EP0289553B1 - Monopulsantenne mit verbesserter nebenstrahlungsunterdrückung - Google Patents

Monopulsantenne mit verbesserter nebenstrahlungsunterdrückung Download PDF

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Publication number
EP0289553B1
EP0289553B1 EP87907265A EP87907265A EP0289553B1 EP 0289553 B1 EP0289553 B1 EP 0289553B1 EP 87907265 A EP87907265 A EP 87907265A EP 87907265 A EP87907265 A EP 87907265A EP 0289553 B1 EP0289553 B1 EP 0289553B1
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EP
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Prior art keywords
sum
quadrants
return energy
difference
excitable elements
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Expired - Lifetime
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EP87907265A
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English (en)
French (fr)
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EP0289553A1 (de
Inventor
Steven W. Bartley
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Raytheon Co
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Hughes Aircraft Co
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q25/00—Antennas or antenna systems providing at least two radiating patterns
    • H01Q25/02—Antennas or antenna systems providing at least two radiating patterns providing sum and difference patterns

Definitions

  • the present invention relates to an antenna system adapted for radar application using sum and difference signals for tracking a target including:
  • the invention relates further to a method of operating an antenna system adapted for radar application using sum and difference signals for tracking a target, including the steps of:
  • the invention relates to optimization of antenna sum and difference patterns, and in particular, to a sidelobe suppression arrangement for a monopulse antenna using sum and difference patterns to track targets.
  • a monopulse antenna may be subdivided into sections, for example, by using horns or quadrants, and the radar then senses the target displacement by comparing the amplitude and phase of the echo signal for each horn or quadrant.
  • the RF circuitry for a conventional antenna divided into quadrants subtracts the output of the left pair from the output of the right pair to sense any imbalance in the azimuth direction (azimuth difference pattern) and the output of the top pair from the output of the bottom pair to sense any imbalance in the elevation direction (elevation difference pattern).
  • azimuth difference pattern the output of the left pair from the output of the right pair to sense any imbalance in the azimuth direction
  • elevation difference pattern elevation difference pattern
  • a sum signal is generated and used as a reference signal, for video input, and for gain control.
  • Document US-3,711,858 is also concerned with a monopulse radar antenna using sidelobe suppression.
  • this antenna wave guide sections are provided in the four quadrants with adjacent ends of the wave guides in the quadrants being staggerd such that certain wave guides in one quadrant extend into the adjacent quadrant and vice-versa. Thereby the lobe of the transition in phase from one quadrant to the other is reduced.
  • an antenna system of the kind mentioned of the outset is characterized in that
  • the present invention is thus characterized, in that the sum signal is calculated as the sum of the return energy of all of the excitable elements; that the azimuth difference signal is calculated as the difference between the sum of the return energy of the excitable elements in the two left-handed quadrants and the left horizontal strip (i.e.
  • the elevation difference signal is calculated as the difference between the sum of the return energy of the excitable elements in the two upper quadrants and the top vertical strip (i.e., an upper segment), and the sum of the return energy of the excitable elements in the two lower quadrants and the bottom vertical strip (i.e., a lower segment).
