CN110995293B - In-band fluctuation suppression device and radio frequency system - Google Patents
In-band fluctuation suppression device and radio frequency system Download PDFInfo
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- CN110995293B CN110995293B CN201911065658.XA CN201911065658A CN110995293B CN 110995293 B CN110995293 B CN 110995293B CN 201911065658 A CN201911065658 A CN 201911065658A CN 110995293 B CN110995293 B CN 110995293B
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- H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
- H04B1/02—Transmitters
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
- H04B1/06—Receivers
- H04B1/10—Means associated with receiver for limiting or suppressing noise or interference
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
- H04B1/06—Receivers
- H04B1/10—Means associated with receiver for limiting or suppressing noise or interference
- H04B1/12—Neutralising, balancing, or compensation arrangements
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- H—ELECTRICITY
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- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/14—Relay systems
- H04B7/15—Active relay systems
- H04B7/155—Ground-based stations
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- H—ELECTRICITY
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- H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
- H04B1/02—Transmitters
- H04B1/04—Circuits
- H04B2001/0408—Circuits with power amplifiers
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
- H04B1/02—Transmitters
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Abstract
The invention provides an in-band fluctuation suppression device and a radio frequency system. Wherein the in-band ripple suppression device includes: the impedance adjusting module is coupled to the surface acoustic wave filter module; the impedance adjusting module is used for adjusting the impedance of the application circuit, so that the frequency response characteristic of the surface acoustic wave filter module is opposite to the response characteristic of the application circuit fluctuating in a band in an operating frequency range. The invention solves the problem of high requirement on the operation frequency of the FPGA because the FPGA is adopted to inhibit the in-band fluctuation in the related technology, and avoids the dependence of the in-band fluctuation inhibiting device on the operation frequency of the FPGA.
Description
Technical Field
The invention relates to the field of communication, in particular to an in-band fluctuation suppression device and a radio frequency system.
Background
The repeater is a base station radio frequency remote device. The repeater station is composed of components or modules such as an antenna, a radio frequency duplexer, a low noise amplifier, a frequency mixer, an electrically tunable attenuator, a filter, a power amplifier and the like, and comprises an uplink link and a downlink link. The basic principle of repeater work is as follows: a forward antenna is used for receiving a downlink signal of a base station into a repeater, a low-noise amplifier is used for amplifying a useful signal, a noise signal in the signal is suppressed, and the signal-to-noise ratio is improved; then the signal is down-converted to an intermediate frequency signal, filtered by a filter, amplified by an intermediate frequency, up-converted to a radio frequency by a frequency shift, amplified by a power amplifier, and transmitted to a mobile station by a backward antenna; at the same time, the mobile station uplink signal is received by the backward antenna, and the same processing as that of the downlink is carried out by the uplink along the reverse path: the signal is transmitted to the base station through a low noise amplifier, a down converter, a filter, a middle amplifier, an up converter and a power amplifier, thereby achieving the bidirectional communication between the base station and the mobile station.
In a radio frequency system of a repeater or other radio frequency remote equipment, a difference value, namely in-band fluctuation, exists between a maximum level and a minimum level in an operating frequency range of the radio frequency system due to collocation of analog devices in the radio frequency system, digital signal interference and the like. For example, the frequency response of duplexers and filters is not flat in the pass band, which results in-band ripple.
In-band fluctuations of no more than 3dB are typically required in repeaters or other radio remote devices. In the related art, a Field Programmable Gate Array (FPGA) is usually used to suppress the in-band fluctuation. For example, after a Finite Impulse Response (FIR) filter is implemented by using an FPGA, an FIR filter is added to a Digital intermediate frequency signal after an Analog-to-Digital Converter (ADC) of a repeater to compensate for in-band fluctuation of a radio frequency system. The principle of the FIR filter for suppressing the in-band fluctuation of the radio frequency system is to generate a feedback signal opposite to the frequency response of the in-band fluctuation according to the original digital intermediate frequency signal, and compensate the digital intermediate frequency signal by using the feedback signal to counteract the in-band fluctuation. However, the suppression of the in-band fluctuation in the above manner not only causes occupation of FPGA resources, but also has a relatively high requirement on the operation frequency of the FPGA.
