CN101950015B - Linear frequency modulation continuous wave radar sensitivity frequency control method - Google Patents
Linear frequency modulation continuous wave radar sensitivity frequency control method Download PDFInfo
- Publication number
- CN101950015B CN101950015B CN201010504178A CN201010504178A CN101950015B CN 101950015 B CN101950015 B CN 101950015B CN 201010504178 A CN201010504178 A CN 201010504178A CN 201010504178 A CN201010504178 A CN 201010504178A CN 101950015 B CN101950015 B CN 101950015B
- Authority
- CN
- China
- Prior art keywords
- receiver
- frequency
- inductance
- sensitivity
- radar
- 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.)
- Active
Links
Images
Landscapes
- Radar Systems Or Details Thereof (AREA)
Abstract
The invention discloses a linear frequency modulation continuous wave radar sensitivity frequency control method. The method is realized in a way that: a second-order band elimination filter is used at the intermediate frequency of a receiver to simulate the echo attenuation characteristic of the target; the second-order band elimination filter is used for reducing the sensitivity of the receiver at short range so as to prevent the short range clutter from saturating the receiver, and used for keeping the receiver at the original gain and sensitivity at long range so as to ensure the acquisition and identification of a small target; the second-order band elimination filter is realized by using an LC network; the center frequency of the band elimination filter is the intermediate frequency of the receiver of the radar system; and the 3 dB bandwidth is determined according to the frequency modulation slope and the action range of the signal transmitted by the radar, and is twice of the 3dB bandwidth corresponding to one third of the maximum action range. The invention has the advantages of simple circuit form and convenient implementation. The test indicates that when the target range is within 10 Km, the amplitude attenuation of the target echo signal is about 46 dB, and the attenuation per frequency octave is about 12 dB.
Description
Technical field
The invention belongs to the application of electronic technology field, relate to a kind of control method, especially a kind of linear frequency modulation continuous wave radar sensitivity control method for frequency.
Background technology
Linear frequency modulation continuous wave (LFMCW) radar receiver export target echo intermediate frequency beat signal amplitude and radar are inversely proportional to the biquadratic of target range; Therefore along with the increase of distance; Signal amplitude decays rapidly, adds the variation of target sizes, and this just requires receiver that very big dynamic range is arranged.Be that remote little target can detect, closely general objective is unlikely to saturated simultaneously.To this problem, people have proposed the notion of sensitivity frequency control (SFC) and have studied, in continuous wave system radar; The pass that can utilize the difference frequency of echoed signal to be directly proportional with target range ties up to the enterprising action attitude compression of frequency field, and by the distance by radar equation, the biquadratic of echoed signal power and target range (Beat Signal frequency in the LFMCW radar) is inversely proportional to; The close-in target echoed signal is strong; The Beat Signal frequency is low, and a little less than the distant object echoed signal, but the Beat Signal frequency is high; The SFC circuit design requires the general approximate 12dB/ frequency multiplication slope of pressing of the interior amplitude versus frequency characte of band to rise; BPF. that adopts at present or numerical-control attenuator go the mode that realizes, all have some problems, adopt BPF. can not satisfy the requirement of 12dB/ frequency multiplication; Adopt numerical-control attenuator, the control more complicated.
Summary of the invention
Defective or deficiency to above-mentioned prior art exists the objective of the invention is to, and a kind of linear frequency modulation continuous wave radar sensitivity control method for frequency is provided.
In order to realize above-mentioned task, the present invention takes following technical solution:
A kind of linear frequency modulation continuous wave radar sensitivity control method for frequency; It is characterized in that this method adopts two rank rejection filters at the receiver intermediate frequency, be used for simulated target echo attenutation characteristic; The sensitivity of receiver is reduced, saturated to prevent that the short range clutter from receiver takes place; When remote, make receiver keep original gain and sensitivity, to guarantee obtaining and distinguishing of little target.
Described two rank rejection filters are realized with the LC network; The centre frequency of rejection filter is the IF-FRE of radar system receiver; Three dB bandwidth confirms according to the chirp rate and the operating distance of radar emission signal, is 2 times of 1/3rd pairing three dB bandwidths of maximum operating range.
Adopt the present invention to adopt the circuit of realizing SFC based on two rank rejection filters, circuit form is simple, and it is convenient to implement, through test shows, target range in 10Km, the about 46dB of target echo signal amplitude fading, and every octave about 12dB that decays.
Description of drawings
Fig. 1 is a circuit block diagram of the present invention;
Fig. 2 is circuit amplitude versus frequency characte figure of the present invention;
Fig. 3 is a basic circuit diagram of the present invention.
Describe in further detail the present invention is done below in conjunction with accompanying drawing and embodiment.
Embodiment
Know-why of the present invention is: the attenuation characteristic that combines the most smooth lowpass prototype filter stopband; When filter order (N) when equaling 2; Its attenuation characteristic satisfies the requirement of 12dB/ frequency multiplication slope, adopts two rank rejection filters at the receiver intermediate frequency so, just ability simulated target echo attenutation characteristic; The sensitivity of receiver is reduced, saturated to prevent that the short range clutter from receiver takes place; When remote, make receiver keep original gain and sensitivity, to guarantee obtaining and distinguishing of little target.
The SFC technology proposes to LFMCW system radar.The LFMCW radar return is proportional with distance with the intermediate frequency beat signal frequency of the mixing output that transmits, and the frequency f of intermediate frequency Beat Signal is:
f=
.τ=
.
Wherein, B is the frequency sweep bandwidth, and T is modulation period, and c is the light velocity, and R is the distance that target arrives radar antenna, and τ is that radar echo signal is with respect to the time delay that transmits.
Its theory diagram is as shown in Figure 1, and two rank rejection filters can be realized with the LC network.The centre frequency of rejection filter is the IF-FRE of radar system receiver, and three dB bandwidth can confirm according to the chirp rate and the operating distance of radar emission signal, is generally 2 times of 1/3rd pairing bandwidth of maximum operating range.
Suppose radar receiver IF-FRE IF=20MHz, the chirp rate of radar emission signal is 15MHz/1mS, and the maximum operating range of radar is 30Km, and the bandwidth that promptly 1/3rd maximum operating ranges are corresponding is 1MHz, so rejection filter centre frequency F
0=20MHz, three dB bandwidth is 2MHz, input, output impedance are 50 Ω.Its Beat Signal amplitude versus frequency characte is as shown in Figure 2.
In practice, circuit theory diagrams are as shown in Figure 3, comprise capacitor C 1, C2, C3 and C4, and inductance L 1, L2 and L3, and wherein, inductance L 3 is as the cascade inductance; Capacitor C 1, C3 and inductance L 1 conduct are as the single order rejection filter, and capacitor C 2, C4 and inductance L 2 are connected as the second order rejection filter, and inductance L 3 is connected between the two rank rejection filters.Its circuit form is simple, and it is convenient to implement.
Capacitor C 1 adopts stability high, and temperature range is wide, appearance value 27P ± 0.2 multi-layer ceramic capacitance; Inductance L 1 adopts high Q value, high stability, and inductance value is 2.3uH ± 0.2.
Capacitor C 2 adopts stability high, and temperature range is wide, appearance value 27P ± 0.2 multi-layer ceramic capacitance; Inductance L 2 adopts high Q value, high stability, and inductance value is 2.3uH ± 0.2.
It is the 390nH wire-wound inductor that inductance L 3 adopts inductance value.
As circuit input and output coupling usefulness, the appearance value all is 220P respectively for capacitor C 3, capacitor C 4.
Because the difference of each producer's components and parts precision causes debug results centre frequency or three dB bandwidth possibly have small difference, can finely tune capacitor C 1, capacitor C 2, inductance L 1, inductance L 2 values, makes it satisfy the corresponding index requirement.
Through test shows, the result is as shown in table 1
Table 1:
Can find out target range in 10Km by last table, the about 46dB of target echo signal amplitude fading, and the about 12dB of every octave decay satisfy its designing requirement.
