US2728912A - Radio beam scanners - Google Patents

Radio beam scanners Download PDF

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Publication number
US2728912A
US2728912A US291475A US29147552A US2728912A US 2728912 A US2728912 A US 2728912A US 291475 A US291475 A US 291475A US 29147552 A US29147552 A US 29147552A US 2728912 A US2728912 A US 2728912A
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US
United States
Prior art keywords
mirror
lens
radio
feed source
axis
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US291475A
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English (en)
Inventor
Wells Edward Marshall
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.)
Marconis Wireless Telegraph Co Ltd
BAE Systems Electronics Ltd
Original Assignee
Marconi Co Ltd
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 Marconi Co Ltd filed Critical Marconi Co Ltd
Application granted granted Critical
Publication of US2728912A publication Critical patent/US2728912A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • 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
    • H01Q3/12—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system using mechanical relative movement between primary active elements and secondary devices of antennas or antenna systems
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q15/00—Devices for reflection, refraction, diffraction or polarisation of waves radiated from an antenna, e.g. quasi-optical devices
    • H01Q15/23—Combinations of reflecting surfaces with refracting or diffracting devices

Definitions

  • This invention relates to radio beam scanners such as are required for radar systems and more specifically toradio beam scanners wherein a sharply directional pencil like beam of ultra high frequency radio energy is required to be scanned over a relatively wide angle comparatively slowly e. g. at the order of several seconds per scanning cycle.
  • the object of the invention is to provide improved mechanically convenient and simple scanners wherein the necessity for moving the radio feed source shall be avoided, wherein difficulties due to loss of focus of the beam during scanning shall be reduced to a minimum and wherein the obtained angle of swing of the radio beam shall be large in relation to the mechanical movement required to produce the required displacement.
  • a radio beam scanner comprises a radio feed source, a radio mirror towards which said source is directed, a radio lens positioned in the path of radio energy reflected by said mirror, and means for swinging said mirror and lens as a unit about an axis of rotation which meets the lens axis at a point substantially in or behind the mirror.
  • radio mirror as above employed is meant any device adapted to reflect substantially all incident radio energy thereon.
  • a radio mirror may be built of, for example, metal sheet, rod or netting and many forms are known.
  • feed source is meant a device, such for example, as a radio horn, a flared wave guide, or a polyrod which, when coupled to a source of radio energy, is adapted to radiate a radio beam to illuminate the mirror.
  • the feed source may be between the lens and the mirror but preferably said source is offset so that the beam axis through the source does not pass through the lens and the mirror is correspondingly tilted with relation to the lens.
  • the lens and the mirror are in effect combined to form a so-called phase corrected mirror with regard to which the source may be offset.
  • the axis of rotation preferably passes through the mirror.
  • the first i. e. the non-reflecting surface of the mirror is preferably arcuate in which case the reflecting surface i. e. that remote from the source, may be stepped as known per se.
  • Such a mirror may be constituted by a matrix of stopped tubes.
  • Figure 1 illustrates a radio beam scanner assembly arranged in accordance with my invention and employing a plane radio mirror, a radio lens and a fixed feed source;
  • Fig. 2 illustrates a radio beam scanner assembly according to my invention and shown in perspective and illustrating particularly the manner of off-setting the feed source;
  • Fig. 3 shows a modified form of my invention embodied in a phase corrected mirror
  • FIG. 4 is an enlarged fragmentary view of a portion of the mirror-lens of Fig. 3;
  • Fig. 5 shows a further modification of my invention in which a dielectric-lens is employed in place of the mirror-lens in the radio beam scanner of my invention and in which a smoothly curved front surface having a stepped rear surface is provided;
  • Fig. 6 shows a further modified form of my invention in which a dielectric-lens is employed having a stepped front surface and a rear smoothly curved surface.
  • a plane radio mirror M, a radio lens L and a fixed feed source F are employed.
  • the feed source F which may for example be a wave guide fed radio beam projector, is between the lens and the mirror and pointed towards the latter.
  • the face LF1 of the lens towards the mirror is arcuate and the other, or front, face LF2 is shown as plane for simplicity but may be stepped in accordance with well known principles so as to appear, in sections, as a series of suitably curved surfaces joining the steps.
  • the axis LX of the lens which is shown by a chain line and in which the focus of the lens lies, passes through the mirror normal to the surface thereof and the mirror and lens are mounted to be movable as a unit for scanning purposes about an axis X of rotation which meets the lens axis LX at the center of curvature of arcuate face LF1.
