WO2004104628A1 - Method and system for unambiguous angle resolution of a sparse wide-band antenna array - Google Patents

Method and system for unambiguous angle resolution of a sparse wide-band antenna array Download PDF

Info

Publication number
WO2004104628A1
WO2004104628A1 PCT/SE2003/000833 SE0300833W WO2004104628A1 WO 2004104628 A1 WO2004104628 A1 WO 2004104628A1 SE 0300833 W SE0300833 W SE 0300833W WO 2004104628 A1 WO2004104628 A1 WO 2004104628A1
Authority
WO
WIPO (PCT)
Prior art keywords
band
antenna
wide
antenna array
array
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.)
Ceased
Application number
PCT/SE2003/000833
Other languages
French (fr)
Inventor
Kent Olof Falk
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Telefonaktiebolaget LM Ericsson AB
Original Assignee
Telefonaktiebolaget LM Ericsson AB
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Telefonaktiebolaget LM Ericsson AB filed Critical Telefonaktiebolaget LM Ericsson AB
Priority to AT03817024T priority Critical patent/ATE483172T1/en
Priority to PCT/SE2003/000833 priority patent/WO2004104628A1/en
Priority to DE60334413T priority patent/DE60334413D1/en
Priority to US10/557,466 priority patent/US7573419B2/en
Priority to EP03817024A priority patent/EP1629301B1/en
Priority to AU2003247297A priority patent/AU2003247297A1/en
Priority to US10/557,768 priority patent/US20060273948A1/en
Priority to EP03759126A priority patent/EP1636607A1/en
Priority to AU2003274857A priority patent/AU2003274857A1/en
Priority to PCT/SE2003/001616 priority patent/WO2004104627A1/en
Publication of WO2004104628A1 publication Critical patent/WO2004104628A1/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q21/00—Antenna arrays or systems
    • H01Q21/06—Arrays of individually energised antenna units similarly polarised and spaced apart
    • H01Q21/20—Arrays of individually energised antenna units similarly polarised and spaced apart the units being spaced along or adjacent to a curvilinear path
    • H01Q21/205—Arrays of individually energised antenna units similarly polarised and spaced apart the units being spaced along or adjacent to a curvilinear path providing an omnidirectional coverage
    • 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
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/02—Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems
    • G01S13/0209—Systems with very large relative bandwidth, i.e. larger than 10 %, e.g. baseband, pulse, carrier-free, ultrawideband
    • 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
    • G01S7/28—Details of pulse systems
    • G01S7/2813—Means providing a modification of the radiation pattern for cancelling noise, clutter or interfering signals, e.g. side lobe suppression, side lobe blanking, null-steering arrays
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q21/00—Antenna arrays or systems
    • H01Q21/06—Arrays of individually energised antenna units similarly polarised and spaced apart
    • H01Q21/08—Arrays of individually energised antenna units similarly polarised and spaced apart the units being spaced along or adjacent to a rectilinear path
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q21/00—Antenna arrays or systems
    • H01Q21/28—Combinations of substantially independent non-interacting antenna units or systems
    • 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
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/02—Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems
    • G01S2013/0236—Special technical features
    • G01S2013/0281—LPI, Low Probability of Intercept radar