Claims (1)
1. linear frequency modulation continuous wave radar sensitivity control method for frequency; It is characterized in that this method adopts the second order rejection filter at the receiver intermediate frequency, is used for simulated target echo attenutation characteristic; The sensitivity of receiver is reduced, saturated to prevent that the short range clutter from receiver takes place; When remote, make receiver keep original gain and sensitivity, to guarantee obtaining and distinguishing of little target;
Described second order bandstop filter is realized with the LC network; The centre frequency of bandstop filter is the IF-FRE of radar system receiver; Three dB bandwidth confirms based on the chirp rate and the operating distance of radar emission signal, is 2 times of 1/3rd pairing three dB bandwidths of maximum operating range;
Described LC network is by capacitor C 1, C2, C3 and C4, and inductance L 1, L2 and L3 composition, and wherein, inductance L 3 is as the cascade inductance; Capacitor C 1, C3 and inductance L 1 are as the single order rejection filter, and capacitor C 2, C4 and inductance L 2 are connected as the second order rejection filter, and inductance L 3 is connected between the second order rejection filter.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201010504178A CN101950015B (en) | 2010-10-12 | 2010-10-12 | Linear frequency modulation continuous wave radar sensitivity frequency control method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201010504178A CN101950015B (en) | 2010-10-12 | 2010-10-12 | Linear frequency modulation continuous wave radar sensitivity frequency control method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101950015A CN101950015A (en) | 2011-01-19 |
| CN101950015B true CN101950015B (en) | 2012-09-26 |
Family
ID=43453580
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201010504178A Active CN101950015B (en) | 2010-10-12 | 2010-10-12 | Linear frequency modulation continuous wave radar sensitivity frequency control method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101950015B (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103675783A (en) * | 2012-09-25 | 2014-03-26 | 中国航天科工集团第二研究院二〇七所 | A broadband multiband imaging coherent processing method |
| CN104076335A (en) * | 2014-06-16 | 2014-10-01 | 西安天和防务技术股份有限公司 | Rader receiving system |
| CN109283517B (en) * | 2018-08-13 | 2023-01-24 | 惠州市德赛西威汽车电子股份有限公司 | Method for dynamically adjusting distance resolution and distance measurement range of FMCW radar |
| CN110471053B (en) * | 2019-08-12 | 2022-12-09 | 深圳市镭神智能系统有限公司 | Variable frequency distance measuring device |
| CN113504512B (en) * | 2021-09-13 | 2021-12-28 | 成都雷通科技有限公司 | Active unmanned supervision miniaturized security radar in ISM frequency band |
| CN115453511B (en) * | 2022-11-09 | 2023-05-02 | 成都四维智慧电子科技有限公司 | Cooperative target accurate distance method based on millimeter wave radar chip |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3611380A (en) * | 1968-05-30 | 1971-10-05 | Philips Corp | Device for frequency correction in a radar equipment |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11287851A (en) * | 1998-03-31 | 1999-10-19 | Anritsu Corp | Radar apparatus |
-
2010
- 2010-10-12 CN CN201010504178A patent/CN101950015B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3611380A (en) * | 1968-05-30 | 1971-10-05 | Philips Corp | Device for frequency correction in a radar equipment |
Non-Patent Citations (3)
| Title |
|---|
| JP特开平11－287851A 1999.10.19 |
| 何李元等.调频连续波雷达灵敏度频率控制技术.《现代雷达》.1998,第20卷(第3期),第92-95页. * |
| 黄文奎等.线性调频连续波雷达灵敏度频率控制实现.《无线通信技术》.2004,(第3期),第55-57页. * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN101950015A (en) | 2011-01-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101950015B (en) | Linear frequency modulation continuous wave radar sensitivity frequency control method | |
| EP2960672B1 (en) | Adjustable self-interference cancellation in an fmcw radar altimeter | |
| US9075144B1 (en) | Digital radar altimeter | |
| CN109787646A (en) | A kind of 6-18GHz Phase amplitude-matched down conversion components | |
| CN103684638A (en) | Intermodulation distortion testing method of high-power device | |
| CN105978522A (en) | Absorption-type band pass filter assembly | |
| CN107576944A (en) | Change radiofrequency signal delay time remote analog system | |
| US10658723B1 (en) | Integrated high pass filter for microwave system in package | |
| CN105429654B (en) | A kind of S-band wave observation radar frequency synthesizer | |
| CN203691393U (en) | C wave band high performance transmit-receive device | |
| US4200840A (en) | Dual detection scheme for compressive receivers | |
| RU2538299C2 (en) | Harmonic filter of short-wave transmitter | |
| CN110931924A (en) | Novel absorption type functional band-pass filter based on phase difference principle | |
| CN208836123U (en) | A kind of 18-30GHz front end receiver component | |
| CN113381779B (en) | Ultra wideband receiver | |
| CN101694901A (en) | Multi-doubling frequency harmonic inhibiting waveguide wave filter | |
| CN107852142A (en) | Radio Frequency Duplexer | |
| CN112671371A (en) | Adjustable program-controlled notch filter | |
| US2543246A (en) | Signal delay device | |
| CN218630168U (en) | FMCW radar close-range strong echo suppression system based on high-pass filter | |
| Moskowitz et al. | Cross-talk considerations in time-division multiplex systems | |
| CN110912569A (en) | Ultrashort wave broadband transceiver | |
| CN219761021U (en) | Isolation improved radio frequency transceiver circuit | |
| US5307514A (en) | Frequency independent strong signal suppressor | |
| CN112014803B (en) | C-band transceiving component system based on linear frequency modulation interrupted continuous wave |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |