US3503072A - Unfolding parabolic antenna - Google Patents

Description

March 24, 1970 H. G. THOMPSON 3,

UNFOLDING PARABOLIC ANTENNA Filed June 28, 1967 3 Sheets-Sheet l INVENTOR HORACE G. THOMPSON BY ymmh W ATTORNEYS March 24, 1970 THOMPSON 3,503,072

UNFOLDING PARABOLIC ANTENNA Filed June 28, 1967 3 Sheets-Sheet 2 INVENT OR HORACE 6. THOMPSON M al 0% ATTORNEYS March 24, 1970 H. c. THOMPSON 3,

UNFOLDING PARABOLIC ANTENNA Filed June 28. 1967 3 Sheets-Sheet 5 INVENT OR.

HORACE G. THOMPSON M w; ATTORNEYS United States Patent O 3,503,072 UNFOLDING PARABOLIC ANTENNA Horace G. Thompson, Accokeek, Md., assignor to the United States of America as represented by the Secretary of the Navy Filed June 28, 1967, Ser. No. 650,160 Int. Cl. H01q 19/12 US. Cl. 343-705 8 Claims ABSTRACT OF THE DISCLOSURE An unfolding antenna for radar scanning and especially suited for use aboard satellites and other space vehicles. The antenna is structurally formed of panels which are unfolded from stowed to extended position by energy from compressed gas.

BACKGROUND OF THE INVENTION Field of the invention The present invention relates to an unfolding type antenna and more particularly to an antenna which is structurally formed of panels that are compactly folded in a stowed position and which are forced to an extended position by energy from compressed gas. The invention is particularly suited for use with radar aboard satellites and other space vehicles.

Description of the prior art In the past decade the technical space capability has increased rapidly and is now at a point where large orbit and space probe vehicles are feasible. These nowfeasible large vehicles allow the use of electronic systerns, such as scanning radar, that require large antennas for optimum performance. For obvious reasons, these large antennas must be compactly stowed during the launching period and later deployed when the vehicle is in space.

Several systems for deploying large antennas in space have been developed. These systems are not entirely satisfactory because these known systems use electric motors with inherent disadvantages relating to weight and electric power requirements. Another, notquite so obvious, disadvantage of these prior systems is that the deployment motors introduce large reaction torques which tend to disturb the stabilized space vehicles.

SUMMARY OF THE INVENTION The general purpoese of this invention is to provide a large antenna which can be deployed in space and which embraces all of the advantages of similarly employed prior antenna systems and possesses none of the aforedescribed disadvantages. To attain this, the present invention contemplates a large antenna which is structurally formed of seven joined panels and which is deployed in space, from a compactly stowed position, by the energy of compressed gas.

It is, therefore, an object of this invention to provide an improved large antenna which can be deployed in space.

Another object is the provision of an improved large antenna which can be deployed in space by the energy of compressed gas.

A still further object of the invention is to provide an improved large antenna which can be deployed in space by the energy of compressed gas and which is structurally formed of seven joined panels.

BRIEF DESCRIPTION OF THE DRAWING Other objects and advantages of the invention will hereinafter become more fully apparent from the fol- 3,503,072 Patented Mar. 24, 1970 "ice DESCRIPTION OF THE INVENTION Referring now to the drawings, wherein like reference characters designate like or corresponding parts throughout the several views, there is shown in FIG. 1 the antenna 10 of the invention in the fully deployed state. The antenna 10 is formed as a parabolic cylinder reflector and typically could be 24 feet across and 40 inches high and suitable for use with L-band scanning radar.

Seven panels, preferably formed of any strong, electromagnetically suitable lightweight-sandwich material, comprise the reflector. As illustrated the curved central panel 12 is hinged on opposite sides to curved panels 14 and 16 which are in turn hinge connected to curved panels 18 and 20. These latter panels are also respectively hinge connected to the outer curved panels 22 and 24.

Telescoping struts 26 and 28 are respectively hinge connected to the outer ends of panels 14 and 16. These struts are also hinge connected to yoke 30 which is rigidly connected to one end to center panel 12 and on the other end to the slotted feed 32. The functional purpose of the compressed gas operated struts 26 and 28 will subsequently be described.

Flexible lines 34 and 36, preferably made of fiberglass, are connected between feed assembly 32 and the center of panels 22 and 24. Similar lines 38 and 40, which for purposes of drafting simplicity are shown only in FIGS. 4 and 5, are connected along the reverse side of the reflector and across hinged links 42 and 44, as shown, between the center panel 12 and the center of outer panels 22 and 24.

Referring now to FIG. 2, the antenna 10 is shown in the stowed condition. For the typical dimensions previously mentioned, the invention requires a stowing space 3 by 4 by 9 feet. In FIG. 2, for purposes of clarity, the lines 34 and 36 are omitted.

