CN107728116A - Radar system and its leakage signal bucking circuit and method - Google Patents
Radar system and its leakage signal bucking circuit and method Download PDFInfo
- Publication number
- CN107728116A CN107728116A CN201710824013.4A CN201710824013A CN107728116A CN 107728116 A CN107728116 A CN 107728116A CN 201710824013 A CN201710824013 A CN 201710824013A CN 107728116 A CN107728116 A CN 107728116A
- Authority
- CN
- China
- Prior art keywords
- signal
- current
- transistor
- output end
- frequency modulation
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
- G01S7/36—Means for anti-jamming, e.g. ECCM, i.e. electronic counter-counter measures
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Radar, Positioning & Navigation (AREA)
- Remote Sensing (AREA)
- Radar Systems Or Details Thereof (AREA)
Abstract
This application discloses radar system and its leakage signal bucking circuit and method.The leakage signal bucking circuit includes multiple current branch, the multiple power branch enables under the position data control of control code respectively, so as to produce the output current of current weights corresponding with the position weight of the control code, wherein, when the envelope signal of CW with frequency modulation is less than predetermined threshold, the output current that the multiple current branch provides is zero, when the envelope signal of the CW with frequency modulation is more than predetermined threshold, the output current that the multiple current branch provides is superimposed upon in the intermediate-freuqncy signal of receiver, the output current sum that the multiple current branch provides forms the compensation electric current corresponding with the numerical value of the control code, so as to offset leakage signal of the CW with frequency modulation signal from transmitter to receiver.
Description
Technical field
The invention belongs to Radar Technology, relates more specifically to radar system and its leakage signal bucking circuit and method.
Background technology
Radar is the electronic equipment using electromagnetic wave detection physics.At work, radar emission radiofrequency signal, and detection
The echo reflected from object, so as to information such as the distances of judgment object.With the development of smart machine, miniradar exists
The application of civil area is more and more extensive.Millimetre-wave radar system has response fast, and precision is high, all weather operations, flexibility height etc.
Feature, the fields such as obstacle avoidance, detection, intelligent cruise have been widely used in it.For example, trailer-mounted radar has been widely used in
Various vehicles, for reminding the distance of barrier.
A kind of most common modulation system of trailer-mounted radar is to use CW with frequency modulation signal.Connected by transmitting with receiving frequency modulation
Continuous ripple signal can detection range and velocity information simultaneously.Because emitter and receiver must work simultaneously, the thunder of transmitting terminal
Receiving terminal can be inevitably leaked into up to CW with frequency modulation signal, and further produces zero intermediate frequency or Low Medium Frequency letter by being mixed
Number.The leakage signal is produced near low frequency, it can direct interference closer object detection, produce radar closely blind
Area.In addition, if leakage signal amplitude is larger to will also decrease the linearity and noise coefficient for receiving baseband circuit, or even saturation base
Band receiver.Therefore, how to offset the leakage signal from emitter to receiver turns into raising receiving sensitivity and reduces radar
The key of blind area.
In existing radar system, suppressed by being physically separated emitter with receiver from emitter to receiver
Signals leakiness, or the signal by improving the isolation of transmitting antenna and reception antenna to suppress from emitter to receiver
Leakage.However, the leakage signal suppressing method is based on physical separation, not only increase the size of radar system, and can only be certain
Reduce the intensity of leakage signal in degree.
Therefore.It is expected the miniaturization for further realizing radar system and the inhibition for improving leakage signal.
The content of the invention
In view of this, it is an object of the invention to provide the leakage signal bucking circuit for radar system, wherein using
Control code pre-sets the size of compensation electric current, when the envelope signal of CW with frequency modulation is more than predetermined threshold, will compensate electric current
It is superimposed upon in intermediate-freuqncy signal, to simplify circuit structure, and the accuracy of leakage signal amendment is improved, so as to improve leakage signal
Inhibition.
According to the first aspect of the invention, there is provided a kind of leakage signal bucking circuit for radar system, the radar
The receiver of system includes frequency mixer, for reception signal to be mixed with CW with frequency modulation to produce intermediate-freuqncy signal, the leakage
Signal cancellation circuit includes：Multiple current branch, the multiple power branch enable under the position data control of control code respectively,
So as to produce the output current of current weights corresponding with the position weight of the control code, wherein, in the CW with frequency modulation
When envelope signal is less than predetermined threshold, the output current that the multiple current branch provides is zero, in the CW with frequency modulation
Envelope signal when being more than predetermined threshold, the output current that the multiple current branch provides is superimposed upon in the intermediate-freuqncy signal,
The output current sum that the multiple current branch provides forms the compensation electric current corresponding with the numerical value of the control code, so as to
Leakage signal of the CW with frequency modulation signal from transmitter to receiver is offset at least in part.
