EP0409927A1 - Self-adaptive directional filtering and polarisation device for radioelectric waves. - Google Patents
Self-adaptive directional filtering and polarisation device for radioelectric waves.Info
- Publication number
- EP0409927A1 EP0409927A1 EP90900891A EP90900891A EP0409927A1 EP 0409927 A1 EP0409927 A1 EP 0409927A1 EP 90900891 A EP90900891 A EP 90900891A EP 90900891 A EP90900891 A EP 90900891A EP 0409927 A1 EP0409927 A1 EP 0409927A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- frames
- antenna
- signal
- wire antenna
- polarization
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000001914 filtration Methods 0.000 title claims description 8
- 230000010287 polarization Effects 0.000 claims abstract description 32
- 238000005562 fading Methods 0.000 claims description 3
- 239000002184 metal Substances 0.000 claims description 3
- 230000003044 adaptive effect Effects 0.000 description 7
- 230000006978 adaptation Effects 0.000 description 5
- 239000011159 matrix material Substances 0.000 description 4
- 238000004804 winding Methods 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 2
- 230000005855 radiation Effects 0.000 description 2
- 230000003321 amplification Effects 0.000 description 1
- 238000003491 array Methods 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000010432 diamond Substances 0.000 description 1
- 239000003989 dielectric material Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 230000005669 field effect Effects 0.000 description 1
- 239000005433 ionosphere Substances 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 230000001629 suppression Effects 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q3/00—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system
- H01Q3/26—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture
- H01Q3/2605—Array of radiating elements provided with a feedback control over the element weights, e.g. adaptive arrays
- H01Q3/2611—Means for null steering; Adaptive interference nulling
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q21/00—Antenna arrays or systems
- H01Q21/24—Combinations of antenna units polarised in different directions for transmitting or receiving circularly and elliptically polarised waves or waves linearly polarised in any direction
- H01Q21/245—Combinations of antenna units polarised in different directions for transmitting or receiving circularly and elliptically polarised waves or waves linearly polarised in any direction provided with means for varying the polarisation
Definitions
- the present invention relates to a self-adaptive filtering device in the direction and polarization of radio waves received on an array of antennas coupled to a receiver.
- a tactical high frequency reception antenna in particular must allow any user to establish radio links with different transmitting stations and to simultaneously listen to the emissions of other users of the high frequency channel.
- the receiver Given the congestion of the high-frequency channel, the receiver must be able to reject signals from interferers, whether intentional or not.
- the known high-frequency tactical adaptive antenna arrays do not make it possible to exploit the polarization of the ionospheric waves.
- RTE COMPTON entitled "The tripole antenna: an adaptative array with a full polarization flexibility” (IEEE trans antenna and propagation Vol: AP 29 n ° 6 NOV 81) the antenna described there has the tactical disadvantage of having to be placed on top of a mast for the radiation patterns of the horizontal dipoles to be correct .
- the object of the invention is to overcome the aforementioned drawbacks.
- the subject of the invention is a self-adaptive filtering device in the direction and polarization of radio waves received on an array of antennas coupled to a receiver, characterized in that the array of antennas is formed by Q crossed frames arranged around a common axis along adjacent dihedrons of the same angular value and by a straight wire antenna of longitudinal axis coinciding with the common axis, and in that the Q frames and the straight wire antenna have the same phase center located at the output terminals of the Q frames and at an end terminal of the wire antenna, and are respectively coupled to an operand input of a summing circuit at Q + 1 inputs through Q + 1 multiplier circuits to multiply the value X j provided for each frame or by the wire antenna by a complex weighting coefficient W j adjustable according to variations in the polarization of the received ionospheric wave and its direct arrival ion in azimuth and site so that the addition of the products X j .W j gives a resultable signal usable by the receiver with
- the antenna according to the invention has the main advantages of being self-adaptive, of having a wide band and a reduced bulk and of possessing radiation properties which are suitable for all distances less than 2000 kilometers.
- the active reception structure obtained thanks to the amplifiers placed in the phase center of each antenna, makes it possible to obtain broadband antenna behavior over a wide range of frequencies between 2 and 30 MHz.
