GB1234778A - Improvements in or relating to surfaces for reflecting microwave energy - Google Patents

Improvements in or relating to surfaces for reflecting microwave energy

Info

Publication number
GB1234778A
GB1234778A GB38619/67A GB3861967A GB1234778A GB 1234778 A GB1234778 A GB 1234778A GB 38619/67 A GB38619/67 A GB 38619/67A GB 3861967 A GB3861967 A GB 3861967A GB 1234778 A GB1234778 A GB 1234778A
Authority
GB
United Kingdom
Prior art keywords
reflector
sub
ferrite
ring
electromagnets
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
Application number
GB38619/67A
Inventor
Wolfgang Hersch
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.)
EMI Ltd
Original Assignee
EMI 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 EMI Ltd filed Critical EMI Ltd
Priority to GB38619/67A priority Critical patent/GB1234778A/en
Priority to US754399A priority patent/US3594804A/en
Publication of GB1234778A publication Critical patent/GB1234778A/en
Expired legal-status Critical Current

Links

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
    • H01Q3/2664—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 electrically moving the phase centre of a radiating element in the focal plane of a focussing device
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q19/00—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic
    • H01Q19/10—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic using reflecting surfaces
    • H01Q19/18—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic using reflecting surfaces having two or more spaced reflecting surfaces
    • H01Q19/19—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic using reflecting surfaces having two or more spaced reflecting surfaces comprising one main concave reflecting surface associated with an auxiliary reflecting surface

Landscapes

  • Aerials With Secondary Devices (AREA)

Abstract

1,234,778. Aerials. E.M.I. Ltd. 26 July, 1968 [22 Aug., 1967], No. 38619/67. Heading H4A. A reflector in a microwave aerial arrangement comprises a layer of ferrite material over a non-ferromagnetic reflecting surface. The magnetic condition of different parts of the layer may be selectively changed by commutating means to produce a scanning system, each part then becoming relatively reflective of microwave energy instead of transparent thereto. As described, a sub-reflector 3 of a Cassegrain type aerial system comprises a thin non-ferromagnetic metallic disc 7 having on the outer annular portion of its reflecting surface a ring 6 of ferrite material. A number of U-shaped electromagnets having cores 8 and energizing windings 9 are located behind the part of the disc 7 which is covered by the ring 6. The poles of each U-shaped magnet are aligned so that each magnet, when energizing current is fed to the respective winding, produces flux lines 11 (shown in Fig. 4) which are parallel to each other. All the windings 9 are coupled to an electrical commutating device 10 by which they are successively energized. Thus, an apparent distortion of the sub-reflector rim is produced, the motion of which leads to a conical scanning of the beam from the associated main reflector when the sub-reflector is illuminated by the aerial feed with waves which are linearly polarized, with their H-vectors perpendicular to the flux lines 11. The ferrite ring 6 may be coated with a quarter-wave thick layer of dielectric material 12 having a dielectric constant approximating to the geometric mean of those of the ferrite material and of the air, to reduce mismatch when the ferrite is transparent to the radio wave. In another embodiment (Fig. 6, not shown) different sectors of the ferrite ring are arranged to be selectively magnetized by means of rod-type electromagnets which each have a single pole adjacent the rear surface of the sub-reflector. Thus, the electromagnets produce a magnetic field normal to the surface of the sub-reflector, and the arrangement may be used with linearly polarized radiation of any direction of H-vector, or with circularly polarized radiation.
GB38619/67A 1967-08-22 1967-08-22 Improvements in or relating to surfaces for reflecting microwave energy Expired GB1234778A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
GB38619/67A GB1234778A (en) 1967-08-22 1967-08-22 Improvements in or relating to surfaces for reflecting microwave energy
US754399A US3594804A (en) 1967-08-22 1968-08-21 Electrically controlled reflective surface employing ferrite material

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB38619/67A GB1234778A (en) 1967-08-22 1967-08-22 Improvements in or relating to surfaces for reflecting microwave energy

Publications (1)

Publication Number Publication Date
GB1234778A true GB1234778A (en) 1971-06-09

Family

ID=10404615

Family Applications (1)

Application Number Title Priority Date Filing Date
GB38619/67A Expired GB1234778A (en) 1967-08-22 1967-08-22 Improvements in or relating to surfaces for reflecting microwave energy

Country Status (2)

Country Link
US (1) US3594804A (en)
GB (1) GB1234778A (en)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5142449A (en) * 1974-10-08 1976-04-10 Univ Shizuoka REFUREKUTAANTENANISONAETSUKETA FUERAITONYORUDENJIHABIIMUNO DENKITEKI HOKOHENKAHO
FR2304192A1 (en) * 1975-03-14 1976-10-08 Thomson Csf SELECTIVE GAIN REDUCTION ANTENNA
GB2164517B (en) * 1984-02-29 1988-02-17 Thomas Michael Benyon Wright Improvements to antenna systems
US5003321A (en) * 1985-09-09 1991-03-26 Sts Enterprises, Inc. Dual frequency feed
CA2160286C (en) * 1994-12-08 1999-01-26 James Gifford Evans Small antennas such as microstrip patch antennas

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1094934A (en) * 1953-11-19 1955-05-25 Lobe scanning microwave antenna
US2866972A (en) * 1956-09-26 1958-12-30 Airtron Inc Microwave polarization apparatus
US2921308A (en) * 1957-04-01 1960-01-12 Hughes Aircraft Co Surface wave device
US3423756A (en) * 1964-09-10 1969-01-21 Rca Corp Scanning antenna feed

Also Published As

Publication number Publication date
US3594804A (en) 1971-07-20

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