CN210430042U - Dual-mode dual-frequency coaxial cavity filter - Google Patents
Dual-mode dual-frequency coaxial cavity filter Download PDFInfo
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- CN210430042U CN210430042U CN201921176442.6U CN201921176442U CN210430042U CN 210430042 U CN210430042 U CN 210430042U CN 201921176442 U CN201921176442 U CN 201921176442U CN 210430042 U CN210430042 U CN 210430042U
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Abstract
The utility model discloses a double-mode double-frequency coaxial cavity filter, which comprises a metal cavity and an input/output port; the metal cavity inner structure is in linear distribution, and is the first coaxial resonant cavity, first coupling resonance window, the second coaxial resonant cavity, second coupling resonance window, the third coaxial resonant cavity in proper order, all is equipped with vertical metal cylinder and horizontal metal cylinder in the first, second, the three coaxial resonant cavities, and first, two coupling resonance windows are constituteed by coupling knot and coupling window, and input and output ports have two, are coaxial feeder, prolong respectively and insert in the vertical metal cylinder of first, three coaxial resonant cavities. The utility model discloses on traditional coaxial filter's basis, increase the metal cylinder of a horizontal direction, then first resonant frequency and the second resonant frequency of resonant cavity can be controlled respectively to these two metal cylinders, realize the dual-frenquency characteristic, have simple structure compactness, can miniaturize, easily tune, bandwidth broad, selectivity advantage such as good.
Description
Technical Field
The utility model belongs to the technical field of microwave communication's technique and specifically relates to indicate a coaxial cavity filter of bimodulus dual-frenquency.
Background
With the rapid development of wireless communication technology and the continuous growth of radio media services, a low-cost, more efficient, and higher-quality wireless communication system requires a high-performance, small-volume, low-loss cavity filter. Compared with microwave filters with other properties, the cavity filter has the advantages of firm structure, stable and reliable performance, smaller volume, moderate Q value, far high-end parasitic passband and good heat dissipation. Therefore, the application of the cavity filter is very common in each large communication base station.
In recent years, studies of cavity filters by scholars have been not limited to single-band high performance, but have been developed toward multi-band high performance. Indeed, with the development of wireless communication services, spectrum resources are increasingly crowded. The current 5G technology develops fire heat, but the communication range is limited due to the high working frequency, so that the 2G-4G communication can be continuously used for a long time in the future. If each frequency band is designed with a filter separately, the system will be larger. The multiband filter helps the system to reduce the size and optimize the system structure. Therefore, a novel dual-band coaxial cavity filter is provided, and two frequency bands are integrated on one filter without adding other additional design modules, such as increasing the cavity order. The method for designing the dual-frequency band is simple and reliable, simple in feeding and compact in circuit structure, the volume of the system is sharply reduced, and the overall performance of the system is improved.
SUMMERY OF THE UTILITY MODEL
The utility model aims to overcome prior art's shortcoming and not enough (coaxial cavity filter is difficult to have the dual-frenquency characteristic promptly, or needs to adopt comparatively complicated other project organization to obtain the dual-frenquency filter), provided a simple structure compactness, can miniaturize, easily harmonious, bandwidth broad, the coaxial cavity filter of bimodulus dual-frenquency that selectivity is good.