  • a conventional five horn antenna for providing sum and difference signals.
  • five horn antennas A,B,C,D,E are arranged with antenna A, the left antenna; B, the top antenna; C, the right antenna; D, the bottom antenna; and E, the antenna filling the center space around which antennas A,B,C, and D are arranged.
  • An elevation difference signal is obtained by subtracting the return energy from antenna D from the return energy of antenna B and an azimuth difference signal is provided by subtracting the return energy of antenna C from the return energy of antenna A.
  • a sum signal is provided by the return energy of antenna E alone.
  • the antenna 10 is shown as having an aperture 12 circular in shape and as having an array of radiating and receiving elements 20.
  • the antenna is a broadband antenna designed to operate, for example, in a missile.
  • the aperture is partitioned into substantially equal and symmetrical quadrants 14, 15, 16 and 17.
  • Quadrants 14 and 15 define the top elevation hemisphere for aperture 12, while quadrants 16 and 17 define the bottom elevation hemisphere for aperture 12. More particularly, quadrant 14 defines the top left quadrant, quadrant 15 the top right quadrant, quadrant 16 the bottom right quadrant, and quadrant 17 the bottom left quadrant.
  • Strip 24 includes strip K, which contains elements which may be taken substantially equally from quadrants 14 and 17.
  • Strip 24 also includes strip I which contains elements which may be taken substantially equally from quadrants 15 and 16.
  • Strip 26 includes strip H, which contains elements which may be taken substantially equally from quadrants 14 and 15 and strip J, which contains elements. which may be taken substantially equally from quadrants 16 and 17.
  • quadrants A, B, C, and D refer to the remainder of quadrants 14, 15, 16, and 17 in FIG. 2a respectively after taking the respective elements for strips 24 and 26.
  • strips 24 and 26 are selectively excluded in generating the difference pattern signals, resulting in a reduction in the sidelobes for the azimuth and elevation difference patterns as further explained below.
  • FIG. 2b there is shown a diagram of the sum and difference network for connecting the return signals from the quadrants and strips of FIG. 2b for achieving low difference pattern sidelobes.
  • the sum pattern to be used for the antenna of FIG. 2a, to be provided by the network of FIG. 2b, is (A + B + C + D) + ( H + I + J + K) ;
  • the azimuth difference pattern is (A + D + K) - (B + C + I) ;
  • the elevation difference pattern is (A + B + H) - (C + D + J) .
  • each quadrant and strip is selectively coupled with that of one other quadrant or strip at parallel hybrids 41, 42, 43, and 44.
  • the hybrids are standard commerically available sum and difference hybrids, i.e, sum and difference magic T's, commonly used in comparator circuits.
  • the coupling coefficient for each hybrid would vary depending on aperture design and would be chosen to provide, as close as possible, an ideal sum distribution pattern.
  • the returns from strips K and I are fed into hybrid 41.
  • the returns from strips H and J are likewise fed into hybrid 42.
  • the returns from quadrants A and D are fed into hybrid 43.
  • the returns from quadrants B and C are fed into hybrid 44.
  • K and I are combined at hybrid 41 to provide (K + I) and the difference is taken at hybrid 41 to provide (K - I).
  • the same process is repeated for H and J at hybrid 42 to provide (H+J) and (H-J); at hybrid 43 to provide (A + D) and (A -D); and at hybrid 44 to provide (B + C) and (B - C).
  • the outputs from hybrids 41, 42, 43, and 44 are selectively added and subtracted to provide further desirable combinations of quadrants A, B, C, D and strips H, I, J, and K.
