CN102195661B - Signal processing apparatus and method for setting filtering characteristic of the same - Google Patents
Signal processing apparatus and method for setting filtering characteristic of the same Download PDFInfo
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- CN102195661B CN102195661B CN201110058620.7A CN201110058620A CN102195661B CN 102195661 B CN102195661 B CN 102195661B CN 201110058620 A CN201110058620 A CN 201110058620A CN 102195661 B CN102195661 B CN 102195661B
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Abstract
The present invention provides a signal processing apparatus and a method for setting a filtering characteristic of the same. The method for setting the filtering characteristic of the signal processing apparatus comprises the following steps: configuring a first signal processing path; and configuring a second signal processing path. When an input signal received at the signal input port includes a first signal component with a first frequency and a second signal component with a second frequency, most of the first signal component is processed by the first signal processing path, and most of the second signal component is processed by the second signal processing path. The signal processing apparatus and the method for setting the filtering characteristic of the signal processing apparatus can effectively filter the unwanted signal component.
Description
Technical field
The present invention has the filtering about a kind of interference signal (blocker signal), and is particularly to one and includes signal processing apparatus of frequency selective circuits (it has mixer module to control the frequency response of this frequency selective circuits) and associated method.
Background technology
Generally speaking, wireless communication receiver needs to possess the ability detecting small-signal in desired frequency band, furthermore, wireless communication receiver needs to detect (in-band) signal in band at the band that existence is very strong under outer (out-of-band, OOB) signal (i.e. interference signal) situation.For the problem that very strong interference signal causes, modal solution is the input band pass filter with high quality factor (quality factor) being applied to wireless communication receiver, for example, surface acoustic wave (surface acoustic wave, SAW) filter may be utilized to provide desired decay for OOB interference signal, but, use surface acoustic wave filter often to cause the significantly increase of hardware cost and board area.
Therefore, pole needs one ball bearing made using framework can be used effectively to decay or eliminate the innovative design of undesired signal component (such as interference signal).
Summary of the invention
In view of this, spy provides following examples:
According to embodiments of the invention, disclose one and include signal processing apparatus of frequency selective circuits (it has mixer module to control the frequency response of this frequency selective circuits) and associated method, to solve the problem.
According to the first level of the present invention, it discloses a kind of signal processing apparatus including frequency selective circuits and signal processing circuit.This frequency selective circuits includes signal input port, the first signal output port, secondary signal output port and frequency response and controls block.This frequency response controls block and is electrically connected between this secondary signal output port and the signal path between this signal input port and this first signal output port, and for carrying out control frequency response according to the frequency of oscillator signal.This signal processing circuit is electrically connected on this frequency selective circuits, and the input signal received for the treatment of this signal input port and process multiple output signals that this first, second signal output port produces respectively.
According to the second aspect of the present invention, it discloses a kind of signal processing apparatus including frequency selective circuits and signal processing circuit.This frequency selective circuits includes signal input port, the first signal output port, secondary signal output port and frequency response and controls block.This frequency response controls block and includes the first mixer module and the first filter module.This first mixer module has the first port, the second port and local oscillated signal input port, wherein this first port is electrically connected on the signal path between this signal input port and this first signal output port, and the first local oscillated signal that this first mixer module receives according to this local oscillated signal input port operates.This first filter module is electrically connected between this second port of this secondary signal output port and this first mixer module.This signal processing circuit is electrically connected on this frequency selective circuits, and includes the first circuit module and second circuit module.This first circuit module is the input signal received for the treatment of this signal input port.This second circuit module is the multiple output signals produced respectively for the treatment of this first, second signal output port.
According to third layer face of the present invention, it discloses a kind of method of filtering characteristic of setting signal processing unit, include following steps: the configuration setting the first signal processing path, to make this first signal processing path, there is the first filtering characteristic, wherein this first signal processing path is positioned among this signal processing apparatus, and is electrically connected to the signal input port of this signal processing apparatus; And the configuration in setting secondary signal process path, to make this secondary signal process path, there is the second filtering characteristic differing from this first filtering characteristic, wherein this secondary signal process path is positioned among this signal processing apparatus, and is electrically connected between this signal input port and this first signal processing path.
The present invention utilizes mixer module to carry out the frequency response of control frequency selective circuit, its framework is simple and can the undesired signal component of filtering (such as interference signal), moreover, by controlling the configuration in unlike signal process path (such as the first signal processing path and be provided with the secondary signal process path of frequency selective circuits), the object of signal shunting is reached to make it have different filtering characteristics respectively, thus, when the input signal that signal input port receives comprises secondary signal composition (such as the undesired signal component) of first signal component (signal component such as wanted) of first frequency and second frequency, in first signal component, major part can handled by the first signal processing path, and major part can handled by this secondary signal process path in this secondary signal composition, therefore, the signal component that major part is wanted will be retained, and most of undesired signal component will by filtering.
Accompanying drawing explanation
Fig. 1 is the schematic diagram of the first embodiment of frequency selective circuits of the present invention.
Fig. 2 is the schematic diagram of the example of the impedance response of the filter module shown in Fig. 1.
Fig. 3 controls the schematic diagram of the example of the input impedance response of block for the frequency response shown in Fig. 1.
Fig. 4 is the schematic diagram of the frequency response of the frequency selective circuits shown in Fig. 1.
Fig. 5 is the schematic diagram of the second embodiment of frequency selective circuits of the present invention.
Fig. 6 is the summary block schematic diagram of the signal processing apparatus with frequency selective circuits.
Fig. 7 is for adopting the schematic diagram of the example of the receiver of the hardware configuration shown in Fig. 6.
Fig. 8 is for adopting the schematic diagram of another example of the receiver of the hardware configuration shown in Fig. 6.
