CN208314194U - The radio frequency microwave system of plant detections of radar is floated applied to water - Google Patents
The radio frequency microwave system of plant detections of radar is floated applied to water Download PDFInfo
- Publication number
- CN208314194U CN208314194U CN201820366704.4U CN201820366704U CN208314194U CN 208314194 U CN208314194 U CN 208314194U CN 201820366704 U CN201820366704 U CN 201820366704U CN 208314194 U CN208314194 U CN 208314194U
- Authority
- CN
- China
- Prior art keywords
- signal
- frequency
- filter
- water
- detections
- 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.)
- Expired - Fee Related
Links
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 title claims abstract description 31
- 238000001514 detection method Methods 0.000 title claims abstract description 21
- 230000005540 biological transmission Effects 0.000 claims abstract description 26
- 230000010355 oscillation Effects 0.000 claims abstract description 15
- 230000005284 excitation Effects 0.000 claims abstract description 12
- 238000012545 processing Methods 0.000 claims abstract description 11
- 230000015572 biosynthetic process Effects 0.000 claims abstract description 10
- 238000003786 synthesis reaction Methods 0.000 claims abstract description 10
- 238000005086 pumping Methods 0.000 claims abstract description 9
- 230000001105 regulatory effect Effects 0.000 claims abstract description 4
- 230000003321 amplification Effects 0.000 claims description 18
- 238000001914 filtration Methods 0.000 claims description 18
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 18
- 238000002156 mixing Methods 0.000 claims description 12
- 238000007667 floating Methods 0.000 claims description 11
- 238000001228 spectrum Methods 0.000 claims description 8
- 230000006870 function Effects 0.000 claims description 6
- 239000013078 crystal Substances 0.000 claims description 5
- 238000000605 extraction Methods 0.000 claims description 5
- 238000004364 calculation method Methods 0.000 claims description 4
- 238000005070 sampling Methods 0.000 claims description 4
- 238000004891 communication Methods 0.000 claims description 3
- 239000000284 extract Substances 0.000 claims description 2
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 claims 2
- 241000196324 Embryophyta Species 0.000 description 15
- 238000004458 analytical method Methods 0.000 description 6
- 238000010586 diagram Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 230000001629 suppression Effects 0.000 description 4
- 240000003826 Eichhornia crassipes Species 0.000 description 3
- 230000006866 deterioration Effects 0.000 description 3
- 238000003780 insertion Methods 0.000 description 3
- 230000037431 insertion Effects 0.000 description 3
- 238000012986 modification Methods 0.000 description 3
- 230000004048 modification Effects 0.000 description 3
- 240000009087 Crescentia cujete Species 0.000 description 2
- 235000005983 Crescentia cujete Nutrition 0.000 description 2
- 235000009797 Lagenaria vulgaris Nutrition 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 238000007726 management method Methods 0.000 description 2
- 238000012795 verification Methods 0.000 description 2
- 229910001218 Gallium arsenide Inorganic materials 0.000 description 1
- 235000014676 Phragmites communis Nutrition 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 239000012141 concentrate Substances 0.000 description 1
- 230000001186 cumulative effect Effects 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 230000002542 deteriorative effect Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 230000007717 exclusion Effects 0.000 description 1
- 230000004927 fusion Effects 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 238000011068 loading method Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 230000006855 networking Effects 0.000 description 1
- 238000010606 normalization Methods 0.000 description 1
- 230000000149 penetrating effect Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000009418 renovation Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 241000894007 species Species 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
- 239000003643 water by type Substances 0.000 description 1
Landscapes
- Radar Systems Or Details Thereof (AREA)
Abstract
The radio frequency microwave system of plant detections of radar is floated the utility model relates to be applied to water, system is powered using the D.C. regulated power supply of complete machine, is made of receiving front-end, data acquisition module, frequency synthesis component three parts；The receiving front-end accesses rf excitation signal, exports after the processing of three-level frequency mixer through filter amplifier, numerical-control attenuator, low-pass filter；The data acquisition module is made of anti-aliasing filter, ADC, FPGA and Ethernet transmission module, for realizing intermediate-freuqncy signal digitlization；The frequency synthesis component is made of clock reference circuit, Waveform generating circuit, transmission channel, interface control circuit, for synchronizing clock signals needed for local oscillation signal, data acquisition module needed for improving receiving front-end and chirped pumping signal.The system is applied to water and floats plant radar sensing system, provides radiofrequency signal processing.
Description
Technical field
The present invention relates to water plants to renovate field, and in particular to a kind of radio frequency for floating plant detections of radar applied to water is micro-
Wave system system.
Background technique
Water floats the key points and difficulties that plant is all river improvement all the time, alien species water calabash especially in recent years
Reed, vitality is strong, and the speed of growth is exceedingly fast, and large stretch of water hyacinth swims in the water surface, goes downstream, unbroken dozens of kilometres, some water
Face is very most to be covered by water hyacinth, and not only polluted water region environment, has an effect on navigation safety, even into urban planning
Landscape waters causes the extensive concern of society.
