CN104639077A - Passive filtering and amplifying circuit - Google Patents
Passive filtering and amplifying circuit Download PDFInfo
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- CN104639077A CN104639077A CN201410736867.3A CN201410736867A CN104639077A CN 104639077 A CN104639077 A CN 104639077A CN 201410736867 A CN201410736867 A CN 201410736867A CN 104639077 A CN104639077 A CN 104639077A
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Abstract
The embodiment of the invention discloses a passive filtering and amplifying circuit. The passive filtering and amplifying circuit comprises a passive filtering circuit body and an amplifying circuit body. The passive filtering circuit body comprises a capacitor element C1, a resistor element R3 and a resistor element R4, the first end of the capacitor element C1 is connected with the first end of the resistor element R3, and the second end of the capacitor element C1 is connected with the first end of the resistor element R4. The amplifying circuit body comprises an operational amplifier A, a resistor element R5 and a resistor element R6. The in-phase input end of the operational amplifier A is connected with the first end of the resistor element R6, the resistor element R5 is connected between the inverted input end of the operational amplifier A and the first output end of the operational amplifier A, and the second end of the resistor element R6 is grounded or is connected with the second output end of the operational amplifier A; the second end of the resistor element R3 is connected with the inverted input end of the operational amplifier A, and the second end of the resistor element R4 is connected with the normal-phase input end of the operational amplifier A. According to the passive filtering and amplifying circuit, the common mode rejection ratio of the amplifying circuit body can be improved to the maximum degree, and meanwhile the circuit structure is simplified.
Description
Technical field
The present invention relates to electronic circuit technology field, be specifically related to a kind of passive filtering amplifying circuit.
Background technology
Common-mode rejection ratio (Common Mode Rejection Ratio, CMRR) be the ratio of the voltage amplification factor of difference mode signal in amplifying circuit and the voltage amplification factor of common-mode signal, for weighing the ability that amplifying circuit amplifies difference mode signal and suppresses common-mode signal, CMRR is larger, and the performance of amplifying circuit is better.
In filter amplification circuit, generally use active power filtering amplifying circuit at present, this just need the resistance value of amplifier positive-negative input end and capacitance symmetry equivalent, the precision of current resistance can reach 0.05%, and the full accuracy of electric capacity is only about 1%, want electric capacity matched difficulty very large, so be difficult to obtain higher CMRR.
Summary of the invention
The embodiment of the present invention provides a kind of passive filtering amplifying circuit, adopts symmetric circuit structure, and the common-mode rejection ratio reducing the amplifying circuit caused due to input impedance mismatch to greatest extent declines, and adopts passive filtering, simplifies circuit structure.
The embodiment of the present invention provides a kind of passive filtering amplifying circuit, can comprise: passive filter circuit and amplifying circuit, wherein:
Passive filter circuit comprises the first capacity cell C1, the 3rd resistive element R3 and the 4th resistive element R4, and the first capacity cell C1 first end connects the 3rd resistive element R3 first end, and the first capacity cell C1 second end connects the 4th resistive element R4 first end;
Amplifying circuit comprises operational amplifier A, the 5th resistive element R5 and the 6th resistive element R6, the in-phase input end of operational amplifier A connects described 6th resistive element R6 first end, the 5th resistive element R5 is connected, second output of the 6th resistive element R6 second end ground connection or concatenation operation amplifier A between the inverting input of operational amplifier A and the first output of operational amplifier A;
Described 3rd resistive element R3 second end of passive filter circuit connects the inverting input of the operational amplifier A of amplifying circuit, and described 4th resistive element R4 second end of passive filter circuit connects the normal phase input end of the operational amplifier A of described amplifying circuit.
Further, passive filtering amplifying circuit also comprises input circuit, wherein: input circuit comprises positive input terminal, negative input end or ground end, the first resistive element R1 and the second resistive element R2, positive input terminal connects the first resistive element R1 first end, negative input end or ground end connection second resistive element R2 first end.
Further, input circuit is specially with the connected mode of described passive filter circuit: the first resistive element R1 second end of input circuit and the first capacity cell C1 first end of passive filter circuit are connected, and the second resistive element R2 second end of input circuit is connected with the first capacity cell C1 second end of passive filter circuit.
Further, the 3rd resistive element R3 is identical with the 4th resistive element R4 resistance, and the 5th resistive element R5 is identical with the 6th resistive element R6 resistance, and the first resistive element R1 is identical with the second resistive element R2 resistance.
Further, operational amplifier A also comprises for the circuit supply interface of connecting circuit supply power voltage VCC and the operational amplifier A power supply interface for concatenation operation amplifier A operating voltage VDD.
Further, input circuit is used for Received signal strength source and control inputs electric current, and passive filter circuit is used for carrying out filtering to input signal and regulating the corner frequency of passive filter circuit, and amplifying circuit is used for amplifying the signal by passive filter circuit.
Further, the common-mode rejection ratio of amplifying circuit is obtained by following formula:
CMRR-R＝20×log[(1+G)/(2×△R/R)]；
Wherein, CMRR-R is the common-mode rejection ratio caused by impedance mismatching, G is the gain of operational amplifier A, G=R5/ (R1+R3), R5 is the resistance value of the 5th resistive element, and R1 is the resistance value of the first resistive element, and R3 is the resistance value of the 3rd resistive element, R is normal resistance, and △ R is the absolute value of the difference of actual resistance and described normal resistance.
Further, the corner frequency of passive filter circuit is obtained by following formula:
F-corner-1＝1/[2×π×C1×(R1//R3+R2//R4)]；
Wherein, F-corner-1 is the corner frequency of passive filter circuit, and C1 is the capacitance of the first capacity cell, R1 is the resistance value of the first resistive element, R3 is the resistance value of the 3rd resistive element, and R2 is the resistance value of the second resistive element, and R4 is the resistance value of the 4th resistive element.
Further, when the first resistive element R1 is identical with the second resistive element R2 resistance and the 3rd resistive element R3 is identical with the 4th resistive element R4 resistance, the computing formula of the corner frequency of passive filter circuit is reduced to:
F-corner-2＝1/[2×π×C1×2×(R1//R3)]；
Wherein, F-corner-2 is the corner frequency of the passive filter circuit when the first resistive element R1 is identical with the second resistive element R2 resistance and the 3rd resistive element R3 is identical with the 4th resistive element R4 resistance, C1 is the capacitance of the first capacity cell, R1 is the resistance value of the first resistive element, and R3 is the resistance value of the 3rd resistive element.