Embodiment
Some vocabulary is employed to censure specific element in the middle of specification and claims.Person of ordinary skill in the field should understand, and hardware manufacturer may call same element with different nouns.This specification and claims book not using the difference of title as the mode of distinguish one element from another, but using element difference functionally as the criterion distinguished." comprising " mentioned in specification and claim is in the whole text an open term, therefore should be construed to " comprise but be not limited to ".In addition, " couple " word comprise directly any at this and be indirectly electrically connected means.Therefore, if describe first device in literary composition to be coupled to the second device, then represent first device and can directly be electrically connected in the second device, or be indirectly electrically connected to the second device through other device or connection means.
Refer to Fig. 1, Fig. 1 is the schematic diagram of the first embodiment of frequency selective circuits of the present invention.In the present embodiment, frequency selective circuits (frequency-selective circuit) 100 includes (but being not limited to) signal input port 102, first signal output port 104, secondary signal output port 116 and frequency response control block (frequency response control block) 106.Signal input port 102 is the input signal S_IN for receive frequency selective circuit 100.First signal output port 104 is electrically connected on signal input port 102 via signal path 108, in addition, the first signal output port 104 and secondary signal output port 116 be respectively used to transmitted frequency selective circuit 100 multiple S_OUT_1 and S_OUT_2 that output signal to other circuit.In the present embodiment, it is for the frequency response on control signal path 108 that frequency response controls block 106, therefore, frequency response controls the oscillator module 114 that block 106 includes (but being not limited to) mixer module 110, filter module 112 and inessential (optional).Mixer module 110 has the first port P_IN, the second port P_OUT and local oscillated signal input port P_LO, wherein the first port P_IN is electrically connected to signal path 108, second port P_OUT is electrically connected to filter module 112, and local oscillated signal input port P_LO is electrically connected to oscillator module 114 (non-essential).The local oscillated signal input S that mixer module 110 receives based on local oscillated signal input port P_LO
lOoperate, and the frequency response of signal path 108 can input S by local oscillated signal
lOfrequency control.About filter module 112, it is electrically connected between the second port P_OUT of mixer module 110 and the secondary signal output port 116 of frequency selective circuits 100.In a design example, mixer module 110 can use passive frequency mixer (passive mixer) to carry out implementation in addition, and filter module 110 can use low pass filter to carry out implementation in addition, but, this is only as the object that example illustrates, for example, in another design example, based on the consideration in actual design, mixer module 110 can adopt active mixer device (active mixer) and/or filter module 112 can adopt other filter configuration (such as band pass filter).
Oscillator module 114 is electrically connected to mixer module 110, and for generation of local oscillated signal input S
lOto mixer module 110.For example (restriction of this non-invention), oscillator module 114 can adopt frequency eliminator (frequency divider) and controlled oscillator processed (such as voltage controlled oscillator (voltage-controlled oscillator, VCO) implementation in addition) is carried out, wherein this voltage controlled oscillator produces oscillator signal, and this frequency eliminator carries out frequency elimination to this oscillator signal and exports the local oscillated signal input S with wanted frequency
lO; In another embodiment, oscillator module 114 can adopt phase-locked loop (phase-locked loop, PLL) or quartz (controlled) oscillator to carry out implementation in addition.Moreover above-mentioned oscillator module 114 also can be used for directly producing the local oscillated signal input S with fixing local oscillating frequency
lO, or produce local oscillated signal input S by fine setting (fine tuning) local oscillating frequency
lO.
Please note, the oscillator module 114 be arranged in frequency response control block 100 is non-essential assemblies, that is, having according to the application-specific of frequency selective circuits 100 frequency source be arranged at outside frequency selective circuits 100 provides to can be used as a desired local oscillated signal input S
lOfrequency signal, then the oscillator module 114 shown in Fig. 1 just can omit.The running of frequency selective circuits 100 will be specified in down.
See also Fig. 2 and Fig. 3.Fig. 2 is the schematic diagram of the example of the impedance response 202 of the filter module 112 shown in Fig. 1, and Fig. 3 controls the schematic diagram of the example of the input impedance response 302 of block 106 for the frequency response shown in Fig. 1.The frequency response of the impedance of filter module (such as low pass filter) 112 can by inputting S based on local oscillated signal
lOcarry out the mixer module (such as passive frequency mixer) 110 that operates and be transferred to local oscillated signal input S
lOfrequency f
lOas shown in characteristic curve 302 (it represents input impedance response that frequency response controls block 106), frequency response controls the input impedance response (i.e. the first port P_IN of self-mixing device module 110 see into the frequency response of input impedance) of block 106 at first frequency f
1there is the first resistance value Z
1and at second frequency f
2there is one second resistance value Z
2, wherein first frequency f
1s is inputted with local oscillated signal
lOfrequency f
lObetween frequency offset be less than second frequency f
2s is inputted with local oscillated signal
lOfrequency f
lObetween frequency offset, and the first resistance value Z
1be greater than the second resistance value Z
2.Further, the impedance response of the filter module 122 representated by characteristic curve 202 according to Fig. 2, frequency response controls the input impedance response of block 106 at local oscillated signal input S
lOfrequency f
lOupper meeting has maximum resistance value, therefore, when the frequency of the signal component transmitted via signal path 108 inputs S away from local oscillated signal
lOfrequency f
lOtime, then frequency response controls block 106 and can present a less input impedance at the first port P_IN of mixer module 110, and therefore, the part or all of electric current of this signal component just can be directed and flow into frequency response and control block 106.On the other hand, as the frequency approach local oscillated signal input S of the signal component transmitted via signal path 108
lOfrequency f
lOtime, then frequency response controls block 106 and can present a larger input impedance at the first port P_IN of mixer module 110, and therefore, the major part of this signal component or whole electric currents just can arrive the first signal output port 104.