Definitions

  • the present invention relates to wide-band antenna arrays, and more particularly to a method and system for unambiguous angle resolution of a sparse wide-band antenna array.
  • Another problem is that array antennas having a large number of elements will be undesired complex and expensive. Furthermore rotating antennas are generally undesired as that implies further mechanical complexity. From a strategic point of view there is also a desire to be able to keep peak power as low as possible to minimize the risk of being detected.
  • Typical solutions of today utilize fully filled arrays and rotating antennas combined with range coded long pulses, for instance using a binary phase code.
  • Signal classification is difficult with present solutions and different hardware solutions have to be used for a respective function category, for instance, a radar function or a jamming function.
  • a method and a system for unambiguous angle resolution of a sparse wideband array antenna in a bistatic or monostatic radar configuration utilize an ultra-wide-band signal, which in a typical embodiment may be continuous bandwidth limited white noise or colored noise.
  • the noise signal is generated and radiated for instance by an omnidirectional transmitting antenna covering the entire reception range of a receiving array.
  • An echo signal is received by the receiving array containing n antenna elements.
  • the n antenna elements are generally positioned with separation distances of several wavelengths without creating strong grating lobes.
  • the convolution of the radiated output signal and the received echo input signal will give the target range information, the individual time- delay setting for each antenna element will give an unambiguous angular resolution.
  • FIG. 1 illustrates an illustrative array antenna according to the present inventive concept
  • FIG. 3 illustrates in a number of graphs a) to f) the auto-correlation function for white bandwidth limited noise using a bandwidth from 200% and down to 6.25%;
  • FIG. 4 illustrates in a graph the convolution of radiated and received signal as a function of signal-to-noise ratio
  • FIG. 5 illustrates in a block diagram three bearing channels
  • FIG. 6 illustrates a wide-band pattern for a linear receive array containing a binary number of 1 to 512 elements for a central noise transmitter
  • FIG. 7 illustrates a wide-band pattern for a circular receiver array containing a binary number of 4 to 2048 elements for a central omnidirectional noise transmitter.
  • a very broad-banded signal which may be continuous band-limited white or colored noise is generated and transmitted by an antenna, which for instance is isotropic in its horizontal plane.
  • the echo signal in a bistatic or monostatic configuration is received by n receiver antennas.
  • the n antennas are spaced at distances of several wavelengths, e.g. 10 wavelengths at fmin. These antennas being placed at separation distances of several wavelengths do not create dominating grating lobes due to the frequency spread achieved by the large bandwidth.
  • grating lobes we refer to periodic repetitions of a main lobe.
  • Each antenna may be a vertical array to increase the gain in the horizontal plane.
  • the transmitting antenna preferably is positioned as far as possible from the receiving antennas and for instance at a different height than the receiving antennas.
  • a structure carrying the transmitter antenna is denoted as reference number 5.
  • a transmitter and n receivers with accompanying signal processing is housed in the electronic unit 7.
  • One transmitter, n receivers with accompanying signal processing being housed in the base of the array.
  • Equation (2) The sum from all n receiver antennas may then for a spot target be written according to Equation (2):
  • the principle for resolution in angular direction is that grating lobes of respective frequency will land in different directions. The level of other lobes than the main lobe seen over the entire bandwidth will be expected to be low as grating lobes over the wide bandwidth generally will counteract each other.
  • the radiated noise signal is assumed to be e(t).
  • Ree( ⁇ ) is the autocorrelation function of e(t). If we presume that e(t) is white bandwidth limited noise from ⁇ x to ⁇ it is easy to prove that the auto-correlation function can be written according to Equation (5) below:
  • ⁇ denotes the noise standard deviation and the mean power of the noise signal is ⁇ 2 .
  • Equation (7) The sum of all n receiver antennas then can be written according to Equation (7):
  • Figure 6 illustrates power normalized to the main beam as function of angle -90 to + 90 degrees for variation of number of elements in binary steps from 1 to 512. As can be seen already with 8 elements a good angular resolution is obtained with a surrounding signal level at - 10 dB .
  • Equation (10) For a second embodiment of the present invention assume a circular array having the main lobe of each antenna element pointing in a radial direction and according to Equation (10) has the simple frequency independent shape:
  • Equation (11) The sum, from all n receiving antennas then can be written according to Equation (11):
  • E ⁇ ( ⁇ ) ⁇ e(t- ⁇ + ⁇ n ( ⁇ )- ⁇ n ( ⁇ )).EL( ⁇ -n 2 ⁇
  • the antenna array may well be formed as a conformal array and calculated in a similar way corresponding to the above examples of the linear and circular array.
  • Simulations Figure 3 demonstrates the auto-correlation function for white bandwidth limited noise according to equation (5). As can be seen a bandwidth of 100% is needed to get the sidelobes down to a reasonable level.
  • Figure 4 illustrates a simulation result when signal-to-noise was varied.
  • the target is an object, 1 meter long, standing still at a distance of 750 meters.
  • the target area as function of distance is an equally distributed random number per distance sample.
  • the sampling rate in this case was 50 GHz.
  • From the response of the convolution the signature of the target can be interpreted in the form of the derivative of target area as function of distance. This may then be used to classify and identify the target by comparison with suitable library data.
  • Figure 5 illustrates a principal block diagram of three bearing channels.
  • Noise source N, antenna elements, power amplifier PA, filters and A/D converters are common for all bearing channels.
  • T By varying the time delays T the direction of the main lobe is selected.
  • many parallel bearing and distance channels are realized, such that the full solid angular sector continuously can be watched, for example almost ⁇ 90° for a linear receiving antenna array and ⁇ 180° for a circular receiver antenna array.
  • FIG. 7 illustrates power normalized to the main beam as function of angle -180 to + 180 degrees for variation of number of elements in binary steps from 4 to 2048.
  • a good angular resolution is obtained at - 12 dB.
  • 8 elements correspond to an inter-element distance corresponding to around 8 wavelengths along the perimeter of the array.
  • Figure 7 further illustrates that a further increase of elements will not mean any significant further improvement from what is already achieved at element distances well above half a wavelength, i.e. 64 elements corresponding to two wavelengths at the lowest frequency.
  • half a wavelength is generally the limit for avoiding grating lobes periodically repeating themselves in an array according to the state of the art.
  • the auto-correlation function for the radiated signal appears in the angular direction.
  • the autocorrelation function as a matter of fact can be chosen such that desired characteristics are obtained.
  • the Fourier transform of the selected autocorrelation function gives necessary power spectrum of the radiated signal.

