig. 6, it is 7.11GHz that the band before adjustment leads to centre frequency, and it is 5.99GHz that the band after adjustment leads to centre frequency.Amplitude be-1dB place adjustment before with adjust after low-pass cut-off frequencies identical, be 1.028GHz.Simulation result meets the effect that the utility model produces.Transverse axis represents the signal frequency of micro-band double frequency filter in the utility model, and the longitudinal axis represents amplitude, comprises insertion loss (the front s of adjustment
21, adjustment after s
21) amplitude and return loss (adjustment before s
11, adjustment after s
11) amplitude.Insertion loss represents the relation between the input power of a signal and the power output of another port signal, and its corresponding mathematical function is: power output/input power (dB)=20*log|s
21|.Return loss represents the relation between the input power of this port signal and the reflection power of signal, and its corresponding mathematical function is as follows: reflection power/incident power=-20*log (s
11).
Fig. 7 leads to the parameter before double frequency filter adjustment according to lower passband, and namely the characteristic impedance of transmission line is Z
1=Z
5=24.15, Z
2=131, Z
3=Z
5=64.15, Z
4=Z
7=83.3, electrical length is θ
1=θ
2=θ
3=θ
4=θ
5=θ
6=θ
7=30 °, the micro-belt substrate dielectric constant selected is 2.55, and medium level is 0.8mm, utilizes the lower passband of full-wave simulation software I E3D to lead to the scattering parameter simulation result figure of double frequency filter, Fig. 8 leads to the parameter after double frequency filter adjustment according to lower passband, and namely the characteristic impedance of transmission line is Z
1=Z
5=37.75, Z
2=104, Z
3=Z
5=69.15, Z
4=Z
7=89.8, electrical length is θ
1=θ
2=θ
3=θ
4=θ
5=θ
6=θ
7=36 °, the micro-belt substrate dielectric constant selected is 2.55, and medium level is 0.8mm, utilizes the lower passband of full-wave simulation software I E3D to lead to the scattering parameter simulation result figure of double frequency filter.In Fig. 7 and Fig. 8, transverse axis represents the signal frequency of micro-band double frequency filter in the present embodiment, and the longitudinal axis represents amplitude.It is 6.99Ghz that band before adjustment leads to centre frequency, it is 5.98Ghz that band after adjustment leads to centre frequency, amplitude be-1dB place adjustment before with adjust after low-pass cut-off frequencies identical, be 0.99Ghz, coincide with the simulation result in Fig. 5 and Fig. 6, can obviously be found out by the scattering parameter result of specific implementation, band after adjustment lead to centre frequency compare adjustment before band lead to centre frequency and move 1GHz, and the cut-off frequency of low pass does not change, not only match with the result of emulation, also on reality realizes, demonstrate the effect that the utility model produces, namely low-pass characteristic does not change, bandpass characteristics can control on a large scale.
Above-described embodiment is the utility model preferably execution mode; but execution mode of the present utility model is not restricted to the described embodiments; change, the modification done under other any does not deviate from Spirit Essence of the present utility model and principle, substitute, combine, simplify; all should be the substitute mode of equivalence, be included within protection range of the present utility model.
Claims (6)
1. plane lower passband leads to a double frequency filter, is produced on medium substrate in the manner of a printed circuit board, it is characterized in that:
The same face of described medium substrate is manufactured with respectively the input feeder line head port1 for inputting electromagnetic wave signal, for exporting output feeder line head port2, the first transmission line (1), the second transmission line (2), the 3rd transmission line (3), the 4th transmission line (4), the 5th transmission line (5), the 6th transmission line (6), the 7th transmission line (7) of electromagnetic wave signal, the another side of this medium substrate is ground plate;
Described input feeder line head port1 is connected with the first end of described second transmission line (2), and described output feeder line head port2 is connected with the second end of described second transmission line (2), and three is located along the same line;
The first end of described first transmission line (1), the first end of the 5th transmission line (5) are connected with described input feeder line head port1 is vertical with the first end of described second transmission line (2) respectively, and towards the opposite;
The first end of described 3rd transmission line (3), the first end of the 6th transmission line (6) are connected with described output feeder line head port2 is vertical with the second end of described second transmission line (2) respectively, and towards the opposite;
The first end of described 4th transmission line (4) is connected with the second end of described 3rd transmission line (3), the first end of described 7th transmission line (7) is connected with the second end of described 6th transmission line (6), and four are located along the same line, the straight line parallel that this straight line and described first transmission line (1) connect into the 5th transmission line (5).
2. a kind of plane lower passband according to claim 1 leads to double frequency filter, it is characterized in that: the characteristic impedance of described first transmission line (1), the 3rd transmission line (3), the 4th transmission line (4) is identical with electrical length with the characteristic impedance of the 5th transmission line (5), the 6th transmission line (6), the 7th transmission line (7) respectively with electrical length, and formed symmetric relation centered by the straight line connected into by described input feeder line head port1, output feeder line head port2 and the second transmission line (2).
3. a kind of plane lower passband according to claim 1 and 2 leads to double frequency filter, it is characterized in that: described second transmission line (2) is high-impedance transmission line.
4. a kind of plane lower passband according to claim 1 and 2 leads to double frequency filter, it is characterized in that:
Described 4th transmission line (4) is not identical with the characteristic impedance of described 3rd transmission line (3), is connected to each other rear formation Stepped Impedance open circuited transmission line;
Described 6th transmission line (6) is not identical with the characteristic impedance of described 7th transmission line (7), is connected to each other rear formation Stepped Impedance open circuited transmission line.
5. a kind of plane lower passband according to claim 1 and 2 leads to double frequency filter, it is characterized in that:
Described first transmission line (1) and described 5th transmission line (5) are open circuited transmission line.
6. a kind of plane lower passband according to claim 1 and 2 leads to double frequency filter, it is characterized in that:
Described transmission line all adopts microstrip transmission line or parallel double conducting wire or parallel many wires or coaxial line or strip line or works in the microstrip line of accurate TEM mould.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420826344.3U CN204375891U (en) | 2014-12-19 | 2014-12-19 | Plane lower passband leads to double frequency filter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420826344.3U CN204375891U (en) | 2014-12-19 | 2014-12-19 | Plane lower passband leads to double frequency filter |
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| Publication Number | Publication Date |
|---|---|
| CN204375891U true CN204375891U (en) | 2015-06-03 |
Family
ID=53332081
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201420826344.3U Withdrawn - After Issue CN204375891U (en) | 2014-12-19 | 2014-12-19 | Plane lower passband leads to double frequency filter |
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| Country | Link |
|---|---|
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104577273A (en) * | 2014-12-19 | 2015-04-29 | 华南理工大学 | Plane low-pass band-pass dual-frequency filter |
-
2014
- 2014-12-19 CN CN201420826344.3U patent/CN204375891U/en not_active Withdrawn - After Issue
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104577273A (en) * | 2014-12-19 | 2015-04-29 | 华南理工大学 | Plane low-pass band-pass dual-frequency filter |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| AV01 | Patent right actively abandoned |
Granted publication date: 20150603 Effective date of abandoning: 20171020 |
|
| AV01 | Patent right actively abandoned |