CN1797842A - Band-pass filter with transmission zero - Google Patents
Band-pass filter with transmission zero Download PDFInfo
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- CN1797842A CN1797842A CN 200410101528 CN200410101528A CN1797842A CN 1797842 A CN1797842 A CN 1797842A CN 200410101528 CN200410101528 CN 200410101528 CN 200410101528 A CN200410101528 A CN 200410101528A CN 1797842 A CN1797842 A CN 1797842A
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Abstract
The band-pass filter includes following parts: loading unit; terminal port resonator through the loading unit is connected to port; coupling unit; inner resonator through the coupling unit is connected to the terminal port resonator. The band-pass filter also includes an external resonator, which through the coupling unit is connected to the terminal port resonator. The external resonator reflects signal equal to resonance frequency in-phase; and reflects signal larger than or smaller than resonance frequency in reversed phase. Thus, the invention generates transmission zero at end of filter, as well as guarantee that suppression capability of stop band at another end is not lowered.
Description
Technical field
The present invention relates to band pass filter, be specifically related to have the band pass filter of transmission zero.
Background technology
The transmission zero technology of band pass filter can produce very high inhibition near the stopband signal its zero point, thereby makes the performance of filter obtain very big improvement.The structure of band pass filter generally comprises input port, output port; Port resonator that is connected with port by charger and the interior resonance device that is of coupled connections by coupling device and port resonator.The band pass filter that has transmission zero at present normally adopts cross-linked mode to realize.Usually will form in a plurality of resonators of band pass filter, the coupling between the adjacent resonators is called direct coupling, and the coupling between non-conterminous two resonators is called cross-couplings.Be coupled with two types: magnetic coupling (inductance coupling high) and electric coupling (capacitive coupling).
For the filter with transmission zero, the cross-linked mode of modal employing three resonators realizes at present.
Fig. 1 is the cross-linked fundamental diagrams of described three resonator magnetic.Structure shown in the figure is the part in the band pass filter, as shown in the figure, forms magnetic between resonator K and K+1 and K+1 and the K+2 in twos and directly is coupled; Form the magnetic cross-couplings simultaneously between K and the K+2.After signal enters resonator K by the other parts of filter, be divided into two-way, separated into two parts after the signal that is higher than resonance frequency enters resonator K enters two branch roads respectively, one the tunnel enters resonator K+2 after the magnetic cross-couplings, will change-90 degree through the transmission of the signal after coupling phase place; Another road directly enters resonator K+1 after the coupling through magnetic, directly enters resonator K+2 after the coupling through magnetic again, will change-270 degree through the transmission of the signal after filtering and coupling phase place; Two paths of signals carries out vector superposed at resonator K+2, because the signal of two branch roads transmission phase phasic difference 180 degree equal zero after inversely adding, therefore will form transmission zero.Transmission zero is positioned at the high-end of passband, the frequency ratio band connection frequency height of transmission zero.
But this defective that exists by the method for magnetic cross-couplings realization transmission zero is: after the signal that is lower than resonance frequency entered resonator K, one road signal imported K+2 into through resonator K+1, because filtering and coupling, the transmission phase place will change-90 and spend; Another road is through being coupled into the signal of K+2, and the transmission phase place also will change-90 degree; Because the phase place of two paths of signals is identical, therefore vector superposed result increases original amplitude in resonator K+2, therefore, has reduced the rejection of low side stopband.Fig. 2 is filter and the above-mentioned high-end frequency response schematic diagram that the filter of transmission zero is arranged that does not have transmission zero.Dotted line is the frequency transmission response that does not have the band pass filter of transmission zero among the figure, and solid line is the frequency transmission response of the band pass filter of the transmission zero that forms of described magnetic cross-couplings.As seen, this filter is to be cost with the rejection of sacrificing the low side stopband to the improvement of the rejection of high-end stopband.
The cross-linked another kind of situation of described three resonators is to adopt electric cross-linked mode.Specifically, form directly coupling of electricity between resonator K and K+1 and K+1 and the K+2 in twos; Form electric cross-couplings simultaneously between K and the K+2.Its transmission course is with mentioned above identical, and different is that therefore after the signal that is lower than resonance frequency enters K+2 through resonator K+1, the transmission phase place will change-90 degree owing to be electric cross-couplings, and the signal that directly enters K+2 transmits phase place and will change+90 spend; In the vector superposed result of resonator K+2 is to produce a transmission zero at low side.
Cross-linked three resonators of this electricity exist and the cross-linked three resonator similar problem of above-mentioned magnetic, that is to say, when the frequency of input signal is higher than resonance frequency, will reduce the rejection of filter low side.High-end and the low side that Fig. 2 and Fig. 3 are respectively at band pass filter produces the frequency response schematic diagram that spreads out of zero point.Dotted line is the frequency transmission response that does not have the band pass filter of transmission zero among two figure, and solid line is the frequency transmission response of the band pass filter of the transmission zero that forms of described electric cross-couplings.As seen, though this filter has improved the rejection of low side stopband, reduced the rejection of high-end stopband.
Another kind of filter with transmission zero adopts the cross-linked mode of four resonators to realize in the prior art.
Fig. 4 is the cross-linked operation principle schematic diagrames of described four resonator magnetic.Structure shown in the figure is the part in the band pass filter, as shown in the figure, forms magnetic between resonator K and K+1 and K+2 and the K+3 in twos and directly is coupled; Form the magnetic cross-couplings simultaneously between K and the K+2; Form electric cross-couplings between K+1 and the K+3.The signal one tunnel of input resonator K enters resonator K+3 through resonator K+2, and another road enters K+3 through resonator K+1; Two paths of signals carries out vector superposed at resonator K+3 after the overcoupling filter action.Resonance frequency by the debugging resonator both can realize being positioned at the high-end transmission zero of passband, also can realize being positioned at the transmission zero of passband low side.
But the filter of this four resonators is same, and to have improvement to filter one end rejection be the defective that is reduced to cost with other end rejection.Specifically, if transmission zero is positioned at the low side of filter passband,, reduced the rejection of high-end stopband though improved the rejection of low side stopband; Similarly, if transmission zero is positioned at the high-end of filter passband,, reduced the rejection of low side stopband though improved the rejection of high-end stopband.
Summary of the invention
The technical problem to be solved in the present invention is: a kind of band pass filter with transmission zero is provided, can improves the rejection of filter one end stopband, can guarantee that the rejection of other end stopband does not reduce simultaneously.
For solving the problems of the technologies described above, the invention provides a kind of band pass filter with transmission zero, comprising:
Charger;
The port resonator that is connected with port by described charger;
Coupling device;
Interior resonance device by described coupling device and the coupling of described port resonator;
Also comprise external resonator by described coupling device and the coupling of described port resonator; Described external resonator will equal the signal homophase reflection of resonance frequency, will be greater than or less than the signal inversion reflection of resonance frequency;
Described port resonator is divided into first tributary signal and second tributary signal with input signal; Described coupling device obtains first tributary signal from described port resonator, is transferred to described external resonator after the coupling; Described external resonator obtains signal from described coupling device, reflects; Described coupling device obtains described signal from described external resonator, turns back to described port resonator after being coupled, and first tributary signal and second tributary signal of described port resonator after with described returning carries out the output of vector superposed back.
Wherein, described port resonator is input port resonator or output port resonator.
Wherein, the coupled modes of described external resonator and port resonator can be magnetic couplings, also can be electric coupling.
In addition, described interior resonance device electric or magnetic is coupled to described port resonator.
Further, described interior resonance device can be that electric or magnetic is directly coupled to described port resonator, also can be that the electric or magnetic cross-couplings is to described port resonator.
Wherein, described external resonator comprises: coaxial cavity resonator, waveguide resonator, dielectric resonator, ceramic pectination resonator and micro-strip resonantor.
Compared with prior art, the invention has the beneficial effects as follows: the present invention is by additional external resonator on the port resonator, utilize external resonator will equal the signal homophase total reflection of resonance frequency, the phase characteristic of the signal inversion total reflection of resonance frequency will be greater than or less than, realized when filter one end produces transmission zero the purpose that the rejection of assurance other end stopband does not reduce.
In addition, described port resonator both can be the input port resonator, also can be the output port resonator.
Further, scheme provided by the invention is all applicable for electric coupling between the resonator and magnetic coupling, because the structure of electric coupling implements complexity with respect to magnetic coupling, debugging is also comparatively difficult, and the present invention can not contain electric coupling, has therefore reduced the realization cost of filter.
And the present invention only needs between the resonator directly that coupling just can realize transmission zero, thereby has avoided being difficult on the structure the cross-linked making that realizes, thereby has simplified manufacture craft, has further reduced cost.