For this purpose, relevant department has carried out relevant renovation.Including being patrolled with ship, vehicle patrols and video monitoring based on it is pre-
It is alert；Cleaning work etc. based on the salvaging of interception concentration and ship cruise salvaging, renovates the certain effect of acquirement.But by the hydrology,
The outburst of the influence of the environmental factors such as weather, geography, water hyacinth has uncertainty, leads to some regions and water calabash in the period
When Lu great Liang concentrates outburst suddenly, blocks fishing operation strength and have too many difficulties to cope with for the moment.Therefore, relevant department is badly in need of establishing a set of with aquatic
The intelligent management method of plant early warning and comprehensive improvement obtains the floating on water plant for flowing through sensing point using detection sensor
Distributed intelligence, and by the information networking of more sensing points and fusion, other comprehensive multi-party meteorological, hydrographic informations judge aquatic plant
The growth tendency and basin overall distribution situation of object are established water plant management early warning mechanism, and are salvaged and made with this reasonable arrangement
Industry strength achievees the purpose that effectively to manage water plant.
Summary of the invention
Penetrating for plant detections of radar is floated applied to water it is an object of the invention to overcome the deficiencies of the prior art and provide a kind of
Frequency microwave system floats plant detections of radar for water, the accuracy of detection can be improved.
The purpose of the present invention is achieved through the following technical solutions:
The radio frequency microwave system of plant detections of radar is floated applied to water, system is powered using the D.C. regulated power supply of complete machine,
The system is made of receiving front-end, data acquisition module, frequency synthesis component three parts；
The receiving front-end accesses rf excitation signal, through filter amplifier, numerical control attenuation after the processing of three-level frequency mixer
Device, low-pass filter output；
The data acquisition module is made of anti-aliasing filter, ADC, FPGA and Ethernet transmission module, for realizing
Intermediate-freuqncy signal digitlization；
The frequency synthesis component is by clock reference circuit, Waveform generating circuit, transmission channel, interface control circuit group
At for synchronizing clock signals and linear frequency modulation needed for local oscillation signal, data acquisition module needed for improving receiving front-end
Pumping signal.
The three-level frequency mixer includes first order frequency mixer, second level frequency mixer, third level frequency mixer；
The rf excitation signal enters first order frequency mixer through limiter, low-noise amplifier, filter and is mixed to obtain
The first intermediate-freuqncy signal of 7.75GHz bandwidth 300MHz；
First intermediate-freuqncy signal enters second level frequency mixer through filter, amplifier and obtains the second of 750MHz bandwidth 500KHz
Intermediate-freuqncy signal；
Second intermediate-freuqncy signal enters third level frequency mixer after filter, amplifier, numerical-control attenuator and obtains 70MHz bandwidth
The third intermediate-freuqncy signal of 5MHz；
Third intermediate-freuqncy signal is exported through filter amplifier, numerical-control attenuator, low-pass filter.
The ADC is configured with configured with clock input interface (XS1) and intermediate frequency input interface (XS2), too net transmission module
Communication interface (XS4), FPGA are configured with sync cap (XS5), and are configured with general power input interface (XS3).
The anti-aliasing filter is mainly used for preventing noise aliasing when ADC bandpass sampling, parameter are as follows: center
Frequency F0=70MHz；BW-1dB=3~5MHz；BW-40dB<40MHz；BW-80dB<70MHz.
ADC sampled data is entered three-level decimation filter by the FPGA after Digital Down Convert, is followed successively by 2 times of pumpings
It takes, 5 times of extractions, 5 times of extractions, is equivalent to the sample rate of 2MHz, is then packed the data to after a high-pass filter solid
The formula of fixing is sent to Ethernet transmission module.
Data are transmitted to computer by network interface by the Ethernet transmission module, and computer will be counted by unpacking software
According to resolving, hard disk, and label time and signal format information is written according to the data length of 1s, while the data being put into
Specified memory is used for Back end data processing.
The clock reference circuit generates 100MHz signal by constant-temperature crystal oscillator, gives all the way through the output of two power splitter of ADP-2-1W
12G does in source comb spectrum driving source, is supplied respectively to 3.5GHz, CRO phase locked source through tetra- road power splitter of SCA-4-10 all the way；
LTC6946-2 output receives three local oscillation signal 820MHz；Transmitting pumping signal 750MHz is exported through LTC6946-1；Through amplifier
13dBm signal is exported for signal processor when acquisition clock.
The Waveform generating circuit work is as follows:
By CRO phase-locked loop circuit generate 3.5GHz signal and comb spectrum generation 12G signal filtered, amplify after be mixed generation
Latter local oscillation signal, a local oscillation signal do a local oscillator for transmission channel and receiving module after filtering, amplification, function point；
Frequency sweep local oscillator divides two-way to do local oscillation signal through amplification, frequency multiplication, filtering generation 7GHz all the way by 3.5G；It gives all the way
AD9914 makees clock, generates 600~900MHz signal, two kinds of signals are after the mixing of HMC558 frequency mixer through filtering, amplification, function
Divide and does two local oscillators to receiving module for transmission channel and output.