In order to achieve the above object, the present invention provides a technical solution: a dual-mode dual-frequency coaxial cavity filter comprises a closed metal cavity and an input/output port; the metal cavity inner structures are distributed in a linear mode and sequentially comprise a first coaxial resonant cavity, a first coupling resonant window, a second coaxial resonant cavity, a second coupling resonant window and a third coaxial resonant cavity; a first vertical metal cylinder and a first horizontal metal cylinder are arranged in the first coaxial resonant cavity, the first horizontal metal cylinder is positioned in the middle of the first coaxial resonant cavity, one end of the first horizontal metal cylinder is embedded in the middle of the first vertical metal cylinder, the other end of the first horizontal metal cylinder is fixed on the inner wall of the first coaxial resonant cavity and is regarded as a short-circuit end, two ends of the first vertical metal cylinder are open-circuited, the distance between the two ends of the first vertical metal cylinder and the distance between the two ends of the first horizontal metal cylinder are equal to the distance between the two ends of the first vertical metal cylinder and the distance between the two ends of the first horizontal metal; a second vertical metal cylinder and a second horizontal metal cylinder are arranged in the second coaxial resonant cavity, the second horizontal metal cylinder is positioned in the middle of the second coaxial resonant cavity, one end of the second horizontal metal cylinder is embedded in the middle of the second vertical metal cylinder, the other end of the second horizontal metal cylinder is fixed on the inner wall of the second coaxial resonant cavity and is regarded as a short-circuit end, two ends of the second vertical metal cylinder are open-circuited, the distance between the two ends of the second vertical metal cylinder and the distance between the two ends of the second; a third vertical metal cylinder and a third horizontal metal cylinder are arranged in the third coaxial resonant cavity, the third horizontal metal cylinder is positioned in the middle of the third coaxial resonant cavity, one end of the third horizontal metal cylinder is embedded in the middle of the third vertical metal cylinder, the other end of the third horizontal metal cylinder is fixed on the inner wall of the third coaxial resonant cavity and is regarded as a short-circuit end, two ends of the third vertical metal cylinder are open-circuited, the distances between the two ends of the third vertical metal cylinder and the top and the bottom of the third coaxial resonant cavity are equal, the first resonant frequency generated by the third coaxial resonant cavity is controlled by the height of the third vertical metal cylinder and the length of the third horizontal metal cylinder together, and the second resonant frequency is controlled only by the height of the third vertical metal cylinder, so that the double-frequency characteristic which is; the first coupling resonant window consists of a first coupling junction and a first coupling window, the first coupling junction is directly inserted into the first vertical metal cylinder and the second vertical metal cylinder, the circle centers of the first coupling junction and the second vertical metal cylinder are positioned on the same straight line, the first coupling window is positioned on one side of the metal cavity, positioned on the same side as the short-circuit ends of the first horizontal metal cylinder, the second horizontal metal cylinder and the third horizontal metal cylinder and also positioned between the first horizontal metal cylinder and the second horizontal metal cylinder, and the first coupling junction and the first coupling window jointly control the coupling strength between the first coaxial resonant cavity and the second coaxial resonant cavity; the second coupling resonant window consists of a second coupling junction and a second coupling window, the second coupling junction is directly inserted into the second vertical metal cylinder and the third vertical metal cylinder, the circle center of the second coupling junction is positioned on the same line with the circle centers of the second vertical metal cylinder and the third vertical metal cylinder, the second coupling window is positioned on the same side as the first coupling window and is positioned between the second horizontal metal cylinder and the third horizontal metal cylinder, and the second coupling junction and the second coupling window jointly control the coupling strength between the second coaxial resonant cavity and the third coaxial resonant cavity; the two input and output ports are coaxial feeder lines, the two input and output ports are respectively extended and inserted into a first vertical metal cylinder of the first coaxial resonant cavity and a third vertical metal cylinder of the third coaxial resonant cavity, the circle centers of the coaxial feeder line joints and the circle centers of the first vertical metal cylinder and the third vertical metal cylinder are on the same straight line, and the inserting heights of the two ends are also the same.
Furthermore, two sides of the metal cavity are respectively provided with an SMA port for mounting two input and output ports.
Further, the first two resonant frequencies of the first coaxial resonant cavity, the second coaxial resonant cavity and the third coaxial resonant cavity are the same.
Further, the positions and parameters of the two parts of the first coupling resonance window and the second coupling resonance window are the same, namely the length, the width and the height of the coupling windows are equal.
Further, the first, second and third vertical metal cylinders are of a hollow structure or a solid structure.
Further, the metal cavity is a square metal cavity.
Compared with the prior art, the utility model, have following advantage and beneficial effect:
1. on the basis of a traditional coaxial filter, a metal cylinder in the horizontal direction is added, so that the two metal cylinders can respectively control the first resonant frequency and the second resonant frequency of the resonant cavity, and the dual-frequency characteristic is realized.
2. The utility model discloses have better in-band filtering characteristic, the outband frequency selective characteristic is good.
3. The utility model has the advantages of simple and compact structure, easy design and easy processing.
Drawings
Fig. 1 is an overall structure schematic diagram of the coaxial cavity dual-band filter provided by the present invention.
Fig. 2 is a schematic diagram of a top-view cross-sectional structure of the coaxial cavity dual-band filter provided by the present invention.
FIG. 3 is a simulation result diagram (solid line is S in the drawing) of the embodiment of the present invention11Dotted line is S21)。
Detailed Description
The present invention will be further described with reference to the following specific embodiments.