Preferably, the frequency mixer includes the first output end and the second output end, and the intermediate-freuqncy signal is described first
The differential signal provided between output end and second output end, the multiple current branch include respectively：First current source
With the second current source, for producing and the constant current of the current weights respective value；The first transistor and second transistor,
It is defeated that first current source from feeder ear is connected to described first via the first transistor and the second transistor respectively
Go out end and second output end；And third transistor and third transistor, second current source is respectively via described
First output end and second output end are connected to the ground by three transistors and the 4th transistor, wherein, working
During, first current source and second current source enable or disable according to the position data of the control code, and described
One transistor and the second transistor are in the conduction state all the time, the third transistor and the 4th transistor difference root
Turned on according to first choice signal complimentary to one another and the second selection signal.
Preferably, the system debug stage or it is upper electric when, set the control code numerical value and the first choice letter
Number and second selection signal level.
Preferably, the grid of the first transistor and the second transistor is connected to constant bias voltage.
According to the second aspect of the invention, there is provided a kind of to be used to offset letting out from transmitter to receiver in radar system
The method of leakage signal, the receiver mix reception signal to produce intermediate-freuqncy signal with CW with frequency modulation, and methods described includes：
Multiple current branch are controlled using the position data of control code, the position with the control code is produced respectively in the multiple current branch
The output current of the corresponding current weights of weight；And the output current that the multiple current branch is provided be superimposed to it is described in
On frequency signal, wherein, when the envelope signal of the CW with frequency modulation is less than predetermined threshold, what the multiple current branch provided
Output current is zero, when the envelope signal of the CW with frequency modulation is more than or equal to predetermined threshold, the multiple current branch
The output current sum of offer forms the compensation electric current corresponding with the numerical value of the control code, so as to offset institute at least in part
State leakage signal.
Preferably, the intermediate-freuqncy signal is the difference letter provided between the first output end and the second output end of frequency mixer
Number, the step of producing the output current in the multiple current branch, includes：Using the first current source and the second current source
Produce the constant current with the current weights respective value；Described first is enabled or disabled according to the position data of the control code
Current source and second current source；The output of the multiple current branch is controlled according to the envelope signal of the CW with frequency modulation
Electric current.
Preferably, controlling the output current of the multiple current branch includes：Believed according to the envelope of the CW with frequency modulation
Number produce first choice signal complimentary to one another and the second selection signal；And use the first choice signal and described second
Selection signal, first path and conducting and the off-state in the second path is controlled respectively, the first path is successively via described
First current source, first output end and second current source, second path successively via first current source,
Second output end and second current source, wherein, when the envelope signal of the CW with frequency modulation is less than predetermined threshold,
The first path and second path disconnect, and are more than or equal to predetermined threshold in the envelope signal of the CW with frequency modulation
When, the conducting of one of the first path and second path and another disconnect, so as to first output end and described
One of second output end provides the constant current.
Preferably, in addition to：The system debug stage or it is upper electric when the numerical value and described first of the control code is set
The level of selection signal and second selection signal.
Preferably, the step of setting the first choice signal and second selection signal includes：The envelope is believed
Number differential signal be separated into the first choice signal and second selection signal.
Preferably, in addition to：According to default complementary control signal, the first choice signal and institute are inverted in separation
State the level of the second selection signal.
According to the third aspect of the invention we, there is provided a kind of radar system, including：Transmitter, for according to CW with frequency modulation
Produce and send signal, launch electromagnetic wave via transmitting antenna；And receiver, for being received via reception antenna from object
Reflection electromagnetic wave, the range information of object is obtained to produce reception signal, the receiver includes：Frequency mixer, for by institute
Reception signal is stated to mix with the CW with frequency modulation to produce intermediate-freuqncy signal, and according to the frequency acquisition of intermediate-freuqncy signal away from
From information；And above-mentioned leakage signal bucking circuit.
Preferably, the receiver also includes polarity selecting circuit, for by the envelope signal of the CW with frequency modulation
Differential signal is separated into first choice signal and the second selection signal, and according to default complementary control signal, in separation
Invert the first choice signal and the level of second selection signal.
Preferably, the polarity selecting circuit includes：3rd input and the 4th input, for receiving the envelope letter
Number；3rd output end and the 4th output end, it is respectively configured to provide the first choice signal and second selection signal；5th
Transistor and the 6th transistor, the input of the two are commonly connected to the 3rd input, and output end is respectively connecting to the 3rd output
End and the 4th output end；And the 7th transistor and the 8th transistor, the input of the two is commonly connected to the 4th input, defeated
Go out end and be respectively connecting to the 3rd output end and the 4th output end, wherein, the complementary control signal control the described 5th to the 8th
The conducting state of transistor so that in the 5th transistor and eight transistor turns, the 6th transistor the 7th is brilliant
Body pipe disconnects, and in the 6th transistor and seven transistor turns, the transistor of the 5th transistor the 8th disconnects.
Preferably, in addition to：Envelope signal generation circuit, the output end of the power amplifier of the transmitter is connected to,
Or the output end of the preamplifier of the receiver, for producing corresponding envelope signal according to the CW with frequency modulation.
