CN1108826A - Electric filter - Google Patents

Electric filter Download PDF

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Publication number
CN1108826A
CN1108826A CN 94117206 CN94117206A CN1108826A CN 1108826 A CN1108826 A CN 1108826A CN 94117206 CN94117206 CN 94117206 CN 94117206 A CN94117206 A CN 94117206A CN 1108826 A CN1108826 A CN 1108826A
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line
coupling
mentioned
end open
electrical length
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CN1043279C (en
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矢吹博幸
松尾道明
佐川守一
牧本三夫
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Panasonic Holdings Corp
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Matsushita Electric Industrial Co Ltd
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Abstract

A kind of filter used in ultra high frequency-super high frequency band communication equipments is that on the 1 wave length ring resonance cavities 12 and 17, the front end open-circuit transmission lines 13, 14, 15 and 16 bare connected to the points locating at the positions with 90 deg. mutual deviation of electric length thus the resonance frequency can be arbitrarily set lower than the resonance frequency of single wave length ring resonance cavity, and the frequency is easily adjusted by adjusting the electric length of the front end open-circuit transmission line. The coupling between filter sections can be implemented by parallel line. The ring resonance cavity can be installed closely and the whole filter can be minimied and planified. The other invention is that the coupling line is coupled at position deviating the center of the propagation path, the frequecy characteristic near by the pass band can be sunk down, less filter section can implement good attenuation charact