- the crossed frames and the monopoly which form the passive part of the aerial make it possible to obtain separate amplitude / phase responses for any elliptical polarized ionospheric wave emitted according to a determined site angle and azimuth.
- the linear combination of these responses makes it possible to repel a jammer in adaptive reception mode and to reduce the fading of the useful signal in the absence of a jammer.
- FIG. 1 a self-adapting antenna structure forming the device according to the invention
- FIG. 2 an embodiment of a device for controlling the antenna structure of FIG. 1 for performing the filtering function in the direction and in polarization of the ionospheric waves arriving on the antenna,
- FIGS. 3a and 3k of the graphs representative of the influence of the relative polarizations of the useful incident waves and of the jammer
- FIGS. 4a and 4b a configuration in a three-dimensional space, of an incident useful plane wave and of a plane wave representative of a jammer, relatively to an antenna according to the invention
- FIG. 5 the place of projection of the electric field vector in the plane yoz of FIG. 3, of an elliptically polarized wave
- the antenna according to the invention which is shown in Figure 1 consists of two rectangular frames 1 and 2, and a wire antenna 3.
- the frames 1 and 2 have roughly identical dimensions and intersect at right angles along a common diagonal connecting two of their opposite vertices referenced, s1 and s2 in Figure 1.
- the wire antenna 3 has a longitudinal axis coincident with the common diagonal passing through the vertices s1 and s2, and is fixed by its ends to each of the two vertices si and s2 respectively, by any known fixing parts, not shown, made of a dielectric material.
- the assembly is fixed by the vertex s2, to a plane base 4 perpendicular to the direction s1 s2 of the vertices.
- the base 4 rests on a tripod 5 formed by three tubes 5a, 5b and 5c to allow the antenna to be placed on the ground.
- FIG. 2 A control device for performing the filtering functions in direction and in polarization, of the waves arriving on the antenna is represented in FIG. 2.
- the frames 1 and 2 are connected by their vertex s2 and their output terminals. to two symmetrical amplifiers 6 and 7, and the wire antenna 3 is connected by the same vertex s2 and by its output terminal to a non-symmetrical amplifier 8.
- This arrangement makes it possible to have the same phase center for the three active aerials formed by the frames 1 and 2, and the wire antenna 3.
- the amplifiers 6, 7, 8 are placed inside the base 4, shown by a closed dotted line and are supplied, as shown in the figure 1 by co-axial cables 9a, 9b, 9c introduced inside the tubes 5a, 5b and 5c of the tripod 5.
- the wire antenna 3 forms with the metal tubes 5a, 5b, 5c and the non-symmetrical amplifier 8 , an active dipole.
- amplifiers 6, 7 and 8 are respectively connected to a first operand input of circuits multiplying complex numbers, these circuits being referenced respectively from 10 to 12 in FIG. 2.
- W i ke j ⁇ i , are applied respectively to the second operand inputs of the multiplier circuits 10, 11, 12 by respective outputs of a signal processor 13.
- the outputs of the multiplier circuits 10 to 12 are respectively connected to operand inputs of a summing circuit 14.
- the result of the summing provided by the summing circuit 14 is applied to a signal input of the processor 13 and to the input of a radio wave receiver 15.
- the polarization of the incident wave on the receiving antenna is a function of the coordinates of the exit point of the ionosphere as well as of the direction of this outgoing wave with respect to the field. magnetic earth.
- the processor 13 which after detection of the summation signal supplied by the summator 14, executes a program which makes it possible to determine the complex weights W 1 , W 2 and W 3 which make the quality of reception of a useful signal in the presence of a jammer.
- LMS LMS which is the abbreviation of "Least Mean Square”.
- RT COMPTON Jr, RJ, HUSS WG Swarner and AA Kalensky Adaptive array for communication Systems: an overview of research at” The Ohio State University “IEEE Trans Antennas Propagat, Vol. AP 24, pages 599 to 607, Sept. 1976.
- the execution of this algorithm makes it possible to maximize the signal / noise ratio at the output of the summing circuit 14.
- X 1 (t), X 2 (t) and X 3 (t) denote respectively the voltages of the signals leaving the amplifiers 6, 7 and 8, and W the matrix of complex weights
- the signal S (t) approximates more or less the desired useful signal D (t) which can be recognized, by any known means not shown, provided that 'there is a "striking" in the modulation of the useful signal.