As shown in fig. 1 and fig. 2, the coaxial cavity dual-frequency filter provided in this embodiment includes a closed metal cavity 13 and two input/ output ports 1 and 12; the metal cavity 1 is a rectangular metal cavity, the structures in the metal cavity are distributed in a linear mode, and the metal cavity sequentially comprises a first coaxial resonant cavity, a first coupling resonant window, a second coaxial resonant cavity, a second coupling resonant window and a third coaxial resonant cavity; the first two resonant frequencies of the first coaxial resonant cavity, the second coaxial resonant cavity and the third coaxial resonant cavity are the same, and the higher-order resonant frequencies are far away from each other, so that a double-frequency filter with a wider stop band and better performance can be obtained; the positions and parameters of the two parts of the first coupling resonance window and the second coupling resonance window are the same, namely the length, the width and the height of the coupling windows are equal.
The first coaxial resonant cavity is internally provided with a first vertical metal cylinder 2 and a first horizontal metal cylinder 3, the first horizontal metal cylinder 3 is positioned in the middle of the first coaxial resonant cavity, one end of the first horizontal metal cylinder 3 is embedded in the middle of the first vertical metal cylinder 2, the other end of the first horizontal metal cylinder is fixed on the inner wall of the first coaxial resonant cavity and is regarded as a short-circuit end, two ends of the first vertical metal cylinder 2 are open-circuited, the distance between the two ends of the first vertical metal cylinder 2 and the distance between the two ends of the first vertical metal cylinder 3 are equal to the distance between the two ends of the first vertical metal cylinder 2 and the distance between the two ends of the first horizontal metal cylinder 3, the first resonant frequency generated by the first coaxial resonant cavity is controlled by the height of the first vertical metal cylinder 2, the second resonant frequency is controlled by the height.
A second vertical metal cylinder 6 and a second horizontal metal cylinder 7 are arranged in the second coaxial resonant cavity, and the placing mode of the second vertical metal cylinder is consistent with that of the first vertical metal cylinder 2 and the first horizontal metal cylinder 3 in the first coaxial resonant cavity, specifically: the second horizontal metal cylinder 7 is located in the middle of the second coaxial resonant cavity, one end of the second horizontal metal cylinder is embedded in the middle of the second vertical metal cylinder 6, the other end of the second horizontal metal cylinder is fixed on the inner wall of the second coaxial resonant cavity and is regarded as a short-circuit end, two ends of the second vertical metal cylinder 6 are open-circuited, the distance between the two ends of the second vertical metal cylinder 6 and the distance between the two ends of the second vertical metal cylinder 7 are equal, the first resonant frequency generated by the second.
A third vertical metal cylinder 10 and a third horizontal metal cylinder 11 are arranged in the third coaxial resonant cavity, and the placing mode of the third vertical metal cylinder is consistent with that of the first vertical metal cylinder 2 and that of the first horizontal metal cylinder 3 in the first coaxial resonant cavity, specifically: the third horizontal metal cylinder 11 is located in the middle of the third coaxial resonant cavity, one end of the third horizontal metal cylinder is embedded in the middle of the third vertical metal cylinder 10, the other end of the third horizontal metal cylinder is fixed on the inner wall of the third coaxial resonant cavity and is regarded as a short-circuit end, two ends of the third vertical metal cylinder 10 are open-circuited, the distance between the two ends of the third vertical metal cylinder and the distance.
The first coupling resonant window is composed of a first coupling junction 4 and a first coupling window 5, the first coupling junction 4 is directly inserted into the first vertical metal cylinder 2 and the second vertical metal cylinder 6, the circle center of the first coupling junction 4 is located on the same straight line with the circle centers of the first vertical metal cylinder 2 and the second vertical metal cylinder 6, the first coupling window 5 is located on one side of the metal cavity, is located on the same side with the short-circuit ends of the first horizontal metal cylinder 3, the second horizontal metal cylinder 7 and the third horizontal metal cylinder 11, and is also located between the first horizontal metal cylinder 3 and the second horizontal metal cylinder 7, and the first coupling junction 4 and the first coupling window 5 jointly control the coupling strength between the first coaxial resonant cavity and the second coaxial resonant cavity.