Description

Electric filter
Small-sized, the cheapness that the present invention relates to that superfrequency (UHF)～hyperfrequency (SHF) frequency range communicator and measuring equipment use and the filter of complanation, also relate to the bimodulus resonant cavity of using in a kind of oscillator, the filter, can form two frequencies at a resonant cavity, or play two-stage resonance.
The annular resonance cavity filter adopts 1 wavelength ring resonator etc. usually in order to reduce radiation loss, though loss is little, has the big problem of shape.For head it off, the dual mode filter at 2 orthogonal modes of a resonant cavity excitation is proposed.Dual mode filter in the past hereinafter is described.
Fig. 6 is the composition diagram of dual mode filter in the past.Among Fig. 6,1 is 1 wavelength ring resonator, and 2-5 is contained in electrical length inclined to one side 90 ° locational coupling capacitance mutually, and 6,7 are input, lead-out terminal, and 8 is phase-shift circuit.9,10 is the splicing ear of phase-shift circuit 8, is connected on this phase-shift circuit 8.
The performance of forming aforesaid dual mode filter is described.
At first, an input signal on the terminal 6 just is coupled to resonant cavity 1 by electric coupling with this signal.The signal wave that the A point is propagated on the ring resonator 1 departs from 18 being positioned at electrical length) ° B that locates some electric field maximum, and propagate into terminal 9 by coupling capacitance 4.Depart from 90 ° C point, D point in A point electrical length from toroidal cavity resonator 1, electric field is 0, does not propagate on the terminal 7,10.Equally, during stimulation terminal 10, there is capable ripple to reach terminal 10.Therefore, prove 2 resonant modes that existence does not intercouple in the 1 wavelength annular resonance cavity filter 1.Here, stimulation terminal 6, the signal wave that will pass to terminal 9 by suitable phase-shift circuit 8 is added on the terminal 10, and then this row ripple only reaches terminal 7.In view of the above, can form, output to the one way signal propagation circuit of terminal 7 by terminal 9,10 from the signal of terminal 6 inputs.That is to say that terminal 6 is during as input terminal, terminal 7 becomes lead-out terminal, and available one 1 wavelength ring resonator is realized 2 grades of filters.
Yet the problem that exists in the said structure is: the common characteristic of filter can only be corresponding with the fixed frequency that 1 wavelength ring resonator electrical length is determined, its frequency characteristic is adjusted difficulty.The resonant cavity electrical length at different levels that the problem that exists is formed filter in addition are 1 wavelength, add that interstage coupling adopts lumped-parameter element or transmission line, thereby filter are difficult to miniaturization, complanation.
The annular resonance cavity filter adopts 1 wavelength ring resonator etc. usually in order to reduce radiation loss, though loss is little, has the big problem of shape.For head it off, the dual mode filter at 2 orthogonal modes of a resonant cavity excitation is proposed.
Dual mode filter in the past hereinafter is described.
Figure 15 is the composition diagram of dual mode filter in the past.Among Figure 15,101,102 is 1 wavelength ring resonator, and 103～107 is coupling capacitance, and 108,109 are input, lead-out terminal.
The performance of forming dual mode filter is as above described.
At first, an input signal on the input terminal 108 just is coupled to 1 wavelength ring resonator 101 by field coupled with this signal.The signal wave that the A point is propagated on this resonant cavity 101 departs from the B point electric field maximum of 180 ° of A points in electrical length, and reaches the C point by coupling capacitance 5.Be positioned on the above-mentioned resonant cavity 101 and depart from 90 ° C, D point from A point electrical length, electric field is 0, does not have and propagates.Therefore, prove that there are 2 resonant modes that do not intercouple in 1 wavelength ring resonator 101.
Again, reach the signal wave that the A of 1 wavelength ring resonator 102 orders through coupling capacitance 106 and reach the B point earlier, pass to C point and D point successively through coupling capacitance 107 again, output to lead-out terminal 109 by electric capacity 104 at last.At this moment, the resonance frequency of 1 wavelength ring resonator 101,102 depends on the electrical length of resonant cavity.
In view of the above, can form the signal one way propagation circuit that outputs to terminal 109 from the signal of terminal 108 inputs.That is to say that terminal 108 is during as input terminal, terminal 109 becomes input terminal, and available 21 wavelength ring resonators are made 4 grades of filters.
Yet the problem that exists in the above-mentioned composition is that the electrical length of the resonant cavitys at different levels of formation filter is 1 wavelength, improves attenuation characteristic and need increase filter order, can not realize miniaturization.In addition, also exist interstage coupling to adopt lumped-parameter element or transmission line, filter is difficult to the problem of miniaturization, complanation.
In the resonant cavity that high band oscillator, filter are used, with regard to banded resonant cavity or microstrip line resonant cavity, 1/4 wave resonance cavity volume is little, thus extensive use, but exist processing method to cause shortcomings such as characteristic instability such as resonance frequency, unloaded Q because of high frequency earthing.Therefore, propose to adopt the bimodulus resonant cavity to carry out the intention of miniaturization, 2 kinds of independent moulds that this bimodulus resonant cavity utilization encourages in the earth-free ring resonator of high band form 2 different resonance frequencys of frequency or play 2 grades of resonance at a resonant cavity.
This bimodulus resonant cavity, the example of knowing have the structure of records such as the microwave study meeting technical data MW92-115 of NEC information communication association.
Hereinafter with reference to Figure 27 explanation bimodulus resonant cavity in the past.
Figure 27 is the oblique view of bimodulus resonant cavity in the past, and 201 is the ring-type single line that is formed by microstrip line among Figure 12, and 202 is lumped parameter electric capacity, and 203 is dielectric substrate, and 204 is earthing conductor.
Among this figure, though single line is a rectangle, its electrical characteristics are identical with annular, and rectangle only is described here.In addition, also available strip line of circuit or microstrip line illustrate typical microstrip line here, the following describes the performance of the bimodulus resonant cavity of said structure.
Input, output coupling circuit omit and do not narrate, the signal (frequency f 1) of field coupled input is departing from annular single line length 1/4 place's voltage minimum from the point that connects lumped parameter electric capacity 202, does not have and propagates, but the other end voltage maximum that connects lumped parameter electric capacity 202, thereby from this end output.Depart from the signal (frequency f 2) that the point of 1/4 annular single line length is imported from the tie point of lumped parameter electric capacity 202, voltage minimum on the point that connects lumped parameter electric capacity 202, do not have to propagate, but depart from voltage maximum on the point of 1/2 annular single line length from the signal input point, output is arranged.In this example, only with a lumped parameter electric capacity, so frequency f 1 is different with f2, but increases the electric capacity of same capacitance or remove lumped parameter electric capacity 2, these two separate resonant modes are with same frequency resonance, and a resonant cavity plays 2 grades.
The resonant cavity of being made up of annular single line 201 and lumped parameter electric capacity 202 encourages the bimodulus resonant cavity of 2 independent moulds to carry out work as an available resonant cavity like this.This resonant cavity high frequency is earth-free, and the loop configuration radiation loss is little, do not damage the characteristics that 1 wavelength annular bimodulus resonant cavity is had, and seeks miniaturization.
Yet, though can not damage the characteristics that 1 wavelength ring resonator has in the above-mentioned structure in the past, seek miniaturization, but the problem that exists is that will to reach the resonance frequency reproducibility good, just must lumped parameter electric capacity precision height, thereby be difficult to realize or increase frequency adjust function, to offset the deviation of the accuracy of manufacture, and number of elements is many, causes poor performance, the cost height.
The present invention solves the above-mentioned technical problem that in the past existed, but its first purpose is to provide the filter of a kind of little shape and complanation, and the line length of 1 wavelength ring resonator is shortened in this filter equivalence, and can carry out the frequency adjustment easily.
The present invention solves the above-mentioned technical problem that in the past existed, and its second purpose is to provide a kind of filter, and wherein the line length of 1 wavelength ring resonator is shortened in equivalence, improves near the attenuation characteristic of passband simultaneously, thereby can realize small-sized and complanation.
The present invention solves above-mentioned technical problem in the past, and its 3rd purpose is to provide a kind of inhibition resonance frequency deviation, seeks to improve the reproducibility and the precision of resonance frequency, and frequency is adjusted small-sized high Q and inexpensive bimodulus resonant cavity easily.
(first invention)
In order to achieve the above object, the present invention makes and will form the 1 wavelength ring resonator electrical length quartering of filter, be connected the 1st transmission line in the 1st position on its circuit on 180 ° the 2nd position with departing from identical characteristics and front end open circuit with above-mentioned the 1st position electrical length, be connected the 2nd transmission line on 180 ° the 4th position with departing from departing from 90 ° the 3rd position again with identical characteristics and front end open circuit with above-mentioned the 3rd position electrical length with above-mentioned the 1st position electrical length, the 1 wavelength ring resonator that will be connected into aforesaid way again disposes by same direction, and the coupling between the resonant cavity adopts parallel coupled line.
(second invention)
In order to achieve the above object, the present invention makes and will constitute the 1 wavelength ring resonator electrical length quartering of filter, the 1st point on this circuit, depart from 90 ° the 2nd point with above-mentioned the 1st electrical length, with above-mentioned the 1st electrical length depart from 180 ° the 3rd with depart from 270 ° the 4th and be connected transmission line with above-mentioned the 1st with identical characteristics and front end open circuit, and the interstage coupling that is connected into 1 wavelength ring resonator of aforesaid way is a parallel coupled line, its coupling electrical length is less than 90 °, to constitute some conduct input of elementary above-mentioned 1 wavelength ring resonator simultaneously, with constitute final stage above-mentioned 1 wavelength ring resonator a bit as exporting, perhaps will constitute some conduct input of 1 wavelength ring resonator of final stage, will depart from some conduct output of 90 ° with above-mentioned input point electrical length.
(the 3rd invention)
In order to achieve the above object, the present invention makes with front end open circuit coupling line or front end open circuit single line and replaces indispensable electric capacity in the miniaturization of bimodulus resonant cavity, and this coupling line or single line is made in the inboard of annular single line.
Again, use open end or its part excision with coupling line or single line, overlapping method is handled the adjustment of resonance frequency.
The present invention is departing from the positive and negative reverse voltage of generation between 180 ° of 2 of locating mutually in length on the ring resonator, and the transmission line of connection front end open circuit, thereby resonance frequency can be set for lower than the resonance frequency of single 1 wavelength ring resonator arbitrarily, can utilize simultaneously the electrical length of method adjusting front end open circuited transmission lines such as finishing, frequency is adjusted easily.Again, the interstage coupling of filter realizes with parallel coupled line, but thereby the ring resonator neighbor configuration, whole filter can miniaturization, complanation.
The present invention is departing from the positive and negative reverse voltage of generation between 180 ° of 2 of locating mutually in electrical length on the ring resonator, and the transmission line of connection front end open circuit, can adjust resonance frequency by regulating this length of transmission line, and realize interstage coupling with parallel coupled line, but the ring resonator neighbor configuration can realize little shape, the complanation of filter.Again, the inter-stage parallel coupled line is coupled in the position of departing from the center, route of transmission, thereby can form near passband and sink, and can make the good filter of attenuation characteristic with few progression.
The present invention utilizes the good photoetching technique of the accuracy of manufacture etc. by said structure, and annular single line and front end open circuit coupling line that forms distributed circuit or front end open circuit single line are made simultaneously, seeks resonant cavity low cost and reproducibility and the precision of improving resonance frequency.Form front end open circuit coupling line or the single line that shortens the cavity length effect together again in the inboard of annular single line, further seek the miniaturization of resonant cavity.