Further, when the resistance of the first resistive element R1 is much larger than the resistance of described 3rd resistive element R3, the corner frequency of passive filter circuit is obtained by following formula:
F-corner-3＝1/[4×π×C1×R3]；
Wherein F-corner-3 be the resistance of the first resistive element R1 much larger than the corner frequency during resistance of the 3rd resistive element R3, R3 is the resistance value of the 3rd resistive element, and C1 is the capacitance of the first capacity cell.
Further, the ratio of F-corner-3 and F-corner-2 is the 3rd resistive element R3 and the rights and interests value of the 4th resistive element R4 in passive filter circuit, and rights and interests value is more than or equal to 0.5.
In embodiments of the present invention, by providing a kind of passive filtering amplifying circuit, at utmost improving the common-mode rejection ratio of amplifying circuit, simplifying circuit structure simultaneously.
Accompanying drawing explanation
In order to be illustrated more clearly in the embodiment of the present invention or technical scheme of the prior art, be briefly described to the accompanying drawing used required in embodiment or description of the prior art below, apparently, accompanying drawing in the following describes is only some embodiments of the present invention, for those of ordinary skill in the art, under the prerequisite not paying creative work, other accompanying drawing can also be obtained according to these accompanying drawings.
Fig. 1 is the structured flowchart of a kind of passive filtering amplifying circuit that the embodiment of the present invention provides;
Fig. 2 is the circuit diagram of a kind of passive filtering amplifying circuit that the embodiment of the present invention provides;
Fig. 3 is the circuit diagram of the another kind of passive filtering amplifying circuit that the embodiment of the present invention provides;
Fig. 4 is the circuit diagram of the another kind of passive filtering amplifying circuit that the embodiment of the present invention provides;
Fig. 5 is the circuit diagram of the another kind of passive filtering amplifying circuit that the embodiment of the present invention provides.
Embodiment
Below in conjunction with the accompanying drawing in the embodiment of the present invention, be clearly and completely described the technical scheme in the embodiment of the present invention, obviously, described embodiment is only the present invention's part embodiment, instead of whole embodiments.Based on the embodiment in the present invention, those of ordinary skill in the art, not making the every other embodiment obtained under creative work prerequisite, belong to the scope of protection of the invention.
Fig. 1 is the structured flowchart of a kind of passive filtering amplifying circuit that the embodiment of the present invention provides.As shown in Figure 1, this passive filtering amplifying circuit comprises passive filter circuit and amplifying circuit, wherein:
Passive filter circuit comprises the first capacity cell C1, the 3rd resistive element R3 and the 4th resistive element R4, and the first capacity cell C1 first end connects the 3rd resistive element R3 first end, and the first capacity cell C1 second end connects the 4th resistive element R4 first end;
Amplifying circuit comprises operational amplifier A, the 5th resistive element R5 and the 6th resistive element R6, the in-phase input end of operational amplifier A connects the 6th resistive element R6 first end, the 5th resistive element R5 is connected, second output (as Fig. 1 (b)) of the 6th resistive element R6 second end ground connection (as Fig. 1 (a)) or concatenation operation amplifier A between the inverting input of operational amplifier A and the first output of operational amplifier A;
3rd resistive element R3 second end of passive filter circuit connects the inverting input of the operational amplifier A of amplifying circuit, and the 4th resistive element R4 second end of passive filter circuit connects the normal phase input end of the operational amplifier A of amplifying circuit.
Concrete, the operation principle of passive filtering amplifying circuit is: first input signal passes through passive filter circuit, passive filter circuit is used for carrying out filtering to input signal, by regulating the size of C1, R3 and R4, regulate the corner frequency of passive filter circuit, realize carrying out filtering to the signal of different frequency range, finally by the signal of passive filter circuit through amplifying circuit, amplifying circuit is used for the amplification to signal, passive filter circuit and amplifying circuit adopt seamless link, decrease the interference of signal, realize the high-fidelity of signal.
Optionally, the 3rd resistive element R3 in passive filter circuit is identical with the resistance of the 4th resistive element R4, the 5th resistive element R5 in amplifying circuit is identical with the resistance of the 6th resistive element R6, adopt symmetrical circuit structure, the common-mode rejection ratio of filter amplification circuit can be improved to greatest extent, the fidelity to signal can be realized to greatest extent.
The embodiment of the present invention, provides a kind of passive filtering amplifying circuit, can regulate the corner frequency of passive filter circuit, adopts symmetric circuit structure, at utmost improves the common-mode rejection ratio of amplifying circuit, adopts passive filtering, simplifies circuit structure.
Fig. 2 is the circuit diagram of a kind of passive filtering amplifying circuit that the embodiment of the present invention provides, and as shown in Figure 2, this passive filtering amplifying circuit comprises input circuit, passive filter circuit and amplifying circuit, wherein:
Input circuit comprises positive input terminal, negative input end, the first resistive element R1 and the second resistive element R2, positive input terminal connects the first resistive element R1 first end, negative input end connects the second resistive element R2 first end, and the first resistive element R1 is identical with the second resistive element R2 resistance.
Passive filter circuit comprises the first capacity cell C1, the 3rd resistive element R3 and the 4th resistive element R4; First capacity cell C1 first end connects the first resistive element R1 second end and the 3rd resistive element R3 first end of input circuit, first capacity cell C1 second end connects the second resistive element R2 second end and the 4th resistive element R4 first end of input circuit, 3rd resistive element R3 second end connects the inverting input of the operational amplifier A of amplifying circuit, 4th resistive element R4 second end connects the normal phase input end of the operational amplifier A of amplifying circuit, and the 3rd resistive element R3 is identical with the 4th resistive element R4 resistance.
Amplifying circuit comprises operational amplifier A, the 5th resistive element R5 and the 6th resistive element R6, the in-phase input end of operational amplifier A connects the 6th resistive element R6 first end, the 5th resistive element R5 is connected between the inverting input of operational amplifier A and the first output of operational amplifier A, 6th resistive element R6 second end ground connection, the 5th resistive element R5 is identical with the 6th resistive element R6 resistance.