Based on above-mentioned observation, frequency response controls block 106 and can be used for decaying significantly or fully stopping undesired signal component in input signal S_IN, and allows the signal component wanted in input signal S_IN to arrive the first signal output port 104 at slight fading or without any when decay.For example, the input signal S_IN that signal input port 102 receives comprises and has first frequency f
1the first signal component and there is second frequency f
2secondary signal composition, as previously mentioned, first frequency f
1s is inputted with local oscillated signal
lOfrequency f
lObetween frequency offset be less than second frequency f
2s is inputted with local oscillated signal
lOfrequency f
lObetween frequency offset, therefore, frequency response controls attenuation that block 106 puts on secondary signal composition and just can be greater than frequency response and control the attenuation that block 106 puts on the first signal component.
Refer to Fig. 4, Fig. 4 is the schematic diagram of the frequency response of the frequency selective circuits 100 shown in Fig. 1.Shown by characteristic curve 314 is omit frequency response when frequency response shown in Fig. 1 controls block 106, and shown by characteristic curve 312 is the frequency response that the frequency response shown in Fig. 1 controls when block 106 is used and is connected to signal path 108 with parallel way.The frequency response with impedance response 302 controls block 106 will cause frequency selective circuits 100 to have the frequency response 312 shown in Fig. 4, and as seen from the figure, the frequency response 312 of frequency selective circuits 100 is at first frequency f
1there is the first gain G
1and at second frequency f
2there is the second gain G
2, as previously mentioned, first frequency f
1s is inputted with local oscillated signal
lOfrequency f
lObetween frequency offset be less than second frequency f
2s is inputted with local oscillated signal
lOfrequency f
lObetween frequency offset, therefore, frequency response controls block 106 and puts on and has second frequency f
2the attenuation of secondary signal composition will be greater than frequency response and control block 106 and put on there is first frequency f
1the attenuation of the first signal component, thus, the first gain G
1just the second gain G can be greater than
2.In this embodiment, the frequency response of frequency selective circuits 100 inputs S in local oscillated signal
lOfrequency f
lOmaximum gain can be had, further, as shown in Figure 4, owing to can present a maximum input impedance at the first port P_IN of mixer module 110, the frequency response in the present embodiment controls block 106 can't equal local oscillated signal input S to frequency
lOfrequency f
lOsignal component apply any decay.
Please note, characteristic curve shown in Fig. 2, Fig. 3 and Fig. 4 is only as the object that example illustrates, for example, by suitably adjust filter module 112 change filter module 112 impedance response and/or control a frequency source (such as non-essential oscillator module 114) change be supplied to mixer module 110 local oscillated signal input S
lOfrequency f
lO, the just frequency response of adjustable frequency selective circuit 100.
As shown in Figure 1, frequency selective circuits 100 has single ended configuration to meet the demand of single-ended applications, but disclosed frequency selective circuits also can adopt differential configuration to meet the demand of differential applications.Refer to Fig. 5, Fig. 5 is the schematic diagram of the second embodiment of frequency selective circuits of the present invention.In the present embodiment, frequency selective circuits 400 includes (but being not limited to) signal input port 402, first signal output port 404, secondary signal output port 416 and frequency response control block 406.Signal input port 402 is for receiving input signal S_IN (its be comprise differential wave that the first input IN+ and second inputs IN-to), and has first input end 401_1 and the second input 401_2 and input IN-to receive the first input IN+ and second respectively.First signal output port 404 is electrically connected on signal input port 402 through signal path 408 (it comprises the first path 407_1 and the second path 407_2), and the first signal output port 404 and secondary signal output port 416 are respectively used to transmit multiplely output signal S_OUT_1 and S_OUT_2, wherein each output signal is differential wave pair, further, first signal output port 404 has the first output 403_1 and the second output 403_2 and exports OUT1-to export the first output OUT1+ and second respectively, in addition, secondary signal output port 416 has the first output 417_1 and the second output 417_2 and exports OUT2-to export the first output OUT2+ and second respectively.Similarly, frequency response control block 406 is the frequency responses for control signal path 408, therefore, frequency response control block 406 includes (but being not limited to) mixer module 410, filter module 412 and non-essential oscillator module 414.For the frequency selective circuits 400 operated under differential mode, mixer module 410 can comprise the first port (it has first input end P_IN+ and the second input P_IN-), the second port (it has the first output P_OUT+ and the second output P_OUT-) and local oscillated signal input port (it has the first local oscillated signal input P_LO+ and the second local oscillated signal input P_LO-).
For example (restriction of this non-invention), mixer module 410 can use two passive frequency mixers or two active mixer devices to carry out implementation in addition, filter module 412 can use two low pass filters to carry out implementation in addition, and frequency source (such as non-essential oscillator module 414) can provide local oscillated signal to input (it includes the first local oscillated signal S_LO+ and the second local oscillated signal S_LO-, is supplied to two frequency mixers in mixer module 410 respectively).First local oscillated signal S_LO+ and the second local oscillated signal S_LO-has same frequency, but but has different phase places, for example, has the phase difference of 90 degree between the first local oscillated signal S_LO+ and the second local oscillated signal S_LO-.Due to skilled persons will read above-mentioned for have single ended configuration frequency selective circuits 100 paragraph after can understand the operation of the frequency selective circuits 400 with differential configuration easily, therefore further illustrating of related frequency selective circuit 400 does not just separately repeat at this.