Landscapes

  • Engineering & Computer Science (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Radar Systems Or Details Thereof (AREA)
  • Variable-Direction Aerials And Aerial Arrays (AREA)
  • Table Equipment (AREA)
  • Measurement And Recording Of Electrical Phenomena And Electrical Characteristics Of The Living Body (AREA)
  • External Artificial Organs (AREA)

Abstract

The present inventive concept for bistatic or monostatic radar utilization discloses a method and a system for unambiguous angle resolution of a sparse wide-band array antenna by utilizing an ultra wide-band signal, generally a wide-band noise signal which may be continuous bandwidth limited white or colored noise. The noise signal is typically generated and radiated by a transmitting antenna covering the entire reception range of a receiving sparse antenna array. An echo signal is received by the sparse receiving array containing n antenna elements, which are generally positioned with separation distances of several wavelengths without creating strong grating lobes due to the type of generated transmit signal. By means of a selected auto-correlation function defining the wide-band noise signal power spectrum, the convolution of the radiated output signal and the received echo input signal will give the target range information, the individual time-delay setting for each antenna element will give an unambiguous angular resolution.

Description

METHOD AND SYSTEM FOR UNAMBIGUOUS ANGLE RESOLUTION OF A SPARSE WIDE-BAND ANTENNA
ARRAY.
TECHNICAL FIELD The present invention relates to wide-band antenna arrays, and more particularly to a method and system for unambiguous angle resolution of a sparse wide-band antenna array.
BACKGROUND
It is complicated or even almost impossible to build classic wide-band array antennas providing good angle resolution. The reason for this is that the separation of the elements is set by the highest frequency, typically half a wavelength at fmax- The physical size of the elements is set by the lowest frequency, typically half a wavelength at fmin. Thus, there is apparently a contradiction between obtaining a wide bandwidth of the antenna and the array density needed to avoid grating lobes at large scan angles.
Another problem is that array antennas having a large number of elements will be undesired complex and expensive. Furthermore rotating antennas are generally undesired as that implies further mechanical complexity. From a strategic point of view there is also a desire to be able to keep peak power as low as possible to minimize the risk of being detected.
Typical solutions of today utilize fully filled arrays and rotating antennas combined with range coded long pulses, for instance using a binary phase code. Signal classification is difficult with present solutions and different hardware solutions have to be used for a respective function category, for instance, a radar function or a jamming function.
Therefore there is a demand for further improvements of wide-band arrays for obtaining also a better angular resolution produced by a less complex solution compared to the state of the art. SUMMARY OF THE INVENTION A method and a system for unambiguous angle resolution of a sparse wideband array antenna in a bistatic or monostatic radar configuration utilize an ultra-wide-band signal, which in a typical embodiment may be continuous bandwidth limited white noise or colored noise. The noise signal is generated and radiated for instance by an omnidirectional transmitting antenna covering the entire reception range of a receiving array. An echo signal is received by the receiving array containing n antenna elements. The n antenna elements are generally positioned with separation distances of several wavelengths without creating strong grating lobes. By means of a selected auto-correlation function defining the wide-band noise signal power spectrum, the convolution of the radiated output signal and the received echo input signal will give the target range information, the individual time- delay setting for each antenna element will give an unambiguous angular resolution.
A system according to the present invention is set forth by the independent claim 1, and further embodiments of the invention are set forth by the dependent claims 2 to 9.
Further a method according to the present invention is set forth by the independent claim 10, and further embodiments are defined by the dependent claims 11 to 17.
SHORT DESCRIPTION OF THE DRAWINGS
The invention, together with further objects and advantages thereof, may best be understood by referring to the following detailed description taken together with the accompanying drawings, in which:
FIG. 1 illustrates an illustrative array antenna according to the present inventive concept; FIG. 2 illustrates a principal embodiment of a wide-band array according to the present invention having the number of receiving antenna elements n = 32;
FIG. 3 illustrates in a number of graphs a) to f) the auto-correlation function for white bandwidth limited noise using a bandwidth from 200% and down to 6.25%;
FIG. 4 illustrates in a graph the convolution of radiated and received signal as a function of signal-to-noise ratio;
FIG. 5 illustrates in a block diagram three bearing channels;
FIG. 6 illustrates a wide-band pattern for a linear receive array containing a binary number of 1 to 512 elements for a central noise transmitter; and
FIG. 7 illustrates a wide-band pattern for a circular receiver array containing a binary number of 4 to 2048 elements for a central omnidirectional noise transmitter.
DETAILED DESCRIPTION
In a typical illustrative embodiment a very broad-banded signal, which may be continuous band-limited white or colored noise is generated and transmitted by an antenna, which for instance is isotropic in its horizontal plane. The echo signal in a bistatic or monostatic configuration is received by n receiver antennas. The n antennas are spaced at distances of several wavelengths, e.g. 10 wavelengths at fmin. These antennas being placed at separation distances of several wavelengths do not create dominating grating lobes due to the frequency spread achieved by the large bandwidth. By grating lobes we refer to periodic repetitions of a main lobe. Each antenna may be a vertical array to increase the gain in the horizontal plane. To minimize leakage between the transmitting antenna and the receiver antennas the transmitting antenna preferably is positioned as far as possible from the receiving antennas and for instance at a different height than the receiving antennas. Figure 1 illustrates a principal shape with n = 3, the transmitting antenna is denoted as 1 and the receiver antennas are denoted 3. A structure carrying the transmitter antenna is denoted as reference number 5. A transmitter and n receivers with accompanying signal processing is housed in the electronic unit 7. Figure 2 illustrates a practical embodiment of a circular array with n = 32, the transmitting antenna sitting elevated in the middle and the receiving antenna in a ring below. One transmitter, n receivers with accompanying signal processing being housed in the base of the array.