In addition, the present invention also can add external resonator on the cross-linked Filter Structures of prior art band basis, can realize the effect that produces transmission zero and the stopband other end is not caused mis-behave equally, therefore be more convenient for satisfying user's different needs, thereby realize higher commercial value.
Description of drawings
Fig. 1 is the cross-linked structure principle chart of the magnetic of three resonators described in the prior art;
Fig. 2 is the cross-linked frequency response schematic diagram of the magnetic of three resonators described in the prior art;
Fig. 3 is the electric cross-linked frequency response schematic diagram of three resonators described in the prior art;
Fig. 4 is the cross-linked structure principle chart of four resonators described in the prior art;
Fig. 5 is the Filter Structures schematic diagram with transmission zero of the present invention;
Fig. 6 is the structure principle chart of first embodiment;
Fig. 7 is the frequency transmission response schematic diagram of first embodiment;
Fig. 8 is the frequency response schematic diagram of second embodiment;
Fig. 9 is the frequency response schematic diagram of the 3rd embodiment.
Embodiment
The transmission zero technology of band pass filter has and can produce higher inhibitory action near the signal zero point, thereby improves the performance of filter; And can use still less cavity numbers, littler volume, the advantage of lower loss, and the position at zero point can regulate arbitrarily beyond the passband as required, therefore obtained using widely, particularly in the communications field, be widely used in the GSM base station, the repeater, tower such as puts at equipment, and present WCDMA, the radio-frequency front-end of systems such as CDMA2000.In design during band pass filter, control the position of transmission zero well can make designed band pass filter more economical, more effective.
The invention discloses a kind of band pass filter, specifically comprise: charger with transmission zero; The port resonator that is connected with port by described charger; Coupling device; Interior resonance device by described coupling device and the coupling of described port resonator; And the full emission resonator by the coupling of described coupling device and described port resonator; Described external resonator will equal the signal homophase transmission of resonance frequency, will be greater than or less than the signal inversion transmission of resonance frequency.
Below introduce concrete operation principle of the present invention in detail.For the ease of understanding the production process of the present invention, at first look back principle known in the prior art related to the present invention to transmission zero.
The coupling filter of arbitrary structures form, all available coupled resonant circuit is analyzed, and this method has been widely used in the design and the analysis of coaxial cavity filter, waveguide filter, dielectric filter, ceramic comb filter and microstrip filter.
For each resonator in the described filter, can equivalence be LC resonant circuit in parallel.Below be the transmission characteristic of LC resonant circuit in parallel:
(1) amplitude characteristic: the signal for the resonator resonant frequency point all passes through, and the signal of disresonance frequence point is that part is passed through, and the frequency departure resonator resonant frequency point of signal is many more, and is few more by the energy of resonator.
(2) phase characteristic: frequency is lower than the signal of resonator resonant frequency point, and its transmission phase place is for just, and frequency is higher than the signal of resonator resonant frequency point, and its transmission phase place is for bearing.
The total reflection phase characteristic of single LC resonant circuit in parallel is: signal frequency is that the reflected phase will of resonator resonant frequency point equals zero.So-called total reflection is meant a kind of situation that the signal that enters resonator all reflects.
In addition, the inductance coupling high equivalence between the resonator becomes the impedance transformer of a perception, and the capacitive coupling equivalence becomes the impedance transformer of a capacitive.Specifically, inductance coupling high is the impedance transformer of a perception, and its transmission phase place is-90 degree; Capacitive coupling is the impedance transformer of a capacitive, and its transmission phase place is+90 degree.
The phase change relation of above-mentioned signal during by resonator and coupled structure (impedance transformer) is as shown in the table:
| Less than resonant frequency point | Equal resonant frequency point | Greater than resonant frequency point | |
| Resonator transmission phase place | 90 | 0 | -90 |
| Resonator total reflection phase place | 180 | 0 | -180 |
| Capacitive coupling transmission phase place | -90 | -90 | -90 |
| Inductance coupling high transmission phase place | 90 | 90 | 90 |
Associated transport characteristic based on above-mentioned resonator, main thought of the present invention is additional external resonator on the port resonator, utilize external resonator full transmitter, phase characteristic, reach when filter one end produces transmission zero the purpose that the rejection of assurance other end stopband does not reduce.Described port resonator both can be the input port resonator, also can be the output port resonator, and concrete condition is in conjunction with hereinafter being illustrated.
In addition, the coupled modes of described external resonator and described port resonator both can be electric coupling, also can be magnetic couplings, and concrete implementation procedure also will be elaborated hereinafter.
Fig. 5 is the Filter Structures schematic diagram with transmission zero of the present invention.Structure shown in the figure is the part of band pass filter, comprises input port resonator, interior resonance device and external resonator.As shown in the figure, interior resonance device magnetic coupling is to the port resonator; Port resonator magnetic is directly coupled to external resonator simultaneously.With the input port is example, and the detailed process that produces transmission zero is as described below:
If the frequency of input signal equals the resonance frequency of external resonator, signal is from port entry port resonator, and part signal is reflected, and residual signal is divided into two-way, and first tributary signal directly is coupled through magnetic, enters external resonator.Because external resonator only is coupled with the port resonator, simultaneously because the frequency of input signal equals the resonance frequency of external resonator, therefore the phase change relation table during by resonator and coupled structure according to the signal shown in above, can learn, the signal that enters external resonator will be by total reflection, and the signal phase of getting back to the port resonator will change-180 degree.Concrete process is as described below: input signal directly is coupled through magnetic, enter external resonator behind phase change-90 degree, because the frequency of input signal equals the frequency of oscillation of external resonator, therefore in external resonator phase change does not take place, and then through all returning the port resonator behind the direct signal after coupling phase place continuation of magnetic change-90 degree, the transmission phase place of signal is-the 90+0-90=-180 degree.It is vector superposed that this road signal and second tributary signal that will enter the interior resonance device carry out at the port resonator, because therefore phase phasic difference 180 degree of two signals equal zero after the stack, promptly produced transmission zero.
Can select electric direct-coupled mode to realize equally for the coupled modes between above-mentioned external resonator and the port resonator.When the frequency of input signal equals the resonance frequency of external resonator, signal is behind port entry port resonator, be divided into two-way, wherein, through direct coupling all turns back to the port resonator through electricity once more after the signal process total reflection that enters external resonator after the direct coupling of electricity, phase place will change+the 90+0+90=180 degree, this road signal with will carry out vector superposed at the interface resonator along second tributary signal that enters the interior resonance device, because phase phasic difference 180 degree of two signals, therefore equal zero after the stack, promptly produced transmission zero.Be easy to draw, owing to will change 180 degree through the transmission of the signal after external resonator total reflection phase place, therefore, no matter the coupled modes between interior resonance device and the port resonator are selected electric coupling or magnetic coupling for use, all can utilize external resonator to reach the purpose that produces transmission zero.
Because it is complicated that the structure of electric coupling implements with respect to magnetic coupling, debugging is also comparatively difficult, and can not contain electric coupling in the filter construction provided by the invention, has therefore reduced the realization cost of filter.
In addition, the present invention is equally applicable to the situation that described external resonator links to each other with the output port resonator.At this moment, signal enters the output port resonator through the interior resonance device, wherein a part of signal is through being coupled into external resonator, through all returning the port resonator after the full emission, phase place will change 180 degree, with another part carry out through the signal of port resonator vector superposed because therefore two paths of signals phase phasic difference 180 degree can produce transmission zero equally.Similarly, electric coupling or magnetic coupling can be selected, also coupled modes can be selected arbitrarily for the coupled modes of interior resonance device for the coupled modes of external resonator.
More than be to utilize external resonator provided by the invention to produce the detailed process of transmission zero.From the above mentioned, when the frequency of oscillation of external resonator is lower than band connection frequency, can produce transmission zero at the low side of filter, when the frequency of oscillation of external resonator is higher than band connection frequency, can be in the high-end generation transmission zero of filter, therefore suitably control the resonance frequency of external resonator, can adjust the position that filter produces zero point.
As mentioned above, utilize the present invention, can produce transmission zero at the high-end or low side of filter.Below analyze the present invention and whether can bring bad influence the filtering performance of filter in the corresponding end of transmission zero.
It still is example with Fig. 5, if the frequency of signal is not equal to the resonance frequency of external resonator, signal is from port entry port resonator, part signal is reflected, residual signal also is to be divided into two-way, first tributary signal directly enters external resonator after the coupling through magnetic successively, after external resonator total reflection, directly be coupled through magnetic again, all return the port resonator, the transmission phase place of signal is-the 90+180-90=0 degree, this signal carries out vector superposed with second tributary signal that will enter the interior resonance device at the port resonator, because the phase place of two signals is identical, therefore the signal after the stack is equivalent to signal and does not change, promptly not to the transmission characteristic generation effect of filter.
Situation for external resonator and the magnetic-coupled situation of port resonator and described external resonator and the coupling of output port resonator can be made similar analysis, does not repeat them here.
From above as can be seen, the present invention only needs between the resonator directly that coupling just can realize transmission zero, thereby has avoided being difficult on the structure the cross-linked making that realizes, thereby has simplified manufacture craft, has further reduced cost.Below, promptly do not exist cross-linked situation, be introduced as a preferred embodiment of the present invention with all resonators " " word arrangement.
First embodiment: each resonator in-line is arranged in the present embodiment, does not have cross-couplings.Do not have cross-linked filter principle schematic as shown in Figure 6, all resonator in-lines are arranged among the figure, directly coupling between each resonator and the adjacent resonators, and external resonator and port resonator directly are coupled.Its signals transmission repeats no more as mentioned before.The position that the suitable resonance frequency of adjusting described external resonator can be coordinated transmission zero.Present embodiment produce transmission zero the frequency transmission response as shown in Figure 7, solid line is partly represented described transmission response with band pass filter of transmission zero among the figure, dotted portion represents not have the transmission response of the band pass filter of transmission zero.Overlap at two curves of an end that does not produce transmission zero.As can be seen, no matter be high-end or low side produces transmission zero, all can the inhibitory action of the stopband of the other end not exerted an influence.
The band pass filter with transmission zero that uses normally has cross-linked filter at present, another advantage of the present invention is exactly simply to improve according to scheme provided by the invention on the basis of existing filter, utilizes external resonator to produce the another one transmission zero on the basis of existing filter.Be specifically described below in conjunction with two embodiment.
In present mobile network, run into the filtering performance exigent while of system through regular meeting to filter low side stopband, require also to have the situation of a higher filter effect at high-end stopband.With the WCDMA system is example, and the free transmission range of the up receiving filter of WCDMA system is 1920MHz to 1980MHz, and the signal transmit frequency band of PHS (Personal access phone system wireless access telephone system) is 1900MHz to 1915MHz.Because the signal transmission power of PHS system is relatively large, can affect to the up reception of WCDMA, therefore,, need the upstream filter of WCDMA to produce a transmission zero at low side in order to suppress the signal of PHS system; Simultaneously since the downlink signal in the WCDMA system generally far above the received signal power of receiver, if it is not carried out Filtering Processing, to cause the circuit of receiver to block, therefore, need the high-end stopband of filter also to have very high inhibitory action this moment.The present invention addresses this problem by the method that has additional external resonator on the cross-linked filter in the prior art.Specific as follows described:
Second embodiment: present embodiment has been enumerated having the improvement situation of the cross-linked filter of three resonance.
Present embodiment is that example describes with three resonance cross-couplings.With above described identical, remain in the present embodiment at external resonator of the port resonator place of filter coupling, there are three resonator magnetic cross-couplings between other resonators.Its signals transmission repeats no more as mentioned before.Fig. 8 is a kind of frequency response schematic diagram that produces transmission zero behind the external resonator.As mentioned before, to produce transmission zero at high-end stopband during three resonator magnetic cross-couplings, be the transmission zero of filter through producing after the cross-couplings zero point of figure middle and high end stopband, be the transmission zero of filter through producing after the external resonator total reflection effect zero point of low side stopband, as seen, in the present embodiment, utilize the present invention that the rejection of the low side stopband of filter is improved, simultaneously the filter effect of the transmission zero that the high-end stopband of filter is not produced exerts an influence.
The 3rd embodiment: present embodiment has been enumerated having the improvement situation of the cross-linked filter of four resonance.
Present embodiment is that example describes with four cross-couplings filters in the situation that low side produces transmission zero.With above described identical, remain in the present embodiment at external resonator of the port resonator place of filter coupling, there are four resonator magnetic cross-couplings between other resonators.Its signals transmission repeats no more as mentioned before.Fig. 9 is a kind of frequency response schematic diagram that produces transmission zero behind the external resonator.As mentioned before, suitably regulate the resonance frequency of resonator, make it produce transmission zero at the low side stopband, be the transmission zero of filter through producing after the cross-couplings zero point of figure low and middle-end stopband, be the transmission zero of filter through producing after the external resonator total reflection effect zero point of high-end stopband, as seen, in the present embodiment, utilize the present invention that the rejection of the high-end stopband of filter is improved, simultaneously the filter effect of the transmission zero that filter low side stopband is not produced produce shadow to.