Refer to Fig. 6, Fig. 6 is the summary block schematic diagram of the signal processing apparatus with frequency selective circuits.Above-mentioned frequency selective circuits can be used in any needs in the application of frequency selectivity signal path.As shown in Figure 6, signal processing apparatus 600 has frequency selective circuits 100/400 and arranges wherein to provide signal path 108/408, wherein signal path 108/408 has selectivity for frequency, in addition, signal processing apparatus 600 separately has signal processing circuit 602, and it comprises the first circuit module 604 and second circuit module 606.First circuit module 604 is electrically connected to the signal input port 102/402 of frequency selective circuits 100/400, and for the treatment of input signal S_IN, and second circuit module 606 is electrically connected to the first signal output port 104/404 and the secondary signal output port 116/416 of frequency selective circuits 100/400, and for the treatment of multiple output signal S_OUT_1 and S_OUT_2.
In one embodiment, the signal processing apparatus 600 shown in Fig. 6 can be one to be had frequency selective circuits 100/400 and integrates receiver wherein.Refer to Fig. 7, Fig. 7 is for adopting the schematic diagram of the example of the receiver of the hardware configuration shown in Fig. 6.Receiver 1400 comprises amplified signal level (signal amplification stage) 1402, frequency reducing level (down-conversion stage) 1404 and frequency selective circuits 1406.Signal processing circuit 602 shown in Fig. 6 is realized by including the receiving circuit 1401 of amplified signal level 1402 with frequency reducing level 1404, and as shown in the figure, first circuit module 604 is realized by amplified signal level 1402, and second circuit module 606 is realized by frequency reducing level 1404.Receiving circuit 1401 can adopt any receiver architecture to be realized, and for example, in the present embodiment, amplified signal level 1402 includes amplifier 1412, such as low noise amplifier (low-noise amplifier, LNA); Frequency reducing level 1404 includes frequency mixer (such as passive frequency mixer) 1414, filter (such as low pass filter 1416), frequency source 1415 and turns impedance amplifier (transimpedance amplifier, TIA) 1417; And frequency selective circuits 1406 includes frequency response control block 1425, it has at least one frequency mixer (such as passive frequency mixer) 1424 and filter (such as low pass filter 1426).Frequency source 1415 can adopt controlled oscillator processed (such as VCO) and frequency eliminator to be realized.In one example, share due to both frequency mixers 1424 and 1414 the same local oscillated signal produced by frequency source 1415 to input, therefore above-mentioned non-essential oscillator module just can omit, but, in another embodiment, the oscillator module (the non-essential oscillator module 114 such as shown in Fig. 1) that the local oscillated signal input needed for frequency mixer 1424 then can be comprised by the frequency response control block 1425 of frequency selective circuits 1406 is supplied.In brief, when with the local oscillated signal needed for frequency mixer 1414, the local oscillated signal input needed for frequency mixer 1424 inputs that in by frequency reducing level 1404, same frequency source is produced, both can have identical frequency, or, when the local oscillated signal input needed for frequency mixer 1424 and the local oscillated signal needed for frequency mixer 1414 input frequency sources different in respectively by frequency reducing level 1404 and frequency selective network 1406 produced time, both then can have different frequencies.
Ideally, in input signal, all undesired signal components (such as out of band signal/interference signal) should be wanted directed and flow through the signal path at frequency mixer 1424 and low pass filter 1426 place, and all signal components (such as inband signaling) wanted should be wanted directed and flow through the signal path at frequency mixer 1414 and low pass filter 1416 place in input signal, and according to the frequency selective characteristic shown in Fig. 2 and Fig. 3, the frequency selective circuits 1406 with frequency mixer 1424 and low pass filter 1426 can interference signal on deamplification path, and then promote the linearity of receiving circuit 1401.But, imperfect due to circuit unit itself, the Part I of the electric current corresponding to undesired signal component may flow through a signal path, and the Part II of electric current corresponding to undesired signal component may flow through another signal path; Similarly, the Part I of the electric current corresponding to the signal component wanted may flow through a signal path, and the Part II of electric current corresponding to the signal component wanted may flow through another signal path, therefore, concept of the present invention is the signal path allowing most of undesired signal component (such as out of band signal/interference signal) in input signal flow through frequency mixer 1424 and low pass filter 1426 place, and the signal component allowing major part in input signal want flows through the signal path at frequency mixer 1414 and low pass filter 1416 place.Moreover, as shown in Figure 7, the input port P1 of low pass filter 1416 is electrically connected to the frequency mixer 1414 in the secondary signal output port 1423 of frequency selective circuits 1406 and frequency reducing level 1404, so the output of frequency selective circuits 1406 can be fed into frequency reducing level 1404 via secondary signal output port 1423.Although the one part of current of the signal component wanted can flow through frequency selective circuits 1406, but, when selective circuit 1406 filters the signal component of this one part of current corresponding, only can apply the decay of very little (negligible) or not apply any decay and the signal component of bypass this one part of current corresponding, therefore, by the signal syntheses of frequency mixer 1414 with the output of low pass filter 1426, composite signal (combined signal) on the input port of low pass filter 1416 can have the very little interference that caused by undesired signal component or not have any interference caused by undesired signal component, therefore make the signal component wanted only have very little Signal Degrade or any Signal Degrade can not be had.
As mentioned above, the combination of frequency mixer 1424 and low pass filter 1426 can control/adjust the frequency response between signal input port 1420 and the first signal output port 1422 on signal path, therefore, frequency reducing level 1404 should suitably design with the assembly in frequency selective circuits 1406, to reach allow most of undesired signal component be directed to object that frequency selective circuits 1406 and the signal component that allows major part want are directed to frequency reducing level 1404.In the present embodiment, low pass filter 1426 comprises the first resistance R1 and the first electric capacity C1, and low pass filter 1416 comprises the second resistance R2 and the second electric capacity C2, please note, the resistance value of the first resistance R1 is the resistance value being specially designed to be greater than the second resistance R2, and first the capacitance of electric capacity C1 be the capacitance being specially designed to be greater than the second electric capacity C2, for example, but not restriction of the present invention, the resistance value of the first resistance R1 can be 800 Ω, the resistance value of the second resistance R2 can be 100 Ω, the capacitance of the first electric capacity C1 can be 300pF, and second the capacitance of electric capacity C2 can be 150pF, thus, the corner frequency (corner frequency) of low pass filter 1426 is just similar to 0.3MHz and can levels off to direct current frequency (DC frequency), the corner frequency of low pass filter 1416 is then similar to 5.3MHz and can away from direct current frequency.