Preferably, the envelope signal realizes the frequency and phase of output signal and the CW with frequency modulation using phaselocked loop
Locking, and use internal control voltage to simulate the envelope of the CW with frequency modulation, so as to obtain the envelope signal.
Leakage signal bucking circuit according to embodiments of the present invention and method, wherein pre-setting compensation electricity using control code
The size of stream, when the envelope signal of CW with frequency modulation is more than predetermined threshold, compensation electric current is superimposed upon in intermediate-freuqncy signal, so as to
Offset leakage signal of the CW with frequency modulation signal from transmitter to receiver.The bucking circuit can simplify circuit structure,
And the accuracy of leakage signal amendment is improved, so as to improve the inhibition of leakage signal, and receiver sensitivity is improved,
Remove due to caused by leakage apart from check frequency.
In a preferred embodiment, the first choice signal and second selection is set to believe using complementary control signal
Number level, so as to set compensation electric current polarity.The leakage signal bucking circuit sets compensation according to advance test result
The size and polarity of electric current, compensation electric current be superimposed upon in intermediate-freuqncy signal, and with the pole of mixed leakage signal in intermediate-freuqncy signal
Property is on the contrary, amplitude is roughly equal, so as to further improve the accuracy of leakage signal amendment, so as to improve leakage signal
Inhibition.
Brief description of the drawings
By the description to the embodiment of the present invention referring to the drawings, above-mentioned and other purposes of the invention, feature and
Advantage will be apparent from,
Fig. 1 shows the schematic block diagram of the radar system according to prior art.
Fig. 2 shows the schematic block diagram of receiver in the radar system according to prior art.
Fig. 3 shows the schematic block diagram of receiver in radar system according to embodiments of the present invention.
Fig. 4 shows the schematic block diagram of envelope signal generation circuit in radar system according to embodiments of the present invention.
Fig. 5 shows showing for polarity selecting circuit and leakage signal bucking circuit in radar system according to embodiments of the present invention
Meaning property block diagram.
Embodiment
The present invention is more fully described hereinafter with reference to accompanying drawing.In various figures, identical element is using similar attached
Icon is remembered to represent.For the sake of clarity, the various pieces in accompanying drawing are not necessarily to scale.In addition, it may not show in figure
Go out some known parts.
It describe hereinafter many specific details of the present invention, such as the structure of device, material, size, processing work
Skill and technology, to be more clearly understood that the present invention.But just as the skilled person will understand, it can not press
The present invention is realized according to these specific details.
Fig. 1 shows the schematic block diagram of the radar system according to prior art.Radar system 100 includes the He of emitter 110
Receiver 120.Emitter 110 includes CW with frequency modulation generation module 111, voltage controlled oscillator 112, power amplifier 113 and hair
Penetrate antenna 114.Receiver 120 includes low-noise amplifier 121, frequency mixer 122, trans-impedance amplifier 123 and reception antenna 124.
In emitter 110, CW with frequency modulation generation module 111 produces frequency with time periodically variable control signal
Vctrll.Voltage controlled oscillator 112 produces frequency with time periodically variable continuous wave signal according to control signal Vctrl.Work(
Rate amplifier 113 continuous wave signal is amplified after via transmitting antenna 114 to outside object emission electromagnetic wave.
In receiver 120, reception antenna 124 is from reflection electromagnetic wave of the external reception from object, so as to be received
Signal.After low-noise amplifier 121 is amplified to reception signal, mixed in frequency mixer 122 with continuous wave signal to produce
Intermediate-freuqncy signal.Trans-impedance amplifier 123 is amplified to the intermediate-freuqncy signal to obtain the sensing signal for being used for characterizing object distance.
The operation principle of above-mentioned radar system 100 is to be believed by measuring the frequency of intermediate-freuqncy signal to obtain the distance of object
Breath.For example, the frequency of intermediate-freuqncy signal is higher, then show that the distance of object is more remote.Vice versa.
As shown in figure 1, the leak path of CW with frequency modulation signal includes coupling and chip chamber coupling between antenna.Due to signal
The frequency response of module on link is not exclusively flat, and the output amplitude of CW with frequency modulation signal can change and change with frequency,
Therefore envelope signal is produced.The CW with frequency modulation signal of the leakage will produce envelope leakage letter after mixing receiving base band
Number.The envelope leakage signal will be amplified by trans-impedance amplifier 123.Receive base band high-pass filter would generally be used balanced different away from
From the signal intensity of launching objects, this high-pass filter decaying envelope leakage signal, but leakage signal will to a certain extent
The dynamic range of trans-impedance amplifier 123 is influenceed, or even saturation receives baseband circuit.
Fig. 2 shows the schematic block diagram of receiver in the radar system according to prior art.
On the basis of shown in Fig. 1, Fig. 2 shows further improved receiver 220.Receiver 220 is put including low noise
Big device 121, frequency mixer 122, trans-impedance amplifier 123, high-pass filter 125, variable gain amplifier 126 and reception antenna 124.