  • the (K + I) output from hybrid 41 and the (H + J) output from hybrid 42 are combined in phase at hybrid 51 for providing at the output of hybrid 51 (H + J + K + I) .
  • the (B + C) output at hybrid 44 is subtracted from the (A + D) output of hybrid 43 at hybrid 52 for providing at the output of hybrid 52 (A +D)-(B + C) , and is combined in phase with (B + C) to provide (A + D + B + C) .
  • the (A-D) output of hybrid 43 is likewise combined with the (B-C) output of hybrid 44 for providing at the output of hybrid 53 (A + B) - (C + D) and is subtracted at hybrid 53 to provide at the output of hybrid 53, (A + C) - (B + D) which is not used and is therefore terminated.
  • hybrid 51 (H + J) + (K + I) is combined with the (A + B) + (C + D) output of hybrid 52 at hybrid 61 to provide (A + B + C + D) + (H + I + J + K) .
  • the (K - I) output of hybrid 41 is combined with the (A + D) - (B + C) output of hybrid 52 at hybrid 62 to provide (A + D + K) - (B + C + I) at the output of hybrid 62.
  • the (H - J) output of hybrid 42 is combined with the (A + B) - (C + D) output of hybrid 53 at hybrid 63 to provide (A + B + H) - (C + D + J) at the output of hybrid 63.
  • FIG. 4a and FIG. 4b Shown in FIG. 4a and FIG. 4b are comparisons of measured data for the original difference signals using the whole ("original") aperture return signal of FIG. 2a compared to the difference signals with the horizontal and vertical strips selectively excluded using the return in FIG. 2b.
  • the difference signals are for all practical purposes symmetrical on either side of boresight and the discussion below applies to the sidelobe patterns on both the right and left of boresight.
  • Fig. 4a Shown is the original configuration elevation sum and difference signals (left side figure) and the elevation difference signal with horizontal strips I and K excluded (right side figure). It is observed from Fig. 4a that the original elevation difference pattern has a near in sidelobe of around -15dB at around 20°. Compare this to the right side figure of 4a, which depicts the elevation difference pattern with the horizontal strip excluded. Here the near in sidelobes rapidly drop to near -25dB at 30° and form deep nulls.
  • Fig. 4b Shown are the original azimuth sum and difference signals (left side figure) and the azimuth difference signal with strips H and J excluded (right side figure).
  • the original azimuth difference pattern displays near-in sidelobes of - 15dB at around 25°.
  • the azimuth difference pattern with the vertical strip excluded is markedly different.
  • the near in sidelobes are -27dB at 25° and deep nulls are formed.
  • Fig. 3a shows an embodiment (not subject of the present invention) wherein a center section of the elements are selectively excluded in generating the difference patterns.
  • Fig. 3b shows a sum and difference network for providing the desired sum and difference signals.
  • the circuit of Fig. 3b has the advantage of using only five hybrids, which is of high utility for applications where space is very important (i.e., missile radar systems, etc.). Data for the embodiment shown in Figs. 3a and 3b is comparable to that for the embodiment shown in Fig. 2a and Fig. 2b.
  • one embodiment of the invention by selectively excluding a vertical strip of elements along the azimuth axis, can reduce the sidelobes for the azimuth difference pattern and, by selectively excluding a horizontal strip of elements along the elevation axis, can reduce the sidelobes for the elevation difference pattern.
  • excluding other predetermined cross section patterns of the aperture may permit further optimization of the signals, i.e., permit other combinations for reducing the sidelobes in the difference pattern while minimizing circuit complexity and maintaining sum signal quality.