  • the emitted scanning beam is, of course, the emergent beam from the lens and it will be seen that it will swing through an angle which is twice that through which the lens-mirror unit is swung. There is no need for any rotational joints in the wave guide to the feed source while the maintenance of sharpness of the emergent scanning beam presents no serious difficulties.
  • Fig. 1 shows the parts in fullline in the central position of the scan and inbroken lines at one extreme position, central and boundary rays for both these positions being conventionally indicated by broken lines marked with arrow heads.
  • Fig. 2 In order to avoid matching difficulties and also to avoid deterioration of the emergent scanning beam due to what may be termed the shadow of the feed source at the center of the lens aperture, it is preferred to modify the above described embodiment by off-setting the feed source and correspondingly tilting the mirror out of a plane parallel to the axis of rotation.
  • Fig. 2 In Fig. 2 the front face LFZ of the lens is shown as stepped and the axis of rotation is shown by a chain line, the mechanical tie members for tying the parts together for rotation as a unit being represented by the lines T.
  • the broken line arrows R represent the arcuate swing about the axis.
  • Fig. 3 shows a preferred form of mirror-lens ML which has a smoothly curved front face ML2 as shown-i. e. the face nearer the feed source Fand a rear face MLl which is stepped as known per se.
  • the mirror-lens shown is of honeycomb or tubular structure, also as known per se.
  • Fig. 4 is a diagrammatic enlargement of the portion of the mirror lens of Fig. 3 ringed round by the circle C.
  • phase correcting mirror In such a phase correcting mirror the rear face MLl is, of course, the reflecting face, and incident energy passes into the open mouths of the honeycomb or tubular sections H (see Fig. 4) to the bottoms thereof, being then reflected back from the bottoms of the said sections, the phase corrections being obtained by reason of the different time delays occasioned by the radio energy in passing down and back along the sections of different lengths.
  • the sections are constituted by brass or other tubes, resembling cartridge cases, of the required different lengths, each stopped at one end.
  • Figs. 3 and 4 have the advantages that any desired surface shapes can easily be built up while shadows due to the steps are largely avoided since the steps are in the reflecting surface.
  • the axis of rotation is at the center of the mirror lens.
  • FIG. 5 shows a modification which differs from that of Figs. 3 and 4 only in that there is employed, in place of the mirror-lens ML a dielectric lens DL with a smoothly curved front surface DL2 and a stepped rear surface DLl, a curved mirror M being arranged behind the lens and close up against it, while in the 0 modification of Fig. 6 the front face DL2 of a dielectric lens is stepped and the rear face is smoothly curved the mirror M being in the form of a silver deposit on the smooth surface.
  • a radio beam scanner comprising a radio feed source adapted to emit a beam of radio energy, a radio mirror, a radio lens which is fixed in relation to said mirror, and means interconnecting said mirror and lens for swinging said mirror and lens as a unit about an axis of rotation which meets the lens axis at a point substantially in or behind the mirror, said source being directed toward said mirror and being fixedly mounted so that upon swinging said mirror and lens as a unit the beam emergent from said lens is scanned through an angle large in relation to the angle of swing of said unit.
  • a scanner as claimed in claim 1 wherein the lens and the mirror are combined to form a phase corrected mirror the non-reflecting surface of the mirror lens being smoothly curved arcuately and wherein the reflecting surface that is remote from the feed source is stepped.
  • a scanner as claimed in claim 1 wherein the lens and the mirror are combined to form a phase corrected mirror and wherein the radio feed source is offset, the non-reflecting surface of the mirror lens being smoothly curved arcuately and the reflecting surface, that is remote from the feed source, being stepped.
  • a scanner as claimed in claim 1 wherein the lens and the mirror are combined to form a phase corrected mirror the non-reflecting surface of the mirror lens being smoothly curved arcuately and the reflecting surface, that is remote from the feed source, being stepped, said phasecorrected mirror being constituted by a matrix of stopped tubes.
  • a scanner as claimed in claim 1 wherein the lens and the mirror are combined to form a phase corrected mirror and the radio feed source is offset so as to be substantially out of the path of the emergent beam from said phase corrected mirror, the non-reflecting surface of the mirror lens being smoothly curved arcuately and the reflecting surface, that is remote from the feed source, being stepped, said phase-corrected mirror being constituted by a matrix of stopped tubes.
  • the lens and the mirror are combined to form a phase corrected mirror-structure consisting of a dielectric lens with one smoothly curved surface'and one stepped surface and a smoothly curved mirror close against said lens.
  • a scanner as claimed in claim 1 wherein the lens and the mirror are combined to form a phase corrected mirror-structure consisting of a dielectric lens with one smoothly curved surface and one stepped surface and a smoothly curved mirror close against said lens, said mirror being constituted by a reflecting deposit on the smoothly curved surface of the lens.