In receiver 220, trans-impedance amplifier 123 is amplified to intermediate-freuqncy signal to be used to characterize object distance to obtain
After sensing signal, high-pass filter 125 is used for the low-frequency noise for filtering out sensing signal.Variable gain amplifier 126 is further
Amplify sensing signal.In receiving circuit 220, CW with frequency modulation leakage signal by frequency mixer 122 produce envelope signal and
Amplify through trans-impedance amplifier 123, so as to form the signals leakiness from emitter to receiver.
In the receiver 220 shown in above-mentioned Fig. 2, frequency modulation can be suppressed to a certain extent using high-pass filter 125 and connected
Low frequency component in continuous ripple leakage signal.Let out however, above-mentioned existing leakage signal suppressing method can only reduce to a certain extent
The intensity of leakage signal.
Fig. 3 shows the schematic block diagram of receiver in radar system according to embodiments of the present invention.
Receiver 320 include low-noise amplifier 121, frequency mixer 122, trans-impedance amplifier 123, high-pass filter 125, can
Variable-gain amplifier 126, envelope signal generation circuit 127, polarity selecting circuit 128, leakage signal bucking circuit 129 and connect
Receive antenna 124.
In receiver 320, reception antenna 124 is from reflection electromagnetic wave of the external reception from object, so as to be received
Signal.After low-noise amplifier 121 is amplified to reception signal, mixed in frequency mixer 122 with continuous wave signal to produce
Intermediate-freuqncy signal.Envelope signal generation circuit 127 produces the envelope signal of CW with frequency modulation.The envelope signal selects electricity via polarity
The selection of road 128 compensation polarity, it is then superimposed with intermediate-freuqncy signal in leakage signal bucking circuit 129, to obtain correction signal.
Trans-impedance amplifier 123 is amplified to correction signal to obtain the sensing signal for being used for characterizing object distance.High-pass filter 125
For filtering out the low-frequency noise of sensing signal.Variable gain amplifier 126 further amplifies sensing signal.
In the receiver 320 shown in above-mentioned Fig. 3, frequency modulation can be suppressed to a certain extent using high-pass filter 125 and connected
Low frequency component in continuous ripple leakage signal.Further enter, using envelope signal generation circuit 127, polarity selecting circuit 128 and let out
Leakage signal bucking circuit 129 can further reduce the amplitude of CW with frequency modulation leakage signal.
In this embodiment, a part of the envelope signal generation circuit 127 as receiver, such as the LO positioned at receiver
The output end of pre-amplification circuit.In alternate embodiments, envelope signal generation circuit 127 can be as one of emitter
Point, such as the PA output ends positioned at emitter.
Fig. 4 shows the schematic block diagram of envelope signal generation circuit in radar system according to embodiments of the present invention.Envelope
Signal generating circuit 127 can detect the envelope signal of CW with frequency modulation.The envelope signal generation circuit 127 includes phase frequency detector
1271st, current source 1272 and 1273, low pass filter 1274, voltage controlled oscillator 1275, Fractional-N frequency device 1276, operational amplifier
1278。
Phase frequency detector 1271 receives the phase difference between input signal REF and feedback signal FB, converts thereof into control
Signal is with the current value in control electric current source 1272 and 1273, so as to produce error signal ERR.ERR is through low pass filtered for the error signal
After ripple device 1274 filters, the control voltage of voltage controlled oscillator 1275 is formed, so as to control the output signal of voltage controlled oscillator 1275
SO frequency.
The in-phase input end of operational amplifier 1278 is connected to the centre of low pass filter 1274 and voltage controlled oscillator 1275
Node, to receive control voltage, inverting input is connected with output end, so as to form follower.In the operational amplifier
1278 output end provides the envelope signal.
Fractional-N frequency device 1276 is connected on the feedback control loop between voltage controlled oscillator 1275 and phase frequency detector 1271, so as to
Feedback signal FB is produced according to the output signal of voltage controlled oscillator 1275, and provided to phase frequency detector 1271.
In the course of the work, when the frequency of output signal proportionally reflects the frequency of input signal, output voltage with
Input voltage keeps fixed phase difference value.The input signal REF of envelope signal generation circuit 127 is CW with frequency modulation signal
REF, output signal are envelope signal ENV.Envelope signal ENV and CW with frequency modulation signal REF frequency and PGC demodulation.By
Varied with frequency in the envelope of millimeter-wave signal, and signal frequency is determined by phaselocked loop internal control VCO control voltage, because
The envelope signal ENV of this CW with frequency modulation can be simulated by control voltage.