The distributed constant electric capacity of front end open circuit coupling line or single line is compared with lumped parameter electric capacity, can make to concentrate electric field to disperse, and loss is very little, thereby can improve the unloaded Q of resonant cavity.
With the open end or the part of front end that this annular single line connected open circuit coupling line or single line excise, overlapping, frequency is easy to adjust.
As mentioned above, replace indispensable electric capacity in the miniaturization of bimodulus resonant cavity with front end open circuit coupling line or single line, and this coupling line or single line are made in the inboard of annular single line, thereby can seek to suppress the resonance frequency deviation, improve resonance frequency reproducibility and precision, realize high Q and inexpensive bimodulus resonant cavity.Again, by the open end or the part of front end is opened a way coupling line or single line excise, overlapping, frequency is easy to adjust.
Fig. 1 is the plane graph of first invention the 1st embodiment median filter.
Fig. 2 is the plane graph of first invention the 2nd embodiment median filter.
Fig. 3 is the plane graph of first invention the 3rd embodiment median filter.
Fig. 4 is the plane graph of first invention the 4th embodiment median filter.
Fig. 5 is the plane graph of first invention the 5th embodiment median filter.
Fig. 6 is filter plane graph in the past.
Fig. 7 is the plane graph of second invention the 1st embodiment median filter.
Fig. 8 is the performance plot of second invention the 1st embodiment median filter.
Fig. 9 is the plane graph of other filters among second invention the 1st embodiment.
Figure 10 is the plane graph of other filters among second invention the 1st embodiment.
Figure 11 is the plane graph of other filters among second invention the 1st embodiment.
Figure 12 is the plane graph of other filters among second invention the 1st embodiment.
Figure 13 is the plane graph of other filters among second invention the 1st embodiment.
Figure 14 is the plane graph of second invention the 2nd embodiment median filter.
Figure 15 is the plane graph of filter in the past.
Figure 16 is the plane graph of bimodulus resonant cavity among the 3rd invention the 1st embodiment.
Figure 17 is the plane graph of bimodulus resonant cavity among the 3rd invention the 2nd embodiment.
Figure 18 is the plane graph of bimodulus resonant cavity among the 3rd invention the 3rd embodiment.
Figure 19 is the plane graph of bimodulus resonant cavity among the 3rd invention the 4th embodiment.
Figure 20 is the plane graph of bimodulus resonant cavity among the 3rd invention the 5th embodiment.
Figure 21 (a) is the A-A cutaway view of bimodulus resonant cavity among the 3rd invention the 6th embodiment.
Figure 21 (b) is the surface conductor layer electrode line plane graph of bimodulus resonant cavity among the 3rd invention the 6th embodiment.
Figure 21 (c) is the internal conductor layer electrode line plane graph of bimodulus resonant cavity among the 3rd invention the 6th embodiment.
Figure 21 (d) is the schematic diagram that bimodulus resonant cavity surface conductor layer and internal conductor layer electrode line overlap situation among the 3rd invention the 6th embodiment.
Figure 21 (e) is the schematic diagram that bimodulus resonant cavity surface conductor layer and internal conductor layer electrode line overlap situation among the 3rd invention the 6th embodiment.
Figure 21 (f) is the schematic diagram that bimodulus resonant cavity surface conductor layer and internal conductor layer electrode line overlap situation among the 3rd invention the 6th embodiment.
Figure 22 is the plane graph of bimodulus resonant cavity among this 3rd invention the 7th embodiment.
Figure 23 (a) is the A-A ' cutaway view of bimodulus resonant cavity among the 3rd invention the 8th embodiment.
Figure 23 (b) is the plane graph of the surface conductor layer electrode line of bimodulus resonant cavity among the 3rd invention the 8th embodiment.
Figure 23 (c) is the plane graph of the internal conductor layer electrode line of bimodulus resonant cavity among the 3rd invention the 8th embodiment.
Figure 24 is the plane graph of bimodulus resonant cavity among the 3rd invention the 9th embodiment.
Figure 25 (a) is the A-A ' cutaway view of bimodulus resonant cavity among the 3rd invention the 10th embodiment.
Figure 25 (b) is the plane graph of the surface conductor layer electrode line of bimodulus resonant cavity among the 3rd invention the 10th embodiment.
Figure 25 (c) is the plane graph of the internal conductor layer electrode line of bimodulus resonant cavity among the 3rd invention the 10th embodiment.
Figure 26 (a) is the A-A ' cutaway view of bimodulus resonant cavity among the 3rd invention the 11st embodiment.
Figure 26 (b) is the plane graph of bimodulus resonant cavity among the 3rd invention the 11st embodiment.
Figure 27 is the oblique view of bimodulus resonant cavity in the past.
Below with reference to above-mentioned description of drawings first invention
Embodiment 1
Fig. 1 (a) is the plane graph of the present invention's the 1st embodiment median filter.Among Fig. 1 (a), 11 is resonant cavity, makes 1 wavelength ring resonator 12 specifically.This ring resonator 12 is departing from the 1st front end open circuited transmission line 13,14 that 180 ° B point setting has identical characteristics with the A point of circuit with from this A point electrical length.In addition, depart from the C point on 90 ° the circuit with A point electrical length and depart from D point on 180 ° the circuit from this C point electrical length being positioned at, the 2nd front end open circuited transmission line 15,16 with identical characteristics is set.17 is the resonant cavity identical with resonant cavity 11, two resonant cavitys are by same direction configuration, with parallel coupled line 18 realization interstage couplings each other, 19,20 and 21,22 for being connected input, the output coupling transmission line that E, G point inclined to one side 90 ° mutually on the electrical length and F, H are ordered respectively, and 23～26 are input, lead-out terminal.
The performance of forming aforesaid filter is described.
At first, an input signal on the input terminal 23 just is coupled to resonant cavity 11 by coupling with transmission line 19.Resonant cavity 11 is made resonance with the electrical length and the 1st front end open circuited transmission line 13, the 14 determined resonance frequency f1 of 1 wavelength ring resonator 12, motivate A point, B point voltage maximum on this resonant cavity 11, the fundamental resonance mould of C point, D point electric current maximum (being that voltage is zero).Then, reach E, the F point of resonant cavity 17 successively, finally export lead-out terminal 25 to by transmission line 21 again by parallel coupled line 18.
On the other hand, the signal wave that encourages during input signal on the input terminal 24 reaches C, the D point of resonant cavity 11 through transmission line 20, reaches G, the H point of resonant cavity 17 more successively by parallel coupled line 18, after transmission line 22 outputs to lead-out terminal 26.At this moment, the resonance frequency f2 of resonant cavity 11 depends on the electrical length of 1 humorous long ring resonator 12 and the electrical length of the 2nd front end open circuited transmission line 15,16.
Such signal wave of propagating mentioned above encourages orthogonal mode respectively in resonant cavity 11,17, long the making of some electricity that is positioned at from the ring resonator departed from 90 ° point, and its electric field is 0, does not have and propagates.Therefore, prove 2 resonant modes that the filter existence does not intercouple and frequency is different of this composition.In view of the above, with frequency f 1 excitation input terminal 23, frequency f 2 excitation input terminals 24, thus only be the capable ripple of f1 in lead-out terminal 25 frequencies of propagation, be the capable ripple of f2 only in lead-out terminal 26 frequencies of propagation.
The following describes the composition of Fig. 1 (b).Only be the point of the A on resonant cavity 11 and be positioned to depart from 180 ° B point with the difference of Fig. 1 (a) among Fig. 1 (b) from this A point electrical length, and the point of the E on the resonant cavity 17 and be positioned at from this E point electrical length and depart from 180 ° F point, connect front end open circuited transmission line 13,14 respectively with identical characteristics.
The performance of such filter of forming mentioned above is described.
Key property is identical with the embodiment of Fig. 1 (a), difference is: during input terminal 24 excitations, resonant cavity is made resonance with the determined resonance frequency f3 of the electrical length of 1 wavelength ring resonator 12, transmission row ripple on lead-out terminal 26, but do not propagate on the lead-out terminal 23,25.
As mentioned above, by adopting composition shown in Figure 1, resonance frequency can be set for lower than single 1 wavelength ring resonator resonance frequency arbitrarily, and can utilize the electrical length of adjusting front end open circuited transmission lines such as inching, and frequency is adjusted easily.In addition, the interstage coupling of filter realizes with parallel coupled line, ring resonator energy neighbor configuration, whole filter Miniaturizable, complanation.
Again, the 1st, the 2nd front end open circuited transmission line 13,14,15,16 is used and 12 whiles of 1 wavelength ring resonator usually, forms with line image, but also can utilize electric processing or chemical treatment etc. to carry out the back assembling after ring resonator 12 forms.
(embodiment 2)
Hereinafter with reference to description of drawings the 2nd embodiment.
Fig. 2 (a) is the plane graph of the present invention's the 2nd embodiment median filter.Among Fig. 2 (a) with the difference of Fig. 1 (a) be to adopt make opposite with embodiment 1 illustrated 1 wavelength ring resonator 17, the 1 wavelength ring resonator 17B that exchanges of the 1st transmission line 13,14 and the 2nd transmission line 15,16 wherein, by same direction configuration, the interstage coupling of resonant cavity realizes with parallel coupled line 18 between 1 wavelength ring resonator 11 and the 17B.
The performance of above-mentioned described such filter of forming is described.
At first, an input signal on the input terminal 23 just is coupled to resonant cavity 11 by coupling with transmission line 19.Resonant cavity 11 is done resonance with the electrical length and the 1st front end open circuited transmission line 13, the 14 determined resonance frequency f1 of 1 wavelength ring resonator 12, on resonator 11, motivate A point, B point voltage maximum, the fundamental resonance mould of C point, D point electric current maximum (being that voltage is zero).Then, reach G, the H point of resonant cavity 17B successively, finally output to lead-out terminal 26 by transmission line 22 again by parallel coupled line 18.
On the other hand, on the input terminal 24 during input signal.The signal wave of excitation reaches C, the D point of resonant cavity 11 through transmission line 20, reaches E, the F point of resonant cavity 17B more successively through parallel coupled line 18, outputs to lead-out terminal 25 by transmission line 21 at last.At this moment, the resonance frequency f2 of resonant cavity 11 depends on the electrical length of 1 wavelength ring resonator 12 and the electrical length of the 2nd front end open circuited transmission line 15,16.
The signal of propagating is like that as mentioned above encouraged orthogonal mode at resonant cavity 11,17B respectively, and some electrical length that are positioned at from the toroidal cavity resonator depart from 90 ° of points, and its electric field is 0, does not have and propagates.Therefore, prove 2 resonant modes that the filter existence does not intercouple and frequency is different of this composition.In view of the above, with frequency f 1 excitation input terminal 23, frequency f 2 excitation input terminals 24, thus only be the capable ripple of f1 in lead-out terminal 26 frequencies of propagation, be the capable ripple of f2 only in lead-out terminal 25 frequencies of propagation.
Key diagram 2(b hereinafter) composition.
Difference with Fig. 2 (a) among Fig. 2 (b) is: the point of the A on resonant cavity 11 and be positioned at and depart from 180 ° B point from this electrical length only, and the point of the G on the resonant cavity 17 and be positioned at and depart from 180 ° H point from this electrical length, connect transmission line 13,14 respectively with identical characteristics and front end open circuit.
The performance of the ring resonator of forming as mentioned above is described.
Key property is identical with the embodiment of Fig. 2 (a), difference is just excitation of input signal on the input terminal 24, the determined resonance frequency f3 of electrical length of 1 wavelength ring resonator 12 of resonant cavity 11 makes resonance, on lead-out terminal 25, propagate the row ripple, but do not propagate on input terminal 23 and the lead-out terminal 26.
As mentioned above, by adopting composition shown in Figure 2, resonance frequency can be set the resonance frequency that is lower than single 1 wavelength ring resonator arbitrarily for, and can utilize the electrical length of adjusting front end open circuited transmission lines such as finishing, and frequency is adjusted easily.In addition, realize the interstage coupling of filter with parallel coupled line, but thereby the ring resonator neighbor configuration, whole filter can miniaturization, complanation.
(embodiment 3)
The 3rd embodiment of the present invention is described with reference to the accompanying drawings.