The transmission channel generates 750MHz by frequency synthesizer and is mixed with frequency sweep local vibration source (7.6~7.9GHz), through filtering
Wave amplification after be mixed with a local oscillator (15.5GHz), export 23.85~24.15GHz signal, by filtering mixing, amplification warp every
It is exported from device.
The performance indexes of the system is as follows:
1) it motivates: 24GHz ± 50MHz (23.85~24.15GHz), power: 1~1.3W, phase noise: L (1K)≤-
103dBc/Hz, L (100K)≤- 113dBc/Hz；
2) local oscillator: 15.5GHz, power: 13dBm ± 1dBm, phase noise: L (1K)≤- 108dBc/Hz, L (100K)
≤-118dBc/Hz；
3) two local oscillator: 7.75GHZ (7.6~7.9), power: 10dBm ± 1dBm；Phase noise: it is better than a local oscillator；
4) three local oscillator: phase noise: 820MHz, power: 10dBm ± 1dBm are better than two local oscillators；
5) clock: 100MHz, power: 13 ± 0.5dBm,
Phase noise: L (1K)≤- 140dBc/Hz, L (100K)≤- 150dBc/Hz；
6) amplitude coincidence in swept-frequency signal modulating bandwidth :≤1dB；
7) clutter: excitation >=60dBc, one local oscillator >=70dBc, two local oscillators >=70dBc, three local oscillators >=70dBc, clock is exported
≥70dBc
8) harmonics restraint: excitation >=55dBc, one local oscillator >=60dBc, two local oscillators >=60dBc, three local oscillators >=60dBc, clock
≥60dBc
9) power fluctuation :≤0.5dB
10) power consumption :≤30W；
11) point frequency and linear modulation alternately export each 1s, linear frequency modulation time 1ms, modulating bandwidth 300MHz, FM linear
Degree≤2/1000.
The beneficial effects of the present invention are: the radio frequency microwave system that this programme provides, which is applied to water, floats plant detections of radar system
System can float plant radar sensing system for water and provide radiofrequency signal processing, so that water floats the detection of plant radar sensing system
Effect is promoted.
Detailed description of the invention
Fig. 1 is clock reference circuit；
Fig. 2 is Waveform generating circuit；
Fig. 3 is transmission channel circuit；
Fig. 4 is 3500MHz CRO oscillator phase curve graph；
Fig. 5 is receiving channel circuit；
Fig. 6 is echo input standing wave curve graph；
Fig. 7 is image frequency degree of suppression curve graph；
Fig. 8 is data acquisition module block diagram；
Fig. 9 is noise aliasing schematic diagram；
Figure 10 is data acquisition module block diagram.
Specific embodiment
Technical solution of the present invention is described in further detail combined with specific embodiments below, but protection scope of the present invention is not
It is confined to as described below.
Radio frequency microwave system is by receiving front-end, data acquisition module (also referred to as A/D module below), frequency synthesis component three
It is grouped as, is concentrated use in the D.C. regulated power supply power supply of complete machine, reception system and the loading together of emission system are placed in antenna branch
In arm, outdoor environment is worked in.
Local oscillation signal needed for frequency synthesis component provides receiving front-end, synchronizing clock signals needed for ADC module, and
Chirped pumping signal.
Frequency synthesis component by clock reference circuit, Waveform generating circuit (below also referred to as frequency sweep local oscillator), transmission channel, connect
The mouth composition such as control circuit and power supply processing, internal circuit is mainly by the constant-temperature crystal oscillator of high stability low phase noise, pectination
Spectrum, Digital Microwave phaselocked loop, mixing and filtering amplification channel, digital control and power supply filter circuit of pressure-stabilizing etc. are constituted.
Clock reference circuit is as shown in Figure 1:
Clock reference circuit generates 100MHz signal by constant-temperature crystal oscillator, gives 12G all the way through the output of two power splitter of ADP-2-1W
Do comb spectrum driving source in source；3.5GHz, CRO phase locked source are supplied respectively to through tetra- road power splitter of SCA-4-10 all the way；LTC6946-2
Output receives three local oscillation signal 820MHz；Transmitting pumping signal 750MHz is exported through LTC6946-1；13dBm is exported through amplifier
Signal is for signal processor when acquisition clock；
Waveform generating circuit is as shown in Figure 2:
One local oscillation signal is filtered with comb spectrum generation 12G signal by CRO phase-locked loop circuit generation 3.5GHz signal, is amplified
For one local oscillator of transmission channel and receiving module after filtering, amplification, function point after mixing generates afterwards.
Frequency sweep local oscillator divides two-way to do local oscillation signal through amplification, frequency multiplication, filtering generation 7GHz all the way by 3.5G；It gives all the way
AD9914 makees clock, generates 600~900MHz signal, two kinds of signals are after the mixing of HMC558 frequency mixer through filtering, amplification, function
Divide and does two local oscillators to receiving module for transmission channel and output；
Transmission channel is as shown in Figure 3:
Transmission channel generates 750MHz by frequency synthesizer and is mixed with frequency sweep local vibration source (7.6~7.9GHz), puts through filtering
It is mixed after big with a local oscillator (15.5GHz), exports 23.85~24.15GHz signal, by filtering mixing, amplified through isolator
Output.
Performance indicator is as follows:
1) it motivates: 24GHz ± 50MHz (23.85~24.15GHz), power: 1~1.3W, phase noise: L (1K)≤-
103dBc/Hz, L (100K)≤- 113dBc/Hz；
2) local oscillator: 15.5GHz, power: 13dBm ± 1dBm, phase noise: L (1K)≤- 108dBc/Hz, L (100K)
≤-118dBc/Hz；
3) two local oscillator: 7.75GHZ (7.6~7.9), power: 10dBm ± 1dBm；Phase noise: it is better than a local oscillator；
4) three local oscillator: phase noise: 820MHz, power: 10dBm ± 1dBm are better than two local oscillators；
5) clock: 100MHz, power: 13 ± 0.5dBm, phase noise: L (1K)≤- 140dBc/Hz, L (100K)≤-
150dBc/Hz；
6) amplitude coincidence in swept-frequency signal modulating bandwidth :≤1dB；
7) clutter: excitation >=60dBc, one local oscillator >=70dBc, two local oscillators >=70dBc, three local oscillators >=70dBc, clock is exported
≥70dBc；
8) harmonics restraint: excitation >=55dBc, one local oscillator >=60dBc, two local oscillators >=60dBc, three local oscillators >=60dBc, clock
≥60dBc；
9) power fluctuation :≤0.5dB
10) power consumption :≤30W；
11) point frequency and linear modulation alternately export each 1s, linear frequency modulation time 1ms, modulating bandwidth 300MHz, FM linear
Degree≤2/1000.
Performance Analysis calculates as follows:
The analysis of (1) one local oscillator main indicator
The factor for influencing phase noise specifications mainly has the phase noise of reference source and the phase of phase demodulation chip low noise and VCO
Position noise.Phase noise within the 10KHz of final output signal depend primarily on reference source phase noise and with phase demodulation core
Piece bottom is made an uproar, and the phase noise other than 100KHz depends primarily on the phase noise of VCO.
1) the Primary Component index of phase noise is influenced:
A. voltage controlled oscillator :≤- 130dBc/Hz@100KHz
B. constant-temperature crystal oscillator :≤- 155dBc/Hz@1KHz
C. phase discriminator: -153dBc/Hz@10kHz offset@100MHz
2) Analysis of Phase Noise of a local oscillator:
A. in loop bandwidth phase noise calculation formula: floor+20Log (f0/fpD)+10LogfpD
Wherein Lfloor is the normalization low noise of PLL chip, and f0/fpD is output frequency divided by the phase demodulation frequency i.e. times frequency
Number N, fpD is phase demodulation frequency.
Bringing above-mentioned parameter into formula can calculate:
Phase noise in loop band is -226+20Log (3500/100)+10Log (100 × 106) ≈ -125dBc/H.
In addition along with the deterioration of Practical Project and the deterioration 2dB of other parameters, the phase noise in loop band can be obtained
For -123dBc/Hz.
B. the phase noise of reference source deterioration calculate (3.5GHz): 20Log (f0/fpD)=20Log (3500/100)=
31dBc/Hz
By with reference to phase noise be -155dBc/Hz@1KHz come calculate deteriorate after phase noise are as follows:
- 155+31=-124dBc/Hz@1KHz；
Phase noise after deteriorating due to reference is higher than the phase noise in loop band, and the phase noise of final output is still
It is -123dBc/Hz@1KHz depending on the phase noise in loop band；Since the signal of 3.5GHz is also mixed with 12GHz signal,
The phase noise of final output depends on a signal source of difference, and 12GHz signal is frequency multiplication form, in addition comb spectrum is deteriorated
Are as follows: -155+20Log (12000/100)+4=109dBc/Hz@1KHz, so the phase noise of one local oscillator of final output are as follows: -
109dBc/Hz@1KHz。
C. the outer Analysis of Phase Noise of loop band
Phase noise outside loop bandwidth depends primarily on the phase noise of VCO itself, and specific index can be according to VCO skill
The phase noise of 100KHz~1MHz phase is estimated in art index.Phase noise estimation outside the loop band of the local vibration source is such as
Under: 130dBc/Hz@100KHz.
2) the noise restraint analysis of a local oscillator:
The spuious of one local oscillator mainly has phase demodulation spuious and is mixed spuious 2 kinds, since the phase demodulation frequency of 3.5GHz phaselocked loop is
100MHz, so phase demodulation is spuious to be respectively distributed to deviate at output frequency 100MHz, specific calculating is as follows:
For the phaselocked loop of charge-pump type, spuious phase demodulation includes mainly two various aspects, first is that leakage is spuious, second is that pulse is miscellaneous
It dissipates, spuious formula is as follows:
Spur=10log (10LeakageSpur/10+10PulseSpur/10)
If phase demodulation leakage current is 1nA, two for calculating it separately below are spuious.