The idea of using a continuous ultra broad-band signal like band-limited white noise is, that only the central lobe can be considered additive for all frequencies within the wide band used. Grating lobes resulting from the different frequencies within the broadband signal will not be added in the same way as the grating lobe pattern will for each separate frequency component being a function of the spacing of antenna elements used. This will result in an angle resolution, which may be used, for instance, for radar purposes. This was simulated in a frequency range of 6 - 18 GHz, which can simply be obtained. The distance to the target is determined by finding the peaks in the convolution between the input and output signal.
Principle for range resolution
Assume an array wherein the main lobe of each antenna element points in a radial direction in the circular case and in a direction θ = 0 in the linear case. Further assume that the diagrams of the elements have the simple frequency independent form according to Equation (1):
Figure imgf000006_0001
The radiated noise signal is assumed to be et(t). The sum from all n receiver antennas may then for a spot target be written according to Equation (2):
Figure imgf000006_0002
Where R, φ are distance and bearing, respectively, to the target, θ means current antenna search angle. Time corrections τn are calculated according to Equation (3) :
Figure imgf000006_0003
Convolution between the radiated and the received signal can, according to Equation (4), be written:
Figure imgf000006_0004
Figure imgf000007_0001
( 2 ft π -σ N-\ WXβ) EL(Θ) Linear array J°» ■ dω
2π ' J ω2 -ω, „=0 EL θ-n Circular array
N
Figure imgf000007_0002
Where & denotes the Fourier transform. We have assumed that et(t) is white bandwidth limited noise from ωλ to ω2 ■
Principle for angle resolution
The principle for resolution in angular direction is that grating lobes of respective frequency will land in different directions. The level of other lobes than the main lobe seen over the entire bandwidth will be expected to be low as grating lobes over the wide bandwidth generally will counteract each other. The radiated noise signal is assumed to be e(t). Ree(τ) is the autocorrelation function of e(t). If we presume that e(t) is white bandwidth limited noise from ωx to ω it is easy to prove that the auto-correlation function can be written according to Equation (5) below:
Figure imgf000007_0003
Here σ denotes the noise standard deviation and the mean power of the noise signal is σ2.
Linear array For a basic first embodiment of the present invention assume a linear array with a length L where the main lobe of each antenna element points in the direction θ = 0 and has the simple frequency independent shape according to Equation (6):
Figure imgf000008_0001
The sum of all n receiver antennas then can be written according to Equation (7):
N-\
EΣ (θ) = EL(θ) - ∑e(t -^ + τn (φ)-τn (θ)) (7) n=0
Where R, φ are distance and bearing to the target, respectively, θ is the current antenna search angle. Time corrections τn are calculated according to Equation (8):
Figure imgf000008_0002
Expected value of the antenna diagram AP(Θ, φ) is calculated according to Equation 9:
AP(θ,φ) = \O Λog{E[El (θ,φ)]} (9) We will now be able to perform the following calculation:
Figure imgf000009_0001
(^ (^))2 ' Σ n=0 m Σ=0 X- (*, (Φ) ~ » (<>) ~ *. (Φ) + *. W)
Figure 6 illustrates power normalized to the main beam as function of angle -90 to + 90 degrees for variation of number of elements in binary steps from 1 to 512. As can be seen already with 8 elements a good angular resolution is obtained with a surrounding signal level at - 10 dB .
Circular array
For a second embodiment of the present invention assume a circular array having the main lobe of each antenna element pointing in a radial direction and according to Equation (10) has the simple frequency independent shape:
Figure imgf000009_0002
The sum, from all n receiving antennas then can be written according to Equation (11):
EΣ (θ) = ∑e(t-^ + τn (φ)-τn (θ)).EL(θ-n 2π
(11) π=0 V N R, φ are distance and bearing to the target, respectively, and θ is the current antenna search angle. Time corrections τn are calculated according to Equation (12):
Figure imgf000010_0001
Expected value of the antenna diagram AP(Θ, φ) is calculated according to Equation (13):
^E(69,^) = 10-log{E[EΣ 2 (69^)]} (13)
Then, we can perform the following calculation:
Figure imgf000010_0002
Conformal array
In yet a third embodiment the antenna array may well be formed as a conformal array and calculated in a similar way corresponding to the above examples of the linear and circular array.
Simulations Figure 3 demonstrates the auto-correlation function for white bandwidth limited noise according to equation (5). As can be seen a bandwidth of 100% is needed to get the sidelobes down to a reasonable level.
For the simulations 100% bandwidth and a center frequency of 12 GHz was chosen. In other words the frequency range of the radar was 6 - 18 GHz. The distance to the target is determined by finding the peaks of the convolution between input and output signal.
Figure 4 illustrates a simulation result when signal-to-noise was varied. In this case the target is an object, 1 meter long, standing still at a distance of 750 meters. The target area as function of distance is an equally distributed random number per distance sample. The sampling rate in this case was 50 GHz. From the response of the convolution the signature of the target can be interpreted in the form of the derivative of target area as function of distance. This may then be used to classify and identify the target by comparison with suitable library data.
Figure 5 illustrates a principal block diagram of three bearing channels. Noise source N, antenna elements, power amplifier PA, filters and A/D converters are common for all bearing channels. By varying the time delays T the direction of the main lobe is selected. In a fully supported system many parallel bearing and distance channels are realized, such that the full solid angular sector continuously can be watched, for example almost ±90° for a linear receiving antenna array and ±180° for a circular receiver antenna array.
The principle for the angular resolution utilized is that grating lobes integrated over the large frequency range become rather low, while signals of a main lobe generally will be summed, which of course clearly comes out from the auto-correlation. Figure 7 illustrates power normalized to the main beam as function of angle -180 to + 180 degrees for variation of number of elements in binary steps from 4 to 2048. As can be seen already with 32 elements a good angular resolution is obtained at - 12 dB. In this simulation for instance 8 elements correspond to an inter-element distance corresponding to around 8 wavelengths along the perimeter of the array. Figure 7 further illustrates that a further increase of elements will not mean any significant further improvement from what is already achieved at element distances well above half a wavelength, i.e. 64 elements corresponding to two wavelengths at the lowest frequency. In standard thinking half a wavelength is generally the limit for avoiding grating lobes periodically repeating themselves in an array according to the state of the art.
As is also seen in Figures 6 and 7 the auto-correlation function for the radiated signal appears in the angular direction. Interesting is that the autocorrelation function as a matter of fact can be chosen such that desired characteristics are obtained. The Fourier transform of the selected autocorrelation function gives necessary power spectrum of the radiated signal.
It will be understood by those skilled in the art that various modifications and changes could be made to the present invention without departure from the spirit and scope thereof, which is defined by the appended claims.