Fig. 5 shows showing for polarity selecting circuit and leakage signal bucking circuit in radar system according to embodiments of the present invention
Meaning property block diagram.In this embodiment, envelope signal ENV selects to produce complementary selection after polarity through polarity selecting circuit 128
Signal SEL1 and SEL2, there is provided to leakage signal bucking circuit 129.Leakage signal bucking circuit 129 will be with envelope signal ENV phases
Corresponding compensation electric current and intermediate-freuqncy signal are superimposed.In this embodiment, the intermediate-freuqncy signal that frequency mixer 122 provides is believed for electric current
Number.
Polarity selecting circuit 128 includes the MOS transistor M1 to M4 of p-type, be connected to difference form two inputs and
Between two output ends.Transistor M1 and M2 are connected in parallel, and source electrode is commonly connected to first input end.Transistor M3 and M4 are in parallel
Connection, source electrode are commonly connected to the second input.Transistor M1 and M3 drain electrode are commonly connected to the first output end, transistor M2
Drain electrode with M4 is commonly connected to the second output end.Further, transistor M1 and M4 turned under control signal S control and
Disconnect, transistor M2 and M3 is turned on and disconnected under control signal SB control.Control signal S and SB are a pair of complementary signals.
When control signal S is high level, transistor M1 and M4 are turned on and transistor M2 and M3 disconnect, so as to which envelope be believed
Output end is sent to number ENV original polarity from input, generates the complementary selection signals SEL1 and SEL2 of the first polarity.Controlling
When signal S is low level, transistor M1 and M4 are disconnected and transistor M2 and M3 are turned on, so as to by envelope signal ENV reversed polarities
Ground is sent to output end from input, generates the complementary selection signals SEL1 and SEL2 of the second polarity.
Leakage signal bucking circuit 129 is connected on the intermediate node of frequency mixer 122 and trans-impedance amplifier 123, for inciting somebody to action
It is superimposed upon by the compensation electric current corresponding with envelope signal ENV in the intermediate-freuqncy signal of the output of frequency mixer 122.Leakage signal is offset
Circuit 129 includes the current branch of multiple different current weights, hereinafter only using the first current branch to illustrate.Using
The control code BC (i.e. binary digit) corresponding with multiple current branch, it can gate corresponding with control code BC position weight
Current weights current branch.
First current branch includes current source IS11 and IS12, MOS transistor M11, M12, M21 and M22 of N-type.Electric current
Source IS11 is connected to from feeder ear via the transistor M11 and M21 that are connected in parallel in frequency mixer 122 and trans-impedance amplifier 123
Intermediate node.Further, the intermediate node is connected to the ground via the transistor M12 and M22 and current source IS12 being connected in parallel.It is brilliant
Body pipe M11 and M21 grid are connected to bias voltage Vbias, so as in the conduction state all the time.Transistor M12 and M22 grid
Pole is connected to polarity selecting circuit 128 to receive selection signal SEL1 and SEL2, that is, being more than predetermined threshold in envelope signal ENV
It is in the conduction state during value.
In this embodiment, transistor M11, M12, M21 and M22 works in switching mode.Envelope signal ENV is used as and opened
Close control signal.Current source IS11 and IS12 compensation electric current are equal, and the current weights of current branch depend on compensation electric current
Current value.For example, the current weights of the first current branch and the second current branch are respectively the benefit of 1 and 2, then the first current branch
Repay electric current is also the compensation electric current of the second current branch 1/2.
In the debugging stage of the receiver 320 shown in Fig. 3, or when upper electric, control signal S electricity can be pre-adjusted
Gentle control code BC numerical value, and the two is stored in receiver 320, for adjusting compensation electric current in the operating condition
Polarity and size.
In the course of the work, if envelope signal ENV is less than predetermined threshold, the conductings of transistor M11 and 21, transistor M12
Disconnected with M22.The current path for flowing to ground via transistor M12 and M22 from node disconnects, from current source IS11 via transistor
The electric current that M11 and M21 is injected into node cancels each other out, and therefore, compensation electric current is zero caused by leakage signal bucking circuit 129.
If envelope signal ENV is more than or equal to predetermined threshold, transistor M11 and M21 conducting, one of transistor M12 and M22 conducting and another
One disconnection.The current path for flowing to ground via one of transistor M12 and M22 from node turns on, and therefore, is passed through from current source IS11
The electric current that node is injected into by transistor M11 and M21 fails to offset, so as to produce the output current with current source IS11 and IS12
Corresponding compensation electric current.
Further, control code BC position data are provided to current source IS11 and IS12 control terminal, to enable electric current branch
Current source in road.As described above, control code BC has the numerical value pre-set.Therefore, leakage signal bucking circuit 129 produces
Compensation electric current be the weight sum of current source enabled with all current branch enabled according to control code.In above-mentioned work
During, the size for compensating electric current is pre-set using control code BC.The compensation electric current of numerical value corresponding with control code BC is superimposed
To caused by frequency mixer 122 in intermediate-freuqncy signal so that envelope signal ENV and the polarity phase of mixed leakage signal in intermediate-freuqncy signal
Instead, amplitude is roughly equal.Thus, mixed leakage signal can utilize superposition and offset and remove in intermediate-freuqncy signal, so as to improve
Inhibition.Therefore, the compensation electric current can offset the leakage signal detected in the output end of trans-impedance amplifier 123, disappear substantially
Except influence of the leakage signal to trans-impedance amplifier dynamic range.