LeakageSpur=BaseLeakageSpur+20log (Leakage/K φ)+20log | CL (s) |
=16.0+20log (1nA/5mA)+20log | CL (s) |
=-118+20log | CL (s) |
PulseSpur=BasePulseSpur+40log (Fspur/1Hz)+20log | CL (s) |
=-306dBc+40log (Fcomp/1Hz)+20log | CL (s) |
=-10+20log | CL (s) |
Spur ≈ PulseSpur=-10+20log | CL (s) |
Phase demodulation leakage current is 1nA, the not determining -306dBc of BasePulseSpur, is worth left and right herein.Due to
Phase demodulation frequency is 100MHz, and frequency is higher, and phase demodulation is spuious mainly to be determined by pulse is spuious, and loop bandwidth generally takes and is less than
500kHz can be very good to inhibit this spuious in this way in the low-pass nature of loop filter.According to previous experiences, this programme is selected
Spurious reduction can be accomplished -85dBc or less by the loop bandwidth of about 500kHz.The spuious of mixing generation is shown in that filter is spuious
Shown in distribution map, mixing and filtering output factors are greater than 75dBc.
(2) remaining index analysis
Two local oscillators, three local oscillators, emit pumping signal spuious and phase noise specifications can be better than a local oscillator index, nothing
Technical difficulty.The index obtained according to verification experimental verification situation is as follows:
750M phase noise specifications:
124dBc/Hz@1KHz,
122dBc/Hz@100KHz,
820M phase noise specifications:
123dBc/Hz@1KHz,
121dBc/Hz@100KHz,
7G phase noise specifications (3.5GHz frequency multiplication):
- 155+31=6=-116dBc/Hz@1KHz；
-120dBc/Hz@100KHz；
Spuious index: >=75dBc.
Output power is determined by the output amplifier of each local oscillator, can be seen that there are larger by the technical indicator of amplifier
Surplus, so being not difficult to realize.
DDS noise objectives and spuious:
Noise objective: -128dBc/Hz@1KHz,
-133dBc/Hz@100KHz。
DDS is spuious: broadband is spuious are as follows: 55dBc
It is 75dBc that 20KHz stepping data are surveyed in the narrowband 500KHz.
The key technical indexes of above-mentioned 3500MHz CRO oscillator is as shown in Figure 4.
Receiving channel circuit is as shown in Figure 5:
Receiving channel signal inputs 23.85GHz~24.15GHz through limiter, low-noise amplifier, filter, a mixing
Mono- intermediate frequency of 7.75GHz bandwidth 300MHz is obtained, amplification obtains the second intermediate frequency 750MHz into second level frequency mixer after filter
(signal bandwidth 500KHz), enter third level frequency mixer the second intermediate frequency 70MHz of output, warp after filter and amplification, numerical-control attenuator
Filter and amplification, numerical-control attenuator amplification are exported in low-pass filter.
Its key technical indexes are as follows:
(1) echo frequency: 24GHz ± 150MHz；
(2) one local frequencies: 15.5GHz；
(3) two local frequencies: (7.75MHz ± 150MHz)；
(4) three local frequencies: 820MHz；
(5) noise coefficient :≤4.5dB (low, room temperature) ,≤5dB (room temperature)；
(6) 5 bit switch of cavity design, for adjusting receiving channel gain, stepping 1dB, decay cumulative errors≤1dB；
(7) channel gain: 50 ± 1dB, when decaying to 0；
(8) Pin1dB >=-20dBm (when decaying to 20dB)；
(9) Pout1dB >=+10dBm (when decaying to 0dB)；
(10) radio-frequency filter bandwidth: BW-1dB >=300MHz (f0=24GHz)；
BW-3dB≤500MHz；
Out-of-band rejection: >=60dB (f0 ± 2G)；
(11) echo channel image frequency degree of suppression: >=70dB (corresponding with the first intermediate frequency and local oscillator)；
(12) receiving channel is to frequency synthesis component isolation: >=80dB；
(13) IF frequency: 70MHz；
(14) if bandpas filter bandwidth: BW-1dB >=5MHz；
BW-40dB≤40MHz；
(15) limiter maximum bears power (CW): >=1.5W；
(16) echo input port standing-wave ratio :≤1.5；
(17) power consumption :≤10W.
Technical indicator analytical calculation
(1) receiver bandwidth calculates
According to linear FM radar principle, the distance of effect target is obtained by the frequency spectrum that measurement deviates intermediate frequency, is calculated public
Formula is as follows:
F in formulabDifference frequency of the position apart from intermediate-freuqncy signal；ΔfFor linear frequency modulation bandwidth；R is target range；Tm is the modulation time；
C is the light velocity.
According to radar general requirement, linear frequency modulation bandwidth is 300MHz, and maximum target distance is 200m, and the modulation time is
1ms, can calculate maximum offset frequency fb is 400kHz.According to actual needs, enough bandwidth are reserved, receiver bandwidth is designed as
500kHz。
(2) noise coefficient, gain, output P-1dB power
NF=NF1+ ((NF2-1)/GP1)+((NF3-1)/(GP1*GP2))+((NF4-1)/(GP1*GP2*GP3)；
Receiving channel: the first order is waveguide transitions, Insertion Loss 0.4dB；The second level is limiter 0.75dB, the third level
It is the 1.8dB fourth stage for low noise block amplifier is echo filter device insertion loss 1.5dB, rear class frequency mixer 8dB etc..
