Inline coaxial balun-fed ultrawideband cornu flared horn antenna

• US 5,973,653 A
• Filed: 07/31/1997
• Issued: 10/26/1999
• Est. Priority Date: 07/31/1997
• Status: Expired due to Fees

• Current Assignee: The United States of America As Represented By The Secretary of Agriculture
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Kragalott, Mark, Pala, William
• Primary Examiner(s): Font, Frank G.
• Assistant Examiner(s): LAUCHMAN, LAYLA G
• Application Number:
  US08/904,275
• Time in Patent Office: 817 Days
• Field of Search: 343/786, 343/767, 343/772, 343/783
• US Class Current: 343/786
• CPC Class Codes: H01Q 13/08 Radiating ends of two-conductor microwave transmission lines, e.g. of coaxial lines, of microstrip lines

Abstract

The inline coaxial balun fed cornu flared horn antenna is formed by transitioning a coaxial transmission line to a parallel-plate transmission line with a Klopfenstein impedance profile and terminating with a flared horn antenna based on a scaled cornu spiral. The cornu spiral is a mathematical plane curve formed by parametrically plotting the scaled cosine Fresnel integral versus the scaled sine Fresnel integral. The antenna has the property that the curvature of the flare increases linearly in proportion to the arc length of the flare. The Klopfenstein impedance profile of the inline balun ensures a low voltage reflection across a wide bandwidth with a minimum transition length and together with the cornu flare satisfies the requirements for a wideband design. The design efficiently radiates and receives a high power pulse of ultrawideband electromagnetic waves over a preferred range of angles in space and transmits a field that is nearly the scaled temporal derivative of the input voltage signal and receives a voltage that is nearly the scaled replica of the incident field.

Claims

1. An antenna comprised of:

an inline balun formed by a coaxial transmission line having an inner and outer conductor that transitions to a parallel plate transmission line with a Klopfenstein impedance profile; and

said antenna, having a cornu spiral flare with a curvature that increases linearly in proportion to the arc length of the flare, connected to said parallel plate transmission line wherein the flared antenna is capable of efficiently transmitting and receiving ultrawideband electromagnetic energy.

2. An antenna, as in claim 1, wherein the center conductor of the coaxial feedline is connected to a first side of the flared antenna and the outer conductor is connected to a second side of the flared antenna.

3. An antenna, as in claim 1, wherein the flared antenna is made of a non-magnetic conducting material.

4. An antenna, as in claim 1, wherein the non-magnetic material is coated with a conductive material.

5. An antenna, as in claim 3, wherein said first and second sides of the parallel plates and flares are rectangular in cross-section.

6. An antenna, as in claim 3, wherein said first and second sides of the flared antenna are flared.

7. An antenna comprising:

an inline balun formed by a coaxial transmission line having an inner and outer conductor that transitions to a parallel plate transmission line with a Klopfenstein impedance profile; and

said antenna, having a cornu spiral flare with a curvature that increases linearly in proportion to the arc length of the flare, connected to said parallel plate transmission line wherein the flared antenna is capable of efficiently transmitting and receiving ultrawideband electromagnetic energy;

wherein the center conductor of the coaxial feedline is connected to a first side of the flared antenna and the outer conductor is connected to a second side of the flared antenna.

8. An antenna comprising:

an inline balun formed by a coaxial transmission line having an inner and outer conductor that transitions to a parallel plate transmission line in a Klopfenstein impedance profile; and

said antenna, having a cornu spiral flare with a first and second side with a curvature that increases linearly in proportion to the arc length of the flare, connected to said parallel plate transmission line wherein the flared antenna is capable of efficiently transmitting and receiving ultrawideband electromagnetic energy;

said first and second sides of the flared antenna being flared.

9. An antenna comprising:

An inline balum formed by a coaxial transmission line haviung an iner and outer conductor that transitions to a paralel plate transmission linre with a Klopfenstein impedance profile; and

said antenna, having a sici spiral flare with a curvature that increases linearly in proportion to the arc length of the flare, connected to said parallel plate transmission line.