Fig. 3 is the plane graph of the present invention's the 3rd embodiment median filter.Difference with Fig. 1 (a) among Fig. 3 is: by the configuration of same direction with the 1st front end open circuited transmission line 13,14 and the 2nd front end open circuited transmission line 15A, 16A make characteristic (for example: 1 shape) identical wavelength ring resonator, with the interstage coupling of parallel coupled line enforcement resonant cavity.
The performance of the filter of forming as mentioned above is described.
At first, an input signal on the input terminal 23 just is coupled to resonant cavity 11 by coupling with transmission line 19.Resonant cavity 11 is made resonance with the electrical length and front end open circuited transmission line 13, the 14 determined resonance frequencys of 1 wavelength ring resonator 12, motivates A, B point voltage maximum on resonant cavity 11; The fundamental resonance mould of C, D point electric current maximum (be voltage be zero), and reach E, the F point of resonant cavity 17, output on lead-out terminal 25 at last successively by parallel coupled line.
On the other hand, the signal wave of input terminal 24 excitations reaches C, the D point of resonant cavity 11 with transmission line 20 through the input coupling, reach G, the H point of resonant cavity 17 again through parallel coupled line 18 successively, reach lead-out terminal 26 enterprising line outputs by the output coupling with transmission line 22 at last.This moment, the resonance frequency of resonant cavity 11 was also above described together, was f1.
The signal wave of propagating like that above encourages orthogonal mode respectively in resonant cavity 11,17, some electrical length that are positioned at from the toroidal cavity resonator depart from 90 ° point, and its electric field is 0, does not have and propagates.Therefore, there are 2 resonant modes not intercoupling in the filter that proves this composition.In view of the above, the capable ripple of frequency f 1 excitation input terminal 23 gained is propagated on lead-out terminal 25, and the capable ripple of frequency f 1 excitation output terminals 24 gained is propagated on lead-out terminal 26.
As mentioned above, by adopting composition shown in Figure 3, resonance frequency can be set the resonance frequency that is lower than single 1 wavelength ring resonator arbitrarily for, and can utilize the electrical length of adjusting front end open circuited transmission lines such as fine setting, and frequency is adjusted easily.In addition, realize the interstage coupling of filter with parallel coupled line, but thereby the ring resonator neighbor configuration, whole filtering Miniaturizable, complanation.
(embodiment 4)
Hereinafter with reference to description of drawings the 4th embodiment of the present invention.
Fig. 4 is the plane graph of the present invention's the 4th embodiment median filter.Be the electrical length of parallel coupled line 18A is made 1 wavelength ring resonator, 12 electrical length (ellipse) less than 90 ° with the difference of Fig. 1 (a) among Fig. 4.Again, the resonant cavity that uses in the present embodiment is the resonant cavity among the embodiment 1, also can but make with the resonant cavity shown in embodiment 2 or the embodiment 3.
Under the property shape of the filter of forming in Fig. 1, the 2nd and the 3rd embodiment, the electrical length of parallel coupled line is 90 ° 1 a wavelength ring resonator electrical length, so the filter interstage coupling is big.During with this structural design narrow bandwidth filter, it is big that want at the interval of resonant cavity, be difficult to reduce useless coupling and circuit area.
Otherwise the filter that present embodiment is formed shortens the coupling electrical length of parallel coupled line, can make the interval of resonant cavity little, can reduce useless coupling and circuit area.
The filter of Zu Chenging as mentioned above, its performance is identical with embodiment 1, so explanation is omitted.
As mentioned above, can cross and adopt composition shown in Figure 4, resonance frequency can be set the resonance frequency that is lower than single 1 wavelength ring resonator arbitrarily for, and can utilize the electrical length of adjusting front end open circuited transmission lines such as fine setting, and frequency is adjusted easily.In addition, with the interstage coupling of the short parallel coupled line realization filter of coupling electrical length, thereby the ring resonator configuration can be very contiguous, the miniaturization of whole filter energy, complanation.
(embodiment 5)
Hereinafter with reference to description of drawings the present invention the 5th embodiment.
Fig. 5 is the plane graph of the present invention's the 5th embodiment median filter.Be to realize that with the parallel coupled line of forming by parallel coupling component 19A, 20A, 21A, 22A respectively 27～30 input coupling and output are coupled with the difference of the composition of Fig. 4 among Fig. 5.Again, resonant cavity used in the present embodiment is the composition of Fig. 1 among the embodiment 1 (a), also can but make with the resonant cavity shown in embodiment 2 or the embodiment 3.
The performance of the filter of forming as mentioned above is described.At first, an input signal on the input terminal 23, just the parallel coupled line of being made up of parallel coupling component 19A 27 is coupled to resonant cavity 11.Resonant cavity 11 is made resonance with the electrical length and the 1st front end open circuited transmission line 13, the 14 determined resonance frequency f1 of 1 wavelength ring resonator, motivates A, B point voltage maximum on the resonant cavity 11, the fundamental resonance mould of C, D point electric current maximum (being that voltage is zero).Then, pass to E, the F point of resonant cavity 17 successively by parallel coupled line 18, the parallel coupled line of forming through parallel coupling component 21A 29 finally outputs to lead-out terminal 25 again.
On the other hand, the parallel coupled line 28 that the signal wave that encourages during input terminal 24 input signals is formed through parallel coupling component 20A reaches C, the D point of resonant cavity 11, reach G, the H point of resonant cavity 17 again through parallel coupled line 18, the parallel coupled line of forming by parallel coupling component 22A 30 outputs to lead-out terminal 26 at last.At this moment, the resonance frequency f2 of resonant cavity 11 depends on the electrical length of 1 wavelength ring resonator 12 and the electrical length of the 2nd front end open circuited transmission line 15,16.
As mentioned above, by adopting composition shown in Figure 5, resonance frequency can be set the resonance frequency that is lower than single 1 wavelength resonant cavity arbitrarily for, and can utilize the electrical length of adjusting front end open circuited transmission lines such as fine setting, and frequency is adjusted easily.In addition, realize the interstage coupling of filter with the short parallel coupled line of coupling electrical length, thereby the ring resonator configuration can be very contiguous, add that input coupling, output coupling also are parallel coupled line, input, output circuit can realize small-sized, simplicity, so but whole filter miniaturization, complanation.
Moreover in the above explanation, embodiment 1～5 is shown filter table 2 level structures that adopt 2 ring resonators always, but the resonant cavity number is unrestricted, and promptly filtering progression is unrestricted, can realize that this is natural with progression arbitrarily.
In sum, the present invention is connected to the front end open circuited transmission line on 1 wavelength ring resonator and is positioned at electrical length and departs from 90 ° of points of locating mutually, thereby resonance frequency can be set the resonance frequency that is lower than single 1 wavelength ring resonator arbitrarily for, and can utilize fine setting to wait the electrical length of adjusting front end open circuited transmission lines, frequency is adjusted easily.In addition, be coupled energy neighbor configuration ring resonator, whole filter Miniaturizable, complanation between line with parallel coupled line realization filter.
Hereinafter with reference to description of drawings second invention.
(embodiment 1)
Fig. 7 is the plane graph of the present invention's the 1st embodiment median filter.Among Fig. 7,111 is resonant cavity, by 1 wavelength ring resonator 102, be connected electrical length on the circuit and depart from mutually that 90 ° A, B, C, D etc. go up and front end open circuited transmission line 113～116 with identical characteristics is formed at 4.117 is the resonant cavity identical with resonant cavity 111, the interstage coupling that realizes between the resonant cavitys with parallel coupled line 118.Again, between the mid point E of parallel coupled line and B point, the D point, between mid point K and G point, the I point, electrical length all equates.119,120 for being connected to input, the output coupling circuit that A point and F are ordered, and 121 are the interstage coupling circuit, and 122 and 123 are input, lead-out terminal.
The performance of the filter of forming as mentioned above is described.
At first, an input signal on the terminal 122 just is coupled to resonant cavity 111 by coupling circuit 119.Resonant cavity 111 resonance motivate A, B point voltage maximum, the fundamental resonance mould of C, D point electric current maximum (being that voltage is 0) in the resonance frequency f1 that the electrical length and the front end open circuited transmission line 113～116 of 1 wavelength ring resonator 12 determined on resonant cavity 111.Then, reach I, H point on the resonant cavity 117 successively by parallel coupled line 118.Above-mentioned coupling is made on the position of the center D, the G that depart from the mutual route of transmission AB, the HI that constitute parallel coupled line and is coupled, thereby can form sagging near passband.Reach signal wave that H orders after coupling circuit 121 reaches C, D point on the resonant cavity 111, reach G, F point on the resonant cavity 117 successively through parallel coupled line 118 again.Equally, the coupling is here also made on the position of the center B, the I that depart from the mutual route of transmission CD, the GF that constitute parallel coupled line and is coupled, thereby can form sagging near passband.Reach signal wave that F orders through coupling circuit 120 output on terminal 123 at last again.Fig. 8 example of frequency characteristic that draws.
Fig. 9 is other filter examples among the present invention the 1st embodiment, be from the parallel coupled line mid point E of resonant cavity 111 different to the electrical length of front end open circuited transmission line tie point B with the difference of Fig. 1 among this figure, and this structure resonance chamber left-right symmetric disposed to electrical length and the above-mentioned mid point E of front end open circuited transmission line tie point D.
The performance of the filter of said structure is described.
Key property is identical with the embodiment of Fig. 7.With the performance difference of Fig. 7 be the attenuation that can sink by the electrical length control of regulating DE and BE.Again, do not change the coupling length and the gap width of parallel coupled line part, the interstage coupling degree is changed.
Figure 10 is other examples of the present invention's the 1st embodiment median filter, be that with the difference of Fig. 7 the parallel coupled line mid point E of resonant cavity 111 is different to the electrical length of front end open circuited transmission line tie point B to electrical length and this mid point E of front end open circuited transmission line tie point D among this figure, and the resonant cavity of this structure is disposed by same direction.
The following describes the performance of the filter of said structure.
Key property is identical with the embodiment of Fig. 7.With the performance difference of Fig. 7 be by regulating the electrical length of DE and BE, do not change the coupling length and the gap width of parallel coupled line part, the interstage coupling degree being changed.
Figure 11 is other examples of the present invention's the 1st embodiment median filter, and the difference with Fig. 7 among this figure is to realize input, output coupling circuit 119,120 with parallel coupled line 124,125.Its key property is identical with Fig. 7, so explanation is omitted.
Figure 12 is other examples of the present invention's the 1st embodiment median filter, and the difference with Fig. 7 among this figure is to realize interstage coupling circuit 121 with parallel coupled line 126.Its key property is identical with Fig. 7, so explanation is omitted.
Figure 13 is other examples of the present invention's the 1st embodiment median filter, and the difference with Fig. 7 among this figure is to realize interstage coupling circuit 121 with the parallel coupled line 127 of the part circuit coupling that makes resonant cavity 111 and 117.Its key property is identical with Fig. 7, and omission is described.
As mentioned above, by adopting the composition shown in Fig. 7-12, resonance frequency can be set the resonance frequency that is lower than single 1 wavelength resonant cavity arbitrarily for, and realize the interstage coupling circuit of filter and input, output coupling circuit with parallel coupled line, so but the ring resonator neighbor configuration can realize small-sized, the complanation of filter.In addition, as shown in Figure 8, make near the characteristic of sinking the passband, can realize the good filter of attenuation characteristic with few progression.
(embodiment 2)
Hereinafter with reference to description of drawings the 2nd embodiment of the present invention.
Figure 14 is the plane graph of the present invention's the 2nd embodiment median filter.Be input, output coupling circuit 119,120 to be connected to electrical length departs from 90 ° A, C 2 points mutually on the resonant cavity 111 with the difference of Fig. 7 among Figure 14.
The performance of the filter of said structure is described.