Noise coefficient, gain, output P-1dB power calculation
Noise coefficient: 3.73dB；
Gain: 51.3dB；
Export P-1dB compression point :+11.88dBm
(3) limiter
Low-noise amplifier maximal input 18dBm, limiter index parameter are as shown in table 1:
NC1817C-1826 is a GaAs MMIC clipping chip, and frequency range covers 18GHz, and insertion loss is in work
Make to be less than 0.9dB in frequency range, input and output standing wave is small less than the 1.4. chip volume, and integrated level is high, and on piece is integrated with defeated
Enter to export capacitance.
Electrical parameter (TA=+25 DEG C)
Table 1
(4) echo inputs standing wave
It receives input standing wave and determines that echo standing wave < 1.5, curve is as shown in Figure 6 by limiter, low-noise amplifier.
(5) image frequency degree of suppression, as shown in Figure 7:
It receives image frequency degree of suppression: receiving down coversion, opposite clutter is easily processed, and joined filtering after low-noise amplifier
Device filters out the signal except 23.85GHz~24.15GHz, high-pass and low-pass filter has been added in intermediate frequency, to local oscillator, radio frequency
Signal is inhibited, and joined bandpass filter in two intermediate frequency local oscillators, and a local frequency is 15.5GHz, down coversion, therefore mirror
Frequent rate is 7.15GHz~7.45GHz, is inhibited from filter, inhibits to be greater than 90dBc.
A/D module
A/D module, i.e. data acquisition module, it is main to realize intermediate-freuqncy signal digitlization, due to receiver output signal intermediate frequency
For 70MHz, and actually useful bandwidth only has 500kHz, and in order to reduce the data volume of rear end output processing.Accordingly, it is considered to
Using lack sampling, and the mode for being drawn into low data rate is realized.
As shown in figure 8, data acquisition module mainly includes anti-aliasing filter, ADC, FPGA and Ethernet transmission module four
A part.Interface has clock to input XS1, and intermediate frequency inputs XS2, power input interface XS3, communication interface XS4 and sync cap
XS5。
It is 12.5 that ADC, which requires significance bit, selects the LTC2207 of Linear company, its Specifeca tion speeification is as follows:
(1) input voltage range (Vpp): 2.25V (11dBm)；
(2) maximum sample frequency: 105MSPS；
(3) without pseudo- peak dynamic range (SFDR): 82dB；
(4) noise floor (Noise Floor): 77.3dBFS；
(5) significance bit: 12.9.
Anti-confusion filtering design
Anti-aliasing filter is mainly used for preventing noise aliasing when ADC bandpass sampling.Anti aliasing bandpass filter
Parameter is as follows: centre frequency F0=70MHz；BW-1dB=3~5MHz；BW-40dB<40MHz；BW-80dB<70MHz
The aliasing schematic diagram of out-of-band noise is as shown in figure 9, be aliased into in-band noise intensity less than -77dB, lower than ADC's
12.5 significance bits.
FPGA is realized
FPGA uses the XC7K325T-1FFG900I of the K7 series of XILINX company, and signal processing flow is as shown in Figure 10.
ADC sampled data enters decimation filter, shared three-level decimation filter (2 times of pumpings after Digital Down Convert
Take, 5 times extract and 5 times extraction), be equivalent to the sample rate of 2MHz, then packed the data to after a high-pass filter
Fixed format is sent to transmission module.
Data are transmitted to computer by network interface by Ethernet transmission module.Computer is by unpacking software, by data solution
It calculates, hard disk, and label time and signal format information is written according to the data length of 1s.Meanwhile the data can also be put into
Specified memory is used for Back end data processing.
The above is only a preferred embodiment of the present invention, it should be understood that the present invention is not limited to described herein
Form should not be regarded as an exclusion of other examples, and can be used for other combinations, modifications, and environments, and can be at this
In the text contemplated scope, modifications can be made through the above teachings or related fields of technology or knowledge.And those skilled in the art institute into
Capable modifications and changes do not depart from the spirit and scope of the present invention, then all should be in the protection scope of appended claims of the present invention
It is interior.
Claims (10)
1. being applied to the radio frequency microwave system that water floats plant detections of radar, system is powered using the D.C. regulated power supply of complete machine,
It is characterized in that, which is made of receiving front-end, data acquisition module, frequency synthesis component three parts；
The receiving front-end accesses rf excitation signal, through filter amplifier, numerical-control attenuator, low after the processing of three-level frequency mixer
Bandpass filter output；
The data acquisition module is made of anti-aliasing filter, ADC, FPGA and Ethernet transmission module, for realizing intermediate frequency
Signal digitlization；
The frequency synthesis component is made of clock reference circuit, Waveform generating circuit, transmission channel, interface control circuit, is used
Synchronizing clock signals needed for local oscillation signal, data acquisition module needed for improving receiving front-end and chirped excitation
Signal.
2. the radio frequency microwave system according to claim 1 for floating plant detections of radar applied to water, which is characterized in that described
Three-level frequency mixer includes first order frequency mixer, second level frequency mixer, third level frequency mixer；
The rf excitation signal enters first order frequency mixer through limiter, low-noise amplifier, filter and is mixed to obtain
The first intermediate-freuqncy signal of 7.75GHz bandwidth 300MHz；
First intermediate-freuqncy signal enters second level frequency mixer through filter, amplifier and obtains the second intermediate frequency of 750MHz bandwidth 500KHz
Signal；
Second intermediate-freuqncy signal enters third level frequency mixer after filter, amplifier, numerical-control attenuator and obtains 70MHz bandwidth 5MHz
Third intermediate-freuqncy signal；
Third intermediate-freuqncy signal is exported through filter amplifier, numerical-control attenuator, low-pass filter.
3. the radio frequency microwave system according to claim 1 for floating plant detections of radar applied to water, which is characterized in that described
ADC is configured with clock input interface (XS1) and intermediate frequency input interface (XS2), and too net transmission module is configured with communication interface
(XS4), FPGA is configured with sync cap (XS5), and is configured with general power input interface (XS3).
4. the radio frequency microwave system according to claim 3 for floating plant detections of radar applied to water, which is characterized in that described
Anti-aliasing filter is mainly used for preventing noise aliasing when ADC bandpass sampling, parameter are as follows: centre frequency F0=
70MHz；BW-1dB=3~5MHz；BW-40dB<40MHz；BW-80dB<70MHz.
5. the radio frequency microwave system according to claim 4 for floating plant detections of radar applied to water, which is characterized in that described
ADC sampled data is entered three-level decimation filter by FPGA after Digital Down Convert, is followed successively by 2 times of extractions, 5 times of extractions, 5 times
It extracts, is equivalent to the sample rate of 2MHz, then packs the data to fixed format after a high-pass filter and be sent to ether
Net transmission module.
6. the radio frequency microwave system according to claim 5 for floating plant detections of radar applied to water, which is characterized in that described
Data are transmitted to computer by network interface by Ethernet transmission module, and data calculation is come out, pressed by unpacking software by computer
Hard disk, and label time and signal format information is written according to the data length of 1s, while the data are put into specified memory, for after
End data processing uses.
7. the radio frequency microwave system according to claim 1 for floating plant detections of radar applied to water, which is characterized in that described
Clock reference circuit generates 100MHz signal by constant-temperature crystal oscillator, does pectination to the source 12G all the way through the output of two power splitter of ADP-2-1W
Driving source is composed, is supplied respectively to 3.5GHz, CRO phase locked source through tetra- road power splitter of SCA-4-10 all the way；LTC6946-2 output receives three
Local oscillation signal 820MHz；Transmitting pumping signal 750MHz is exported through LTC6946-1；Through amplifier output 13dBm signal for signal
Processor is when acquisition clock.
8. the radio frequency microwave system according to claim 7 for floating plant detections of radar applied to water, which is characterized in that described
Waveform generating circuit work is as follows:
3.5GHz signal and comb spectrum are generated by CRO phase-locked loop circuit and generate after 12G signal is filtered, amplified that be mixed generation latter
Local oscillation signal, a local oscillation signal do a local oscillator for transmission channel and receiving module after filtering, amplification, function point；
Frequency sweep local oscillator divides two-way to do local oscillation signal through amplification, frequency multiplication, filtering generation 7GHz all the way by 3.5G；It is done all the way to AD9914
Clock, generates 600~900MHz signal, and two kinds of signals are logical for emitting through filtering, amplification, function point after the mixing of HMC558 frequency mixer
Road and output do two local oscillators to receiving module.
9. the radio frequency microwave system according to claim 8 for floating plant detections of radar applied to water, which is characterized in that described
Transmission channel generates 750MHz by frequency synthesizer and is mixed with 7.6~7.9GHz of frequency sweep local vibration source, with one after filter and amplification
Local oscillator 15.5GHz mixing, exports 23.85~24.15GHz signal, exports by filtering mixing, amplification through isolator.