If directly frequency reducing receiver (direct conversion receiver, DCR) framework is used, the signal component then wanted in input signal directly will be downconverted to direct current frequency, and in input signal, undesired signal component (such as interference signal) then can by the frequency be directly downconverted to far above direct current frequency.For being positioned at the signal component that direct current frequency is wanted, resistance value due to the first resistance R1 is greater than the resistance value of the second resistance R2, therefore low pass filter 1416 equiva lent impedance seen by the signal component wanted will be less than low pass filter 1426 equiva lent impedance seen by the signal component wanted, so the signal component that major part is wanted will be directed to frequency reducing level 1404.
For being positioned at far above the undesired signal component in the frequency of direct current frequency, capacitance due to the first electric capacity C1 is greater than the capacitance of the second electric capacity C2, therefore low pass filter 1426 equiva lent impedance seen by undesired signal component will be less than low pass filter 1416 equiva lent impedance seen by undesired signal component, so most of undesired signal component will be directed to frequency selective circuits 1406.
Moreover, in order to further promote frequency selectivity, the size of frequency mixer 1414 can specially be designed to much smaller than frequency mixer 1414 1424 size, in other words, the conduction resistance value (turn-on resistance) of frequency mixer 1414 will be greater than the conduction resistance value of frequency mixer 1424, for example, but not restriction of the present invention, the conduction resistance value of frequency mixer 1414 can be 28 Ω, it is much smaller than the resistance value of the second resistance R2, and the conduction resistance value of frequency mixer 1424 can be 7 Ω, it is much smaller than the resistance value of the first resistance R1, therefore, although the conduction resistance value of frequency mixer 1414 can be greater than the conduction resistance value of frequency mixer 1424 because of the less frequency mixer size of frequency mixer 1414 itself, but the signal component that in input signal, major part is wanted still can via handled by frequency reducing level 1404, chief reason is that the flow direction of the electric current of the signal component wanted determined by the resistance value of the first resistance R1 and the second resistance R2.But the conduction resistance value due to frequency mixer 1424 is less than the conduction resistance value of frequency mixer 1414, therefore signal component undesired in input signal still can be contributed to guide to frequency selective circuits 1406 to carry out further signal transacting.Note that the corner frequency due to low pass filter 1426 is specially designed near direct current frequency, therefore the undesired signal component guiding to frequency selective circuits 1406 can by complete filtering.
In brief, for inband signaling (signal component namely wanted), it can be shunted at the electric current at signal input port 1420 place and produces the first electric current of the signal path flowing through frequency selective circuits 1406 place respectively and flow through second electric current of another signal path at frequency reducing level 1404 place, please note, the input impedance of the frequency selective circuits 1406 seen from signal input port 1420 due to inband signaling (signal component namely wanted) is the input impedance being designed to the frequency reducing level 1404 seen from signal input port 1420 much larger than inband signaling (signal component namely wanted), therefore the second electric current will much larger than the first electric current, in addition, because frequency selective circuits 1406 is the signal components belonging to out of band signal (i.e. undesired interference signal) for filtering, therefore, the first electric current flowing through frequency selective circuits 1406 still can continue the signal component carrying inband signaling, export with the smear of frequency mixer 1414 (it receives the second electric current) more afterwards and combine, thus, under the receiver architecture shown in Fig. 7, in inband signaling, most signal component will be retained.
For out of band signal (i.e. undesired interference signal), it also can be shunted at the electric current at signal input port 1420 place and produces the first electric current of the signal path flowing through frequency selective circuits 1406 place respectively and flow through second electric current of another signal path at frequency reducing level 1404 place, please note, the input impedance of the frequency reducing level 1404 seen from signal input port 1420 due to out of band signal is the input impedance being designed to the frequency selective circuits 1406 seen much larger than out of band signal from signal input port 1420, therefore the first electric current will much larger than the second electric current, because frequency selective circuits 1406 is the signal components belonging to out of band signal (i.e. undesired interference signal) for filtering, therefore, under the receiver architecture shown in Fig. 7, in out of band signal, most signal component will by filtering.
Although low pass filter 1416 makes its corner frequency (such as 5.3MHz) far above the corner frequency (such as 0.3MHz) of low pass filter 1426, but low pass filter 1416 itself still can filtering be any has the undesired signal component of frequency higher than its corner frequency, and the L that effectively decays
rej (dB)following equation can be used simply to be represented:
Wherein Z
mrepresent the input impedance of the signal path at frequency reducing level 1404 place, Z
srepresent the input impedance of the signal path at frequency selective circuits 1406 place, f represents the deviation frequency (blocker offset frequency) of interference signal itself, and f
c1represent the corner frequency of low pass filter 1416.
In embodiments of the present invention, each filter in low pass filter 1416 and 1426 can use current-mode (current-mode) low pass filter to carry out implementation to perform the filtering of interference signal, therefore, turn the output port P2 that impedance amplifier 1417 just can be coupled to low pass filter 1416, be converted to voltage signal to carry out further signal transacting to be exported by the electric current of low pass filter 1416.
