Pick-up horn for high power thermal vacuum testing of spacecraft payloads

Abstract

A pick-up horn for absorbing radiation emitted by a transmit antenna is provided. The pick-up horn includes at least one outer metal wall forming a metal body and at least one interior surface disposed in the metal body, forming at least one chamber in the metal body. The pick-up horn further includes a front metal surface disposed at a front end of the metal body, having at least one opening corresponding to the at least one chamber, and at least one high-power absorbing load disposed within the at least one chamber and in contact with the at least one interior surface. The pick-up horn may further include a serpentine coolant path disposed within the metal body between an outer surface of the at least one outer metal wall and the at least one high-power absorbing load.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. In the drawings:

FIGS. 1A to 1C depict various views of a pick-up horn according to one embodiment of the present invention;

FIG. 2 depicts a partial cut-away view of a pick-up horn according to another embodiment of the present invention;

FIGS. 3A to 3C depict frontal views of pick-up horns according to various embodiments of the present invention;

FIG. 4 depicts a pick-up horn disposed in front of a transmit antenna according to one embodiment of the present invention;

FIG. 5 is a block diagram depicting a pick-up horn arranged in a test configuration;

FIG. 6 is a graph illustrating the low return loss experienced by a flight horn when tested by a pick-up horn according to one embodiment of the present invention; and

FIG. 7 is a graph illustrating the low leakage experienced by a flight horn when tested by a pick-up horn according to one embodiment of the present invention.

Claims

1. A pick-up horn for absorbing radiation emitted by an antenna, the pick-up horn comprising: at least one outer metal wall forming a metal body;at least one interior surface disposed in the metal body and forming at least one chamber in the metal body;a front metal surface disposed at a front end of the metal body, and having at least one opening corresponding to the at least one chamber; andat least one high-power absorbing load disposed within the at least one chamber and in contact with the at least one interior surface.

2. The pick-up horn of claim 1, further comprising a coolant path disposed within the metal body, the coolant path including a coolant inlet and a coolant outlet, each of which is disposed on an outer surface of the at least one outer metal wall.

3. The pick-up horn of claim 2, wherein the coolant path is a serpentine coolant path disposed between an outer surface of the at least one outer metal wall and the at least one high-power absorbing load.

4. The pick-up horn of claim 1, further comprising at least one thermocouple disposed between the at least one high-power absorbing load and the at least one interior surface.

5. The pick-up horn of claim 4, wherein the at least one thermocouple is disposed in a groove in the at least one high-power absorbing load, the groove being located adjacent to the at least one interior surface.

6. The pick-up horn of claim 1, further comprising a radio frequency-transparent debris shield disposed over the front metal surface.

7. The pick-up horn of claim 1, further comprising an RF choke in the form of an annular groove disposed in an outer region of the front metal surface.

8. The pick-up horn of claim 1, further comprising at least one vent hole for providing an outgassing path between an outer surface of the at least one outer metal wall and the at least one interior surface.

9. The pick-up horn of claim 1, wherein the at least one chamber is a plurality of chambers, and wherein the front metal surface has an opening corresponding to each chamber, and the openings disposed nearer to a center of the front metal surface are larger than the openings disposed farther from the center.

10. The pick-up horn of claim 1, wherein the at least one opening is sufficiently large to accommodate any polarization of the radiation emitted by the antenna.

11. The pick-up horn of claim 1, wherein the at least one opening is sufficiently large to accommodate a plurality of higher order modes of the radiation emitted by the antenna.

12. The pick-up horn of claim 1, wherein the at least one opening is rectangular in shape.

13. The pick-up horn of claim 1, wherein the at least one high-power absorbing load is substantially wedge-shaped.

14. The pick-up horn of claim 1, wherein the at least one opening is elliptical in shape.

15. The pick-up horn of claim 1, wherein the at least one high-power absorbing load has a substantially conical shape.

16. The pick-up horn of claim 1, wherein the at least one high-power absorbing load is bonded to the at least one interior surface by a layer of thermally conductive bonding epoxy.

17. The pick-up horn of claim 1, wherein the at least one high-power absorbing load is a ceramic high-power absorbing load.

18. The pick-up horn of claim 1, wherein the pick-up horn is substantially RF-transparent to the antenna while absorbing the radiation emitted by the antenna.

19. A pick-up horn for absorbing radiation emitted by an antenna, the pick-up horn comprising: at least one outer metal wall forming a metal body;a plurality of interior surfaces disposed in the metal body and forming a plurality of chambers in the metal body;a front metal surface disposed at a front end of the metal body, and having a plurality of openings corresponding to the plurality of chambers;a plurality of ceramic high-power absorbing loads, each high-power absorbing load disposed within a corresponding one of the plurality of chambers and in contact with at least one of the plurality of interior surfaces; anda serpentine coolant path disposed within the metal body between an outer surface of the at least one outer metal wall and the plurality of ceramic high-power absorbing loads, the coolant path including a coolant inlet and a coolant outlet, each of which is disposed on the outer surface of the at least one outer metal wall.

20. The pick-up horn of claim 19, further comprising an RF choke in the form of an annular groove disposed in an outer region of the front metal surface.