At first, an input signal on the terminal 122 just is coupled to resonant cavity 111 by coupling circuit 119.Resonant cavity 111 is made resonance with the resonance frequency f1 that the electrical length and the front end open circuited transmission line 113-116 of 1 wavelength resonant cavity 112 determined, motivates A, B point voltage maximum on resonant cavity 111, the fundamental resonance mould of C, D point electric current maximum (being that voltage is D).Then, reach I, H point on the resonant cavity 117 successively through parallel coupled line 118.Above-mentioned coupling is made on the position of the center D, the G that depart from the mutual route of transmission AB, the HI that constitute parallel coupled line and is coupled, thereby can form sagging near passband.After reaching signal wave that H orders and reaching F, the G point of resonant cavity 117, reach D, C point on the resonant cavity 111 successively through parallel coupled line 118 again through coupling circuit 121.Equally, the coupling is here also made on the position of the center B, the I that depart from the mutual route of transmission CD, the GF that constitute parallel coupled line and is coupled, and sink so form near passband.Again, reach signal wave that C orders, output to lead-out terminal 123 at last through coupling circuit 120.Present embodiment is the circuit structure corresponding to Fig. 7, also can but use corresponding to the circuit structure of Fig. 9-12.
As mentioned above, by adopting composition shown in Figure 14, resonance frequency can be set the resonance frequency that is lower than single 1 wavelength resonant cavity arbitrarily for, and realize the interstage coupling circuit of filter and input, output coupling circuit with parallel coupled line, so but the ring resonator neighbor configuration can realize small-sized, the complanation of filter.In addition, make near the characteristic of sinking the passband again, just can realize the filter that attenuation characteristic is good with few progression.
Among the embodiment 1,2, filter table is shown 4 level structures that adopt 21 wavelength ring resonators, but the resonant cavity number is unrestricted, also is that filter order is unrestricted, can realize that this is self-evident with any number of stages again, always.
In sum, the present invention is in 1 wavelength ring resonator, the front end open circuited transmission line is connected to is positioned at electrical length and departs from mutually on 90 ° of points of locating, can adjust resonance frequency by regulating this length of transmission line, and realize the interstage coupling circuit of filter and input, output coupling circuit with parallel coupled line, so but the ring resonator neighbor configuration can realize small-sized, the complanation of filter.In addition, can form near passband and sink, progression seldom just can be realized the filter that attenuation characteristic is good.
Hereinafter with reference to description of drawings the 3rd invention.
(embodiment 1)
Figure 16 is the plane graph of bimodulus resonant cavity among the present invention the 1st embodiment, omits dielectric substrate and earthing conductor among the figure.In Figure 16,210 circularize and single line that characteristic impedance is constant for doing; 211 for front end open circuit coupling line part, is made up of the coupling line 211a, the 211b that establish 1 annular single line inboard; 212,213 is the importing single line of the open circuit coupling line part 211 from single line 210 to front end.
Bimodulus resonant cavity to said structure illustrates its performance below.
Identical as the key property of bimodulus resonant cavity with in the past resonant cavity, omit explanation.Yet, with Figure 27 in the past the electric capacity of lumped parameter shown in the example be connected into front end open circuit coupling line part 211 formed distributed capacitance, this coupling line part 211 is imported single line 212,213, receive annular single line 210 length 1/2 outside, be made in the inboard of annular single line 210, thereby the performance of cheap and small-sized bimodulus resonant cavity can be arranged.Required capacitance hour, the coupling of coupling line can design at interval broad, thereby it is good to make reproducibility, can reduce the resonance frequency deviation.Compare with lumped parameter electric capacity, can also make and concentrate electric field to disperse, thereby the loss that coupling line part 211 is produced is very little, can improve the unloaded Q of resonant cavity.When resonance frequency departs from required frequency, also can be made in the front end open circuit part of the coupling line part 211 of annular single line 210 inboards by excision, change Coupled Line Length of Band, adjust frequency easily.
As mentioned above, utilize present embodiment, then realize indispensable electric capacity in the ring resonator miniaturization with the distributed capacitance of coupling line part 211, thereby, promote the resonant cavity cost degradation, improve and make reproducibility, reduce the resonance frequency deviation, seek to improve unloaded Q.Form above-mentioned coupling line part 211 again in the inboard of annular single line 210, thereby can further realize the small capacity double mode resonant cavity.Even under the situation of required frequency, also can adjust frequency easily by adjusting Coupled Line Length of Band in the resonance frequency deviation.
(embodiment 2)
Hereinafter with reference to description of drawings the 2nd embodiment of the present invention.
Figure 17 is the plane graph of bimodulus resonant cavity among the present invention the 2nd embodiment.Difference with Figure 16 among Figure 17 is: single line 220 has been cut into the right angle part, and makes characteristic impedance constant; The front end open circuit coupling circuit part 221 that coupling line 221a, 221b are formed is made pectination.222,223 is the importing single line of the coupling line 221 identical with Figure 16.
Bimodulus resonant cavity to said structure illustrates its performance below.
Single line 220 has been cut into the right angle part, and makes characteristic impedance constant, thereby form to adopt under the situation of filter etc. of a plurality of resonant cavitys, compares with circular single line, can do to such an extent that wasted space is less.Pectination is made by the front end open circuit portion 221 that coupling line 221a, 221b are formed again, thereby if Coupled Line Length of Band, coupling are identical at interval, this can obtain bigger distributed capacitance, can realize the miniaturization of resonant cavity.If distributed capacitance identical (Coupled Line Length of Band is constant) then is coupled big at interval, thereby makes the reproducibility height, and further reduces the resonance frequency deviation.
As mentioned above, utilize present embodiment, then compare with common parallel coupled line, front end open circuit coupling line part 221 can obtain bigger unit length distributed capacitance, thereby can seek to shorten coupling length, makes the resonant cavity miniaturization.If coupling length is identical, then, can improve the making reproducibility because of coupling is big at interval, reduce the resonance frequency deviation.
Self-evident, though coupling line is a pectination in the present embodiment, also can be wavy coupling line.
(embodiment 3)
Hereinafter with reference to description of drawings the 3rd embodiment of the present invention.
Figure 18 is the plane graph of bimodulus resonant cavity among the present invention the 3rd embodiment.Be that the characteristic impedance of the front end open circuited transmission line 231 formed of coupling line 231a, 231b reduces with the difference of Figure 17 among Figure 18.Same with Figure 16,230 is annular single line, and 232,233 is the importing single line of coupling line.
Bimodulus resonant cavity to said structure illustrates its performance below.
Between coupling line 231a, 231b the formed distributed capacitance, by reducing to depend on coupling line 231a, 231b parity mode characteristic impedance (Z 0O, Z 0E) Ji subduplicate characteristic impedance can strengthen the direct-to-ground capacitance of coupling line 231a, 231b thereby more miniaturization of resonant cavity.
As mentioned above, utilize present embodiment by reducing coupling line 231a, the 231 number characteristic impedances of front end that 231b forms open circuit coupling line part, the distributed capacitance between coupling line 231a, 231b, can utilize the effect of line mutual-ground capacitor, cavity length is shortened dramatically.
(embodiment 4)
Hereinafter with reference to description of drawings the 4th embodiment of the present invention.
Figure 19 is the plane graph of bimodulus resonant cavity among the present invention the 4th embodiment.Difference with Figure 16 among Figure 19 is: the link position of coupling line 241a, front end that 241b forms open circuit coupling line part 241 is located at the bight of ringed line; The width difference of coupling line 241a, 241b is for asymmetric.Same with Figure 16,240 is annular single line, and 242,243 is the importing single line of coupling line 241.
Bimodulus resonant cavity to said structure illustrates its performance below.
The link position of the annular single line 240 by parallel coupled line part 241 that front end is opened a way is placed on the bight, not only can do coupling length longer, can strengthen the distributed capacitance between the coupling line, and by coupling line 241a, 241b being made the different unsymmetric structure of line width, the direct-to-ground capacitance of coupling line 241a, 241b also can strengthen, thereby can seek cavity length and shorten significantly.
As mentioned above, utilize present embodiment, then the annular single line link position of the open circuit of the front end by coupling line 241a, 241b are formed coupling line part 241 is placed on the bight, not only can do coupling length longer, can strengthen the distributed capacitance between coupling line 241a, the 241b, and, can strengthen the direct-to-ground capacitance of coupling line 241a, 241b etc. by coupling line 241a, 241b being made the different unsymmetric structure of line width.Thereby the distributed capacitance between coupling line 241a, 241b, add the effect of utilizing circuit that electric capacity is strengthened, the length of resonant cavity can shorten dramatically.
Self-evident, not limited though the annular single line link position of the coupling line part 241 of in the present embodiment front end being opened a way is placed on the bight, can connect at any part.In addition, in the present embodiment coupling line 241a, 241b are made unsymmetric structure, not only utilize the coupling distributed capacitance, and the effect of utilizing direct-to-ground capacitance to strengthen again, reach the shortening of cavity length, but certainly also can be taken as coupling line 241a, symmetrical structure that the 241b width is identical.
(embodiment 5)
Hereinafter with reference to description of drawings the 5th embodiment of the present invention.
Figure 20 is the plane graph of bimodulus resonant cavity among the present invention the 5th embodiment.Difference with Figure 16 among Figure 20 is to utilize coupling line 251b, 251c and 251f, 251e that dual front end open circuit coupling line part 251a, 251d are set.250 be with Figure 16 in identical annular single line, 252a, 252b and 253a, 253b are the importing single line of coupling line 251b, 251c and 251e, 251f.
Bimodulus resonant cavity to said structure illustrates its performance below.
Front end open circuit coupling line part 251a, 251d are dual, thereby if Coupled Line Length of Band, coupling are identical at interval, 2 times coupling capacitance in the time of then can getting substance, when the effect that cavity length shortens is substance 2 times.If distributed capacitance identical (the coupling line length is constant), then the interval of coupling line 251b, 251c and 251c, 251f is wide, can improve the reproducibility of making, further reduces the resonance frequency deviation.
As mentioned above, utilize present embodiment, dual front end open circuit 251a, 251d then by adopting coupling line 251b, 251c and 251e, 251f to be formed, not only can get big distributed capacitance, reach the resonant cavity miniaturization, and if distributed capacitance identical (the coupling line length is constant), then the interval of coupling line 251b, 251c and 251e, 251f is wide, can improve the reproducibility of making, reduce the resonance frequency deviation.
Self-evident, though in the present embodiment by making the dual coupling line part of the identical symmetrical structure of line width 251a, 251d, reach the shortening of cavity length, also the different dual coupling coupling of the unsymmetric structure line part of available line width.In addition, be taken as dual coupling line part 251a, 251d in the present embodiment, but also available certainly more coupling line.
(embodiment 6)
Hereinafter with reference to description of drawings the 6th embodiment of the present invention.
Figure 21 is the bimodulus resonant cavity among the present invention the 6th embodiment, Figure 21 (a) is its A-A ' cutaway view, Figure 21 (b) is a surface conductor layer electrode line schematic diagram, Figure 21 (c) is an internal conductor layer electrode line schematic diagram, and Figure 21 (d)-Figure 21 (f) is the schematic diagram that the surface conductor layer and the electrode line of internal conductor layer overlap situation.Difference with Figure 16-20 among Figure 21 is not to be to bring distributed capacitance by forming same planar coupling line, but form substrate is made sandwich construction, accompanies the coupling line that dielectric 2 conductors form by the centre and brings distributed capacitance.
Among Figure 21,260 be with Figure 16 in identical annular single line; 261 are front end open circuit coupling line part; 262,253 for electrode line (comprise and import the single line part), is connected to annular single line 260, and accompany 2 front end that conductor constituted open circuit coupling line parts 261 of dielectric 264 in the middle of forming; 265 is earthing conductor.
