US2342721A - Parabolic reflector - Google Patents
Parabolic reflector Download PDFInfo
- Publication number
- US2342721A US2342721A US414479A US41447941A US2342721A US 2342721 A US2342721 A US 2342721A US 414479 A US414479 A US 414479A US 41447941 A US41447941 A US 41447941A US 2342721 A US2342721 A US 2342721A
- Authority
- US
- United States
- Prior art keywords
- reflector
- mirror
- parabolic reflector
- parabolic
- focus
- 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
Links
- 230000005855 radiation Effects 0.000 description 6
- 230000000694 effects Effects 0.000 description 4
- 230000003287 optical effect Effects 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 1
- 230000001627 detrimental effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 230000002452 interceptive effect Effects 0.000 description 1
- 238000012216 screening Methods 0.000 description 1
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F21—LIGHTING
- F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
- F21V7/00—Reflectors for light sources
- F21V7/04—Optical design
Definitions
- This invention relates to the directional transmission of intelligence and is more particularly concerned with arrangements of .the kind having a parabolic reector and a radiator in the focus thereof.l
- a convex mirror that may be of parabolic or hyperbolic shape or may be of the globular, cylindrical or any similar type, is disposed in front of the radiator arranged in the focus, as will be understood from the following description and the acccnipanying ⁇ drawing,l in which Fig. 1 is a diagrammatic sectional View of a prior arrangement, Fig. lo is a diagrammatic sectional View showing one embodiment of the invention, Fig. 2 is a graph which illustrates radiation conditions, Fig. 3 is a diagrammatic sectional view of an arrangement similar to that shown in Fig. 1b, Fig. 4a is a diagrammatic sectional View illustrating an improvement upon the arrangement shown in Fig. 1b, Fig. 4b ⁇ is a diagram of the radiation pattern produced by the arrangement according to Fig. 4a.
- the radiation-collecting effect should as far as possible be small, that is to say, should be quasi optical, in order on the one hand to reduce the listening range and on the other hand to enable the use of small sending power.
- the customary reflectors being somewhat large in depth have a great collecting effect. Also, the use of such large reflectors meets with difficulties which for economical reasons make it desirable to restrict the collecting effect.
- a sof-called calotte A formed as a concave mirror of semiglobular or other suitable shape, is arranged to utilize the direct radiation in a manner to light up the reflector B and thereby to prevent the direct rays and the reflected rays from interfering outside the reflector.
- a calotte so arranged does not improve the directivity rand is suitable only in the case of reflectors having a large focal distance and a small depth. In the case of all the other reflectors the efliciency is impaired in the mid-zone by a so-called shading eifect due to the screening property of the calotte A.
- the novel system shown in Fig. 1b has a refleeting calotte formed as a sort of convex opti cal mirror C by which the direct rays from a radiator S, located in the focus of reflector B, are guided in a special manner.
- the directivity of the radiation characteristic is increased by values up to While the detrimental shading effect of concave mirrors, such as mirror A, Fig. la, is obviated.
- mirror C Another advantage due to mirror C is that the l secondary maxima arising in the case of higher maxima of reflection are reduced, as can be seen in Fig. 2.
- radiator S instead of one radiator S a number of radiators or groups thereof may be provided.
- Fig. 3 shows two radiators Sl, S2..
- F denotes the focus of reflector B.
- an additional radiator S may be arranged within mirror C in order to produce an additional directive beam. This is not possible in prior devices.
- the latter arrangement is particularly suitable for producing radiation patterns to be followed by ships, the broad directional beam serving to give a presignal.
- a directional wave transmitter comprising a concave parabolic reflector, a source of radio frequency energy located at the reiiector focus, the arrangement being such that Waves radiating from the source will be reflected in parallel beams, a shield located on the reflector axis beyond the focus in position to intercept outwardly directed waves from said source, and means for projecting a substantial portion of said intercepted energy into the axial zone beyond saidv in claim 1, in which the reflector extends axially beyond the mirror surface.
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- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Aerials With Secondary Devices (AREA)
Description
Feb. 29, 1944. Y BOERNER 2,342,721
PARABOLIC REFLECTOR Filed 0G12. 10, 1941 /n venl'or: I
Patented Feb. ze, 1944 UNITED PARABOLIC REFLECTOR Rudolf Boerner, Berlin, Germany; vested in the Alien Property Custodian Application Qctober 10, 1941, Serial No. 414,479 In Germany January 20, 1940 (Cl. Z50-11) 3 Claims.
This invention relates to the directional transmission of intelligence and is more particularly concerned with arrangements of .the kind having a parabolic reector and a radiator in the focus thereof.l
According to the invention a convex mirror, that may be of parabolic or hyperbolic shape or may be of the globular, cylindrical or any similar type, is disposed in front of the radiator arranged in the focus, as will be understood from the following description and the acccnipanying` drawing,l in which Fig. 1 is a diagrammatic sectional View of a prior arrangement, Fig. lo is a diagrammatic sectional View showing one embodiment of the invention, Fig. 2 is a graph which illustrates radiation conditions, Fig. 3 is a diagrammatic sectional view of an arrangement similar to that shown in Fig. 1b, Fig. 4a is a diagrammatic sectional View illustrating an improvement upon the arrangement shown in Fig. 1b, Fig. 4b` is a diagram of the radiation pattern produced by the arrangement according to Fig. 4a.