When there is no undesired signal component (such as out of band signal/interference signal) in the input signal that signal input port 1420 receives, because the first resistance R1 in low pass filter 1426 and the second resistance R2 in low pass filter 1416 is resistive device, therefore the loss of signal of the signal component wanted may be caused and gain is deteriorated, in the present embodiment, first resistance R1 and the second resistance R2 can use variable resistor to carry out implementation in addition, and interference detector 1436 may be utilized to detect the existence of interference signal in input signal and produces detecting result accordingly.When not having interference signal in this detecting result indicative input signal (it is unnecessary for representing that the filtering of interference signal operates), interference detector 1436 separately can adjust the first resistance R1 to be reduced the resistance value of the first resistance R1 and/or adjusts the resistance value that the second resistance R2 reduces the second resistance R2.For example, but not restriction of the present invention, the resistance value of the first resistance R1/ second resistance R2 can be adjusted to zero (i.e. short circuit), thus, because the undesired loss of signal that resistive device (such as the first resistance R1 and the second resistance R2) causes just can alleviate effectively.Please note, when the resistance value of the first resistance R1 is downgraded, the corner frequency of low pass filter 1426 will increase, and when the resistance value of the second resistance R2 is downgraded, the corner frequency of low pass filter 1416 will increase, but, owing to now there is not any interference signal in input signal, therefore, the adjustment of corner frequency can't have any impact for the Signal reception of wanted signal.
Note that and use interference detector only to illustrate as example to adjust low pass filter 1416 and 1426 adaptively according to the detecting result of interference signal, but not restriction of the present invention, in another embodiment, interference detector 1436 can be omitted.In other words, no matter whether use interference detector, the acceptor circuit of any applying frequency selective circuit 1406 all can fall into category of the present invention.
Fig. 8 is for adopting the schematic diagram of another example of the receiver of the hardware configuration shown in Fig. 6.The circuit framework of the receiver 1500 shown in Fig. 8 is similar to the circuit framework of the receiver 1400 shown in Fig. 7, as shown in the figure, frequency response in selective circuit 1506 shown in Fig. 8 controls block 1525 and at least comprises frequency mixer 1424 and low pass filter 1526, in another design variation, frequency response controls block separately can comprise non-essential oscillator module (oscillator module 114 such as shown in Fig. 1).Receiver 1400 shown in Fig. 7 and Fig. 8, main difference part between 1500 is that the output of low pass filter 1526 in the selective circuit 1506 shown in Fig. 8 combines with the output of low pass filter 1416 in frequency reducing level 1404, therefore, the composite signal obtained based on the output of low pass filter 1416 and 1526 just can be processed by turning impedance amplifier 1417, this circuit framework can reach equally and allow most of electric current of inband signaling flow through the signal path at frequency reducing level place and to allow most of electric current in out of band signal flow through the object of the signal path at frequency selective network place.Because skilled persons will can understand the technical characteristic of receiver 1500 easily after reading the above-mentioned paragraph for the receiver 1400 shown in Fig. 7, therefore just separately do not repeat in this.
Please note, the frequency selective characteristic with the receiver (as shown in Figures 7 and 8) of multipath filtering is adjusted by the setting of the frequency mixer on unlike signal path and/or filter, thus, receiver just can be decayed undesired out of band signal/interference signal more effectively, and then promotes the linearity of receiver.
As illustrated in figs. 7 and 8, in receiver 1400 and 1500, any one has single ended configuration to meet the demand of single-ended applications, but, in receiver 1400 and 1500, any one also can have differential configuration to meet the demand of differential applications via suitably revising, and this is spirit according to the invention and fall into category of the present invention also.Moreover, the filter be arranged in frequency selective circuits 1406/1506 is not confined to low pass filter, for example, as long as the signal component wanted is downconverted in the passband (passband) of filter module, filter module also can be band pass filter.
Generally speaking, the method of the filtering characteristic of setting signal processing unit of the present invention can comprise following steps: setting is arranged in this signal processing apparatus and is electrically connected to the configuration of the first signal processing path of the signal input port of this signal processing apparatus, to make it have the first filtering characteristic; And setting is electrically connected on the configuration in the secondary signal process path between this signal input port and this first signal processing path, to make it have the second filtering characteristic differing from this first filtering characteristic in this signal processing apparatus.When the input signal that this signal input port receives comprises first signal component with first frequency and the secondary signal composition with second frequency, this first signal component most is by this first signal processing path process, and this secondary signal composition most is processed by this secondary signal process path.
The foregoing is only preferred embodiment of the present invention, all equalizations done according to the claims in the present invention change and modify, and all should belong to covering scope of the present invention.
Claims (25)
1. a signal processing apparatus, includes:
Frequency selective circuits, includes:
Signal input port;
First signal output port;
Secondary signal output port; And
Frequency response controls block, is electrically connected between signal path between this signal input port and this first signal output port and this secondary signal output port, and it is for carrying out control frequency response according to the frequency of oscillator signal that this frequency response controls block; And
Signal processing circuit, is electrically connected on this frequency selective circuits, and wherein this signal processing circuit is the input signal that receives for the treatment of this signal input port and processes multiple output signals that this first, second signal output port produces respectively;
Wherein the output of this frequency response control block is fed into this signal processing circuit via this secondary signal output port and converges with this first signal output port; Wherein, this input signal comprises the signal component wanted of different frequency and undesired signal component, and the attenuation that this frequency response control block puts on this undesired signal component is greater than the attenuation that this frequency response control block puts on the signal component that this is wanted; Or it is unattenuated to this signal component wanted to undesired signal component decay that this frequency response controls block.
2. signal processing apparatus as claimed in claim 1, it is characterized in that: this input signal comprises first signal component with first frequency and the secondary signal composition with second frequency, frequency offset between this frequency of this first frequency and this oscillator signal is less than the frequency offset between this frequency of this second frequency and this oscillator signal, and this frequency response controls attenuation that block puts on this secondary signal composition and is greater than this frequency response and controls the attenuation that block puts on this first signal component.