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  • Variable-Direction Aerials And Aerial Arrays (AREA)
  • Radar Systems Or Details Thereof (AREA)

Claims (3)

  1. Antennensystem, das für Radareinsatz adaptiert ist und zum Verfolgen eines Zieles Summen- und Differenzsignale verwendet, mit:
    a) einer Monopulsantenne (10), welche
    a1) eine Querschnittsfläche aufweist, um Energie in Richtung eines Zieles auszusenden und um Rücklaufenergie zu empfangen;
    a2) ein Array von erregbaren Elementen (20) aufweist, welche symmetrisch um eine Azimut- sowie eine Elevationsachse angeordnet sind; wobei
    a3) die Querschnittsfläche längs der Elevationsachse in einen linken und einen rechten horizontalen Streifen (K,I), längs der Azimutachse in einen oberen und einen unteren vertikalen Streifen (H,J), sowie in vier Quadranten (A,B,C,D) aufgeteilt ist, wobei jeder der Streifen (K,I;H,J) und Quadranten (A,B,C,D) mehrere der erregbaren Elemente (20) enthält;
    b) Schaltungsmitteln, die an die erregbaren Elemente (20) gekoppelt sind, wobei die Schaltungsmittel unter Verwendung von Rücklaufenergie von den erregbaren Elementen (20) ein Summensignal sowie Azimut- und Elevations-Differenzsignale erzeugen, wobei das Azimut-Differenzsignal unter Auslassung der Rücklaufenergie von den erregbaren Elementen (20) in den vertikalen Streifen (H,J) berechnet wird, und wobei das Elevations-Differenzsignal unter Auslassung der Rücklaufenergie von den erregbaren Elementen (20) in den horizontalen Streifen (K,I) berechnet wird;
    dadurch gekennzeichnet, daß
    c) die Schaltungsmittel
    c1) das Summensignal als die Summe der Rücklaufenergie von allen erregbaren Elementen (20) bereitstellen,
    c2) das Azimut-Differenzsignal bereitstellen als die Differenz zwischen
    c2.1) der Summe aus der Rücklaufenergie von den erregbaren Elementen (20) in den beiden linken der Quadranten (A,D) und dem linken horizontalen Streifen (K), sowie
    c2.2) der Summe aus der Rücklaufenergie von den erregbaren Elementen (20) in den beiden rechten der Quadranten (B,C) und dem rechten horizontalen Streifen (I),
    c3) das Elevations-Differenzsignal bereitstellen als die Differenz zwischen
    c3.1) der Summe aus der Rücklaufenergie von den erregbaren Elementen (20) in den beiden oberen der Quadranten (A,B) und dem oberen vertikalen Streifen (H), sowie
    c3.2) der Summe aus der Rücklaufenergie von den erregbaren Elementen (20) in den unteren beiden der Quadranten (D,C) und den unteren vertikalen Streifen (J).
  2. Antennensystem nach Anspruch 1, dadurch gekennzeichnet, daß die Schaltungsmittel eine hybrides Netzwerk (41-44;51-53;61-63) umfassen.
  3. Verfahren zum Betreiben eines für Radareinsatz adaptierten Antennensystemes, das Summen- und Differenzsignale verwendet, um ein Ziel zu verfolgen, mit dem Schritten:
    a) Aussenden von Energie in Richtung des Zieles und Empfangen von Rücklaufenergie mit einer Monopulsantenne (10);
    b) Aufteilen einer Querschnittsfläche der Monopulsantenne (10) in einen linken und einen rechten horizontalen Streifen (K,I) längs der Elevationsachse, einen oberen und einen unteren vertikalen Streifen längs der Azimutachse, sowie in vier Quadranten (A,B,C,D), wobei jeder der Streifen (K,I;H,J) und Quadranten (A,B,C,D) mehrere erregbare Elemente (20) umfaßt, die symmetrisch um die Azimut- und Elevationsachse angeordnet sind;
    c) Koppeln der Rücklaufenergie von den erregbaren Elementen (20) der Monopulsantenne (10) an Schaltungsmittel,
    d) mit den Schaltungsmitteln Erzeugen von
    d1) einem Summensignal,
    d2) einem Azimut-Differenzsignal, wobei die Rücklaufenergie von den erregbaren Elementen (20) in den vertikalen Streifen (H,J) ausgelassen wird,
    d3) einem Elevations-Differenzsignal, wobei die Rücklaufenergie von den erregbaren Elementen (20) in den horizontalen Streifen (K,I) ausgelassen wird,
    gekennzeichnet durch die Schritte:
    e) Erzeugen des Summensignales als Summe aus der Rücklaufenergie von allen erregbaren Elementen (20),
    f) Erzeugen des Azimut-Differenzsignales als Differenz zwischen
    f1) der Summe aus der Rücklaufenergie von den erregbaren Elementen (20) in den beiden linken der Quadranten (A,D) und dem linken horizontalen Streifen (K) sowie
    f2) der Summe aus der Rücklaufenergie von den erregbaren Elementen (20) in den beiden rechten der Quadranten (B,C) und dem rechten horizontalen Streifen (I),
    g) Erzeugen des Elevations-Differenzsignales als Differenz zwischen
    g1) der Summe aus der Rücklaufenergie von den erregbaren Elementen (20) in den beiden oberen der Quadranten (A,B) und dem oberen vertikalen Streifen (H) sowie
    g2) der Summe aus der Rücklaufenergie von den erregbaren Elementen (20) in den beiden unteren der Quadranten (D,C) sowie dem untern vertikalen Streifen (J).
EP87907265A 1986-11-17 1987-10-01 Monopulsantenne mit verbesserter nebenstrahlungsunterdrückung Expired - Lifetime EP0289553B1 (de)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP92116842A EP0544081B1 (de) 1986-11-17 1987-10-01 Monopulsantenne mit verbesserter Nebenkeulenunterdrückung