Claims

CLAIMS 1. A system for unambiguous angular resolution in connection with a sparse wide-band antenna array for bistatic or monostatic radar operation, characterized in that an ultra wide-band band microwave signal is generated and radiated via a transmitter antenna; a receiving microwave antenna array is formed by n of individual antenna elements generally distributed at distances of several wavelengths; whereby a resulting radar range echo response is achieved as a convolution between sampled radiated wide-band output signal and sampled total input signal received by the receiving antenna array as echoes from a target object, the convolution result being read out as a signature of the target.
2. The system according to claim 1, characterized in that the ultra wide-band microwave signal is generated as band-limited white noise, the convolution result being read out as a signature of the target for 100% bandwidth approximately in form of the derivative of the target area as function of distance.
3. The system according to claim 1 , characterized in that the ultra wide-band microwave signal is generated as band-limited colored noise, by using a selected auto-correlation function for the generated noise.
4. The system according to claim 1 , characterized in that the ultra wide-band microwave signal comprises a frequency range of the same order as the center frequency.
5. The system according to claim 1, characterized in that the antenna arrays are linear arrays.
6. The system according to claim 1, characterized in that the antenna arrays are circular arrays.
7. The system according to claim 1 , characterized in that the antenna array is formed as an conformal array.
8. The system according to claim 1, characterized in that in an monostatic circular configuration an omnidirectional transmitting antenna array is generally positioned at another height than the n receiving microwave antenna arrays to minimize leakage between transmit and receive antennas.
9. The system according to claim 6, characterized in that the transmitter antenna array and the n receiving antenna arrays are omnidirectional .
10. A method for obtaining unambiguous angular resolution in connection with a sparse wide-band antenna array for bistatic or monostatic radar operation, characterized by the steps of generating an ultra wide-band band microwave signal being radiated via a transmitter antenna; arranging a receiving microwave antenna array formed by n of individual antenna elements generally distributed at distances of several wavelengths; achieving a resulting radar range echo response by a convolution between sampled radiated ultra wide-band output signal and sampled total input signal received by the receiving antenna array as echoes from a target object, reading out the result of the convolution as a signature of the target.
11. The method according to claim 10, characterized by the further steps of generating the ultra wide-band microwave signal as band-limited white noise, and reading out the convolution result as a signature of the target for 100% bandwidth approximately in form of the derivative of the target area as function of distance.
12. The method according to claim 10, characterized by the further step of generating the ultra wide-band microwave signal as band-limited colored noise by using a selected auto-correlation function for the generated noise.
13. The method according to claim 10, characterized by the further step of generating the ultra wide-band microwave signal in a frequency range having an order about equal to the value of the center frequency.
14. The method according to claim 10, characterized by the further step of using linear arrays as receiving antenna.
15. The method according to claim 10, characterized by the further step of using circular arrays as receiving antenna.
16. The method according to claim 10, characterized by the further step of using an conformal array as antenna.
17. The method according to claim 10, characterized by the further step of in a monostatic circular configuration generally positioning an omnidirectional transmitting antenna array at a different height compared to the receiving microwave antenna array to minimize leakage between transmit and receive antennas.
18. The method according to claim 15, characterized by the further step of making the transmitter antenna array and the n receiving antenna arrays omnidirectional
* * * * *
PCT/SE2003/000833 2003-05-21 2003-05-21 Method and system for unambiguous angle resolution of a sparse wide-band antenna array Ceased WO2004104628A1 (en)