Bimodulus resonant cavity to said structure illustrates its performance below.
An end that is connected annular single line 260 in the front end open circuit coupling line part 261 with the electrode line 262 of annular single line 260 on same one side.In the second-class office of counting from the tie point of electrode line 262 of annular single line length through hole is set, connects and composes another electrode line 263 of front end open circuit coupling unit 261.Like this, constitute front end open circuit coupling line part 261, utilize the length of the distributed capacitance shortening resonant cavity between the electrode 262,263 by folder dielectric 264 between the electrode line 262,263.Required capacitance can be adjusted, be controlled by the coincidence situation of electrode line 262,263.Specifically, can form that electrode all overlaps shown in Figure 21 (d), electrode shown in Figure 21 (e) partially overlap or Figure 21 (f) shown in the not equal all situations of upper/lower electrode line thickness.By the electrode line 263 that forms on the refacing conductor layer, can adjust the distributed capacitance value easily.
As mentioned above, utilize present embodiment, then constitute front end open circuit coupling line part 261 by 2 conductors that accompany dielectric 264 by the centre, do not need the size high accuracy, just can obtain distributed capacitance between bigger coupling line, and, can adjust resonance frequency easily by the electrode line 263 on the refacing conductor layer.
Self-evident, the situation of the identical up and down or below broad of explanation coupling line width in the present embodiment, but not limited.
(embodiment 7)
Hereinafter with reference to description of drawings the 7th embodiment of the present invention.
Figure 22 is the plane graph of bimodulus resonant cavity among the present invention the 7th embodiment.Be that open end row with coupling line 271a, 271b forms front end open circuit coupling line part 271 for same direction with the difference of Figure 16-21 among Figure 22.270 is the annular single line identical with Figure 16,272, the 273 importing single lines for front end open circuit coupling line part 271.
Bimodulus resonant cavity to said structure illustrates its performance below.
It is identical with embodiment 1-6 that available front end open circuit coupling line 271 constitutes the distributed capacitance aspect, omits explanation.Importing single line 272,273 line lengths are equated, and make the same direction of open end of front end open circuit coupling line part 271, repair the open end of two coupling line 271a, 271b simultaneously, thereby can not destroy in maximum this resonant cavity symmetry of single line 270 length fourth class branch separating degrees, adjust resonance frequency easily.Become asymmetricly if change to import the line length of single line 272,273, it is long that then the distance between the separating degree maximum point can depart from 1/4 single line, has under the situation of composition filter etc., can set many advantages such as input, outgoing position arbitrarily.
As mentioned above, utilize present embodiment, then be taken as same direction, can not destroy the symmetry of resonant cavity, adjust resonance frequency easily by beginning with coupling line 271a, 271b.
Self-evident, form coupling line 271a, 271b from lead-in wire 272,273 at both direction in the present embodiment, but also can only form, and coupling line 271a, 271b can be made pectination, wavy in a direction.
(embodiment 8)
Hereinafter with reference to description of drawings the 8th embodiment of the present invention.
Figure 23 is the bimodulus resonant cavity of the present invention the 8th embodiment, and Figure 23 (a) is an A-A ' cutaway view, and Figure 23 (b) is the plane graph of surface conductor layer electrode line, and Figure 23 (c) is the plane graph of internal conductor layer electrode line.Difference with Figure 16-22 among Figure 23 is not to be to bring distributed capacitance by forming same planar coupling line, but form substrate is made sandwich construction, accompanies dielectric 2 coupling lines that conductor constituted by the centre and brings distributed capacitance.
Among Figure 23,280 be with Figure 22 in identical annular single line; 281 are front end open circuit coupling line part; 282,283 is electrode line, is connected to annular single line 280, and forms by the centre and accompany the front end open circuit coupling line part 281 that 2 conductors of dielectric 284 constitute; 285 is grounding electrode; 286,287 importing single lines for front end open circuit coupling line part 281.
Bimodulus resonant cavity to said structure illustrates its performance below.
The line length that imports single line 286,287 is equated, front end opened a way be connected an end of annular single line 280 in the coupling line part 281 with annular single line 280 electrode line 282 at grade, point of bisection in these annular single line 280 length is provided with through hole, connects and composes another annular lines 283 of front end open circuit coupling line part 281.Like this, with the method formation front end open circuit coupling line part 281 of folder dielectric 284 between the electrode 282,283, and by the shortening of the distributed capacitance between this electrode 282,283 cavity length.Required capacitance can be adjusted, be controlled by the coincidence situation of electrode line 282,283.
As mentioned above, utilize present embodiment, then because of making front end open circuit coupling line part 281 rows be same direction, and form coupling line by 2 conductors that the centre accompanies dielectric 284, so do not need the dimensional accuracy height, just can obtain distributed capacitance between bigger coupling line, can adjust resonance frequency easily by the electrode line on the refacing conductor layer simultaneously.
In the present embodiment, the coupling line width is identical up and down, but not limited certainly.
(embodiment 9)
Hereinafter with reference to description of drawings the 9th embodiment of the present invention.
Figure 24 is the plane of bimodulus resonant cavity among the present invention the 9th embodiment.The difference of Figure 24 and Figure 16-23 be in the bimodulus resonant cavity 2 mutually independently resonance frequency all increase distributed capacitance.
Among Figure 24,290 is the annular single line identical with Figure 16; The 291 front end open circuit coupling line parts of being formed for the coupling line 291a, the 291b that are made in annular single line inboard; 292,293 importing single lines for front end open circuit coupling line part 281; 294,295 for forming the front end open circuit single line of distributed capacitance.
Bimodulus resonant cavity to said structure illustrates its performance below.
This resonant cavity can encourage two separate resonant modes, the vibration frequency of determining that mould has depends on the distributed capacitance of annular single line 290, front end open circuit coupling line part 291 and imports single line 292,293 that the resonance frequency that another mould has depends on the distributed capacitance of annular single line 290, front end open circuit single line 294,295.The resonance frequency of this two resonant mode can be identical, also can be different, and a resonant cavity can encourage two kinds of resonance frequencys or play two-stage same frequency resonant cavity.
As mentioned above, utilize present embodiment, then, can constitute the small capacity double mode resonant cavity at grade with the method for combination front end open circuit coupling line and front end open circuit single line.
In the present embodiment, the coupling line that front end open circuit coupling line 291 adopts as shown in Figure 16, the coupling line shown in also available Figure 17-Figure 23 certainly.
(embodiment 10)
Hereinafter with reference to description of drawings the 10th embodiment of the present invention.
Figure 25 is the bimodulus resonant cavity of the present invention the 10th embodiment, and Figure 25 (a) is its A-A ' cutaway view, and Figure 25 (b) is the plane graph of surface conductor layer electrode line, and Figure 25 (c) is the plane graph of internal conductor layer electrode line.
Difference with Figure 24 among Figure 25 is that the distributed capacitance of realizing 2 separate frequencies in the bimodulus resonant cavity is coupling line.Among this figure, 300 be with Fig. 1 in identical annular single line; 301 is to form at grade with annular single line 300, and by the coupling line 301a that is located at this single line inboard, front end that 301b the forms coupling line part of opening a way; 302 for being formed on the front end open circuit coupling line part that coupling line 302a, 302b on the Different Plane are formed with annular single line 300; 303-306 is the importing single line of front end open circuit coupling line part 301,302; 307 is dielectric; 308 is earthing conductor.
Bimodulus resonant cavity to said structure illustrates its performance below.
This resonant cavity can encourage 2 separate resonant modes, the resonance frequency of a mould depends on the distributed capacitance of annular single line 300, front end open circuit coupling line part 301 and imports single line 303,304 that the resonance frequency of another mould depends on the distributed capacitance of annular single line 300, front end open circuit coupling line part 302 and imports single line 305,306.But this two resonant modes resonance frequency is identical, also can be inequality, and a resonant cavity can encourage two kinds of resonance frequencys or play two-stage same frequency resonant cavity.
As mentioned above, utilize present embodiment, 2 then separate resonant modes are provided with front end open circuit coupling line part respectively, thereby can realize the miniaturization of bimodulus resonant cavity.
Though front end open circuit coupling line part 301,302 is with as shown in Figure 16 coupling line in the present embodiment, the combination of embodiment shown in certain also available Figure 17-23 realizes.Form annular single line 260,280,300 by internal conductor layer among Figure 21,23,25 the embodiment, but also can be made on the surface conductor layer certainly.Among the embodiment of Figure 16-23, only one of 2 humorous centers of percussion of bimodulus resonant cavity increases the coupling line distributed capacitance, but resembles as shown in Figure 24, and 2 resonant modes all increase the coupling line distributed capacitance, and further shortening cavity length can certainly.
(embodiment 11)
Hereinafter with reference to description of drawings the 11st embodiment of the present invention.
Figure 26 is the bimodulus resonant cavity of the present invention the 11st embodiment, and Figure 26 (a) is its A-A ' cutaway view, and Figure 26 (b) is its plane graph.
Difference with Figure 16 among Figure 26 is that front end open circuit coupling line is covered.Among Figure 16,310 be with Figure 16 in identical annular single line; 311 is to form at grade with annular single line 310, and by the coupling line 311a that is located at this single line inboard, front end that 311b the forms coupling line part of opening a way; 312,313 importing single lines for front end open circuit coupling line part 311; 314 for covering metal; 315 is covering dielectric; 316 is dielectric; 317 is earthing conductor.
Bimodulus resonant cavity to said structure illustrates its performance below.
The top foundation of front end open circuit coupling line part 311 is by covering the covered structure that metal 314 and covering dielectric 315 are formed, thereby do not change the interval of coupling line 311a, 311b, also can do to such an extent that the degree of coupling is big, also is that distributed capacitance is big, can realize the resonant cavity miniaturization.If distributed capacitance is identical, then the interval of coupling line 311a, 311b can be strengthened, and can improve the reproducibility of making, and further reduces the resonance frequency deviation.Cover metal 314 by finishing, can adjust resonance frequency easily.
As mentioned above, utilize present embodiment, then set up covered structure above the front end open circuit coupling line part 311, thereby can do to such an extent that distributed capacitance is big, make the bimodulus resonant cavity realize miniaturization, and can adjust frequency easily by finishing covering metal 314.
The covered structure that explanation is made up of covering metal 314 and covering dielectric 315 in the present embodiment, but also can only use covering dielectric certainly, adjust frequency by changing its thickness and dielectric constant.
In sum, the present invention realizes indispensable lumped parameter electric capacity in the miniaturization of bimodulus resonant cavity by the distributed capacitance of preceding open circuit coupling line or front end open circuit single line, and utilize and make the good photoetching technique of precision, make the front end open circuit coupling line or the front end open circuit single line of annular single line and formation distributed capacitance simultaneously, thereby can when seeking the resonant cavity cost degradation, seek to improve the reproducibility and the precision of resonance frequency.To work the front end open circuit coupling line or the single line that shorten the cavity length effect again and be made in annular single line inboard, can further work for the resonant cavity miniaturization.
Compare with lumped parameter electric capacity, concentrate electric field to disperse, can make the loss that produces in the distributed constant capacitive part of front end open circuit coupling line very little, can make the high bimodulus resonant cavity of unloaded Q.
Also can adjust resonance frequency easily by the open end of coupling line or single line or its part being excised or overlapping.
In sum, utilize the present invention, available simple production process is made the good bimodulus resonant cavity that volume is little and have high Q value.