It should be noted that herein, such as first and second or the like relational terms are used merely to a reality
Body or operation make a distinction with another entity or operation, and not necessarily require or imply and deposited between these entities or operation
In any this actual relation or order.Moreover, term " comprising ", "comprising" or its any other variant are intended to
Nonexcludability includes, so that process, method, article or equipment including a series of elements not only will including those
Element, but also the other element including being not expressly set out, or it is this process, method, article or equipment also to include
Intrinsic key element.In the absence of more restrictions, the key element limited by sentence "including a ...", it is not excluded that
Other identical element also be present in process, method, article or equipment including the key element.
According to embodiments of the invention as described above, these embodiments do not have all details of detailed descriptionthe, not yet
It is only described specific embodiment to limit the invention.Obviously, as described above, can make many modifications and variations.This explanation
Book is chosen and specifically describes these embodiments, is in order to preferably explain the principle and practical application of the present invention, so that affiliated
Technical field technical staff can be used using modification of the invention and on the basis of the present invention well.The present invention is only by right
The limitation of claim and its four corner and equivalent.
Claims (15)
1. a kind of leakage signal bucking circuit for radar system, the receiver of the radar system includes frequency mixer, is used for
Reception signal is mixed to produce intermediate-freuqncy signal with CW with frequency modulation, the leakage signal bucking circuit includes：
Multiple current branch, the multiple power branch enable under the position data control of control code respectively, so as to produce and institute
The output current of the corresponding current weights of position weight of control code is stated,
Wherein, when the envelope signal of the CW with frequency modulation is less than predetermined threshold, the output of the multiple current branch offer
Electric current is zero,
When the envelope signal of the CW with frequency modulation is more than predetermined threshold, the output current that the multiple current branch provides is folded
It is added in the intermediate-freuqncy signal, the output current sum that the multiple current branch provides forms the numerical value phase with the control code
Corresponding compensation electric current, so as to offset leakage letter of the CW with frequency modulation signal from transmitter to receiver at least in part
Number.
2. leakage signal bucking circuit according to claim 1, wherein, the frequency mixer includes the first output end and second
Output end, the intermediate-freuqncy signal is the differential signal provided between first output end and second output end, described
Multiple current branch include respectively：
First current source and the second current source, for producing the constant current with the current weights respective value；
The first transistor and second transistor, first current source is from feeder ear respectively via the first transistor and described
Second transistor is connected to first output end and second output end；And
Third transistor and third transistor, second current source is respectively via the third transistor and the 4th crystal
First output end and second output end are connected to the ground by pipe,
Wherein, in the course of the work, first current source and second current source open according to the position data of the control code
With or disabling, the first transistor and the second transistor are in the conduction state all the time, the third transistor and described
4th transistor turns on according to first choice signal complimentary to one another and the second selection signal respectively.
3. leakage signal bucking circuit according to claim 2, wherein, the system debug stage or it is upper electric when, institute is set
State the numerical value and the first choice signal and the level of second selection signal of control code.
4. leakage signal bucking circuit according to claim 2, wherein, the first transistor and the second transistor
Grid be connected to constant bias voltage.
5. a kind of method for being used to offset the leakage signal from transmitter to receiver in radar system, the receiver will connect
The collection of letters number is mixed with CW with frequency modulation to produce intermediate-freuqncy signal, and methods described includes：
Multiple current branch are controlled using the position data of control code, are produced respectively and the control code in the multiple current branch
The corresponding current weights of position weight output current；And
The output current that the multiple current branch provides is superimposed in the intermediate-freuqncy signal,
Wherein, when the envelope signal of the CW with frequency modulation is less than predetermined threshold, the output of the multiple current branch offer
Electric current is zero,
When the envelope signal of the CW with frequency modulation is more than or equal to predetermined threshold, the output that the multiple current branch provides is electric
Flow sum and form the compensation electric current corresponding with the numerical value of the control code, so as to offset the leakage signal at least in part.
6. according to the method for claim 5, wherein, the intermediate-freuqncy signal is defeated in the first output end of frequency mixer and second
The step of going out between end the differential signal provided, the output current is produced in the multiple current branch includes：
The constant current with the current weights respective value is produced using the first current source and the second current source；
First current source and second current source are enabled or disabled according to the position data of the control code；
The output current of the multiple current branch is controlled according to the envelope signal of the CW with frequency modulation.
7. according to the method for claim 6, wherein, controlling the output current of the multiple current branch includes：
First choice signal complimentary to one another and the second selection signal are produced according to the envelope signal of the CW with frequency modulation；And
Using the first choice signal and second selection signal, control respectively first path and the second path conducting and
Off-state, the first path is successively via first current source, first output end and second current source, institute
The second path is stated successively via first current source, second output end and second current source,
Wherein, when the envelope signal of the CW with frequency modulation is less than predetermined threshold, the first path and second path
Disconnect,
When the envelope signal of the CW with frequency modulation is more than or equal to predetermined threshold, the first path and second path it
One conducting and another disconnection, so as to provide the constant current to one of first output end and second output end.
8. the method according to claim 11, in addition to：
The system debug stage or it is upper electric when numerical value and the first choice signal and described second of the control code are set
The level of selection signal.
Wherein, 9. the step of the first choice signal and second selection signal according to the method for claim 8, is set
Suddenly include：The differential signal of the envelope signal is separated into the first choice signal and second selection signal.
10. the method according to claim 11, in addition to：According to default complementary control signal, in separation described in reversion
The level of first choice signal and second selection signal.
11. a kind of radar system, including：
Transmitter, signal is sent for being produced according to CW with frequency modulation, launches electromagnetic wave via transmitting antenna；And
Receiver, for receiving the reflection electromagnetic wave from object via reception antenna, to produce reception signal to obtain object
Range information,
The receiver includes：
Frequency mixer, for the reception signal to be mixed to produce intermediate-freuqncy signal, and according to intermediate frequency with the CW with frequency modulation
Range information described in the frequency acquisition of signal；And
Leakage signal bucking circuit according to any one of claim 1 to 4.
12. radar system according to claim 11, wherein, the receiver also includes polarity selecting circuit, for inciting somebody to action
The differential signal of the envelope signal of the CW with frequency modulation is separated into first choice signal and the second selection signal, and according to pre-
If complementary control signal, separation when invert the first choice signal and the level of second selection signal.
13. radar system according to claim 12, wherein, the polarity selecting circuit includes：
3rd input and the 4th input, for receiving the envelope signal；
3rd output end and the 4th output end, it is respectively configured to provide the first choice signal and second selection signal；
5th transistor and the 6th transistor, the input of the two are commonly connected to the 3rd input, and output end is respectively connecting to
3rd output end and the 4th output end；And
7th transistor and the 8th transistor, the input of the two are commonly connected to the 4th input, and output end is respectively connecting to
3rd output end and the 4th output end,
Wherein, the complementary control signal controls the conducting state of the 5th to the 8th transistor so that brilliant the described 5th
When body pipe and eight transistor turns, the transistor of the 6th transistor the 7th disconnects, and in the 6th transistor and the
During seven transistor turns, the transistor of the 5th transistor the 8th disconnects.
14. radar system according to claim 12, in addition to：
Envelope signal generation circuit, before being connected to the output end of the power amplifier of the transmitter, or the receiver
The output end of amplifier is put, for producing corresponding envelope signal according to the CW with frequency modulation.
15. radar system according to claim 14, wherein, the envelope signal using phaselocked loop realize output signal with
The frequency and PGC demodulation of the CW with frequency modulation, and use internal control voltage to simulate the bag of the CW with frequency modulation
Network, so as to obtain the envelope signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710824013.4A CN107728116B (en) | 2017-09-13 | 2017-09-13 | Radar system and leakage signal cancellation circuit and method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710824013.4A CN107728116B (en) | 2017-09-13 | 2017-09-13 | Radar system and leakage signal cancellation circuit and method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107728116A true CN107728116A (en) | 2018-02-23 |
| CN107728116B CN107728116B (en) | 2020-10-16 |
Family
ID=61204625
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710824013.4A Active CN107728116B (en) | 2017-09-13 | 2017-09-13 | Radar system and leakage signal cancellation circuit and method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107728116B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112558020A (en) * | 2020-12-26 | 2021-03-26 | 南京理工大学 | Linear frequency modulation continuous wave radar transmitting and receiving isolation intermediate frequency circuit |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100767413B1 (en) * | 2006-06-07 | 2007-10-18 | 한국과학기술원 | Radar apparatus with transmitter leakage canceller |