Disclosure of Invention
Based on the above, the invention provides an in-band fluctuation suppression device and a radio frequency system, which are used for solving the problem of high requirement on the operation frequency of an FPGA (field programmable gate array) due to the adoption of the FPGA to suppress the in-band fluctuation.
In a first aspect, the present invention provides an in-band wave suppression device including: the impedance adjusting module is coupled to the surface acoustic wave filter module and used for adjusting the impedance of an application circuit, so that the frequency response characteristic of the surface acoustic wave filter module is opposite to the response characteristic of in-band fluctuation of the application circuit in a working frequency range.
In one possible implementation, the impedance adjusting module is coupled to an input and/or an output of the saw filter module.
In one possible implementation, the impedance adjusting module includes: a first impedance adjustment module coupled to an input of the SAW filter module and a second impedance adjustment module coupled to an output of the SAW filter module.
In one possible implementation, the first impedance adjusting module and the second impedance adjusting module have the same circuit topology.
In one possible implementation, the first impedance adjusting module and the second impedance adjusting module have different circuit topologies.
In one possible implementation, the impedance adjusting module includes: the impedance adjusting module includes: one or more impedance adjustment sub-circuits; the plurality of impedance adjusting sub-circuits are connected in series and/or in parallel.
In one possible implementation, the impedance adjustment sub-circuit includes at least one of: the circuit comprises an L-shaped impedance adjusting sub-circuit, a T-shaped impedance adjusting sub-circuit and a pi-shaped impedance adjusting sub-circuit.
In a possible implementation manner, the configuration manner of the parameter of the impedance adjusting module includes one of the following: online debugging configuration and simulation configuration.
In a second aspect, the present invention provides a radio frequency system comprising one or more in-band ripple suppression devices according to the first aspect.
In one possible implementation, the radio frequency system includes an uplink and a downlink; wherein the in-band ripple suppression device is coupled between two stabilizing impedance circuits of the uplink and/or the in-band ripple suppression device is coupled between two stabilizing impedance circuits of the downlink.
The invention provides an in-band fluctuation suppression device and a radio frequency system. The in-band fluctuation suppression device adopts the impedance adjusting module to adjust the impedance of the application circuit, so that the frequency response characteristic of the surface acoustic wave filter module of the in-band fluctuation suppression device is opposite to the response characteristic of the application circuit in the in-band fluctuation within the working frequency range, the problem that the requirement on the operation frequency of an FPGA is high due to the fact that the FPGA is adopted to suppress the in-band fluctuation in the related art is solved, and the dependence of the in-band fluctuation suppression device on the operation frequency of the FPGA is avoided.
The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below to provide a more thorough understanding of the invention.
Drawings
In order to more clearly illustrate the embodiments of the present invention or technical solutions in related arts, the drawings needed to be used in the description of the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without inventive labor.
Fig. 1 is a block diagram of the structure of an in-band ripple suppression apparatus according to an embodiment of the present invention;
fig. 2 is an amplitude diagram of an output waveform of the surface acoustic wave filter module in the case where the electrode impedance of the surface acoustic wave filter module matches the impedance of the application circuit according to the embodiment of the present invention;
fig. 3 is an amplitude diagram of an output waveform of the surface acoustic wave filter module in the case where the electrode impedance of the surface acoustic wave filter module is mismatched with the impedance of the application circuit according to the embodiment of the present invention;
fig. 4 is a phase diagram of an output waveform of the surface acoustic wave filter module in the case where the electrode impedance of the surface acoustic wave filter module matches the impedance of the application circuit according to the embodiment of the present invention;
fig. 5 is a phase diagram of an output waveform of the surface acoustic wave filter module in the case where the electrode impedance of the surface acoustic wave filter module is mismatched with the impedance of the application circuit according to the embodiment of the present invention;
FIG. 6 is a first topology of an impedance adjustment sub-circuit according to an embodiment of the present invention;
FIG. 7 is a second topology of an impedance adjustment sub-circuit according to an embodiment of the present invention;
FIG. 8 is a topology diagram three of an impedance adjustment sub-circuit according to an embodiment of the present invention;
FIG. 9 is a topological diagram of an in-band ripple suppression device according to a preferred embodiment of the present invention;
fig. 10 is a block diagram of a radio frequency system according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. All other examples, which can be obtained by a person skilled in the art without making any creative effort based on the examples in the present invention, belong to the protection scope of the present invention.
It is to be noted that, in the embodiments of the present invention, relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising … …" does not exclude the presence of additional identical elements in the process, method, article, or apparatus that comprises the element.
In an embodiment of the present invention, an in-band fluctuation suppression device is provided. Fig. 1 is a block diagram of a configuration of an in-band ripple suppression apparatus according to an embodiment of the present invention, as shown in fig. 1, the in-band ripple suppression apparatus including: an impedance adjusting module 20, a surface acoustic wave filter module 10, wherein the impedance adjusting module 20 is coupled to the surface acoustic wave filter module 10.
Wherein the impedance adjusting module 20 is used to adjust the impedance of the application circuit so that the response characteristic of the saw filter module 10 is opposite to the response characteristic of the application circuit fluctuating in-band within the operating frequency range.
The in-band fluctuation suppression device can be connected in series in a radio frequency system of radio frequency remote units such as a repeater station, a remote optical fiber unit and the like so as to suppress in-band fluctuation of the radio frequency system.
The saw filter module 10 generally includes an impedance matching network and a saw filter, wherein the saw filter is made of a material having a piezoelectric effect, such as quartz, lithium niobate, barium titanate crystal, and the like. The acoustic surface filter has an input interdigital transducer and an output interdigital transducer. When an input interdigital transducer is connected with an alternating voltage signal, the surface of the piezoelectric crystal substrate generates vibration and excites a sound wave with the same frequency as an external signal, the sound wave is mainly transmitted along the direction of the surface of the substrate and the lifting direction of the interdigital electrode, the sound wave in one direction is absorbed by a sound absorption material, and the sound wave in the other direction is transmitted to the output interdigital transducer and converted into an electric signal to be output.
Since the acoustic surface filter performs interconversion between an acoustic signal and an electric signal by the interdigital transducer, the acoustic surface filter has a characteristic of a triple echo. That is, when a main signal in the form of a surface acoustic wave reaches an output electrode in the acoustic surface filter, it is converted into an electric signal output by the inverse piezoelectric effect of the output interdigital transducer. However, the output electrode can also be regarded as an input electrode, and then the output interdigital transducer of the output electrode converts a part of the main signal converted into an electric signal into a surface acoustic wave through the piezoelectric effect and transmits the surface acoustic wave to the direction of the input electrode; after the surface acoustic wave reaches the input electrode, the surface acoustic wave is reflected to the output electrode in a similar mode, so that multiple echoes are formed, and the amplitude and the phase of an output signal of the surface acoustic wave filter are changed due to the multiple echoes, so that the quality of the output signal is reduced.
In addition, the impedance of the application circuit connected to the saw filter module affects the triple echo of the saw filter, and further affects the frequency response characteristics of the saw filter module. The influence of the impedance of the application circuit to which the surface acoustic wave filter module is connected on the frequency response characteristic of the surface acoustic wave filter module will be described below through experiments.
In a circuit, the standard impedance is typically 50 ohms or 75 ohms, which is typically determined by the transmission line impedance in the circuit. Under the condition of impedance matching, namely the signal source internal impedance is equal to the characteristic impedance of the connected transmission line in magnitude and phase, or the characteristic impedance of the transmission line is equal to the characteristic impedance of the connected load in magnitude and phase, the transmission line can obtain the maximum power or the energy carried on the transmission line can be completely absorbed by the load. Therefore, the impedance of the electrodes on the input electrode and the output electrode of the surface acoustic wave filter module is usually adjusted to a standard impedance by the matching network, and the frequency response characteristic of the surface acoustic wave filter module is also usually a frequency response characteristic in the case where the electrode impedance is matched to the impedance of the connected application circuit.