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  • Aerials With Secondary Devices (AREA)
US291475A 1951-06-05 1952-06-03 Radio beam scanners Expired - Lifetime US2728912A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB13364/51A GB693263A (en) 1951-06-05 1951-06-05 Improvements in or relating to radio beam scanners

Publications (1)

Publication Number Publication Date
US2728912A true US2728912A (en) 1955-12-27

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US291475A Expired - Lifetime US2728912A (en) 1951-06-05 1952-06-03 Radio beam scanners

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US (1) US2728912A (enrdf_load_html_response)
BE (1) BE511867A (enrdf_load_html_response)
FR (1) FR1057717A (enrdf_load_html_response)
GB (1) GB693263A (enrdf_load_html_response)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3305867A (en) * 1963-11-05 1967-02-21 Raytheon Co Antenna array system
US5606334A (en) * 1995-03-27 1997-02-25 Amarillas; Sal G. Integrated antenna for satellite and terrestrial broadcast reception
US20070290805A1 (en) * 2006-06-09 2007-12-20 Nec Corporation Wireless communication system and wireless communication method
US20080238790A1 (en) * 2007-04-02 2008-10-02 Mcgrath Daniel T Rotating Screen Dual Reflector Antenna

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2268834B (en) * 1980-12-04 1994-06-22 Racal Mesl Ltd Radar arrangements and methods of detecting different types of targets
DE3144466A1 (de) * 1981-11-09 1983-07-07 AEG-Telefunken Nachrichtentechnik GmbH, 7150 Backnang Steuerbare antennenanordnung

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2479673A (en) * 1945-08-20 1949-08-23 Rca Corp Directional microwave transmission system having dielectric lens
US2530098A (en) * 1945-05-03 1950-11-14 Lester C Van Atta Antenna
US2547416A (en) * 1946-12-19 1951-04-03 Bell Telephone Labor Inc Dielectric lens
CA479967A (en) * 1952-01-01 Raytheon Manufacturing Company Antenna system
US2599763A (en) * 1948-12-31 1952-06-10 Bell Telephone Labor Inc Directive antenna system
US2599895A (en) * 1946-01-16 1952-06-10 Us Navy Eta-plane horn
US2605414A (en) * 1945-06-13 1952-07-29 Keary Thomas Joseph Fan beam radiator
US2617030A (en) * 1946-03-21 1952-11-04 Rca Corp Radio mirror
US2629828A (en) * 1946-03-05 1953-02-24 Willoughby M Cady Scanning device
US2678393A (en) * 1950-09-30 1954-05-11 Raytheon Mfg Co Radar scanning system

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA479967A (en) * 1952-01-01 Raytheon Manufacturing Company Antenna system
US2530098A (en) * 1945-05-03 1950-11-14 Lester C Van Atta Antenna
US2605414A (en) * 1945-06-13 1952-07-29 Keary Thomas Joseph Fan beam radiator
US2479673A (en) * 1945-08-20 1949-08-23 Rca Corp Directional microwave transmission system having dielectric lens
US2599895A (en) * 1946-01-16 1952-06-10 Us Navy Eta-plane horn
US2629828A (en) * 1946-03-05 1953-02-24 Willoughby M Cady Scanning device
US2617030A (en) * 1946-03-21 1952-11-04 Rca Corp Radio mirror
US2547416A (en) * 1946-12-19 1951-04-03 Bell Telephone Labor Inc Dielectric lens
US2599763A (en) * 1948-12-31 1952-06-10 Bell Telephone Labor Inc Directive antenna system
US2678393A (en) * 1950-09-30 1954-05-11 Raytheon Mfg Co Radar scanning system

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3305867A (en) * 1963-11-05 1967-02-21 Raytheon Co Antenna array system
US5606334A (en) * 1995-03-27 1997-02-25 Amarillas; Sal G. Integrated antenna for satellite and terrestrial broadcast reception
US20070290805A1 (en) * 2006-06-09 2007-12-20 Nec Corporation Wireless communication system and wireless communication method
US20080238790A1 (en) * 2007-04-02 2008-10-02 Mcgrath Daniel T Rotating Screen Dual Reflector Antenna
EP1983612A3 (en) * 2007-04-02 2008-11-26 Raython Company Rotating screen dual reflector antenna
US7576701B2 (en) 2007-04-02 2009-08-18 Raytheon Company Rotating screen dual reflector antenna

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Publication number Publication date
FR1057717A (fr) 1954-03-10
GB693263A (en) 1953-06-24
BE511867A (enrdf_load_html_response)

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