- the processor 13 performs in known manner a sampling of the waveforms of the si gnals D (t) and S (t) , and an error signal E (j) is calculated for each corresponding sample j of the two signals
- the processor 13 then calculates the values of the weights W 1 , W 2 and W 3 so that at all times the response of the device is equal, or as close as possible, to the desired response.
- the system of equations to be solved is therefore a system of N equations with three unknowns.
- the LMS algorithm allows iteration to obtain this minimum value by calculating the relationship for each iteration:
- the embodiment of the device according to the invention described above can be extended to other embodiments comprising any number Q of crossed frames, arranged around a common axis along adjacent dihedrons of the same angular value. and a straight wire antenna with a longitudinal axis merging with the common axis, the set ble frames and wire antennas thus having the same phase center located at the signal output terminals of the Q frames and the wire antenna.
- the system of equation (3) is always valid and is reduced to a system of N equations with Q + 1 unknown in which the coefficients W 1 to W Q + 1 are the unknowns.
- the adaptive antenna according to the invention provides, as the graphs in Figures 3a, 3k show, protection against jammers at least equal to 20 decibels.
- the angles of elevation ⁇ (u) and ⁇ (b) of arrival on the antenna of the useful plane wave and that of the jammer are those represented in FIG. 4a.
- the corresponding azimuths ⁇ (u) and ⁇ (v) are those shown in Figure 4b.
- Characteristic angles and ⁇ of an elliptically polarized wave relative to an orthonormal coordinate system yoz are those represented in FIG. 5.
- the angle ⁇ is the angle counted positively in the trigonometric direction between the axis oy and the major axis of the ellipse.
- the angle X b is chosen as a parameter and takes the values of 30 °, 15 °, 0 °, -15 ° and -30 °.
- the width for a signal / noise ratio of 10 dB of the peak is constantly less than 30 °.
- the site angle of the jammer ⁇ (b) is fixed at 20 ° and the site angle ⁇ (u) of the useful signal is plotted on the abscissa for values comprised from 0 to 90 °. It appears that the signal / noise ratio is minimum for the 90 ° polarization value, and that it is greater than 20 db for an elevation angle difference greater than 40 °.
- FIG. 3i shows that there is little difference in the signal / noise ratio when the angle of elevation varies, for frequencies from 3 to 30 MHz.
- the useful wave and the jammer wave have the same elevation angle
- the azimuth ⁇ (b) of the jammer is set to 0
- the azimuth ⁇ (u) of the useful signal is chosen as a parameter.
- the value of ⁇ (u) is plotted on the abscissa and varies from 0 to 360 °. It is found that a difference in azimuth angle greater than 40 ° is sufficient to obtain a gain of 20 decibels in signal / noise ratio.
- the polarization is close to the right circular polarization or to the left circular polarization.
- Choosing one of these polarizations has the advantage that it makes it possible to reduce the depth of the fading.
- a switch can be placed on the receiver 15 to allow activate the adaptive function of the antenna to remove any jammer at any time.
- FIG. 6 An embodiment of a symmetrical amplifier 6 or 7 is shown in Figure 6.
- This amplifier has two identical amplification channels 16 and 17 arranged symmetrically with respect to a ground line M. As the two channels are identical, only the first channel 16 is shown inside a line formed in dotted lines. It comprises, connected in this order in series, a low pass filter, an amplifier transistor 19 polarized in common base, coupled through an impedance transformer 20 to an amplifier transistor 21 polarized according to the common emitter mode. The output of the first channel 16 is formed by the collector of the transistor 21.
- the outputs U 1 and U 2 of the first and second channels 16 and 17 are respectively connected to the ends of the primary winding at mid point connected to the ground circuit M, of an impedance transformer 22.
- the inputs E 1 and E 2 of the first and second channels are formed by the inputs of the low pass filters 18 of each of the channels and are connected to the output terminals of the frames 1 and 2 of the antenna.
- FIG. 7 An embodiment of a non-symmetrical amplifier 8 is shown in FIG. 7.