In the experiment, the electrode impedance of the tested surface acoustic wave filter module is 50 ohms, and the pass band is 1710-1735 MHz. And the input electrode and the output electrode of the surface acoustic wave filter module are respectively connected with an impedance adjusting module in series so as to adjust the impedance of the application circuit to be matched with or mismatched with the electrode impedance of the surface acoustic wave filter module. Under the conditions of impedance matching and impedance mismatching, square waves with the same amplitude and phase are input to the input end of the surface acoustic wave filter module, and an oscilloscope is adopted to respectively observe the changes of the amplitude and the phase of the output waveform of the surface acoustic wave filter module.
Fig. 2 and 3 respectively show amplitude diagrams of output waveforms of the surface acoustic wave filter module under the conditions of impedance matching and mismatching between the electrode impedance of the surface acoustic wave filter module and the impedance of an application circuit within a passband 1710-1735 MHz. It can be observed from fig. 2 and 3 that the amplitude of the waveform of the saw filter module changes after the impedance of the application circuit changes from impedance matching with the electrodes to impedance mismatching with the electrodes.
Fig. 4 and 5 show phase diagrams of output waveforms of the surface acoustic wave filter module in the situation that the impedance of the electrode of the surface acoustic wave filter module is matched with and mismatched with the impedance of the application circuit within the pass band of 1710-1735 MHz, respectively. It can be observed from fig. 4 and 5 that the phase of the waveform of the saw filter module changes after the impedance of the application circuit changes from impedance matching with the electrodes to impedance mismatching with the electrodes.
The reason for the above change is that the impedance of the application circuit affects the vibration of the interdigital transducer inside the acoustic surface filter, including the characteristics exhibited after the superposition of the three echoes, and the initial performance of the acoustic surface filter is changed.
The above experimental results show that the impedance change of the application circuit will affect the frequency response characteristics of the saw filter module.
In the embodiment of the present invention, it is made use of the property that the response characteristic of the surface acoustic wave filter module is influenced by the impedance of the application circuit, so that the frequency response characteristic of the surface acoustic wave filter module can be adjusted to be opposite to the response characteristic of the application circuit fluctuating in-band within the operating frequency range by adjusting the impedance of the application circuit.
Specifically, in the present embodiment, an impedance adjusting module 20 is added to the saw filter module 10 to adjust the impedance of the application circuit, so that the frequency response characteristic of the saw filter module 10 is opposite to the response characteristic of the application circuit in-band fluctuation in the operating frequency range, and further, the triple echo of the saw filter is superimposed on the initial signal to cancel the in-band fluctuation of the initial signal, thereby realizing the in-band fluctuation compensation of the application circuit in the operating frequency range. By adopting the mode, the in-band fluctuation is effectively inhibited by using the matching of the impedance adjusting module 20, the surface acoustic wave filter module 10 and other analog devices, the problem that the requirement on the operation frequency of the FPGA is high because the in-band fluctuation is inhibited by adopting the FPGA in the related technology is solved, and the occupation of FPGA resources is also avoided. In addition, the in-band ripple suppression device based on the surface acoustic wave filter module 10 also has the advantages of simple manufacturing process, good passband characteristics, high reliability, high consistency, small volume and strong universality.
In this example, according to the passband of the application circuit, a surface acoustic wave filter module which is the same as or slightly larger than the passband of the application circuit can be selected, and an in-band fluctuation suppression device is built, so as to realize in-band fluctuation compensation of the application circuits with different passbands.
In this embodiment, the impedance adjusting module 20 may be coupled in series to the input terminal of the saw filter module 10, may also be coupled in series to the output terminal of the saw filter module 10, or may be coupled to the impedance adjusting module 20 at the input terminal and the output terminal of the saw filter module 10, respectively. Preferably, coupling the impedance adjusting module 20 to the input terminal and the output terminal of the saw filter module 10 can improve the effect of suppressing the in-band ripple and simplify the difficulty of configuring the parameters of the impedance adjusting module 20.