10. -9 described in any item radio frequency microwave systems for floating plant detections of radar applied to water according to claim 1, feature
It is, the performance indexes of the system is as follows:
1) it motivates: 24GHz ± 50MHz (23.85~24.15GHz), power: 1~1.3W, phase noise: L (1K)≤-
103dBc/Hz, L (100K)≤- 113dBc/Hz；
2) local oscillator: 15.5GHz, power: 13dBm ± 1dBm, phase noise: L (1K)≤- 108dBc/Hz, L (100K)≤-
118dBc/Hz；
3) two local oscillator: 7.75GHZ (7.6~7.9), power: 10dBm ± 1dBm；Phase noise: it is better than a local oscillator；
4) three local oscillator: phase noise: 820MHz, power: 10dBm ± 1dBm are better than two local oscillators；
5) clock: 100MHz, power: 13 ± 0.5dBm,
Phase noise: L (1K)≤- 140dBc/Hz, L (100K)≤- 150dBc/Hz；
6) amplitude coincidence in swept-frequency signal modulating bandwidth :≤1dB；
7) output clutter: excitation >=60dBc, one local oscillator >=70dBc, two local oscillators >=70dBc, three local oscillators >=70dBc, clock >=
70dBc
8) harmonics restraint: excitation >=55dBc, one local oscillator >=60dBc, two local oscillators >=60dBc, three local oscillators >=60dBc, clock >=
60dBc
9) power fluctuation :≤0.5dB
10) power consumption :≤30W；
11) it puts and alternately exports each 1s, linear frequency modulation time 1ms, modulating bandwidth 300MHz with linear modulation frequently, fm linearity≤
2/1000。
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201820366704.4U CN208314194U (en) | 2018-03-16 | 2018-03-16 | The radio frequency microwave system of plant detections of radar is floated applied to water |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201820366704.4U CN208314194U (en) | 2018-03-16 | 2018-03-16 | The radio frequency microwave system of plant detections of radar is floated applied to water |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN208314194U true CN208314194U (en) | 2019-01-01 |
Family
ID=64721411
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201820366704.4U Expired - Fee Related CN208314194U (en) | 2018-03-16 | 2018-03-16 | The radio frequency microwave system of plant detections of radar is floated applied to water |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN208314194U (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108254745A (en) * | 2018-03-16 | 2018-07-06 | 成都锦江电子系统工程有限公司 | The radio frequency microwave system of plant detections of radar is floated applied to water |
| CN111224622A (en) * | 2019-11-21 | 2020-06-02 | 中电科仪器仪表有限公司 | Noise signal generating device and method with adjustable center frequency and bandwidth |
| CN114373662A (en) * | 2021-12-31 | 2022-04-19 | 核工业西南物理研究院 | Adjustable waveform device applied to microwave excitation source |
-
2018
- 2018-03-16 CN CN201820366704.4U patent/CN208314194U/en not_active Expired - Fee Related
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108254745A (en) * | 2018-03-16 | 2018-07-06 | 成都锦江电子系统工程有限公司 | The radio frequency microwave system of plant detections of radar is floated applied to water |
| CN108254745B (en) * | 2018-03-16 | 2023-09-29 | 成都锦江电子系统工程有限公司 | Radio frequency microwave system applied to radar detection of water-float plants |
| CN111224622A (en) * | 2019-11-21 | 2020-06-02 | 中电科仪器仪表有限公司 | Noise signal generating device and method with adjustable center frequency and bandwidth |
| CN111224622B (en) * | 2019-11-21 | 2023-07-25 | 中电科思仪科技股份有限公司 | Noise signal generating device and method with adjustable center frequency and bandwidth |
| CN114373662A (en) * | 2021-12-31 | 2022-04-19 | 核工业西南物理研究院 | Adjustable waveform device applied to microwave excitation source |
| CN114373662B (en) * | 2021-12-31 | 2023-12-26 | 核工业西南物理研究院 | Adjustable waveform device applied to microwave excitation source |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108254745A (en) | The radio frequency microwave system of plant detections of radar is floated applied to water | |
| CN208314194U (en) | The radio frequency microwave system of plant detections of radar is floated applied to water | |
| US5355513A (en) | Transponder with reply frequency derived from frequency of received interrogation signal | |
| CN201774528U (en) | Integrated Ku-waveband comprehensive digital coding instruction transmitting and receiving device | |
| CN103412317A (en) | Radio-frequency circuit structure for achieving function of converting GNSS satellite signals into baseband signals | |
| CN106533437B (en) | A kind of thin step frequency source circuit in broadband | |
| CN106487401A (en) | A kind of AIS receiver based on Super heterodyne principle | |
| CN105572645A (en) | S wave band wave observation radar radio frequency simulation front end circuit | |
| CN206450823U (en) | Radar transmission power is measured and automatic frequency tracking system | |
| CA2632062A1 (en) | Automatic gain control locked on to the received power probability density | |
| CN203554424U (en) | Eight-element antenna array-based GNSS anti-interference receiver radio frequency front-end device | |
| CN201197142Y (en) | Satellite beacon receiver | |
| CN106353740A (en) | Radio responding calibration equipment based on time sequence pulse encoding | |
| CN105429654A (en) | Frequency synthesizer for S-band wave observation radar | |
| CN108169720A (en) | X-band low phase noise navigation frequency modulated continuous wave radar emission system | |
| CN209765034U (en) | X-waveband vehicle-mounted detection radar receiving device | |
| CN205982623U (en) | Marine complex electromagnetic environment's outboard active jamming radio frequency source under battle conditions of simulation | |
| CN205027895U (en) | Biggest intermediate frequency energy tracking radar receiving system of self -adaptation | |
| CN106888015A (en) | A kind of broadband frequency agility millimeter-wave frequency synthesizer | |
| CN213602633U (en) | Radar integrated chip | |
| CN209299240U (en) | A kind of high performance wideband Receiver Module | |
| CN205232206U (en) | S wave band wave observation radar frequency synthesizer | |
| CN207817194U (en) | X-band low phase noise navigation frequency modulated continuous wave radar emission system | |
| CN209088926U (en) | One kind being based on DDS high-performance broadband signal source | |
| CN208013416U (en) | A kind of microwave Doppler radar system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20190101 |