Claims (44)

1, a kind of filter is characterized in that utilizing the quadrature resonant mode of 1 wavelength ring resonator, and adopt parallel coupled line in the interstage coupling of resonant cavity.
2, filter as claimed in claim 1, it is characterized in that the electrical length quartering with above-mentioned 1 wavelength ring resonator, be connected the 1st transmission line in the 1st position on this circuit on 180 ° the 2nd position with departing from identical characteristics and front end open circuit with above-mentioned the 1st position electrical length, be connected the 2nd transmission line with identical characteristics and front end open circuit on 180 ° the 4th position with departing from above-mentioned the 3rd position electrical length departing from 90 ° the 3rd position with above-mentioned the 1st position electrical length again, the 1 wavelength ring resonator that will be connected into aforesaid way again disposes by same direction.
3, filter as claimed in claim 2, it is characterized in that with comprise above-mentioned 1 wavelength ring resonator on the circuit of the 1st and the 3rd position parallel the configuration coupling line, in input coupling and output coupling, adopt parallel coupled line.
4, filter as claimed in claim 1, it is characterized in that the electrical length quartering with 1 wavelength ring resonator, be connected the transmission line with identical characteristics and front end open circuit in the 1st position of this circuit with departing from 180 ° the 2nd position with above-mentioned the 1st position electrical length, the 1 wavelength ring resonator that will be connected into aforesaid way again disposes by same direction.
5, filter as claimed in claim 4, it is characterized in that in input coupling and output coupling, adopting parallel coupled line with comprising the 1st position on the above-mentioned 1 wavelength ring resonator and paralleling the configuration coupling line with circuit that above-mentioned the 1st position electrical length departs from 90 ° the 3rd position.
6, filter as claimed in claim 1, it is characterized in that the electrical length quartering with 1 wavelength ring resonator, be connected the 1st transmission line in the 1st position on this circuit on 180 ° the 2nd position with departing from identical characteristics and front end open circuit with above-mentioned the 1st position electrical length, be connected the 2nd transmission line on 180 ° the 4th position with departing from departing from 90 ° the 3rd position again, will be connected into 1 wavelength ring resonator of aforesaid way and above-mentioned 1 wavelength ring resonator again and connect the 1st transmission line and exchange afterwards with the 2nd transmission line that 1 wavelength ring resonator of composition disposes by same direction with identical characteristics and front end open circuit with above-mentioned the 3rd position electrical length with above-mentioned the 1st position electrical length.
7, filter as claimed in claim 6, it is characterized in that with comprise above-mentioned 1 wavelength ring resonator on the circuit of the 1st and the 3rd position parallel the configuration coupling line, in input coupling and output coupling, adopt parallel coupled line.
8, filter as claimed in claim 1, it is characterized in that the electrical length quartering with 1 wavelength ring resonator, be connected the transmission line with identical characteristics and front end open circuit in the 1st position on this circuit on 180 ° the 2nd position with departing from above-mentioned the 1st position electrical length, the 1 wavelength ring resonator that will be connected into 1 wavelength ring resonator of aforesaid way and above-mentioned 1 wavelength transmission line that ring resonator connects composition after 90 ° of same direction electrical length skews again disposes by same direction.
9, filter as claimed in claim 8, it is characterized in that in input coupling and output coupling, adopting parallel coupled line with comprising the 1st position on the above-mentioned 1 wavelength ring resonator and paralleling the configuration coupling line with circuit that above-mentioned the 1st position electrical length departs from 90 ° the 3rd position.
10, filter as claimed in claim 1, it is characterized in that the electrical length quartering with 1 wavelength ring resonator, in the 1st position on this circuit, depart from 180 ° the 2nd position with above-mentioned the 1st position electrical length and be connected transmission line on 90 ° the 3rd, the 4th position with identical characteristics and front end open circuit with departing from above-mentioned the 1st position electrical length, the 1 wavelength ring resonator that will be connected into aforesaid way again disposes by same direction.
11, filter as claimed in claim 10, it is characterized in that with comprise above-mentioned 1 wavelength ring resonator on the circuit of the 1st and the 3rd position parallel the configuration coupling line, in input coupling and output coupling, adopt parallel coupled line.
12, a kind of filter, it is characterized in that the electrical length quartering with 1 wavelength ring resonator, the 1st point on this circuit, depart from 90 ° the 2nd point with above-mentioned the 1st electrical length, depart from 180 ° the 3rd with above-mentioned the 1st electrical length and be connected transmission line with identical characteristics and front end open circuit with departing from 270 ° the 4th with above-mentioned the 1st electrical length, and the interstage coupling of adjacent resonators is a parallel coupled line, and will constitute elementary above-mentioned 1 wavelength ring resonator a bit as input, with constitute final stage above-mentioned 1 wavelength ring resonator a bit as exporting.
13, filter as claimed in claim 12, the coupling electrical length that it is characterized in that parallel coupled line are less than 90 °, and the mid point of this parallel coupled line is equal to the electrical length of the front end open circuited transmission line tie point that is positioned at above-mentioned mid point both sides.
14, filter as claimed in claim 12, the coupling electrical length that it is characterized in that parallel coupled line is less than 90 °, and the mid point of this parallel coupled line is unequal to the electrical length of the front end open circuited transmission line tie point that is positioned at above-mentioned mid point both sides, and 1 wavelength ring resonator left-right symmetric with said structure disposes again.
15, filter as claimed in claim 12, the coupling electrical length that it is characterized in that parallel coupled line is less than 90 °, and the mid point of this parallel coupled line is unequal to the electrical length of the front end open circuited transmission line tie point that is positioned at above-mentioned mid point both sides, and 1 wavelength ring resonator with said structure disposes by same direction again.
16, filter as claimed in claim 12 is characterized in that all adopting parallel coupled line in input coupling, the output coupling.
17, filter as claimed in claim 12, the input point electrical length that it is characterized in that constituting 1 elementary wavelength ring resonator depart from 90 ° a bit, with the output point electrical length of the 1 wavelength ring resonator that constitutes final stage depart from 90 ° a bit, the interstage coupling between these 2 adopts parallel coupled line.
18, a kind of filter, the electrical length quartering of 1 wavelength ring resonator of this filter will be formed, the 1st point on this circuit, depart from 90 ° the 2nd point with above-mentioned the 1st electrical length, depart from 180 ° the 3rd with above-mentioned the 1st electrical length and be connected transmission line with identical characteristics and front end open circuit with departing from 270 ° the 4th with above-mentioned the 1st electrical length, in the 1 wavelength ring resonator that it is characterized in that connecting as stated above, the interstage coupling of adjacent resonators is a parallel coupled line, and will constitute 1 elementary wavelength ring resonator a bit as input, will with above-mentioned input point electrical length depart from 90 ° a bit as output.
19, filter as claimed in claim 18, the coupling electrical length that it is characterized in that parallel coupled line are less than 90 °, and the mid point of this parallel coupled line is equal to the electrical length of the front end open circuited transmission line tie point that is positioned at above-mentioned mid point both sides.
20, filter as claimed in claim 18, the coupling electrical length that it is characterized in that parallel coupled line is less than 90 °, and the mid point of this parallel coupled line is unequal to the electrical length of the front end open circuited transmission line tie point that is positioned at above-mentioned mid point both sides, and 1 wavelength ring resonator left-right symmetric with said structure disposes again.
21, filter as claimed in claim 18, the coupling electrical length that it is characterized in that parallel coupled line is less than 90 °, and the mid point of this parallel coupled line is unequal to the electrical length of the front end open circuited transmission line tie point that is positioned at above-mentioned mid point both sides, and 1 wavelength ring resonator with said structure disposes by same direction again.
22, filter as claimed in claim 18 is characterized in that adopting parallel coupled line in input coupling, the output coupling.
23, filter as claimed in claim 18, it is characterized in that constituting on the 1 wavelength ring resonator of final stage a bit and and above-mentioned some electrical length depart from 90 ° a bit between interstage coupling adopt parallel coupled line.
24, a kind of bimodulus resonant cavity is characterized in that having: the annular single line that strip line or microstrip line are formed; On with the relative position in each position of the above-mentioned annular single line length quartering, be connected to the front end open circuit coupling line of above-mentioned annular single line through the importing single line.
25, a kind of bimodulus resonant cavity is characterized in that having the annular single line of strip line or microstrip line composition, and has front end open circuit coupling line; On with one group of relative position in each position of the above-mentioned annular single line length quartering, connect above-mentioned front end open circuit coupling line, another not wiring of group relative position through importing single line.
26, a kind of bimodulus resonant cavity is characterized in that, has the annular single line that strip line or microstrip line are formed, and has front end open circuit coupling line; On with one group of relative position in the position of the above-mentioned annular single line length quartering, connect above-mentioned front end open circuit coupling line through importing single line, another group relative position connects front end open circuit single line.
27, a kind of bimodulus resonant cavity is characterized in that having the annular single line of strip line or microstrip line composition, and has front end open circuit coupling line; On with one group of relative position in the position of the above-mentioned annular single line length quartering, connect above-mentioned front end open circuit coupling line through importing single line, also connect front end open circuit coupling line on another group relative position through importing single line.
28,, it is characterized in that the line length of above-mentioned importing single line from above-mentioned annular single line tie point to above-mentioned front end open circuit coupling line equates as each described bimodulus resonant cavity among the claim 24-27.
29,, it is characterized in that above-mentioned importing single line is unequal to the line length of above-mentioned front end open circuit coupling line from above-mentioned annular single line tie point as each described bimodulus resonant cavity among the claim 24-27.
30,, it is characterized in that same one side goes up and the relative parallel coupled line in open end position is formed above-mentioned front end open circuit coupling line by being formed on as each described bimodulus resonant cavity among the claim 24-27.
31,, it is characterized in that going up and the open end position is in unidirectional parallel coupled line and forms above-mentioned front end open circuit coupling line by being formed on one side as each described bimodulus resonant cavity among the claim 24-27.
32,, it is characterized in that the certain at interval and coupling line width of the coupling of front end open circuit coupling line gradually changes as each described bimodulus resonant cavity among the claim 24-27.
33,, it is characterized in that forming front end open circuit coupling line by being formed on pectination on the one side or wavy coupling line as each described bimodulus resonant cavity among the claim 24-27.
34,, it is characterized in that forming front end open circuit coupling line by being formed on many parallel coupled lines on the one side as each described bimodulus resonant cavity among the claim 24-27.
35,, it is characterized in that the composition of front end open circuit coupling line comprises that by the centre dielectric two-layer formed coupling line is up and down arranged as each described bimodulus resonant cavity among the claim 24-27.
36, bimodulus resonant cavity as claimed in claim 35 is characterized in that by the centre dielectric two-layer formed coupling line up and down being arranged, and begins certain-length from front end on its length direction and overlaps up and down.
37, bimodulus resonant cavity as claimed in claim 35 is characterized in that by the centre dielectric two-layer formed coupling line up and down being arranged, and center unanimity on its Width overlaps up and down fully.
38, bimodulus resonant cavity as claimed in claim 35 is characterized in that by the centre dielectric two-layer formed coupling line up and down being arranged, and the center is inconsistent on its Width, and only part overlaps up and down.
39, bimodulus resonant cavity as claimed in claim 35 is characterized in that by the centre dielectric two-layer formed coupling line up and down being arranged, and its width is different up and down.
40,, it is characterized in that front end open circuit coupling line is provided with covering in the above as each described bimodulus resonant cavity among the claim 30-39.
41,, it is characterized in that carrying out the frequency adjustment by the front end or the part of the coupling of excision front end open-circuit line as each described bimodulus resonant cavity among the claim 30-39.
42,, it is characterized in that carrying out the frequency adjustment by the front end of front end open-circuit line coupling or a part is in addition overlapping as each described bimodulus resonant cavity among the claim 30-39.
43,, it is characterized in that carrying out the frequency adjustment by the front end or the part of excision front end open-circuit line as each described bimodulus resonant cavity among claim 26 or the claim 30-39.
44,, it is characterized in that carrying out the frequency adjustment by the front end or the part of front end open-circuit line is overlapping in addition as each described bimodulus resonant cavity among claim 26 or the claim 30-39.
CN94117206A 1994-10-05 1994-10-05 Electric filter Expired - Lifetime CN1043279C (en)