The second coupling resonant window is composed of a second coupling junction 8 and a second coupling window 9, the second coupling junction 8 is directly inserted into the second vertical metal cylinder 6 and the third vertical metal cylinder 10, the circle center of the second coupling junction 8 is in the same line with the circle centers of the second vertical metal cylinder 6 and the third vertical metal cylinder 10, the second coupling window 9 is on the same side as the first coupling window 5 and is located between the second horizontal metal cylinder 7 and the third horizontal metal cylinder 11, and the second coupling junction 8 and the second coupling window 9 jointly control the coupling strength between the second coaxial resonant cavity and the third coaxial resonant cavity.
The vertical metal cylinders in the first, second and third coaxial resonators may be hollow or solid.
Two sides of the metal cavity 13 are respectively provided with an SMA port for installing two input and output ports 1 and 12, the two input and output ports 1 and 12 are coaxial feeder lines, the two input and output ports are respectively extended and inserted into a first vertical metal cylinder 2 of the first coaxial resonant cavity and a third vertical metal cylinder 10 of the third coaxial resonant cavity, the circle center of the coaxial feeder line joint and the circle centers of the first vertical metal cylinder 2 and the third vertical metal cylinder 10 are on the same straight line, and the inserting heights of the two ends are also the same.
The center frequencies of the designed dual-mode dual-frequency coaxial cavity filter are 900MHz and 1800 MHz. The three-dimensional simulation software HFSS is used for simulating and optimizing the coaxial dual-frequency filter, and the optimized main structural parameters are as follows: l is2＝L10＝60mm,L3＝L7＝L11＝25mm,L4＝L8＝22.1mm,L5＝L9＝6mm,L6＝56.1mm,H4＝H8＝52mm,H1＝H12＝59mm。
As shown in FIG. 3, the scattering simulation results of the dual-mode dual-band coaxial cavity filter of the embodiment are shown, wherein the horizontal axis represents the input signal frequency ranging from 0.5GHz to 3.0GHz and the vertical axis represents the amplitude, including the return loss S11Amplitude (solid line) and insertion loss S of21Is measured (dashed line). The central working frequency of the filter is 900MHZ and 1800MHZ, the relative bandwidth of 3dB is 29.86 percent and 15.12 percent respectively, the insertion loss is 0.0007dB and 0.0013dB respectively, the return loss is reduced to be lower than 20dB, and a transmission zero point is arranged between the two pass bands. As can be seen from the figure, the dual-mode dual-frequency coaxial cavity filter has the advantages of wide bandwidth, high selectivity, high out-of-band rejection and the like.
To sum up, the utility model provides a coaxial cavity filter of bimodulus dual-frenquency, it compares with traditional coaxial filter, has had the metal cylinder of a horizontal direction more, has consequently introduced a relatively independent new mode. The two resonance modes obtain double-frequency characteristics, and each passband characteristic is independently adjustable. In a word, the utility model discloses the wave filter structure symmetry is simple, and is small, and the dual band passband loss is low, and the selectivity is good, and the stop band is wide, and restraines the degree height, has actual spreading value, is worth promoting.
The above-mentioned embodiments are only preferred embodiments of the present invention, and the scope of the present invention is not limited thereto, so that all the changes made according to the shape and principle of the present invention should be covered within the protection scope of the present invention.