Concrete, this passive filtering amplifying circuit adopts Differential Input and Single-end output.The first resistive element R1 in input circuit and the second resistive element R2 is used for control inputs electric current, and the first resistive element R1 is identical with the second resistive element R2 resistance, adopts symmetric circuit structure; The 3rd resistive element R3 in passive filter circuit, the 4th resistive element R4 and the first capacity cell C1 corner frequency deciding passive filter circuit, the 3rd resistive element R3 is identical with the 4th resistive element R4 resistance, adopts symmetric circuit structure; Be connected the 5th resistive element R5 between the inverting input of the operational amplifier A in amplifying circuit and the first output of operational amplifier A and form feedback circuit, 6th resistive element R6 is used for the input current of control algorithm amplifier A, 5th resistive element R5 is identical with the 6th resistive element R6 resistance, adopts symmetric circuit structure.
As a kind of possible execution mode, the corner frequency of this passive filtering amplifying circuit is determined by F-corner-1=1/ [2 × π × C1 × (R1//R3+R2//R4)].
Wherein, F-corner-1 is the corner frequency of passive filter circuit, and C1 is the capacitance of the first capacity cell, R1 is the resistance value of the first resistive element, R3 is the resistance value of the 3rd resistive element, and R2 is the resistance value of the second resistive element, and R4 is the resistance value of the 4th resistive element.Determine that the factor of corner frequency F-corner-1 size comprises C1, R1, R2, R3 and R4.
As a kind of possible execution mode, when the first resistive element R1 is identical with the second resistive element R2 resistance and the 3rd resistive element R3 is identical with the 4th resistive element R4 resistance, the corner frequency of this passive filter circuit is reduced to:
F-corner-2＝1/[2×π×C1×2×(R1//R3)]；
Wherein, F-corner-2 is the corner frequency of the passive filter circuit when the first resistive element R1 is identical with the second resistive element R2 resistance and the 3rd resistive element R3 is identical with the 4th resistive element R4 resistance, C1 is the capacitance of the first capacity cell, R1 is the resistance value of the first resistive element, and R3 is the resistance value of the 3rd resistive element.Determine that the factor of corner frequency F-corner-2 size comprises C1, R1 and R3.
As a kind of possible execution mode, when the resistance of the first resistive element R1 is much larger than the resistance of described 3rd resistive element R3, the corner frequency of passive filter circuit is obtained by following formula:
F-corner-3＝1/[4×π×C1×R3]；
Wherein F-corner-3 be the resistance of the first resistive element R1 much larger than the corner frequency during resistance of the 3rd resistive element R3, R3 is the resistance value of the 3rd resistive element, and C1 is the capacitance of the first capacity cell.
It is pointed out that the resistance of the resistance of the first resistive element R1 in the embodiment of the present invention much larger than the 3rd resistive element R3 is more than five times or five times of the resistance of R3 much larger than the resistance that can be R1.
The ratio (namely F-corner-3 is divided by F-corner-2) of F-corner-3 and F-corner-2 is the 3rd resistive element R3 and the rights and interests value of the 4th resistive element R4 in passive filter circuit, and rights and interests value is more than or equal to 0.5, the upper range of rights and interests value can be infinitely close to 1.The size of rights and interests value directly reflects the 3rd resistive element R3 and the 4th resistive element R4 role size in filtering.It should be noted that, rights and interests value can be obtained by the ratio of F-corner-3 and F-corner-2, also can be obtained by F-corner-3 and the ratio of the corner frequency of surveying corner frequency or equivalent deformation circuit (increasing other components and parts on the basis of passive filter circuit C1, R3, R4 of the present invention).
Determine that the factor of corner frequency F-corner-3 size only has C1 and R3, R4 (now R3 and R4 resistance is equal), after introducing corner frequency F-corner-3, only need the capacitance size of adjustment first capacity cell C1 and the resistance size of the 3rd resistive element R3 (or R4), the corner frequency needed for adjustment that can be convenient and simple.As a kind of possible execution mode, the common-mode rejection ratio that this passive filtering amplifying circuit is caused by impedance mismatching is determined by CMRR-R=20 × log [(1+G)/(2 × △ R/R)];
Wherein, CMRR-R is the common-mode rejection ratio caused by impedance mismatching, G is the gain of operational amplifier, G=R5/ (R1+R3), R5 is the resistance value of described 5th resistive element, and R1 is the resistance value of described 3rd resistive element, and R3 is the resistance value of described 3rd resistive element, R is normal resistance, and △ R is the absolute value of the difference of actual resistance and normal resistance.Because the nominal value of resistance and actual measured value have a certain distance, gap is less, and the permissible variation of resistance is less, the precision of resistance is higher, such as, the permissible variation of the resistance used in circuit is one thousandth, then represent that △ R/R is 0.001, the permissible variation of the resistance used in circuit is 5/10000ths, then represent that △ R/R is 0.0005, the precision of resistance is higher, and △ R/R is less, CMRR-R is larger, and the antijamming capability of circuit is stronger.
Optionally, according to active power filtering amplifying circuit, the common-mode rejection ratio that active power filtering amplifying circuit is caused by impedance mismatching is determined by CMRR_impedance=20 × log [(1+G)/(2 × Δ impedance/impedance)];
Wherein, CMRR_impedance is the common-mode rejection ratio caused by impedance mismatching, G is the gain of operational amplifier, and impedance is nominal signal source impedance values, and Δ impedance is the absolute value of the difference of actual signal source impedance values and nominal signal source impedance values.
Concrete, because the precision of current resistance can reach 0.05%, and the full accuracy of electric capacity is only about 1%, in active power filtering amplifying circuit, because Δ impedance comprises reactance mismatch that electric capacity causes and the resistance mismatch that resistance causes, and in passive filtering amplifying circuit, △ R only comprises the resistance mismatch that resistance causes, cause CMRR_impedance to be less than CMRR-R in passive filter circuit, therefore adopt passive filtering amplifying circuit effectively can improve common-mode rejection ratio.In addition, the capacity cell in passive filtering amplifying circuit only has one, does not need to consider electric capacity coupling, uses an electric capacity at least lesser than active filter circuit, simplifies circuit structure.
As a kind of possible execution mode, the operational amplifier A of this passive filter circuit also comprises for the circuit supply interface of connecting circuit supply power voltage VCC and the operational amplifier power supply interface for concatenation operation amplifier operating voltage VDD.
The embodiment of the present invention, provides a kind of passive filtering amplifying circuit, adopts symmetric circuit structure, at utmost improves the common-mode rejection ratio of amplifying circuit, adopts passive filtering, simplifies circuit structure.