Priority Applications (10)

Application Number Priority Date Filing Date Title
AT03817024T ATE483172T1 (en) 2003-05-21 2003-05-21 METHOD AND SYSTEM FOR UNambiguous angular resolution of a sparse broadband antenna array
PCT/SE2003/000833 WO2004104628A1 (en) 2003-05-21 2003-05-21 Method and system for unambiguous angle resolution of a sparse wide-band antenna array
DE60334413T DE60334413D1 (en) 2003-05-21 2003-05-21 METHOD AND SYSTEM FOR UNBALANCED ANGLE RESOLUTION OF A PERMANENT BROAD ANTENNA GROUP
US10/557,466 US7573419B2 (en) 2003-05-21 2003-05-21 Method and system for unambiguous angle resolution of a sparse wide-band antenna array
EP03817024A EP1629301B1 (en) 2003-05-21 2003-05-21 Method and system for unambiguous angle resolution of a sparse wide-band antenna array
AU2003247297A AU2003247297A1 (en) 2003-05-21 2003-05-21 Method and system for unambiguous angle resolution of a sparse wide-band antenna array
US10/557,768 US20060273948A1 (en) 2003-05-21 2003-10-20 Selectable range lobes using wide-band array
EP03759126A EP1636607A1 (en) 2003-05-21 2003-10-20 Selectable range lobes using wide-band array
AU2003274857A AU2003274857A1 (en) 2003-05-21 2003-10-20 Selectable range lobes using wide-band array
PCT/SE2003/001616 WO2004104627A1 (en) 2003-05-21 2003-10-20 Selectable range lobes using wide-band array

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/SE2003/000833 WO2004104628A1 (en) 2003-05-21 2003-05-21 Method and system for unambiguous angle resolution of a sparse wide-band antenna array

Publications (1)

Publication Number Publication Date
WO2004104628A1 true WO2004104628A1 (en) 2004-12-02

Family

ID=33476139

Family Applications (2)

Application Number Title Priority Date Filing Date
PCT/SE2003/000833 Ceased WO2004104628A1 (en) 2003-05-21 2003-05-21 Method and system for unambiguous angle resolution of a sparse wide-band antenna array
PCT/SE2003/001616 Ceased WO2004104627A1 (en) 2003-05-21 2003-10-20 Selectable range lobes using wide-band array

Family Applications After (1)

Application Number Title Priority Date Filing Date
PCT/SE2003/001616 Ceased WO2004104627A1 (en) 2003-05-21 2003-10-20 Selectable range lobes using wide-band array

Country Status (6)

Country Link
US (2) US7573419B2 (en)
EP (2) EP1629301B1 (en)
AT (1) ATE483172T1 (en)
AU (2) AU2003247297A1 (en)
DE (1) DE60334413D1 (en)
WO (2) WO2004104628A1 (en)

Families Citing this family (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4283170B2 (en) * 2003-12-17 2009-06-24 株式会社デンソー Object detection device
JP4447946B2 (en) * 2004-03-22 2010-04-07 富士通テン株式会社 Radar equipment
WO2006028395A1 (en) * 2004-09-10 2006-03-16 Industrial Research Limited Imaging system
EP1788940A4 (en) * 2004-09-10 2009-09-09 Ind Res Ltd PROCESS FOR SYNTHETIC FOCUSING
US20090024026A9 (en) * 2004-09-10 2009-01-22 Simpkin Ray A Imaging system
US7755535B2 (en) * 2006-02-09 2010-07-13 Telefonaktiebolaget Lm Ericsson (Pub) Radar system comprising at least two spatially separated antenna units
WO2007105963A1 (en) * 2006-03-10 2007-09-20 Industrial Research Limited Imaging system
US7884757B2 (en) * 2007-10-18 2011-02-08 Tialinx, Inc. Scanning ultra wideband impulse radar
US9250319B2 (en) * 2010-10-21 2016-02-02 Reutech Radar Systems (Proprietary) Limited Floodlight radar system for detecting and locating moving targets in three dimensions
CN103983948B (en) * 2014-05-29 2016-05-25 西安电子科技大学 Angle on target Joint method of estimation based on rarefaction representation
CN104931948B (en) * 2015-05-25 2018-03-06 西安电子科技大学昆山创新研究院 A kind of improved method of reception scheme of FDA radars based on conventional beams scanning
JP2017044689A (en) * 2015-08-27 2017-03-02 日本電産エレシス株式会社 Radar antenna and radar apparatus
US11923924B2 (en) * 2018-02-26 2024-03-05 Parallel Wireless, Inc. Miniature antenna array with polar combining architecture
WO2019196017A1 (en) * 2018-04-10 2019-10-17 海能达通信股份有限公司 Antenna device
CN108777371B (en) * 2018-04-10 2020-11-17 海能达通信股份有限公司 Antenna device