The above only is a preferred implementation of the present invention; should be pointed out that for those skilled in the art, under the prerequisite that does not break away from the principle of the invention; can also make some improvements and modifications, these improvements and modifications also should be considered as protection scope of the present invention.
Claims (8)
1, a kind of band pass filter with transmission zero comprises:
Charger;
The port resonator that is connected with port by described charger;
Coupling device;
Interior resonance device by described coupling device and the coupling of described port resonator;
It is characterized in that: also comprise external resonator by described coupling device and the coupling of described port resonator; Described external resonator will equal the signal homophase reflection of resonance frequency, will be greater than or less than the signal inversion reflection of resonance frequency;
Described port resonator is divided into first tributary signal and second tributary signal with input signal; Described coupling device obtains first tributary signal from described port resonator, is transferred to described external resonator after the coupling; Described external resonator obtains signal from described coupling device, reflects; Described coupling device obtains described signal from described external resonator, turns back to described port resonator after being coupled, and first tributary signal and second tributary signal of described port resonator after with described returning carries out the output of vector superposed back.
2, the band pass filter with transmission zero according to claim 1 is characterized in that: described port resonator is input port resonator or output port resonator.
3, the band pass filter with transmission zero according to claim 2 is characterized in that: described external resonator magnetic coupling is to described port resonator.
4, the band pass filter with transmission zero according to claim 2 is characterized in that: described external resonator is electrically coupled to described port resonator.
5, according to any one described band pass filter with transmission zero in the claim 1 to 4, it is characterized in that: described interior resonance device electric or magnetic is coupled to described port resonator.
6, the band pass filter with transmission zero according to claim 5 is characterized in that: described interior resonance device electric or magnetic is directly coupled to described port resonator.
7, the band pass filter with transmission zero according to claim 5 is characterized in that: described interior resonance device electric or magnetic cross-couplings is to described port resonator.
8, the band pass filter with transmission zero according to claim 5 is characterized in that, described external resonator comprises: coaxial cavity resonator, waveguide resonator, dielectric resonator, ceramic pectination resonator and micro-strip resonantor.
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| Application Number | Priority Date | Filing Date | Title |
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| CN 200410101528 CN1797842A (en) | 2004-12-21 | 2004-12-21 | Band-pass filter with transmission zero |
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| CN 200410101528 CN1797842A (en) | 2004-12-21 | 2004-12-21 | Band-pass filter with transmission zero |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103117438A (en) * | 2013-03-04 | 2013-05-22 | 电子科技大学 | Terahertz waveguide cavity filter |
| CN109950669A (en) * | 2019-02-18 | 2019-06-28 | 摩比科技（深圳）有限公司 | Dielectric waveguide filter |
| CN112671370A (en) * | 2020-09-03 | 2021-04-16 | 江苏灿勤科技股份有限公司 | Filter and radio transceiver |
| WO2022126393A1 (en) * | 2020-12-15 | 2022-06-23 | 华为技术有限公司 | Dielectric filter, transceiver, and base station |
-
2004
- 2004-12-21 CN CN 200410101528 patent/CN1797842A/en active Pending
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103117438A (en) * | 2013-03-04 | 2013-05-22 | 电子科技大学 | Terahertz waveguide cavity filter |
| CN109950669A (en) * | 2019-02-18 | 2019-06-28 | 摩比科技（深圳）有限公司 | Dielectric waveguide filter |
| CN112671370A (en) * | 2020-09-03 | 2021-04-16 | 江苏灿勤科技股份有限公司 | Filter and radio transceiver |
| WO2022048130A1 (en) * | 2020-09-03 | 2022-03-10 | 江苏灿勤科技股份有限公司 | Filter and radio transceiving device |
| CN112671370B (en) * | 2020-09-03 | 2024-06-11 | 江苏灿勤科技股份有限公司 | Filter and radio transceiver |
| WO2022126393A1 (en) * | 2020-12-15 | 2022-06-23 | 华为技术有限公司 | Dielectric filter, transceiver, and base station |
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