Fig. 3 is the circuit diagram of the another kind of passive filtering amplifying circuit that the embodiment of the present invention provides, and as shown in Figure 3, this passive filtering amplifying circuit comprises input circuit, passive filter circuit and amplifying circuit, wherein:
Input circuit comprise positive input terminal, hold, the first resistive element R1 and the second resistive element R2, positive input terminal connects the first resistive element R1 first end, ground end connection second resistive element R2 first end, the first resistive element R1 is identical with the second resistive element R2 resistance.
Passive filter circuit comprises the first capacity cell C1, the 3rd resistive element R3 and the 4th resistive element R4; First capacity cell C1 first end connects the first resistive element R1 second end and the 3rd resistive element R3 first end of input circuit, first capacity cell C1 second end connects the second resistive element R2 second end and the 4th resistive element R4 first end of input circuit, 3rd resistive element R3 second end connects the inverting input of the operational amplifier A of amplifying circuit, 4th resistive element R4 second end connects the normal phase input end of the operational amplifier A of amplifying circuit, and the 3rd resistive element R3 is identical with the 4th resistive element R4 resistance;
Amplifying circuit comprises operational amplifier A, the 5th resistive element R5 and the 6th resistive element R6, the in-phase input end of operational amplifier A connects the 6th resistive element R6 first end, the 5th resistive element R5 is connected between the inverting input of operational amplifier A and the first output of operational amplifier A, 6th resistive element R6 second end ground connection, the 5th resistive element R5 is identical with the 6th resistive element R6 resistance.
Concrete, this passive filtering amplifying circuit adopts non-equilibrium input and Single-end output.The first resistive element R1 in input circuit and the second resistive element R2 is used for control inputs electric current, and the first resistive element R1 is identical with the second resistive element R2 resistance, adopts symmetric circuit structure; The 3rd resistive element R3 in passive filter circuit, the 4th resistive element R4 and the first capacity cell C1 corner frequency deciding passive filter circuit, the 3rd resistive element R3 is identical with the 4th resistive element R4 resistance, adopts symmetric circuit structure; Be connected the 5th resistive element R5 between the inverting input of the operational amplifier A in amplifying circuit and the first output of operational amplifier A and form feedback circuit, 6th resistive element R6 is used for the input current of control algorithm amplifier, 5th resistive element R5 is identical with the 6th resistive element R6 resistance, adopts symmetric circuit structure.
As a kind of possible execution mode, the corner frequency of this passive filtering amplifying circuit is determined by F-corner-1=1/ [2 × π × C1 × (R1//R3+R2//R4)],
Wherein, F-corner-1 is the corner frequency of passive filter circuit, and C1 is the capacitance of the first capacity cell, R1 is the resistance value of the first resistive element, R3 is the resistance value of the 3rd resistive element, and R2 is the resistance value of the second resistive element, and R4 is the resistance value of the 4th resistive element.Determine that the factor of corner frequency F-corner-1 size comprises C1, R1, R2, R3 and R4.
As a kind of possible execution mode, when the first resistive element R1 is identical with the second resistive element R2 resistance and the 3rd resistive element R3 is identical with the 4th resistive element R4 resistance, the computing formula of the corner frequency of this passive filter circuit is reduced to:
F-corner-2＝1/[2×π×C1×2×(R1//R3)]；
Wherein, F-corner-2 is the corner frequency of the passive filter circuit when the first resistive element R1 is identical with the second resistive element R2 resistance and the 3rd resistive element R3 is identical with the 4th resistive element R4 resistance, C1 is the capacitance of the first capacity cell, R1 is the resistance value of the first resistive element, and R3 is the resistance value of the 3rd resistive element.Determine that the factor of corner frequency F-corner-2 size comprises C1, R1 and R3 (or R4, because now the resistance of R3 and R4 is equal).
As a kind of possible execution mode, when the resistance of the first resistive element R1 is much larger than the resistance of described 3rd resistive element R3, the corner frequency of passive filter circuit is obtained by following formula:
F-corner-3＝1/[4×π×C1×R3]；
Wherein F-corner-3 be the resistance of the first resistive element R1 much larger than the corner frequency during resistance of the 3rd resistive element R3, R3 is the resistance value of the 3rd resistive element, and C1 is the capacitance of the first capacity cell.
It is pointed out that the resistance of the resistance of the first resistive element R1 in the embodiment of the present invention much larger than the 3rd resistive element R3 is more than five times or five times of the resistance of R3 much larger than the resistance that can be R1.
The ratio (namely F-corner-3 is divided by F-corner-2) of F-corner-3 and F-corner-2 is the 3rd resistive element R3 and the rights and interests value of the 4th resistive element R4 in passive filter circuit, and rights and interests value is more than or equal to 0.5, the upper range of rights and interests value can be infinitely close to 1.The size of rights and interests value directly reflects the 3rd resistive element R3 and the 4th resistive element R4 role size in filtering.It should be noted that, rights and interests value can be obtained by the ratio of F-corner-3 and F-corner-2, also can be obtained by F-corner-3 and the ratio of the corner frequency of surveying corner frequency or equivalent deformation circuit (increasing other components and parts on the basis of passive filter circuit C1, R3, R4 of the present invention).
Determine that the factor of corner frequency F-corner-3 size only has C1 and R3, R4 (now R3 and R4 resistance is equal), after introducing corner frequency F-corner-3, only need the capacitance size of adjustment first capacity cell C1 and the resistance size of the 3rd resistive element R3 (or R4), the corner frequency needed for adjustment that can be convenient and simple.
As a kind of possible execution mode, the common-mode rejection ratio that this passive filtering amplifying circuit is caused by impedance mismatching is determined by CMRR-R=20 × log [(1+G)/(2 × △ R/R)];
Wherein, CMRR-R is the common-mode rejection ratio caused by impedance mismatching, G is the gain of operational amplifier, G=R5/ (R1+R3), R5 is the resistance value of described 5th resistive element, and R1 is the resistance value of described 3rd resistive element, and R3 is the resistance value of described 3rd resistive element, R is normal resistance, and △ R is the absolute value of the difference of actual resistance and normal resistance.Because the nominal value of resistance and actual measured value have a certain distance, gap is less, and the permissible variation of resistance is less, the precision of resistance is higher, such as, the permissible variation of the resistance used in circuit is one thousandth, then represent that △ R/R is 0.001, the permissible variation of the resistance used in circuit is 5/10000ths, then represent that △ R/R is 0.0005, the precision of resistance is higher, and △ R/R is less, CMRR-R is larger, and the antijamming capability of circuit is stronger.