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5446461A (en) * 1994-04-28 1995-08-29 Hughes Missile Systems Company Concrete penetrating imaging radar
US20020190915A1 (en) * 2001-02-26 2002-12-19 Barnes Mark A. Impulse radar antenna array and method

Family Cites Families (39)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3346862A (en) * 1962-05-24 1967-10-10 Martin Marietta Corp Correlation detection systems
US3281842A (en) * 1963-01-16 1966-10-25 Sperry Rand Corp Electronic means for suppressing range side lobes of a compressed pulse signal
US3441931A (en) * 1968-01-22 1969-04-29 Raytheon Co Moving target indicator clutter reducing apparatus
US4042928A (en) * 1974-03-22 1977-08-16 Esl Incorporated Technique of characterizing the nature of a radiation path transfer function by a few constants
US4114153A (en) 1974-06-26 1978-09-12 Neidell Norman S Echo location systems
US4099182A (en) * 1975-02-13 1978-07-04 Raytheon Company Signal receiver
US4144153A (en) * 1975-10-03 1979-03-13 Takiron Co., Ltd. Radiation process for producing 1,2-polybutadiene foamed products
US4062928A (en) * 1977-03-17 1977-12-13 American Hydrocarbon Company Process for the preparation of nitric acid
US4150378A (en) * 1978-03-13 1979-04-17 International Standard Electric Corporation Height finding radar
US4450531A (en) * 1982-09-10 1984-05-22 Ensco, Inc. Broadcast signal recognition system and method
DE3417073A1 (en) * 1984-05-09 1985-11-14 Licentia Patent-Verwaltungs-Gmbh, 6000 Frankfurt RADAR ARRANGEMENT
US4644356A (en) * 1984-10-31 1987-02-17 The United States Of America As Represented By The Secretary Of The Air Force Bistatic coherent radar receiving system
US4894660A (en) * 1988-10-12 1990-01-16 General Electric Company Range sidelobe reduction by aperiodic swept-frequency subpulses
US5140332A (en) * 1989-07-13 1992-08-18 Westinghouse Electric Corp. Short pulse radar system with a long pulse transmitter
US5210820A (en) * 1990-05-02 1993-05-11 Broadcast Data Systems Limited Partnership Signal recognition system and method
US5093670A (en) * 1990-07-17 1992-03-03 Novatel Communications, Ltd. Logarithmic periodic antenna
GB9211086D0 (en) * 1992-05-23 1992-07-15 Cambridge Consultants Short range electromagnetic sensing signal processing
US5519400A (en) * 1993-04-12 1996-05-21 The Regents Of The University Of California Phase coded, micro-power impulse radar motion sensor
US5351053A (en) * 1993-07-30 1994-09-27 The United States Of America As Represented By The Secretary Of The Air Force Ultra wideband radar signal processor for electronically scanned arrays
RU2101717C1 (en) 1994-09-26 1998-01-10 Государственный центральный научно-исследовательский радиотехнический институт Method for measurement of effective scattering area and device which implements said method
US5574747A (en) * 1995-01-04 1996-11-12 Interdigital Technology Corporation Spread spectrum adaptive power control system and method
US5644314A (en) * 1996-03-29 1997-07-01 The United States Of America As Represented By The Secretary Of The Army Portable geophysical system using an inverse collocation-type metehodology
JPH1093322A (en) * 1996-09-18 1998-04-10 Honda Motor Co Ltd Antenna device
US6131013A (en) * 1998-01-30 2000-10-10 Motorola, Inc. Method and apparatus for performing targeted interference suppression
JP3910291B2 (en) * 1998-02-16 2007-04-25 本田技研工業株式会社 In-vehicle radar system
JP3316561B2 (en) * 1998-07-06 2002-08-19 株式会社村田製作所 Array antenna device and wireless device
US6014099A (en) * 1998-11-09 2000-01-11 The United States Of America As Represented By The Secretary Of The Army Isar method to analyze radar cross sections
US6115113A (en) * 1998-12-02 2000-09-05 Lockheed Martin Corporation Method for increasing single-pulse range resolution
US7065162B1 (en) * 1999-04-16 2006-06-20 Parkervision, Inc. Method and system for down-converting an electromagnetic signal, and transforms for same
US6114987A (en) * 1999-05-29 2000-09-05 Sensor Technologies & Systems, Inc. Dual-loop linearizer for FM-CW radar
US6539308B2 (en) * 1999-06-25 2003-03-25 Input/Output Inc. Dual sensor signal processing method for on-bottom cable seismic
AU2001232025A1 (en) * 2000-02-08 2001-08-20 Cambridge Consultants Limited Methods and apparatus for obtaining positional information
US6397154B1 (en) * 2000-07-07 2002-05-28 Research Electronics International Correlation method for surveillance device detection
RU2166769C1 (en) 2000-10-09 2001-05-10 Ткач Владимир Николаевич System detecting and identifying objects including elements with nonlinear volt-ampere characteristics
US6518914B1 (en) * 2000-11-02 2003-02-11 Totalförsvarets Forskningsinstitut Synthetic aperture radar system capable of detecting moving targets
FR2820507B1 (en) * 2001-02-07 2003-03-28 Onera (Off Nat Aerospatiale) REJECTION OF CLOTS IN A PASSIVE RADAR RECEIVER OF OFDM SIGNALS
US7227852B2 (en) * 2001-09-21 2007-06-05 Sony Corporation Wireless transmission system, wireless transmission method, wireless reception method, transmitting apparatus and receiving apparatus
US7109939B2 (en) * 2002-05-14 2006-09-19 Hrl Laboratories, Llc Wideband antenna array
US7538717B2 (en) * 2002-12-20 2009-05-26 Saab Ab Adaptive ground clutter cancellation