Applications Claiming Priority (2)

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US93157186A 1986-11-17 1986-11-17
US931571 1986-11-17

Related Child Applications (1)

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EP92116842.3 Division-Into 1992-10-01

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EP0289553A1 EP0289553A1 (de) 1988-11-09
EP0289553B1 true EP0289553B1 (de) 1993-07-28

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EP92116842A Expired - Lifetime EP0544081B1 (de) 1986-11-17 1987-10-01 Monopulsantenne mit verbesserter Nebenkeulenunterdrückung
EP87907265A Expired - Lifetime EP0289553B1 (de) 1986-11-17 1987-10-01 Monopulsantenne mit verbesserter nebenstrahlungsunterdrückung

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JP (1) JPH0682980B2 (de)
DE (1) DE3786787T2 (de)
IL (1) IL84113A (de)
WO (1) WO1988004109A1 (de)

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3786787T2 (de) * 1986-11-17 1993-11-18 Hughes Aircraft Co Monopulsantenne mit verbesserter nebenstrahlungsunterdrückung.
JPH01268210A (ja) * 1988-04-19 1989-10-25 Mitsubishi Electric Corp アンテナ装置
GB2279529B (en) * 1989-05-18 1995-05-31 Plessey Co Plc Radar
JPH0834382B2 (ja) * 1989-09-01 1996-03-29 デイエックスアンテナ株式会社 自動追尾用平面アンテナ
JPH06100643B2 (ja) * 1991-12-17 1994-12-12 宇宙開発事業団 モノパルス追尾装置
FR2870992B1 (fr) * 2004-06-01 2006-09-01 Amp C3C Sa Antenne de telecommunications pour ensemble de poursuite
DE102004040015B4 (de) 2004-08-16 2006-12-07 S.M.S., Smart Microwave Sensors Gmbh Verfahren und Vorrichtung zur Detektion eines von einer Sendeantenne ausgesandten elektromagnetischen Signals
US8593334B2 (en) 2011-07-29 2013-11-26 The Boeing Company Split aperture monopulse antenna system

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Publication number Priority date Publication date Assignee Title
US3711858A (en) * 1971-02-24 1973-01-16 Westinghouse Electric Corp Monopulse radar antenna structure
US3965475A (en) * 1975-05-30 1976-06-22 The United States Of America As Represented By The United States Administrator Of The National Aeronautics And Space Administration Switchable beamwidth monopulse method and system
DE2736497A1 (de) * 1977-08-12 1979-02-22 Siemens Ag Monopulserregersystem fuer eine strahlungsgespeiste antenne
US4754286A (en) * 1984-10-18 1988-06-28 Siemens Aktiengesellschaft Line-fed phase controlled antenna
DE3786787T2 (de) * 1986-11-17 1993-11-18 Hughes Aircraft Co Monopulsantenne mit verbesserter nebenstrahlungsunterdrückung.

Non-Patent Citations (3)

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Title
"Introduction to Radar Systems", 2nd Edition, M.I.Skolnik, 1984, Mc Graw-Hill, pp 162-163 *
IEEE Transactions on Antennas and Propagation, volume AP-22, no. 3, May 1974, N.S. Wong et al."A multielement high power monopulse feed with low sidelobe and high aperture efficiency", pages 402-407 see figures 3,5; paragraph:"Description of 32-element monopulse feed", *
Patent Abstracts of Japan, volume 7, no. 258 (E-211)(1403), 17 November 1983, & JP, A, 58142607 (NIPPON DENSHIN DENWA KOSHA) 24 August 1983 *

Also Published As

Publication number Publication date
DE3786787T2 (de) 1993-11-18
EP0289553A1 (de) 1988-11-09
DE3786787D1 (de) 1993-09-02
EP0544081B1 (de) 1995-11-22
IL84113A (en) 1991-08-16
JPH01502151A (ja) 1989-07-27
EP0544081A1 (de) 1993-06-02
JPH0682980B2 (ja) 1994-10-19
WO1988004109A1 (en) 1988-06-02

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