Optionally, according to active power filtering amplifying circuit, the common-mode rejection ratio that active power filtering amplifying circuit is caused by impedance mismatching is determined by CMRR_impedance=20 × log [(1+G)/(2 × Δ impedance/impedance)];
Wherein, CMRR_impedance is the common-mode rejection ratio caused by impedance mismatching, G is the gain of operational amplifier, and impedance is nominal signal source impedance values, and Δ impedance is the absolute value of the difference of actual signal source impedance values and nominal signal source impedance values.
Concrete, because the precision of current resistance can reach 0.05%, and the full accuracy of electric capacity is only about 1%, in active power filtering amplifying circuit, because Δ impedance comprises reactance mismatch that electric capacity causes and the resistance mismatch that resistance causes, and in passive filtering amplifying circuit, △ R only comprises the resistance mismatch that resistance causes, cause CMRR_impedance to be less than CMRR-R in passive filter circuit, therefore adopt passive filtering amplifying circuit effectively can improve common-mode rejection ratio.In addition, the capacity cell in passive filtering amplifying circuit only has one, does not need to consider electric capacity coupling, uses an electric capacity at least lesser than active passive filter circuit, simplifies circuit structure.
As a kind of possible execution mode, the operational amplifier A of this passive filter circuit also comprises for the circuit supply interface of connecting circuit supply power voltage VCC and the operational amplifier power supply interface for concatenation operation amplifier operating voltage VDD.
The embodiment of the present invention, provides a kind of passive filtering amplifying circuit, adopts symmetric circuit structure, at utmost improves the common-mode rejection ratio of amplifying circuit, adopts passive filtering, simplifies circuit structure.
Fig. 4 is the circuit diagram of the another kind of passive filtering amplifying circuit that the embodiment of the present invention provides, and as shown in Figure 4, this passive filtering amplifying circuit comprises input circuit, passive filter circuit and amplifying circuit, wherein:
Input circuit comprise positive input terminal, hold, the first resistive element R1 and the second resistive element R2, positive input terminal connects the first resistive element R1 first end, ground end connection second resistive element R2 first end, the first resistive element R1 is identical with the second resistive element R2 resistance.
Passive filter circuit comprises the first capacity cell C1, the 3rd resistive element R3 and the 4th resistive element R4; First capacity cell C1 first end connects the first resistive element R1 second end and the 3rd resistive element R3 first end of input circuit, first capacity cell C1 second end connects the second resistive element R2 second end and the 4th resistive element R4 first end of input circuit, 3rd resistive element R3 second end connects the inverting input of the operational amplifier A of amplifying circuit, 4th resistive element R4 second end connects the normal phase input end of the operational amplifier A of amplifying circuit, and the 3rd resistive element R3 is identical with the 4th resistive element R4 resistance;
Amplifying circuit comprises operational amplifier A, the 5th resistive element R5 and the 6th resistive element R6, the in-phase input end of operational amplifier A connects the 6th resistive element R6 first end, the 5th resistive element R5 is connected between the inverting input of operational amplifier A and the first output of operational amplifier A, second output of the 6th resistive element R6 second end concatenation operation amplifier A, the 5th resistive element R5 is identical with the 6th resistive element R6 resistance.
Concrete, this passive filtering amplifying circuit adopts non-equilibrium input and difference output.The first resistive element R1 in input circuit and the second resistive element R2 is used for control inputs electric current, and the first resistive element R1 is identical with the second resistive element R2 resistance, adopts symmetric circuit structure; The 3rd resistive element R3 in passive filter circuit, the 4th resistive element R4 and the first capacity cell C1 corner frequency deciding passive filter circuit, the 3rd resistive element R3 is identical with the 4th resistive element R4 resistance, adopts symmetric circuit structure; Be connected the 5th resistive element R5 between the inverting input of the operational amplifier A in amplifying circuit and the first output of operational amplifier A and form feedback circuit, 6th resistive element R6 is used for the input current of control algorithm amplifier, 5th resistive element R5 is identical with the 6th resistive element R6 resistance, adopts symmetric circuit structure.
As a kind of possible execution mode, the corner frequency of this passive filtering amplifying circuit is determined by F-corner-1=1/ [2 × π × C1 × (R1//R3+R2//R4)],
Wherein, F-corner-1 is the corner frequency of passive filter circuit, and C1 is the capacitance of the first capacity cell, R1 is the resistance value of the first resistive element, R3 is the resistance value of the 3rd resistive element, and R2 is the resistance value of the second resistive element, and R4 is the resistance value of the 4th resistive element.Determine that the factor of corner frequency F-corner-1 size comprises C1, R1, R2, R3 and R4.
As a kind of possible execution mode, when the first resistive element R1 is identical with the second resistive element R2 resistance and the 3rd resistive element R3 is identical with the 4th resistive element R4 resistance, the corner frequency of this passive filter circuit is reduced to:
F-corner-2＝1/[2×π×C1×2×(R1//R3)]；
Wherein, F-corner-2 is the corner frequency of the passive filter circuit when the first resistive element R1 is identical with the second resistive element R2 resistance and the 3rd resistive element R3 is identical with the 4th resistive element R4 resistance, C1 is the capacitance of the first capacity cell, R1 is the resistance value of the first resistive element, and R3 is the resistance value of the 3rd resistive element.Determine that the factor of corner frequency F-corner-2 size comprises C1, R1 and R3.
As a kind of possible execution mode, when the resistance of the first resistive element R1 is much larger than the resistance of described 3rd resistive element R3, the corner frequency of passive filter circuit is obtained by following formula:
F-corner-3＝1/[4×π×C1×R3]；
Wherein F-corner-3 be the resistance of the first resistive element R1 much larger than the corner frequency during resistance of the 3rd resistive element R3, R3 is the resistance value of the 3rd resistive element, and C1 is the capacitance of the first capacity cell.
It is pointed out that the resistance of the resistance of the first resistive element R1 in the embodiment of the present invention much larger than the 3rd resistive element R3 is more than five times or five times of the resistance of R3 much larger than the resistance that can be R1.