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Application Number Priority Date Filing Date Title
CN94117206A CN1043279C (en) 1994-10-05 1994-10-05 Electric filter

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Application Number Priority Date Filing Date Title
CN94117206A CN1043279C (en) 1994-10-05 1994-10-05 Electric filter

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CNB98107426XA Division CN1306649C (en) 1993-10-04 1994-10-05 Filter

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CN1043279C CN1043279C (en) 1999-05-05

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102084540A (en) * 2009-07-10 2011-06-01 Kmw株式会社 Multi-mode resonant filter
WO2013071774A1 (en) * 2011-11-15 2013-05-23 华为技术有限公司 Filtering device, base station system and frequency channel switching method
CN105322254A (en) * 2015-11-19 2016-02-10 南京邮电大学 Direct-feed planar dual-mode ring band-pass filter with adjustable bandwidth

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2654283C2 (en) * 1976-11-30 1982-04-15 Siemens AG, 1000 Berlin und 8000 München Filter for very short electromagnetic waves
US4327342A (en) * 1980-07-10 1982-04-27 U.S. Philips Corporation Bandstop filter for very high frequency transmission lines and biassing circuit for a very high frequency transistor comprising this filter
US5017897A (en) * 1990-08-06 1991-05-21 Motorola, Inc. Split ring resonator bandpass filter with differential output

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102084540A (en) * 2009-07-10 2011-06-01 Kmw株式会社 Multi-mode resonant filter
US8618894B2 (en) 2009-07-10 2013-12-31 Kmw Inc. Multi-mode resonant filter
WO2013071774A1 (en) * 2011-11-15 2013-05-23 华为技术有限公司 Filtering device, base station system and frequency channel switching method
CN105322254A (en) * 2015-11-19 2016-02-10 南京邮电大学 Direct-feed planar dual-mode ring band-pass filter with adjustable bandwidth

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