- It comprises two symmetrical channels 23 and 24 each comprising a field effect transistor amplifier.
- An impedance adapter transformer 2 comprising a primary winding ensures by two secondary windings the coupling of the wire antenna 3 to the gates of the transistors 25 of each of the channels.
- An impedance adapter formed by transformers 27, 28 and 29 combines the signals amplified by each of channels 23 and 24 into a single output signal.
Landscapes
- Variable-Direction Aerials And Aerial Arrays (AREA)
- Radio Transmission System (AREA)
Abstract
Le dispositif comprend un réseau d'antennes (1, 2, 3) formé par Q cadres (1, 2) croisés disposés autour d'un axe commun (s1 s2) suivant des dièdres adjacents de même valeur angulaire et une antenne rectiligne filaire (3) d'axe longitudinal confondu avec l'axe commun (s1 s2). Les Q cadres (1, 2) et l'antenne rectiligne filaire (3) ont un même centre de phase (s2) situé aux bornes de sortie des Q cadres et à une borne d'extrémité de l'antenne filaire. Ils sont couplés respectivement à une entrée d'opérande d'un circuit sommateur (14) à Q+1 entrées au travers de Q+1 circuits multiplieurs (10, 11, 12) pour multiplier la valeur Xj fournie pour chaque cadre (1, 2) ou par l'antenne filaire (3) par un coefficient complexe de pondération Wj ajustable -en fonction des variations de la polarisation de l'onde ionosphérique reçue et de sa direction d'arrivée en azimut et site pour que l'addition des produits Xj.Wj donne un signal résultant exploitable par le récepteur (15) avec un rapport signal utile/bruit maximum. Application: récepteurs d'ondes électro-magnétiques haute fréquence.The device comprises an array of antennas (1, 2, 3) formed by Q crossed frames (1, 2) arranged around a common axis (s1 s2) along adjacent dihedrons of the same angular value and a wired straight antenna ( 3) with a longitudinal axis coincident with the common axis (s1 s2). The Q frames (1, 2) and the straight wire antenna (3) have the same phase center (s2) located at the output terminals of the Q frames and at an end terminal of the wire antenna. They are respectively coupled to an operand input of a summing circuit (14) with Q + 1 inputs through Q + 1 multiplier circuits (10, 11, 12) to multiply the value Xj supplied for each frame (1, 2) or by the wire antenna (3) by a complex weighting coefficient Wj adjustable -depending on variations in the polarization of the received ionospheric wave and its direction of arrival in azimuth and site so that the addition of products Xj.Wj gives a resulting signal which can be used by the receiver (15) with a maximum useful signal / noise ratio. Application: high frequency electromagnetic wave receivers.
Description
Claims
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR8817482A FR2641420B1 (en) | 1988-12-30 | 1988-12-30 | SELF-ADAPTIVE FILTERING DEVICE IN DIRECTION AND POLARIZATION OF RADIO-ELECTRIC WAVES RECEIVED ON A NETWORK OF ANTENNAS COUPLED TO A RECEIVER |
FR8817482 | 1988-12-30 | ||
PCT/FR1989/000672 WO1990007802A1 (en) | 1988-12-30 | 1989-12-22 | Self-adaptive directional filtering and polarisation device for radioelectric waves |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0409927A1 true EP0409927A1 (en) | 1991-01-30 |
EP0409927B1 EP0409927B1 (en) | 1995-02-08 |
Family
ID=9373619
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP90900891A Expired - Lifetime EP0409927B1 (en) | 1988-12-30 | 1989-12-22 | Self-adaptive directional filtering and polarisation device for radioelectric waves received from an antenna net coupled to an receiver |
Country Status (7)
Country | Link |
---|---|
US (1) | US5124711A (en) |
EP (1) | EP0409927B1 (en) |
CA (1) | CA2006494A1 (en) |
DE (1) | DE68921073T2 (en) |
ES (1) | ES2067732T3 (en) |
FR (1) | FR2641420B1 (en) |
WO (1) | WO1990007802A1 (en) |
Families Citing this family (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2256107A (en) * | 1991-05-24 | 1992-11-25 | Commw Of Australia | Radar supervisory system. |
FR2716538B3 (en) * | 1994-02-18 | 1995-12-15 | Thomson Csf | Method for locating transmitters. |
US6317098B1 (en) * | 1999-08-23 | 2001-11-13 | Lucent Technologies Inc. | Communication employing triply-polarized transmissions |
GB2354115A (en) * | 1999-09-09 | 2001-03-14 | Univ Surrey | Adaptive multifilar antenna |
US6754511B1 (en) * | 2000-02-04 | 2004-06-22 | Harris Corporation | Linear signal separation using polarization diversity |
DE10209060B4 (en) * | 2002-03-01 | 2012-08-16 | Heinz Lindenmeier | Reception antenna arrangement for satellite and / or terrestrial radio signals on vehicles |
US8264405B2 (en) * | 2008-07-31 | 2012-09-11 | Raytheon Company | Methods and apparatus for radiator for multiple circular polarization |
FR2938346B1 (en) * | 2008-11-07 | 2010-12-31 | Thales Sa | METHOD FOR DETERMINING THE ARRIVAL DIRECTION OF A HIGH-FREQUENCY ELECTROMAGNETIC WAVE |
US9615274B2 (en) * | 2011-08-23 | 2017-04-04 | Azimuth Systems, Inc. | Plane wave generation within a small volume of space for evaluation of wireless devices |
KR20130071799A (en) * | 2011-12-21 | 2013-07-01 | 한국전자통신연구원 | Signal transmitting/receiving apparatus and method for controlling polarization |
RU2552530C2 (en) * | 2013-08-01 | 2015-06-10 | Федеральное государственное бюджетное учреждение науки Институт земного магнетизма, ионосферы и распространения радиоволн им. Н.В. Пушкова Российской академии наук (ИЗМИРАН) | Method of obtaining ionogram |
CN104218920A (en) * | 2014-08-29 | 2014-12-17 | 南京理工大学 | Partitioning concurrence based adaptive digital beamforming method and implementing device thereof |
CN112039494B (en) * | 2020-08-13 | 2023-10-20 | 北京电子工程总体研究所 | Low-pass filtering method, device, equipment and medium for overcoming azimuth zero crossing |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB1222520A (en) * | 1968-02-08 | 1971-02-17 | Ltv Electrosystem Inc | Improvements in directionally selective energy receiving systems |
US4612549A (en) * | 1983-12-23 | 1986-09-16 | General Electric Company | Interference canceller loop having automatic nulling of the loop phase shift for use in a reception system |
US4675685A (en) * | 1984-04-17 | 1987-06-23 | Harris Corporation | Low VSWR, flush-mounted, adaptive array antenna |
WO1986001340A1 (en) * | 1984-08-20 | 1986-02-27 | Österreichisches Forschungszentrum Seibersdorf Gmb | Antenna construction |
-
1988
- 1988-12-30 FR FR8817482A patent/FR2641420B1/en not_active Expired - Lifetime
-
1989
- 1989-12-22 EP EP90900891A patent/EP0409927B1/en not_active Expired - Lifetime
- 1989-12-22 CA CA002006494A patent/CA2006494A1/en not_active Abandoned
- 1989-12-22 ES ES90900891T patent/ES2067732T3/en not_active Expired - Lifetime
- 1989-12-22 US US07/571,555 patent/US5124711A/en not_active Expired - Fee Related
- 1989-12-22 DE DE68921073T patent/DE68921073T2/en not_active Expired - Fee Related
- 1989-12-22 WO PCT/FR1989/000672 patent/WO1990007802A1/en active IP Right Grant
Non-Patent Citations (1)
Title |
---|
See references of WO9007802A1 * |
Also Published As
Publication number | Publication date |
---|---|
DE68921073T2 (en) | 1995-06-01 |
FR2641420A1 (en) | 1990-07-06 |
US5124711A (en) | 1992-06-23 |
EP0409927B1 (en) | 1995-02-08 |
FR2641420B1 (en) | 1991-05-31 |
ES2067732T3 (en) | 1995-04-01 |
DE68921073D1 (en) | 1995-03-23 |
WO1990007802A1 (en) | 1990-07-12 |
CA2006494A1 (en) | 1990-06-30 |
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