The ratio (namely F-corner-3 is divided by F-corner-2) of F-corner-3 and F-corner-2 is the 3rd resistive element R3 and the rights and interests value of the 4th resistive element R4 in passive filter circuit, and rights and interests value is more than or equal to 0.5, the upper range of rights and interests value can be infinitely close to 1.The size of rights and interests value directly reflects the 3rd resistive element R3 and the 4th resistive element R4 role size in filtering.It should be noted that, rights and interests value can be obtained by the ratio of F-corner-3 and F-corner-2, also can be obtained by F-corner-3 and the ratio of the corner frequency of surveying corner frequency or equivalent deformation circuit (increasing other components and parts on the basis of passive filter circuit C1, R3, R4 of the present invention).
Determine that the factor of corner frequency F-corner-3 size only has C1 and R3, R4 (now R3 and R4 resistance is equal), after introducing corner frequency F-corner-3, only need the capacitance size of adjustment first capacity cell C1 and the resistance size of the 3rd resistive element R3 (or R4), the corner frequency needed for adjustment that can be convenient and simple.As a kind of possible execution mode, the common-mode rejection ratio that this passive filtering amplifying circuit is caused by impedance mismatching is determined by CMRR-R=20 × log [(1+G)/(2 × △ R/R)].
Wherein, CMRR-R is the common-mode rejection ratio caused by impedance mismatching, G is the gain of operational amplifier, G=R5/ (R1+R3), R5 is the resistance value of described 5th resistive element, and R1 is the resistance value of described 3rd resistive element, and R3 is the resistance value of described 3rd resistive element, R is normal resistance, and △ R is the absolute value of the difference of actual resistance and normal resistance.Because the nominal value of resistance and actual measured value have a certain distance, gap is less, and the permissible variation of resistance is less, the precision of resistance is higher, such as, the permissible variation of the resistance used in circuit is one thousandth, then represent that △ R/R is 0.001, the permissible variation of the resistance used in circuit is 5/10000ths, then represent that △ R/R is 0.0005, the precision of resistance is higher, and △ R/R is less, CMRR-R is larger, and the antijamming capability of circuit is stronger.Optionally, according to active power filtering amplifying circuit, the common-mode rejection ratio that active power filtering amplifying circuit is caused by impedance mismatching is determined by CMRR_impedance=20 × log [(1+G)/(2 × Δ impedance/impedance)].
Wherein, CMRR_impedance is the common-mode rejection ratio caused by impedance mismatching, G is the gain of operational amplifier, and impedance is nominal signal source impedance values, and Δ impedance is the absolute value of the difference of actual signal source impedance values and nominal signal source impedance values.
Concrete, because the precision of current resistance can reach 0.05%, and the full accuracy of electric capacity is only about 1%, in active power filtering amplifying circuit, because Δ impedance comprises reactance mismatch that electric capacity causes and the resistance mismatch that resistance causes, and in passive filtering amplifying circuit, △ R only comprises the resistance mismatch that resistance causes, cause CMRR_impedance to be less than CMRR-R in passive filter circuit, therefore adopt passive filtering amplifying circuit effectively can improve common-mode rejection ratio.In addition, the capacity cell in passive filtering amplifying circuit only has one, does not need to consider electric capacity coupling, uses an electric capacity at least lesser than active passive filter circuit, simplifies circuit structure.
As a kind of possible execution mode, the operational amplifier A of this passive filter circuit also comprises for the circuit supply interface of connecting circuit supply power voltage VCC and the operational amplifier power supply interface for concatenation operation amplifier operating voltage VDD.
The embodiment of the present invention, provides a kind of passive filtering amplifying circuit, adopts symmetric circuit structure, at utmost improves the common-mode rejection ratio of amplifying circuit, adopts passive filtering, simplifies circuit structure.
Fig. 5 is the circuit diagram of the another kind of passive filtering amplifying circuit that the embodiment of the present invention provides, and as shown in Figure 5, this passive filtering amplifying circuit comprises input circuit, passive filter circuit and amplifying circuit, wherein:
Input circuit comprises positive input terminal, negative input end, the first resistive element R1 and the second resistive element R2, positive input terminal connects the first resistive element R1 first end, negative input end connects the second resistive element R2 first end, and the first resistive element R1 is identical with the second resistive element R2 resistance.
Passive filter circuit comprises the first capacity cell C1, the 3rd resistive element R3 and the 4th resistive element R4; First capacity cell C1 first end connects the first resistive element R1 second end and the 3rd resistive element R3 first end of input circuit, first capacity cell C1 second end connects the second resistive element R2 second end and the 4th resistive element R4 first end of input circuit, 3rd resistive element R3 second end connects the inverting input of the operational amplifier A of amplifying circuit, 4th resistive element R4 second end connects the normal phase input end of the operational amplifier A of amplifying circuit, and the 3rd resistive element R3 is identical with the 4th resistive element R4 resistance;
Amplifying circuit comprises operational amplifier A, the 5th resistive element R5 and the 6th resistive element R6, the in-phase input end of operational amplifier A connects the 6th resistive element R6 first end, the 5th resistive element R5 is connected between the inverting input of operational amplifier A and the first output of operational amplifier A, second output of the 6th resistive element R6 second end concatenation operation amplifier A, the 5th resistive element R5 is identical with the 6th resistive element R6 resistance.
Concrete, this passive filtering amplifying circuit adopts Differential Input and difference output.The first resistive element R1 in input circuit and the second resistive element R2 is used for control inputs electric current, and the first resistive element R1 is identical with the second resistive element R2 resistance, adopts symmetric circuit structure; The 3rd resistive element R3 in passive filter circuit, the 4th resistive element R4 and the first capacity cell C1 corner frequency deciding passive filter circuit, the 3rd resistive element R3 is identical with the 4th resistive element R4 resistance, adopts symmetric circuit structure; Be connected the 5th resistive element R5 between the inverting input of the operational amplifier A in amplifying circuit and the first output of operational amplifier A and form feedback circuit, 6th resistive element R6 is used for the input current of control algorithm amplifier, 5th resistive element R5 is identical with the 6th resistive element R6 resistance, adopts symmetric circuit structure.
As a kind of possible execution mode, the corner frequency of this passive filtering amplifying circuit is determined by F-corner-1=1/ [2 × π × C1 × (R1//R3+R2//R4)],
Wherein, F-corner-1 is the corner frequency of passive filter circuit, and C1 is the capacitance of the first capacity cell, R1 is the resistance value of the first resistive element, R3 is the resistance value of the 3rd resistive element, and R2 is the resistance value of the second resistive element, and R4 is the resistance value of the 4th resistive element.Determine that the factor of corner frequency F-corner-1 size comprises C1, R1, R2, R3 and R4.