| CN101258690A (en) * | 2005-09-06 | 2008-09-03 | 三菱电机株式会社 | Leakage signal canceller |
| CN102393512A (en) * | 2011-09-28 | 2012-03-28 | 中国电子科技集团公司第十研究所 | Single-antenna frequency-modulated continuous-wave radar radio frequency passive cancellation method |
| CN104569930A (en) * | 2014-12-29 | 2015-04-29 | 北京理工雷科电子信息技术有限公司 | Leakage signal cancellation circuit of linear frequency modulation continuous wave radar |
| WO2016031108A1 (en) * | 2014-08-28 | 2016-03-03 | 株式会社ソシオネクスト | Fmcw radar |
| CN106125052A (en) * | 2016-06-23 | 2016-11-16 | 复旦大学 | The removing method of a kind of Modulation Continuous Wave Radar modulation leakage and system |
| CN106533473A (en) * | 2016-12-21 | 2017-03-22 | 湖南纳雷科技有限公司 | Radio frequency cancellation system and method for continuous wave radar |
-
2017
- 2017-09-13 CN CN201710824013.4A patent/CN107728116B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101258690A (en) * | 2005-09-06 | 2008-09-03 | 三菱电机株式会社 | Leakage signal canceller |
| KR100767413B1 (en) * | 2006-06-07 | 2007-10-18 | 한국과학기술원 | Radar apparatus with transmitter leakage canceller |
| CN102393512A (en) * | 2011-09-28 | 2012-03-28 | 中国电子科技集团公司第十研究所 | Single-antenna frequency-modulated continuous-wave radar radio frequency passive cancellation method |
| WO2016031108A1 (en) * | 2014-08-28 | 2016-03-03 | 株式会社ソシオネクスト | Fmcw radar |
| CN104569930A (en) * | 2014-12-29 | 2015-04-29 | 北京理工雷科电子信息技术有限公司 | Leakage signal cancellation circuit of linear frequency modulation continuous wave radar |
| CN106125052A (en) * | 2016-06-23 | 2016-11-16 | 复旦大学 | The removing method of a kind of Modulation Continuous Wave Radar modulation leakage and system |
| CN106533473A (en) * | 2016-12-21 | 2017-03-22 | 湖南纳雷科技有限公司 | Radio frequency cancellation system and method for continuous wave radar |
Non-Patent Citations (2)
| Title |
|---|
| KAIHUI LIN ET AL.: "A Ka-Band FMCW Radar Front-End With Adaptive Leakage Cancellation", 《IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES》 * |
| 张鹏 等: "基于DSP的FMCW雷达泄漏对消系统分析", 《火控雷达技术》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112558020A (en) * | 2020-12-26 | 2021-03-26 | 南京理工大学 | Linear frequency modulation continuous wave radar transmitting and receiving isolation intermediate frequency circuit |
| CN112558020B (en) * | 2020-12-26 | 2023-11-21 | 南京理工大学 | Linear frequency modulation continuous wave radar receiving and transmitting isolation intermediate frequency circuit |
Also Published As
| Publication number | Publication date |
|---|---|
| CN107728116B (en) | 2020-10-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP2973994B1 (en) | Logarithmic amplifier with universal demodulation capabilities | |
| CN101281220B (en) | Capacitance testing circuit and capacitance-type sensor interface circuit chip thereof | |
| US6678506B1 (en) | Extended range power detector | |
| CN103650355A (en) | Non-foster circuit stabilization circuit and method | |
| US7057426B2 (en) | Frequency converter, orthogonal demodulator and orthogonal modulator | |
| CN101477147B (en) | Circuit for detecting radio frequency power | |
| CN106877943A (en) | The accurate measurement of the transmission power calibrated using loopback in RF transceivers | |
| CN103795351B (en) | Receiver radio frequency front-end circuit and low noise amplifier | |
| US20040224655A1 (en) | Adaptive diversity receiver architecture | |
| WO2014101881A1 (en) | A temperature independent cmos radio frequency power detector | |
| CN107728116A (en) | Radar system and its leakage signal bucking circuit and method | |
| US8471550B2 (en) | Delivered power detection for power amplifiers and related systems and methods | |
| US4028645A (en) | Automatic impedance matching using resistive and reactive diodes | |
| CN116318048B (en) | Data acquisition card circuit | |
| CN104122437A (en) | Silicon substrate power detector | |
| US4283693A (en) | Amplitude tilt compensating apparatus | |
| CN101409701A (en) | Local oscillation buffer and method for correcting phase mismatch | |
| KR102463539B1 (en) | Radar, signal control circuit and signal control method | |
| CN104639270B (en) | CMOS (Complementary Metal Oxide Semiconductor) integrated receiving signal intensity indicator with process stability | |
| KR100994272B1 (en) | An integrated rf level detector usable for automatic power level control | |
| CN103490770B (en) | A kind of fast lockign apparatus based on C-band continuous wave answering machine | |
| CN201846316U (en) | Automatic gain control circuit of zero intermediate frequency receiver | |
| CN203933647U (en) | Signal magnitude detector and comprise the wireless receiver of this signal magnitude detector | |
| WO2003088497A1 (en) | Quadrature phase control loop | |
| US4158843A (en) | Automatic direction finder antenna preamplifier processor |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| CB02 | Change of applicant information |
Address after: Room 901, 10 / F, floor 1, basement 1, building 5, No. 666, shengxia road and No. 122, Yindong Road, China (Shanghai) pilot Free Trade Zone, Pudong New Area, Shanghai 201210 Applicant after: Micro electronics technology (Shanghai) Co., Ltd. Address before: 201210 Shanghai Pudong New Area free trade test area, 666 Sheng Xia Road, No. 122 Silver Winter Road, 5 underground 1 floors, 1_10 layer 901 room Applicant before: Micro electronics technology (Shanghai) Co., Ltd. |
|
| CB02 | Change of applicant information | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |