Broadband antenna

• US 5,111,213 A
• Filed: 01/23/1990
• Issued: 05/05/1992
• Est. Priority Date: 01/23/1990
• Status: Expired due to Fees

• Current Assignee: Astron Corporation
• Original Assignee: Astron Corporation
• Inventors: Jahoda, Joseph R., Shergold, Steven D.
• Primary Examiner(s): Wimer, Michael C.
• Application Number:
  US07/468,666
• Time in Patent Office: 833 Days
• Field of Search: 343/705, 343/749, 343/722, 343/860, 343/740, 343/802, 343/790, 343/731, 343/737, 343/739, 343/752, 343/818, 343/865, 343/872, 343/895
• US Class Current: 343/722
• CPC Class Codes: H01Q 1/285 Aircraft wire antennas means for trailing H01Q1/30
• CPC Class Codes: H01Q 11/02 Non-resonant antennas, e.g. travelling-wave antenna Yagi antennas H01Q19/30
• CPC Class Codes: H01Q 21/30 Combinations of separate antenna units operating in different wavebands and connected to a common feeder system
• CPC Class Codes: H01Q 5/335 at the feed, e.g. for impedance matching
• CPC Class Codes: H01Q 5/40 Imbricated or interleaved structures; Combined or electromagnetically coupled arrangements, e.g. comprising two or more non-connected fed radiating elements
• CPC Class Codes: H01Q 5/48 Combinations of two or more dipole type antennas

Abstract

Wideband antenna systems may provide continuous coverage over the VLF, HF, VHF, and UHF frequency ranges. Matching transformers, insertion resistors and damping elements are integral parts of these antenna systems.

Claims

1. A wideband antenna system for continuous coverage of the 1.5 MHz to 30 MHz radio frequency spectrum which is coaxial cable fed and having low VSWR, comprising:

a coaxially fed wideband balun having a low impedance input and a high impedance output;

at least one wire radiating element, said element having a first and second end, said first end connected to said wideband balun high impedance output;

at lest one insertion resistor, said resistor having a first and second end, wherein said insertion resistor first end is connected to said radiating element second end; and

at least one radio frequency damping element, said damping element connected to the second end of said insertion resistor;

at least one first stabilizing resistor connected to said wire radiating element first end; and

at least one second stabilizing resistor connected to said wire radiating element second end.

2. An antenna system according to claim 1, wherein said wideband balun has an input impedance of 50 ohms and an output impedance of 200 ohms.

3. An antenna system according to claim 1, wherein said wire radiating element is helically wound.

4. An antenna system according to claim 1, wherein said wire radiating element is folded.

5. An antenna system according to claim 1, wherein said wire radiating element is from 20 to 64 feet in length.

6. An antenna system according to claim 1, wherein said insertion resistor is 270 ohms.

7. An antenna system according to claim 1, wherein said damping element is a coaxial cable linear capacitor.

8. An antenna system according to claim 7, wherein said coaxial cable linear capacitor is 18 feet in length.

9. An antenna system according to claim 1, wherein said damping element is a wire.

10. An antenna system according to claim 9, wherein said wire is from 9 to 11 feet in length.

11. An antenna system according to claim 1, further comprising:

a passive switching element connected between said insertion resistor and said radiating element.

12. An antenna system according to claim 11, wherein said passive switching element is an inductor.

13. An antenna system according to claim 11, wherein said passive switching element is a capacitor.

14. An antenna system according to claim 11, wherein said passive switching element is a combination of capacitors and inductors.

15. An antenna system according to claim 1, further comprising:

a radio frequency compensation means connected between said wire radiating element and said balun output, for adjusting antenna system characteristics and correcting for close proximity metal structures and associated ground currents.

16. An antenna system according to claim 1, further comprising:

a radio frequency compensation means connected between said wire radiating element and said insertion resistor configured to adjust the characteristics of the antenna system and correcting for close proximity metal structures.

17. An antenna system according to claim 15, wherein said radio frequency compensation means comprises a capacitor.

18. An antenna system according to claim 1, wherein the first and second stabilizing resistors are nominally 1500 ohms.

19. An antenna system as recited in claim 1, further comprising:

at least one cylindrical vertical self supporting structure, transparent to radio waves, enclosing said wire radiating element, insertion resistor and damping element.

20. An antenna system as recited in claim 1, wherein said wire radiating element is externally mountable, and said wideband balun, insertion resistor and damping element are internally mountable in an aircraft structure.

21. An antenna system as recited in claim 1, wherein a watertight structure, transparent to radio waves, encloses said wire radiating element, balun, insertion resistor and damping element.

22. An antenna system according to claim 1, wherein said wire radiating element is conformably coated to a structure.

23. An antenna system according to claim 22 wherein said structure is metallic.

24. An antenna system according to claim 1, wherein said antenna system is coupled to reflector elements.

25. An antenna system according to claim 1, wherein said antenna system is coupled to redirector elements.

26. An antenna system according to claim 1, wherein said insertion resistor is mounted inside said radiating element.

27. A wideband antenna system for continuous coverage of the 1.5 MHz to 30 MHz radio frequency spectrum which is coaxial cable fed and having low VSWR, comprising:

a coaxially fed wideband balun having a low impedance input and a high impedance output;

at least one wire radiating element, said element having a first and second end, said first end connected to said wideband balun high impedance output;

at least one passive switching means, said switching means having a first and second end, wherein said passive switching means first end is connected to the second end of said radiating element;

at least one insertion resistor, said insertion resistor having a first and second end, wherein said insertion resistor first end is connected to the second end of said passive switching means; and

at least one radio frequency damping element, said damping element connected to the second end of said insertion resistor.

28. A wideband ground independent balanced antenna system for continuous coverage of the 1.5 MHz to 30 MHz radio frequency spectrum which is coaxial cable fed and having low VSWR, comprising:

a coaxially fed wideband balun having a low impedance input and a high impedance balanced output;

at least two wire radiating elements, each having a first and second end, said first ends connected to the wideband balun high impedance output;

at least two passive switching means, each having a first and second end, wherein said passive switching means first end is connected to a radiating element second end;

at least two insertion resistors, each having a first and second end, wherein said insertion resistor first end is connected to a passive switching means second end; and

at least two radio frequency damping elements each connected to a second end of an insertion resistor, wherein each wire element is connected to a passive switching means, each passive switching means is connected to an insertion resistor, and each insertion resistor is connected to a damping element.

29. An antenna system according to claim 28, further comprising:

a passive switching element connected between said insertion resistors and said radiating elements.