As a kind of possible execution mode, when the first resistive element R1 is identical with the second resistive element R2 resistance and the 3rd resistive element R3 is identical with the 4th resistive element R4 resistance, the computing formula of the corner frequency of this passive filter circuit is reduced to:
F-corner-2＝1/[2×π×C1×2×(R1//R3)]；
Wherein, F-corner-2 is the corner frequency of the passive filter circuit when the first resistive element R1 is identical with the second resistive element R2 resistance and the 3rd resistive element R3 is identical with the 4th resistive element R4 resistance, C1 is the capacitance of the first capacity cell, R1 is the resistance value of the first resistive element, and R3 is the resistance value of the 3rd resistive element.Determine that the factor of corner frequency F-corner-2 size comprises C1, R1 and R3.
As a kind of possible execution mode, when the resistance of the first resistive element R1 is much larger than the resistance of described 3rd resistive element R3, the corner frequency of passive filter circuit is obtained by following formula:
F-corner-3＝1/[4×π×C1×R3]；
Wherein F-corner-3 be the resistance of the first resistive element R1 much larger than the corner frequency during resistance of the 3rd resistive element R3, R3 is the resistance value of the 3rd resistive element, and C1 is the capacitance of the first capacity cell.
It is to be noted, the resistance of the first resistive element R1 in the embodiment of the present invention much larger than the resistance of the 3rd resistive element R3 much larger than being more than five times or five times of the resistance of R3 for the resistance of R1, such as, can select ten times or 20 times or larger multiple according to actual needs.
The ratio (namely F-corner-3 is divided by F-corner-2) of F-corner-3 and F-corner-2 is the 3rd resistive element R3 and the rights and interests value of the 4th resistive element R4 in passive filter circuit, and rights and interests value is more than or equal to 0.5, the upper range of rights and interests value can be infinitely close to 1.The size of rights and interests value directly reflects the 3rd resistive element R3 and the 4th resistive element R4 role size in filtering.It should be noted that, rights and interests value can be obtained by the ratio of F-corner-3 and F-corner-2, also can be obtained by F-corner-3 and the ratio of the corner frequency of surveying corner frequency or equivalent deformation circuit (increasing other components and parts on the basis of passive filter circuit C1, R3, R4 of the present invention).
Determine that the factor of corner frequency F-corner-3 size only has C1 and R3, R4 (now R3 and R4 resistance is equal), after introducing corner frequency F-corner-3, only need the capacitance size of adjustment first capacity cell C1 and the resistance size of the 3rd resistive element R3 (or R4), the corner frequency needed for adjustment that can be convenient and simple.As a kind of possible execution mode, the common-mode rejection ratio that this passive filtering amplifying circuit is caused by impedance mismatching is determined by CMRR-R=20 × log [(1+G)/(2 × △ R/R)];
Wherein, CMRR-R is the common-mode rejection ratio caused by impedance mismatching, G is the gain of operational amplifier, G=R5/ (R1+R3), R5 is the resistance value of described 5th resistive element, and R1 is the resistance value of described 3rd resistive element, and R3 is the resistance value of described 3rd resistive element, R is normal resistance, and △ R is the absolute value of the difference of actual resistance and normal resistance.Because the nominal value of resistance and actual measured value have a certain distance, gap is less, and the permissible variation of resistance is less, the precision of resistance is higher, such as, the permissible variation of the resistance used in circuit is one thousandth, then represent that △ R/R is 0.001, the permissible variation of the resistance used in circuit is 5/10000ths, then represent that △ R/R is 0.0005, the precision of resistance is higher, and △ R/R is less, CMRR-R is larger, and the antijamming capability of circuit is stronger.
Optionally, according to active power filtering amplifying circuit, the common-mode rejection ratio that active power filtering amplifying circuit is caused by impedance mismatching is determined by CMRR_impedance=20 × log [(1+G)/(2 × Δ impedance/impedance)];
Wherein, CMRR_impedance is the common-mode rejection ratio caused by impedance mismatching, G is the gain of operational amplifier, and impedance is nominal signal source impedance values, and Δ impedance is the absolute value of the difference of actual signal source impedance values and nominal signal source impedance values.
Concrete, because the precision of current resistance can reach 0.05%, and the full accuracy of electric capacity is only about 1%, in active power filtering amplifying circuit, because Δ impedance comprises reactance mismatch that electric capacity causes and the resistance mismatch that resistance causes, and in passive filtering amplifying circuit, △ R only comprises the resistance mismatch that resistance causes, cause CMRR_impedance to be less than CMRR-R in passive filter circuit, therefore adopt passive filtering amplifying circuit effectively can improve common-mode rejection ratio.In addition, the capacity cell in passive filtering amplifying circuit only has one, does not need to consider electric capacity coupling, uses an electric capacity at least lesser than active filter circuit, simplifies circuit structure.
As a kind of possible execution mode, the operational amplifier A of this passive filter circuit also comprises for the circuit supply interface of connecting circuit supply power voltage VCC and the operational amplifier power supply interface for concatenation operation amplifier operating voltage VDD.
The embodiment of the present invention, provides a kind of passive filtering amplifying circuit, adopts symmetric circuit structure, at utmost improves the common-mode rejection ratio of amplifying circuit, adopts passive filtering, simplifies circuit structure.
Above disclosedly be only present pre-ferred embodiments, certainly can not limit the interest field of the present invention with this, therefore according to the equivalent variations that the claims in the present invention are done, still belong to the scope that the present invention is contained.
Claims (10)
1. a passive filtering amplifying circuit, is characterized in that, comprising: passive filter circuit and amplifying circuit, wherein:
Described passive filter circuit comprises the first capacity cell C1, the 3rd resistive element R3 and the 4th resistive element R4, described first capacity cell C1 first end connects described 3rd resistive element R3 first end, and described first capacity cell C1 second end connects described 4th resistive element R4 first end;
Described amplifying circuit comprises operational amplifier A, the 5th resistive element R5 and the 6th resistive element R6, the in-phase input end of described operational amplifier A connects described 6th resistive element R6 first end, described 5th resistive element R5 is connected, described 6th resistive element R6 second end ground connection or connect the second output of described operational amplifier A between the inverting input of described operational amplifier A and the first output of described operational amplifier A;
Described 3rd resistive element R3 second end of described passive filter circuit connects the inverting input of the described operational amplifier A of described amplifying circuit, and described 4th resistive element R4 second end of described passive filter circuit connects the normal phase input end of the described operational amplifier A of described amplifying circuit.