Claims (6)
1. A dual-mode dual-frequency coaxial cavity filter is characterized in that: comprises a closed metal cavity and an input/output port; the metal cavity inner structures are distributed in a linear mode and sequentially comprise a first coaxial resonant cavity, a first coupling resonant window, a second coaxial resonant cavity, a second coupling resonant window and a third coaxial resonant cavity; a first vertical metal cylinder and a first horizontal metal cylinder are arranged in the first coaxial resonant cavity, the first horizontal metal cylinder is positioned in the middle of the first coaxial resonant cavity, one end of the first horizontal metal cylinder is embedded in the middle of the first vertical metal cylinder, the other end of the first horizontal metal cylinder is fixed on the inner wall of the first coaxial resonant cavity and is regarded as a short-circuit end, two ends of the first vertical metal cylinder are open-circuited, the distance between the two ends of the first vertical metal cylinder and the distance between the two ends of the first horizontal metal cylinder are equal to the distance between the two ends of the first vertical metal cylinder and the distance between the two ends of the first horizontal metal; a second vertical metal cylinder and a second horizontal metal cylinder are arranged in the second coaxial resonant cavity, the second horizontal metal cylinder is positioned in the middle of the second coaxial resonant cavity, one end of the second horizontal metal cylinder is embedded in the middle of the second vertical metal cylinder, the other end of the second horizontal metal cylinder is fixed on the inner wall of the second coaxial resonant cavity and is regarded as a short-circuit end, two ends of the second vertical metal cylinder are open-circuited, the distance between the two ends of the second vertical metal cylinder and the distance between the two ends of the second; a third vertical metal cylinder and a third horizontal metal cylinder are arranged in the third coaxial resonant cavity, the third horizontal metal cylinder is positioned in the middle of the third coaxial resonant cavity, one end of the third horizontal metal cylinder is embedded in the middle of the third vertical metal cylinder, the other end of the third horizontal metal cylinder is fixed on the inner wall of the third coaxial resonant cavity and is regarded as a short-circuit end, two ends of the third vertical metal cylinder are open-circuited, the distances between the two ends of the third vertical metal cylinder and the top and the bottom of the third coaxial resonant cavity are equal, the first resonant frequency generated by the third coaxial resonant cavity is controlled by the height of the third vertical metal cylinder and the length of the third horizontal metal cylinder together, and the second resonant frequency is controlled only by the height of the third vertical metal cylinder, so that the double-frequency characteristic which is; the first coupling resonant window consists of a first coupling junction and a first coupling window, the first coupling junction is directly inserted into the first vertical metal cylinder and the second vertical metal cylinder, the circle centers of the first coupling junction and the second vertical metal cylinder are positioned on the same straight line, the first coupling window is positioned on one side of the metal cavity, positioned on the same side as the short-circuit ends of the first horizontal metal cylinder, the second horizontal metal cylinder and the third horizontal metal cylinder and also positioned between the first horizontal metal cylinder and the second horizontal metal cylinder, and the first coupling junction and the first coupling window jointly control the coupling strength between the first coaxial resonant cavity and the second coaxial resonant cavity; the second coupling resonant window consists of a second coupling junction and a second coupling window, the second coupling junction is directly inserted into the second vertical metal cylinder and the third vertical metal cylinder, the circle center of the second coupling junction is positioned on the same line with the circle centers of the second vertical metal cylinder and the third vertical metal cylinder, the second coupling window is positioned on the same side as the first coupling window and is positioned between the second horizontal metal cylinder and the third horizontal metal cylinder, and the second coupling junction and the second coupling window jointly control the coupling strength between the second coaxial resonant cavity and the third coaxial resonant cavity; the two input and output ports are coaxial feeder lines, the two input and output ports are respectively extended and inserted into a first vertical metal cylinder of the first coaxial resonant cavity and a third vertical metal cylinder of the third coaxial resonant cavity, the circle centers of the coaxial feeder line joints and the circle centers of the first vertical metal cylinder and the third vertical metal cylinder are on the same straight line, and the inserting heights of the two ends are also the same.
2. The dual-mode dual-frequency coaxial cavity filter of claim 1, wherein: and two SMA ports are respectively arranged on two sides of the metal cavity and used for mounting two input and output ports.
3. The dual-mode dual-frequency coaxial cavity filter of claim 1, wherein: the first two resonant frequencies of the first coaxial resonant cavity, the second coaxial resonant cavity and the third coaxial resonant cavity are the same.
4. The dual-mode dual-frequency coaxial cavity filter of claim 1, wherein: the positions and parameters of the two parts of the first coupling resonance window and the second coupling resonance window are the same, namely the length, the width and the height of the coupling windows are equal.
5. The dual-mode dual-frequency coaxial cavity filter of claim 1, wherein: the first, second and third vertical metal cylinders are of a hollow structure or a solid structure.
6. The dual-mode dual-frequency coaxial cavity filter of claim 1, wherein: the metal cavity is a square metal cavity.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110429361A (en) * | 2019-07-25 | 2019-11-08 | 华南理工大学 | A kind of bimodulus double-frequency coaxial cavity body filter |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110429361A (en) * | 2019-07-25 | 2019-11-08 | 华南理工大学 | A kind of bimodulus double-frequency coaxial cavity body filter |
| CN110429361B (en) * | 2019-07-25 | 2024-01-26 | 华南理工大学 | Dual-mode dual-frequency coaxial cavity filter |
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