FIGS. 3, 4 and 5 show the progressive deployment of antenna 10 from the stowed position shown in FIG. 2 to the fully deployed position illustrated in FIG. 5. This deployment is accomplished by the energy of compressed gas which is carried in and released in and then causes the extension of the telescoping struts 26 and 28. It can be seen from FIGS. 2-5 that the extension of the struts 26 and 28 and the restraint exercised by lines 34 and 36 cause the panels 14, 16, 18, 20, 22, and 24 of the antenna 10 to gradually transform from the very narrow W shape of the stowed position shown in FIG. 2 to the progressively wider W shapes of FIG. 3 and 4 and finally to the fully deployed parabolic cylinder shape of FIG. 5. This gradual transformation occurs about the rigid assembly of panel 12, yoke 30 and feed 32 which provides a strong backbone for the entire antenna.

The lines 38 and 40, which are connected to panel 12 and hinged links 42 and 44, are provided to prevent the outer panels 22 and 24 from swinging too far forward under the urging forces exerted by the telescoping struts 26 and 28 and the lines 34 and 36.

It is apparent from the drawings that the reaction forces arising in the extension of the struts 26 and 28 and the accompanying deployment of the antenna 10 will be largely self-cancelling since the struts extend in directions which are nearly opposite. The self-cancellation of the deployment forces is an advantageous feature of the invention, especially where the antenna is used on a space vehicle, since the disturbance to the stability of the space vehicle, particularly in the direction of flight, is minimized.

The contemplated environment of the antenna 10, although it will be easily appreciated that the invention is not limited to such application, is on board a satellite or space probe. During the launching the antenna is stowed inside the space vehicle and at the appropriate time is moved to the exterior of the vehicle by means which are not a part of the invention. The typical antenna previously dimensionally described weighs under 65 pounds and is moved from the inside to the outside of a space vehicle through a hatch opening of 3.2 by 42 inches.

After the antenna is outside the space vehicle, the compressed gas is released by some control means which is not a part of the invention but typically could be electrically controlled valves. The antenna is then deployed by the energy of the released compressed gas, but, as previously mentioned the deployment forces will be largely self-cancelling and therefore will not disturb the sta bility of the space vehicle. Subsequently the antenna 10 is used as desired, for example, with scanning L-band radar in which event the antenna is rotated by some mechanism which is connected to the yoke 30.

There has been disclosed an improved large antenna which can be deployed in space by the energy of compressed gas and which is structurally formed of seven joined panels. Additional, more detailed, information concerning the invention may be found in NRL Report 6480, published Dec. 28, 1966 by the Naval Research Laboratory, Washington, DC and titled An Unfolding Mechanically Scanned Antenna for a Satellite-Borne Radar.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood, that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

What is claimed and desired to be secured by Letters Patent of the United States is:

1. An antenna for use with a space vehicle comprising:

a yoke attached to said vehicle;

an antena feed rigidly connected to said yoke;

a rectangular central panel rigidly connected to said yoke;

at least one side panel hinge connected to each of the opposite longer sides of said rectangular central panel and first and second telescoping strut means hinge connected respectively between said yoke and said side panels, said first and second telescoping strut means being extensibly energized for moving said side panels from a folded, stowed state to a deployed state wherein said central panel and said side panels form a parabolic cylinder shaped reflector,

2. An antenna as set forth in claim 1 wherein said extensible energization is accomplished by the release of compressed gas within said first and second telescoping strut means.

3. An antenna as set forth in claim 2 wherein said first and second telescoping strut means face in substantially opposite directions.

4. An antenna as set forth in claim 3 and further including flexible line means connected between said side panels and the rigidly connected assembly of said yoke, said central panel and said feed for limiting the movement of said side panels to the deployed state.

5. An antenna for use with a space vehicle comprising:

a yoke attached to said vehicle;

an antena feed rigidly connected to said yoke;

a rectangular central panel rigidly connected to said yoke;

a first plurality of curved side panels hinge connected to each other and to one of the longer sides of said rectangular central panel;

a second plurality of curved side panels hinge connected to each other and to the other of the longer sides of said rectangular central panel and first and second telescoping strut means hinge connected respectively between said first and second pluralities of curved side panels and said yoke, said first and second telescoping strut means being extensibly energized for moving said first and second plurality of curved side panels from a folded, stowed state to a deployed state whereinsaid central panel and said side panels form a parabolic cylinder shaped reflector.

6. An antenna as set forth in claim 5 wherein said extensible energization is accomplished by the release of compressed gas within said first and second telescoping strut means.

7. An antenna as set forth in claim 6 wherein said first and second telescoping strut means face in substantially opposite directions.

8. An antenna as set forth in claim 7 and further including flexible line means connected between the rigidly connected assembly of said yoke, said central panel and said feed and said first and second pluralities of curved side panels for limiting the movement of said side panels to the deployed state.

References Cited UNITED STATES PATENTS 2,945,234 7/1960 Driscoll 3439 15 FOREIGN PATENTS 216,556 5/1969 Switzerland.

ELI LIEBERMAN, Primary Examiner US. Cl. X.R.

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