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5446461A (en) * 1994-04-28 1995-08-29 Hughes Missile Systems Company Concrete penetrating imaging radar
US20020190915A1 (en) * 2001-02-26 2002-12-19 Barnes Mark A. Impulse radar antenna array and method

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
ANDERSON ET AL.: "Ultra-wideband beamforming in sparse arrays", MICROWAVES, ANTENNAS AND PROPAGATION, IEE PROCEEDINGS H, vol. 138, no. 4, August 1991 (1991-08-01), pages 342 - 346, XP002994695 *

Also Published As

Publication number Publication date
US20060273948A1 (en) 2006-12-07
US7573419B2 (en) 2009-08-11
EP1629301B1 (en) 2010-09-29
ATE483172T1 (en) 2010-10-15
AU2003247297A1 (en) 2004-12-13
DE60334413D1 (en) 2010-11-11
EP1629301A1 (en) 2006-03-01
AU2003274857A1 (en) 2004-12-13
US20060250299A1 (en) 2006-11-09
WO2004104627A1 (en) 2004-12-02
EP1636607A1 (en) 2006-03-22

Similar Documents

Publication Publication Date Title
US7994965B2 (en) Surveillance apparatus and method
US7573419B2 (en) Method and system for unambiguous angle resolution of a sparse wide-band antenna array
US5361072A (en) Gated FMCW DF radar and signal processing for range/doppler/angle determination
CN104011558B (en) The aperture beams analysis method of coding and equipment
CN113866709A (en) A Phased Array Crossed Multi-beam Amplitude Ratio Direction Finding Method
CN101278441A (en) Synthetic aperture perimeter array radar
JPH1093335A (en) Zero redundant planar array with circular symmetry over broad frequency range
He et al. Range-ambiguous clutter suppression for the SAR-GMTI system based on extended azimuth phase coding
US11509385B1 (en) Angle diversity multiple input multiple output radar
Wang et al. Space-time coding technique for coherent frequency diverse array
Yang et al. DDMA MIMO radar system for low, slow, and small target detection
Li et al. Joint transmit-receive subarray synthesis optimization for hybrid MIMO phased-array radar
Bregman Design concepts for a sky noise limited low frequency array
Stange et al. Multiplicatively processed antenna arrays for DBF radar applications
US12607710B2 (en) Multiple-input multiple-output radar system
Trizna A bistatic HF radar for current mapping and robust ship tracking
Le Marshall et al. MIMO radar array for termite detection and imaging
Metz et al. Performance of thinned antenna arrays using nonlinear processing in DBF radar applications
Jianqi et al. Researches of a new kind of advanced meter wave radar
RU2794466C1 (en) Method for surveying airspace by a pulse-doppler radar station with an active phased antenna array
US12405339B2 (en) Systems, methods, and apparatus for processing high frequency signals
Contu et al. Direction of arrival estimation using a cluster of beams in a cone-shaped digital array radar
Ikesee Beamforming implementation using software-defined radio
Takayama et al. MIMO imaging radar with enhanced range-azimuth sidelobe suppression
Sinha et al. Low-Cost Ultra-Wideband Fractal Antenna Array For L-Band Beam Squint Applications

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NI NO NZ OM PH PL PT RO RU SC SD SE SG SK SL TJ TM TN TR TT TZ UA UG US UZ VC VN YU ZA ZM ZW

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): GH GM KE LS MW MZ SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LU MC NL PT RO SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
WWE Wipo information: entry into national phase

Ref document number: 2003817024

Country of ref document: EP

WWE Wipo information: entry into national phase

Ref document number: 2006250299

Country of ref document: US

Ref document number: 10557466

Country of ref document: US

WWP Wipo information: published in national office

Ref document number: 2003817024

Country of ref document: EP

WWP Wipo information: published in national office

Ref document number: 10557466

Country of ref document: US

NENP Non-entry into the national phase

Ref country code: JP