2. passive filtering amplifying circuit according to claim 1, is characterized in that, described passive filtering amplifying circuit also comprises input circuit, wherein:
Described input circuit comprises positive input terminal, negative input end or ground end, described first resistive element R1 and described second resistive element R2, described positive input terminal connects described first resistive element R1 first end, and described negative input end or ground end connect described second resistive element R2 first end.
3. passive filtering amplifying circuit according to claim 2, is characterized in that, the connected mode of described input circuit and described passive filter circuit is specially:
First resistive element R1 second end of described input circuit is connected with the first capacity cell C1 first end of described passive filter circuit, and the second resistive element R2 second end of described input circuit is connected with the first capacity cell C1 second end of described passive filter circuit.
4. passive filtering amplifying circuit according to claim 3, it is characterized in that, described 3rd resistive element R3 is identical with described 4th resistive element R4 resistance, described 5th resistive element R5 is identical with described 6th resistive element R6 resistance, and described first resistive element R1 is identical with described second resistive element R2 resistance.
5. passive filtering amplifying circuit according to claim 4, it is characterized in that, described operational amplifier A also comprises for the circuit supply interface of connecting circuit supply power voltage VCC and the operational amplifier power supply interface for being connected described operational amplifier A operating voltage VDD.
6. the passive filtering amplifying circuit according to any one of claim 2-5, is characterized in that, the common-mode rejection ratio of described amplifying circuit is obtained by following formula:
CMRR-R＝20×log[(1+G)/(2×△R/R)]；
Wherein, CMRR-R is the common-mode rejection ratio caused by impedance mismatching, G is the gain of described operational amplifier A, G=R5/ (R1+R3), R5 is the resistance value of described 5th resistive element, and R1 is the resistance value of described first resistive element, and R3 is the resistance value of described 3rd resistive element, R is normal resistance, and △ R is the absolute value of the difference of actual resistance and described normal resistance.
7. the passive filtering amplifying circuit according to any one of claim 2-5, is characterized in that, the corner frequency of described passive filter circuit is obtained by following formula:
F-corner-1＝1/[2×π×C1×(R1//R3+R2//R4)]；
Wherein, F-corner-1 is the corner frequency of described passive filter circuit, C1 is the capacitance of described first capacity cell, R1 is the resistance value of described first resistive element, R3 is the resistance value of described 3rd resistive element, R2 is the resistance value of described second resistive element, and R4 is the resistance value of described 4th resistive element.
8. the passive filtering amplifying circuit according to claim 4 or 5, is characterized in that, the corner frequency of described passive filter circuit is obtained by following formula:
F-corner-2＝1/[2×π×C1×2×(R1//R3)]；
Wherein, F-corner-2 is the corner frequency of the described passive filter circuit when described first resistive element R1 is identical with described second resistive element R2 resistance and described 3rd resistive element R3 is identical with described 4th resistive element R4 resistance, C1 is the capacitance of described first capacity cell, R1 is the resistance value of described first resistive element, and R3 is the resistance value of described 3rd resistive element.
9. passive filtering amplifying circuit according to claim 8, is characterized in that, when the resistance of described first resistive element R1 is much larger than the resistance of described 3rd resistive element R3, the corner frequency of described passive filter circuit is obtained by following formula:
F-corner-3＝1/[4×π×C1×R3]；
Wherein F-corner-3 be the resistance of described first resistive element R1 much larger than the corner frequency during resistance of described 3rd resistive element R3, R3 is the resistance value of described 3rd resistive element, and C1 is the capacitance of described first capacity cell.
10. passive filtering amplifying circuit according to claim 9, it is characterized in that, the ratio of described F-corner-3 and F-corner-2 is described 3rd resistive element R3 and the rights and interests value of described 4th resistive element R4 in described passive filter circuit, and described rights and interests value is more than or equal to 0.5.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105628156A (en) * | 2015-12-22 | 2016-06-01 | 无锡信大气象传感网科技有限公司 | Amplifying and filtering circuit-based vehicle axle load monitoring system |
| CN107645286A (en) * | 2017-08-30 | 2018-01-30 | 南京理工大学 | A kind of C-band distributed ultra wide-band filtered power amplification module |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6091292A (en) * | 1998-03-31 | 2000-07-18 | Matsushita Electric Industrial Co., Ltd. | High efficiency power amplifying apparatus |
| US20090091403A1 (en) * | 2007-10-08 | 2009-04-09 | Markus Hemmerlein | Contactless transmission of a differential signal between a transmitter and a receiver |
| CN101577519A (en) * | 2009-06-12 | 2009-11-11 | 上海微电子装备有限公司 | Linear motor driver |
| CN201854398U (en) * | 2010-11-24 | 2011-06-01 | 于丽丽 | Wireless earphone for foreign language listening teaching |
-
2014
- 2014-12-05 CN CN201410736867.3A patent/CN104639077B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6091292A (en) * | 1998-03-31 | 2000-07-18 | Matsushita Electric Industrial Co., Ltd. | High efficiency power amplifying apparatus |
| US20090091403A1 (en) * | 2007-10-08 | 2009-04-09 | Markus Hemmerlein | Contactless transmission of a differential signal between a transmitter and a receiver |
| CN101577519A (en) * | 2009-06-12 | 2009-11-11 | 上海微电子装备有限公司 | Linear motor driver |
| CN201854398U (en) * | 2010-11-24 | 2011-06-01 | 于丽丽 | Wireless earphone for foreign language listening teaching |
Non-Patent Citations (1)
| Title |
|---|
| 白金蕾: "魅族发布旗舰手机MX4Pro", 《新浪新闻中心 中国青年报：HTTP://NEWS.SINA.COM.CN/O/2014-11-27/064031209636.SHTML》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105628156A (en) * | 2015-12-22 | 2016-06-01 | 无锡信大气象传感网科技有限公司 | Amplifying and filtering circuit-based vehicle axle load monitoring system |
| CN107645286A (en) * | 2017-08-30 | 2018-01-30 | 南京理工大学 | A kind of C-band distributed ultra wide-band filtered power amplification module |
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