In many cases, as when transmitting secret communications, the radiation-collecting effect should as far as possible be small, that is to say, should be quasi optical, in order on the one hand to reduce the listening range and on the other hand to enable the use of small sending power. The customary reflectors, being somewhat large in depth have a great collecting effect. Also, the use of such large reflectors meets with difficulties which for economical reasons make it desirable to restrict the collecting effect.
In prior arrangements the direct radiation in the case of parabolic reiiectors is either collected with the aid of a separate wave channel or is directed against the reflector in order to underso total reflection.
For instance, as shown in Fig. 1a,a sof-called calotte A, formed as a concave mirror of semiglobular or other suitable shape, is arranged to utilize the direct radiation in a manner to light up the reflector B and thereby to prevent the direct rays and the reflected rays from interfering outside the reflector. A calotte so arranged does not improve the directivity rand is suitable only in the case of reflectors having a large focal distance and a small depth. In the case of all the other reflectors the efliciency is impaired in the mid-zone by a so-called shading eifect due to the screening property of the calotte A.
The novel system shown in Fig. 1b has a refleeting calotte formed as a sort of convex opti cal mirror C by which the direct rays from a radiator S, located in the focus of reflector B, are guided in a special manner. In fact, the rays .are reflected by mirror C and then by reflector B so that the rays outgoing from the reflector are not parallel to its axis but converge or run toward it. As a result, the directivity of the radiation characteristic is increased by values up to While the detrimental shading effect of concave mirrors, such as mirror A, Fig. la, is obviated.
Another advantage due to mirror C is that the l secondary maxima arising in the case of higher maxima of reflection are reduced, as can be seen in Fig. 2.
Instead of one radiator S a number of radiators or groups thereof may be provided. For instance, Fig. 3 shows two radiators Sl, S2.. F denotes the focus of reflector B.
As shown in Fig. 4a an additional radiator S may be arranged within mirror C in order to produce an additional directive beam. This is not possible in prior devices.
The latter arrangement is particularly suitable for producing radiation patterns to be followed by ships, the broad directional beam serving to give a presignal.
What is claimed is:
1. A directional wave transmitter comprising a concave parabolic reflector, a source of radio frequency energy located at the reiiector focus, the arrangement being such that Waves radiating from the source will be reflected in parallel beams, a shield located on the reflector axis beyond the focus in position to intercept outwardly directed waves from said source, and means for projecting a substantial portion of said intercepted energy into the axial zone beyond saidv in claim 1, in which the reflector extends axially beyond the mirror surface.
3'. An arrangement according to claim 1, wherein the said convex mirror surface is a parabolic reector.
RUDOLF ,BOERNER
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE2342721X | 1940-01-20 |
Publications (1)
Publication Number | Publication Date |
---|---|
US2342721A true US2342721A (en) | 1944-02-29 |
Family
ID=7995112
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US414479A Expired - Lifetime US2342721A (en) | 1940-01-20 | 1941-10-10 | Parabolic reflector |
Country Status (1)
Country | Link |
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US (1) | US2342721A (en) |
Cited By (24)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2458885A (en) * | 1944-12-15 | 1949-01-11 | Bell Telephone Labor Inc | Directive antenna system |
US2471284A (en) * | 1945-05-25 | 1949-05-24 | Bell Telephone Labor Inc | Directive antenna system |
US2480143A (en) * | 1946-09-11 | 1949-08-30 | Standard Telephones Cables Ltd | Directive antenna system |
US2483575A (en) * | 1944-07-26 | 1949-10-04 | Bell Telephone Labor Inc | Directional microwave antenna |
US2530079A (en) * | 1945-04-03 | 1950-11-14 | Henry J Riblet | Directive antenna system |
US2531455A (en) * | 1942-02-04 | 1950-11-28 | Sperry Corp | Directive antenna structure |
US2542844A (en) * | 1943-08-14 | 1951-02-20 | Bell Telephone Labor Inc | Microwave directive antenna |
US2671854A (en) * | 1945-09-06 | 1954-03-09 | Halpern Julius | Conical scanning antenna |
US2689304A (en) * | 1949-09-16 | 1954-09-14 | Fairchild Engine & Airplane | Scanning device |