3. signal processing apparatus as claimed in claim 1, it is characterized in that: the frequency response of this frequency selective circuits has the first gain on the first frequency channel and on second frequency, has the second gain, frequency offset between this frequency of this first frequency and this oscillator signal is less than the frequency offset between this frequency of this second frequency and this oscillator signal, and this first gain is greater than this second gain.
4. signal processing apparatus as claimed in claim 1, it is characterized in that: the input impedance response that this frequency response controls block has the first resistance value on the first frequency channel and on second frequency, has the second resistance value, frequency offset between this frequency of this first frequency and this oscillator signal is less than the frequency offset between this frequency of this second frequency and this oscillator signal, and this first resistance value is greater than this second resistance value.
5. signal processing apparatus as claimed in claim 1, is characterized in that: this frequency response controls block and includes:
Mixer module, there is the first port, the second port and local oscillated signal input port, wherein this first port is electrically connected on this signal path between this signal input port and this first signal output port, and this oscillator signal that this mixer module receives according to this local oscillated signal input port operates; And
Filter module, between this second port being electrically connected on this secondary signal output port and this mixer module.
6. signal processing apparatus as claimed in claim 1, is characterized in that: this signal processing circuit is receiving circuit.
7. a signal processing apparatus, includes:
Frequency selective circuits, includes:
Signal input port;
First signal output port;
Secondary signal output port; And
Frequency response controls block, includes:
First mixer module, there is the first port, the second port and local oscillated signal input port, wherein this first port is electrically connected on the signal path between this signal input port and this first signal output port, and the first local oscillated signal input that this first mixer module receives according to this local oscillated signal input port operates; And
First filter module, between this second port being electrically connected on this secondary signal output port and this first mixer module; And
Signal processing circuit, is electrically connected on this frequency selective circuits, and this signal processing circuit includes:
First circuit module, for the treatment of the input signal that this signal input port receives; And
Second circuit module, for the treatment of multiple output signals that this first, second signal output port produces respectively;
Wherein the output of this frequency response control block is fed into this second circuit module via this secondary signal output port and converges with this first signal output port; Wherein, this input signal comprises the signal component wanted of different frequency and undesired signal component, and the attenuation that this frequency response control block puts on this undesired signal component is greater than the attenuation that this frequency response control block puts on the signal component that this is wanted; Or it is unattenuated to this signal component wanted to undesired signal component decay that this frequency response controls block.
8. signal processing apparatus as claimed in claim 7, it is characterized in that: this signal processing circuit is receiving circuit, this first circuit module is the amplified signal level of this receiving circuit, and this second circuit module is the frequency reducing level of this receiving circuit.
9. signal processing apparatus as claimed in claim 8, is characterized in that: this frequency reducing level includes:
Second mixer module, it operates according to the input of this first local oscillated signal;
Second filter module, there is the input port being electrically connected on this second mixer module and this secondary signal output port, and the composite signal that the output based on this second mixer module and this first filter module is obtained is fed into this input port of this second filter module; And
Oscillator module, inputs to this first, second mixer module for generation of this first local oscillated signal.
10. signal processing apparatus as claimed in claim 9, it is characterized in that: in this first filter module, the resistance value of the first resistance is greater than the resistance value of the second resistance in this second filter module, and in this first filter module, the capacitance of the first electric capacity is greater than the capacitance of the second electric capacity in this second filter module.
11. signal processing apparatus as claimed in claim 9, is characterized in that: the conduction resistance value of this second mixer module is greater than the conduction resistance value of this first mixer module.
12. signal processing apparatus as claimed in claim 8, is characterized in that: this frequency response controls block and separately includes:
First oscillator module, is electrically connected on this first mixer module and inputs to this first mixer module for generation of this first local oscillated signal; And
This frequency reducing level includes:
Second mixer module, it operates according to one second local oscillated signal input;
Second oscillator module, is electrically connected on this second mixer module and inputs to this second mixer module for generation of this second local oscillated signal; And
Second filter module, there is the input port being electrically connected on this second mixer module and this secondary signal output port, and the composite signal that the output based on this second mixer module and this first filter module is obtained is fed into this input port of this second filter module.
13. signal processing apparatus as claimed in claim 12, it is characterized in that: in this first filter module, the resistance value of the first resistance is greater than the resistance value of the second resistance in this second filter module, and in this first filter module, the capacitance of the first electric capacity is greater than the capacitance of the second electric capacity in this second filter module.
14. signal processing apparatus as claimed in claim 12, is characterized in that: the conduction resistance value of this second mixer module is greater than the conduction resistance value of this first mixer module.
15. signal processing apparatus as claimed in claim 8, is characterized in that: this frequency reducing level includes:
Second mixer module, it operates according to the input of this first local oscillated signal;
Second filter module, there is the input port being electrically connected on this second mixer module and the output port being electrically connected to this secondary signal output port, and composite signal is produced based on the output of this second filter module and this first filter module; And
Oscillator module, inputs to this first, second mixer module for generation of this first local oscillated signal.
16. signal processing apparatus as claimed in claim 15, it is characterized in that: in this first filter module, the resistance value of the first resistance is greater than the resistance value of the second resistance in this second filter module, and in this first filter module, the capacitance of the first electric capacity is greater than the capacitance of the second electric capacity in this second filter module.
17. signal processing apparatus as claimed in claim 15, is characterized in that: the conduction resistance value of this second mixer module is greater than the conduction resistance value of this first mixer module.