The impedance adjusting module 20 in this embodiment may be composed of one or more impedance adjusting sub-circuits. These impedance adjusting sub-circuits include, but are not limited to, at least one of: the circuit comprises an L-shaped impedance adjusting sub-circuit, a T-shaped impedance adjusting sub-circuit and a pi-shaped impedance adjusting sub-circuit. And the number of each type of impedance adjusting subcircuit can be configured according to the requirement, and the connection mode among the impedance adjusting subcircuits can be series connection and/or parallel connection.
In some embodiments, the L-shaped impedance adjusting sub-circuit is an L-shaped circuit composed of at least two types of elements of resistance, capacitance, and inductance. The L-shaped impedance adjusting sub-circuit has the advantages of simple circuit and low cost. In view of reducing power loss, the L-type impedance adjusting sub-circuit uses inductive and capacitive elements as much as possible, and does not use resistors as much as possible. Therefore, the L-type impedance adjusting sub-circuit of the present embodiment is preferably one of the 8 kinds of circuits shown in fig. 6.
In some embodiments, the T-shaped impedance adjusting sub-circuit is a T-shaped circuit composed of at least two types of elements of a resistor, a capacitor and an inductor. The T-type impedance adjusting sub-circuit tries to use inductive and capacitive elements and tries not to use resistors in view of reducing power loss. Two preferred T-type impedance adjusting sub-circuits are shown in fig. 7.
In some embodiments, the pi-type impedance modifier sub-circuit comprises a pi-type circuit of at least two types of elements selected from the group consisting of resistors, capacitors, and inductors. The pi-type impedance adjusting sub-circuit tries to use inductive and capacitive elements and does not use resistors in consideration of reducing power loss. Two preferred pi-type impedance modifier sub-circuits are shown in fig. 8.
In addition, the preferable scheme of the impedance adjusting sub-circuit is that a mode that a capacitor is connected with the surface acoustic wave filter module in series and an inductor is connected with the surface acoustic wave filter module in parallel is adopted, so that the effects of isolating direct current and providing an electrostatic discharge channel are achieved.
Optionally, an in-band fluctuation suppression apparatus is provided in the present embodiment. Fig. 9 is a topological diagram of an in-band ripple suppression device according to a preferred embodiment of the present invention, which, as shown in fig. 9, includes: four inductors, four capacitors, and a surface acoustic wave filter module 10. The inductor and the capacitor form an L-shaped impedance adjusting sub-circuit, and the total number of the L-shaped impedance adjusting sub-circuits is four. Two of the L-shaped impedance adjusting sub-circuits are coupled in series and then coupled to the input terminal of the saw filter module 10, and the other two L-shaped impedance adjusting sub-circuits are coupled in series and then coupled to the output terminal of the saw filter module 10.
It should be noted that, although the circuit topologies of the impedance adjusting modules connected in series at the front end and the back end of the saw filter module 10 shown in fig. 9 are the same, the present invention is not limited to this, that is, the circuit topologies of the impedance adjusting modules connected in series at the front end and the back end of the saw filter module 10 may also be different.
In this embodiment, the manner of configuring the parameters of the impedance adjusting module includes, but is not limited to: an online debug configuration and/or an analog simulation configuration. The online debugging configuration refers to that an impedance adjusting module is connected in series to an application circuit, and then the parameters of the impedance adjusting module are debugged to obtain the parameters of the appropriate impedance adjusting module by debugging the parameters of the impedance adjusting module and detecting the fluctuation condition in a band at the same time. The analog simulation configuration refers to performing analog simulation on an application circuit in a computer and testing parameter configuration of various impedance adjusting modules, after obtaining parameters capable of meeting requirements, designing the impedance adjusting modules according to the parameters obtained by the analog simulation, and finally accessing the impedance adjusting modules into an actual application circuit to realize compensation of in-band fluctuation. The above parameter configuration modes can also be used together or in combination with other parameter configuration modes. The impedance of the application circuit after the impedance adjustment by the impedance adjustment module may be matched or mismatched with the electrode impedance of the surface acoustic wave filter module.
A radio frequency system is also provided in an embodiment. Fig. 10 is a block diagram of a radio frequency system according to an embodiment of the present invention, and as shown in fig. 10, the radio frequency system includes one or more in-band ripple suppression devices, and in-band ripple compensation of the radio frequency system is realized by disposing the in-band ripple suppression devices in the radio frequency system.
In the present embodiment, the radio frequency system includes an uplink and a downlink; according to the in-band fluctuation situation of the uplink and the downlink, in-band fluctuation suppression devices can be selectively inserted into the uplink and/or the downlink to realize in-band fluctuation compensation. Preferably, the in-band ripple suppression means is interposed between two stable impedance circuits of the uplink or downlink.
In this embodiment, the uplink may include: a Low Noise Amplifier (LNA) circuit, an analog-to-digital converter (ADC), a first in-band ripple suppression device, and a reverse operation (REV) interface, the downlink may include: the system comprises a power amplifier circuit, a digital-to-analog converter (DAC), a second in-band fluctuation suppression device and a forward rotation operation (FWD) interface, wherein the coupling relation in an uplink is preferably as follows: the REV interface, the LNA circuit, the first in-band fluctuation suppression device, and the ADC are coupled in this order, and the coupling relationship in the downlink is preferably: and the DAC, the second in-band fluctuation suppression device, the power amplification circuit and the FWD interface are coupled in sequence. In the embodiment, one in-band fluctuation suppression device is coupled between the ADC and the LAN circuit, and the other in-band fluctuation suppression device is coupled between the DAC and the power amplifier circuit, and since the ports of the ADC, the LAN, the digital-to-analog converter, and the power amplifier circuit have the characteristic of stabilizing impedance, the impedance adjustment module of the in-band fluctuation suppression device does not affect the characteristics of other devices at the front end or the rear end after changing the impedance of the application circuit, thereby ensuring the stability of the radio frequency system.
The radio frequency system provided by the embodiment can enhance the suppression capability of the in-band fluctuation by inserting the in-band fluctuation suppression device in the uplink and downlink, and can reduce the link self-excitation risk by inserting the in-band fluctuation suppression device between the stable impedance circuits so as not to affect the circuit standing wave.
The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.
Claims (10)
1. An in-band fluctuation suppression apparatus, characterized by comprising: an impedance adjustment module, a surface acoustic wave filter module, the impedance adjustment module coupled to the surface acoustic wave filter module, wherein,
the impedance adjusting module is used for adjusting the impedance of the application circuit, so that the frequency response characteristic of the surface acoustic wave filter module is opposite to the response characteristic of in-band fluctuation of the application circuit in an operating frequency range;
wherein the impedance adjusting module is composed of at least two types of elements of a resistor, a capacitor and an inductor;
wherein the surface acoustic wave filter module includes: a sound surface filter; the impedance adjusting module is used for adjusting the impedance of the application circuit, so that the frequency response characteristic of the surface acoustic wave filter module is opposite to the response characteristic of the application circuit fluctuating in a band in an operating frequency range, and the impedance adjusting module comprises:
the impedance adjusting module is used for adjusting the impedance of the application circuit, so that the triple echo of the acoustic surface filter is superposed with the initial signal of the acoustic surface filter to counteract the in-band fluctuation of the initial signal.
2. The in-band ripple suppression device of claim 1, wherein the impedance adjustment module is coupled to an input and/or an output of the SAW filter module.
3. The in-band ripple suppression device of claim 2, wherein the impedance adjustment module comprises: a first impedance adjustment module coupled to an input of the SAW filter module and a second impedance adjustment module coupled to an output of the SAW filter module.
4. The in-band ripple suppression device of claim 3, wherein the first impedance adjustment module and the second impedance adjustment module have the same circuit topology.
5. The in-band ripple suppression device of claim 3, wherein the first impedance adjustment module and the second impedance adjustment module have different circuit topologies.
6. The in-band fluctuation suppression apparatus according to any one of claims 1 to 5, wherein the impedance adjustment module includes: one or more impedance adjusting sub-circuits; the plurality of impedance adjusting sub-circuits are connected in series and/or in parallel.
7. The in-band ripple suppression device of claim 6, wherein the impedance adjustment subcircuit comprises at least one of: l-type impedance adjusting sub-circuit, T-type impedance adjusting sub-circuit, and pi-type impedance adjusting sub-circuit.
8. The in-band ripple suppression device of claim 1, wherein the parameters of the impedance adjustment module are configured in a manner comprising one of: online debugging configuration and simulation configuration.
9. A radio frequency system, characterized in that it comprises one or more in-band ripple suppression devices according to any one of claims 1 to 8.
10. The radio frequency system of claim 9, wherein the radio frequency system comprises an uplink and a downlink; wherein the in-band ripple suppression device is coupled between two stabilizing impedance circuits of the uplink and/or the in-band ripple suppression device is coupled between two stabilizing impedance circuits of the downlink.
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| CN201911065658.XA CN110995293B (en) | 2019-11-04 | 2019-11-04 | In-band fluctuation suppression device and radio frequency system |
| PCT/CN2020/126399 WO2021088848A1 (en) | 2019-11-04 | 2020-11-04 | In-band fluctuation suppression device and radio frequency system |
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| CN110995293B (en) * | 2019-11-04 | 2022-06-07 | 三维通信股份有限公司 | In-band fluctuation suppression device and radio frequency system |
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| CN101217267A (en) * | 2008-01-03 | 2008-07-09 | 中兴通讯股份有限公司 | A sound surface wave filter module |
| CN201860328U (en) * | 2010-11-03 | 2011-06-08 | 三维通信股份有限公司 | Digital repeater of in-band fluctuation compensation |
| CN106849898A (en) * | 2016-12-13 | 2017-06-13 | 北京中科飞鸿科技有限公司 | A kind of 17% relative bandwidth low-loss SAW filter and preparation method thereof |
| CN206272584U (en) * | 2016-12-23 | 2017-06-20 | 无锡市好达电子有限公司 | A kind of SAW filter with interior match circuit |
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| JP3424971B2 (en) * | 1994-01-20 | 2003-07-07 | 松下電器産業株式会社 | Surface acoustic wave filter |
| US5528206A (en) * | 1994-11-23 | 1996-06-18 | Murata Manufacturing Co., Ltd. | Surface acoustic wave filter with attenuated spurious emissions |
| JP2002176333A (en) * | 2000-12-07 | 2002-06-21 | Fujitsu Media Device Kk | Surface acoustic wave filter |
| JP2005045475A (en) * | 2003-07-28 | 2005-02-17 | Murata Mfg Co Ltd | Surface acoustic wave device and communications apparatus |
| JP2007053563A (en) * | 2005-08-17 | 2007-03-01 | Nippon Dempa Kogyo Co Ltd | Surface acoustic wave filter module and method for manufacturing the same |
| CN110995293B (en) * | 2019-11-04 | 2022-06-07 | 三维通信股份有限公司 | In-band fluctuation suppression device and radio frequency system |
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| CN101217267A (en) * | 2008-01-03 | 2008-07-09 | 中兴通讯股份有限公司 | A sound surface wave filter module |
| CN201860328U (en) * | 2010-11-03 | 2011-06-08 | 三维通信股份有限公司 | Digital repeater of in-band fluctuation compensation |
| CN106849898A (en) * | 2016-12-13 | 2017-06-13 | 北京中科飞鸿科技有限公司 | A kind of 17% relative bandwidth low-loss SAW filter and preparation method thereof |
| CN206272584U (en) * | 2016-12-23 | 2017-06-20 | 无锡市好达电子有限公司 | A kind of SAW filter with interior match circuit |
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| CN110995293A (en) | 2020-04-10 |
| WO2021088848A1 (en) | 2021-05-14 |
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