US2755374A (en) * | 1952-03-13 | 1956-07-17 | Ott Walter | Reflecting system |
US2759182A (en) * | 1945-03-24 | 1956-08-14 | Bell Telephone Labor Inc | Directive antenna systems |
US2831187A (en) * | 1945-06-23 | 1958-04-15 | Harris Frederick | Radio direction finding system |
US2942264A (en) * | 1958-03-31 | 1960-06-21 | Ryan Aeronautical Co | Coaxial antenna |
US2942265A (en) * | 1958-03-31 | 1960-06-21 | Ryan Aeronautical Co | Enclosed coaxial antenna |
US2976535A (en) * | 1949-03-24 | 1961-03-21 | Bell Telephone Labor Inc | Cosecant squared antenna-reflector systems |
US3045239A (en) * | 1949-12-14 | 1962-07-17 | Westinghouse Electric Corp | Parabolic feed system |
US3133284A (en) * | 1959-03-02 | 1964-05-12 | Rca Corp | Paraboloidal antenna with compensating elements to reduce back radiation into feed |
US3209361A (en) * | 1963-01-14 | 1965-09-28 | James E Webb | Cassegrainian antenna subreflector flange for suppressing ground noise |
US3218643A (en) * | 1961-03-01 | 1965-11-16 | Peter W Hannan | Double-reflector antenna with critical dimensioning to achieve minimum aperture blocking |
US3231892A (en) * | 1962-06-26 | 1966-01-25 | Philco Corp | Antenna feed system simultaneously operable at two frequencies utilizing polarization independent frequency selective intermediate reflector |
US3231893A (en) * | 1961-10-05 | 1966-01-25 | Bell Telephone Labor Inc | Cassegrainian antenna with aperture blocking compensation |
US3826911A (en) * | 1973-07-02 | 1974-07-30 | Raytheon Co | Catoptric lens arrangement |
US3965455A (en) * | 1974-04-25 | 1976-06-22 | The United States Of America As Represented By The Secretary Of The Navy | Focused arc beam transducer-reflector |
US5003321A (en) * | 1985-09-09 | 1991-03-26 | Sts Enterprises, Inc. | Dual frequency feed |
-
1941
- 1941-10-10 US US414479A patent/US2342721A/en not_active Expired - Lifetime
Cited By (24)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2531455A (en) * | 1942-02-04 | 1950-11-28 | Sperry Corp | Directive antenna structure |
US2542844A (en) * | 1943-08-14 | 1951-02-20 | Bell Telephone Labor Inc | Microwave directive antenna |
US2483575A (en) * | 1944-07-26 | 1949-10-04 | Bell Telephone Labor Inc | Directional microwave antenna |
US2458885A (en) * | 1944-12-15 | 1949-01-11 | Bell Telephone Labor Inc | Directive antenna system |
US2759182A (en) * | 1945-03-24 | 1956-08-14 | Bell Telephone Labor Inc | Directive antenna systems |
US2530079A (en) * | 1945-04-03 | 1950-11-14 | Henry J Riblet | Directive antenna system |
US2471284A (en) * | 1945-05-25 | 1949-05-24 | Bell Telephone Labor Inc | Directive antenna system |
US2831187A (en) * | 1945-06-23 | 1958-04-15 | Harris Frederick | Radio direction finding system |
US2671854A (en) * | 1945-09-06 | 1954-03-09 | Halpern Julius | Conical scanning antenna |
US2480143A (en) * | 1946-09-11 | 1949-08-30 | Standard Telephones Cables Ltd | Directive antenna system |
US2976535A (en) * | 1949-03-24 | 1961-03-21 | Bell Telephone Labor Inc | Cosecant squared antenna-reflector systems |
US2689304A (en) * | 1949-09-16 | 1954-09-14 | Fairchild Engine & Airplane | Scanning device |
US3045239A (en) * | 1949-12-14 | 1962-07-17 | Westinghouse Electric Corp | Parabolic feed system |
US2755374A (en) * | 1952-03-13 | 1956-07-17 | Ott Walter | Reflecting system |
US2942264A (en) * | 1958-03-31 | 1960-06-21 | Ryan Aeronautical Co | Coaxial antenna |
US2942265A (en) * | 1958-03-31 | 1960-06-21 | Ryan Aeronautical Co | Enclosed coaxial antenna |
US3133284A (en) * | 1959-03-02 | 1964-05-12 | Rca Corp | Paraboloidal antenna with compensating elements to reduce back radiation into feed |
US3218643A (en) * | 1961-03-01 | 1965-11-16 | Peter W Hannan | Double-reflector antenna with critical dimensioning to achieve minimum aperture blocking |
US3231893A (en) * | 1961-10-05 | 1966-01-25 | Bell Telephone Labor Inc | Cassegrainian antenna with aperture blocking compensation |
US3231892A (en) * | 1962-06-26 | 1966-01-25 | Philco Corp | Antenna feed system simultaneously operable at two frequencies utilizing polarization independent frequency selective intermediate reflector |
US3209361A (en) * | 1963-01-14 | 1965-09-28 | James E Webb | Cassegrainian antenna subreflector flange for suppressing ground noise |
US3826911A (en) * | 1973-07-02 | 1974-07-30 | Raytheon Co | Catoptric lens arrangement |
US3965455A (en) * | 1974-04-25 | 1976-06-22 | The United States Of America As Represented By The Secretary Of The Navy | Focused arc beam transducer-reflector |
US5003321A (en) * | 1985-09-09 | 1991-03-26 | Sts Enterprises, Inc. | Dual frequency feed |
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