18. signal processing apparatus as claimed in claim 8, is characterized in that: this frequency response controls block and separately includes:
First oscillator module, is electrically connected on this first mixer module and inputs to this first mixer module for generation of this first local oscillated signal; And
This frequency reducing level includes:
Second mixer module, it operates according to the second local oscillated signal input;
Second oscillator module, is electrically connected on this second mixer module and inputs to this second mixer module for generation of this second local oscillated signal; And
Second filter module, there is the input port being electrically connected on this second mixer module and the output port being electrically connected to this secondary signal output port, and composite signal is produced based on the output of this second filter module and this first filter module.
19. signal processing apparatus as claimed in claim 18, it is characterized in that: in this first filter module, the resistance value of the first resistance is greater than the resistance value of the second resistance in this second filter module, and in this first filter module, the capacitance of the first electric capacity is greater than the capacitance of the second electric capacity in this second filter module.
20. signal processing apparatus as claimed in claim 18, is characterized in that: the conduction resistance value of this second mixer module is greater than the conduction resistance value of this first mixer module.
21. signal processing apparatus as claimed in claim 7, separately include:
Interference detector, for detecting the existence of interference signal in this input signal and producing detecting result accordingly;
Wherein when this detecting result indicate in this input signal not there is this interference signal time, this interference detector separately can adjust at least one resistance that this frequency response controls in block and this second circuit module, to reduce the resistance value of this resistance.
22. signal processing apparatus as claimed in claim 7, is characterized in that: this second circuit module includes and turns impedance amplifier, convert voltage signal to for being exported by electric current.
The method of the filtering characteristic of 23. 1 kinds of setting signal processing unit, includes:
Set the configuration of the first signal processing path, to make this first signal processing path have the first filtering characteristic, wherein this first signal processing path is positioned among this signal processing apparatus, and is electrically connected to the signal input port of this signal processing apparatus; And
The configuration in setting secondary signal process path, to make this secondary signal process path, there is the second filtering characteristic differing from this first filtering characteristic, wherein this secondary signal process path is positioned among this signal processing apparatus, and is electrically connected between this signal input port and this first signal processing path;
The output in this secondary signal process path is fed in this first signal processing path via the output port in this secondary signal process path to converge with the output port of this first signal processing path;
Wherein, this signal processing apparatus has the first filter module be arranged on this first signal processing path and the second filter module be arranged on this secondary signal process path; The step setting the configuration of this first signal processing path includes: set the resistance value of the first resistance in this first filter module and set the capacitance of the first electric capacity in this first filter module; And the step of the configuration setting this secondary signal process path includes: the resistance value of the second resistance in this second filter module is set greater than this resistance value of this first resistance, and the capacitance of the second electric capacity in this second filter module is set greater than this capacitance of this first electric capacity.
The method of the filtering characteristic of 24. setting signal processing unit as claimed in claim 23, it is characterized in that: when the input signal that this signal input port receives comprises first signal component with first frequency and the secondary signal composition with second frequency, in this first signal component, major part is by this first signal processing path process, and in this secondary signal composition, major part is processed by this secondary signal process path.
The method of the filtering characteristic of 25. setting signal processing unit as claimed in claim 24, separately includes:
Detect in this input signal that this signal input port receives and whether there is this secondary signal composition, and produce detecting result accordingly; And
When this detecting result indicate in this input signal not there is this secondary signal composition time, adjust at least one resistance on this first signal processing path and this secondary signal process path, to reduce the resistance value of this resistance.
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| CN201410662212.6A CN104539301B (en) | 2010-03-18 | 2011-03-11 | The method of the filtering characteristic of signal processing apparatus and setting signal processing unit |
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| US37027010P | 2010-08-03 | 2010-08-03 | |
| US61/370,270 | 2010-08-03 | ||
| US12/959,345 US9130642B2 (en) | 2010-03-18 | 2010-12-02 | Frequency-selective circuit with mixer module implemented for controlling frequency response, and related signal processing apparatus and method |
| US12/959,345 | 2010-12-02 | ||
| US13/039,322 US8391823B2 (en) | 2010-03-18 | 2011-03-03 | Signal processing apparatus having frequency-selective circuit with mixer module implemented for controlling frequency response and related method thereof |
| US13/039,322 | 2011-03-03 |
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| US9793935B2 (en) * | 2015-07-02 | 2017-10-17 | Mediatek Inc. | Multi-mixer system and method for reducing interference within multi-mixer system |
| CN109547923B (en) * | 2018-11-19 | 2021-09-28 | 海能达通信股份有限公司 | Positioning signal processing method, communication terminal and storage medium |
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| GB2453622A (en) * | 2008-08-21 | 2009-04-15 | Cambridge Silicon Radio Ltd | Receiver with tunable filter arranged to reduce interference from a frequency hopping transmitter |
| CN101436869A (en) * | 2008-11-27 | 2009-05-20 | 华为技术有限公司 | Equivalent radio frequency belt defect wave filter circuit, radio frequency chip and receiver |
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| WO2003055086A1 (en) * | 2001-12-20 | 2003-07-03 | Agency For Science, Technology And Research | High dynamic range receiver |
| US8086205B2 (en) * | 2008-05-02 | 2011-12-27 | Infineon Technologies Ag | Multimode receiver with active blocker suppression |
| JP2010016785A (en) * | 2008-06-03 | 2010-01-21 | Nippon Telegr & Teleph Corp <Ntt> | Receiving device and receiving method |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| GB2453622A (en) * | 2008-08-21 | 2009-04-15 | Cambridge Silicon Radio Ltd | Receiver with tunable filter arranged to reduce interference from a frequency hopping transmitter |
| CN101436869A (en) * | 2008-11-27 | 2009-05-20 | 华为技术有限公司 | Equivalent radio frequency belt defect wave filter circuit, radio frequency chip and receiver |
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