RADIATING COAXIAL CABLE

• US 20070001788A1
• Filed: 06/26/2006
• Published: 01/04/2007
• Est. Priority Date: 06/30/2005
• Status: Active Grant

• Current Assignee: Institut Scientifique de Service Public
• Original Assignee: Institut Scientifique de Service Public
• Inventors: Pirard, Willy
• Granted Patent: US 7,498,906 B2
• Time in Patent Office: Days
• US Class Current: 333/237
• CPC Class Codes: H01Q 13/203 Leaky coaxial lines

Abstract

A radiated mode coaxial cable comprising an outer conductor provided with a periodic aperture array, comprising a plurality (n) of apertures or aperture sets, repeated along the length of said outer conductor whereas a constant spacing s separates the left end of the first aperture of one array and the left end of the first aperture of a next array, wherein each array comprises at least 10 apertures or aperture sets, whereas the global length L (in mm) of the apertures or aperture sets is larger than (10 D/n)^1/2 where D is the diameter of the cable (in mm) and whereas the aperture spacing (d) in between two successive apertures or aperture sets is larger than 1.5 w where w is the aperture width in the cable axis direction, and wherein the spacing s between two successive aperture arrays is selected so that λ_opt.1/(√ε_r−0.866)<s<λ_opt.2/(√ε_r−1), where λ_opt.1 and λ_opt.2 are respectively the upper and lower limits of the optimal wavelength range the radiated mode coaxial cable is designed for and where F, represents the relative dielectric constant of the radiating cable.

Claims

1. A radiated mode coaxial cable comprising an outer conductor provided with a periodic aperture array, comprising a plurality (n) of apertures or aperture sets, repeated along the length of said outer conductor, wherein a constant spacing (s) separates the left end of the first aperture of one array and the left end of the first aperture of a next array wherein each array of n apertures comprises at least 10 apertures or aperture sets, wherein the (n) apertures or aperture sets have a global length L in the direction transverse to the cable axis at least equal to (10 D/n)^1/2, where D is the diameter of the cable and wherein the aperture spacing (d) in between two successive apertures or aperture sets is larger than 1.5 w;

where w is the aperture width in the cable axis direction and wherein the spacing (s) between successive aperture arrays is selected so that

λ

_opt.1/(√

ε

_r−

0.866)<

s<

λ

_opt2/(√

ε

_r−

1);

where λ

_opt.1- and -λ

_opt.2- are respectively the upper and lower limits of the optimal wavelength ranges the radiated mode coaxial cable is designed for, and where ε

_r represents the relative dielectric constant of the radiating cable.

2. The radiating cable of claim 1, wherein the distance (d) between the two successive apertures or aperture sets is equal to s/2n±

20%

3. The radiating cable of claim 1, wherein the wavelength range of the radiated mode coaxial cable is designed for corresponds to substantially one octave (with λ

_opt.2=λ

_opt.1/2), whereas s is at least equal to 3.7 λ

_opt.1.

4. The radiating cable of claim 1, wherein the periodic aperture array involves a number (n) of apertures or aperture sets of at least 14.

5. The radiating cable of claim 1, wherein the cable is designed for radiating at an angle θ

₁, essentially between 150° and

180°

with respect to the longitudinal axis of the radiating cable, where θ

₁=arcos{λ

/s−

√

ε

_r}-.