Ulta-wideband magnetic antenna

• US 20020154064A1
• Filed: 04/23/2002
• Published: 10/24/2002
• Est. Priority Date: 09/09/1997
• Status: Active Grant

• Current Assignee: Time Domain Corporation (Humatics Corporation)
• Original Assignee: Time Domain Corporation (Humatics Corporation)
• Inventors: Barnes, Mark Andrew
• Granted Patent: US 6,621,462 B2
• Time in Patent Office: Days
• US Class Current: 343/770
• CPC Class Codes: H01Q 13/10 Resonant slot antennas
• CPC Class Codes: H01Q 21/29 Combinations of different interacting antenna units for giving a desired directional characteristic H01Q25/00 takes precedence
• CPC Class Codes: H01Q 9/005 for radiating non-sinusoidal waves
• CPC Class Codes: H01Q 9/28 Conical, cylindrical, cage, strip, gauze, or like elements having an extended radiating surface; Elements comprising two conical surfaces having collinear axes and adjacent apices and fed by two-conductor transmission lines waveguide horns or mouths H01Q13/00; slot antennas H01Q13/00

Abstract

An ultra-wideband magnetic antenna includes a planar conductor having a first and a second slot about an axis. The slots are substantially leaf-shaped having a varying width along the axis. The slots are interconnected along the axis. A cross polarized antenna system is comprised of an ultra-wideband magnetic antenna and an ultra-wideband dipole antenna. The magnetic antenna and the dipole antenna are positioned substantially close to each other and they create a cross polarized field pattern. The present invention provides isolation between a transmitter and a receiver in an ultra-wideband system. Additionally, the present invention allows isolation among radiating elements in an array antenna system.

Claims

1. A method of transmitting and receiving signals using a cross polarized antenna system, comprising:

(a) providing at least a first ultra-wideband (UWB) antenna radiating a first E field and a first H field;

(b) providing at least a second ultra-wideband (UWB) antenna radiating a second E field and a second H field;

(c) positioning said first UWB antenna substantially close to said second UWB antenna; and

(d) creating a cross polarized field pattern, wherein said first E field and said first H field are substantially orthogonal to said second E field and said second H field.

2. The method of claim 1, wherein said method further comprises

(e) providing said first UWB antenna, which is a magnetic UWB antenna;

and

(f) providing said second UWB antenna, which is an electric UWB antenna.

3. The method of claim 2, wherein said method further comprises providing said magnetic UWB antenna, wherein said magnetic UWB antenna comprises:

(i) a planar conductor sheet having a first and a second slot placed about an axis and said slots being interconnected about said axis, said first and second slots having a width, w, along said axis that varies substantially continuously from a central point to a distal end of each slot, and

(ii) a pair of terminals located about an axis such that said UWB magnetic antenna transmits and receives electromagnetic waves when energized at said terminals and generates a signal across said terminals when excited by electromagnetic waves.

4. The method of claim 2, wherein said method further comprises:

(g) positioning said UWB electric antenna substantially parallel to said UWB magnetic antenna.

5. The method of claim 4, wherein said method further comprises:

(h) positioning said UWB electric antenna and said UWB magnetic antenna at a distance of 0.44λ

apart, whereby λ

is a signal'"'"'s wavelength either received or transmitted by the cross polarized antenna system.

6. The method of claim 2, wherein said method further comprises:

(g) positioning said UWB electric antenna in the same plane with said UWB magnetic antenna.

7. The method of claim 2, wherein said method further comprises:

(g) positioning said UWB electric antenna side by side with said UWB magnetic antenna; and

(h) placing said antennas on a back reflector, thereby producing an additional signal gain within the cross polarized antenna system.

8. The method of claim 2, wherein said method further comprises:

(g) providing said UWB electric antenna to receive signals; and

(h) providing said UWB magnetic antenna to transmit signals.

9. The method of claim 2, wherein said method further comprises:

(g) providing said UWB electric antenna to transmit signals; and

(h) providing said UWB magnetic antenna to receive signals.

10. The method of claim 3, wherein said method further comprises:

(g) providing said UWB magnetic antenna comprising said first and said second slots having said width, w, defined as

$w=\frac{1}{4<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{Cos}<br><br>\text{\hspace{1em}<br><br>}\left[l<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{\pi <br><br>}\right]<br><br>\left(1-\mathrm{Cos}<br><br>\left[l<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{\pi <br><br>}\right]\right)}$

 

and is a perpendicular distance between a point on an edge of each said slot and said axis, and wherein 1 is a length of each said slot.

11. The method of claim 3, wherein said method further comprises:

(g) positioning said first slot and said second slot of said UWB magnetic antenna symmetrically about said axis.

12. The method of claim 3, wherein said method further comprises:

(g) positioning said first slot and said second slot of said UWB magnetic antenna asymmetrically about said axis.

13. The method of claim 3, wherein said method further comprises:

(g) providing said planar conductor sheet having a length of at least λ

_c/2 and width of at least λ

_c/4, where λ

_c is a wavelength of the center frequency of a selected bandwidth.

14. The method of claim 3, wherein said method further comprises:

(g) providing said planar conductor sheet having a length of approximately 5.25 inches and a width of approximately 2.5 inches.

15. The method of claim 3, wherein said method further comprises:

(g) providing said first slot and said second slot which are substantially leaf-shaped.