Excitation and use of guided surface wave modes on lossy media

Patent metadata

Field	Value
Publication number	US-9912031-B2
Application number	US-201313789538-A
Country	US
Kind code	B2
Filing date	Mar 7, 2013
Priority date	Mar 7, 2013
Publication date	Mar 6, 2018
Grant date	Mar 6, 2018

Abstract

Disclosed are various embodiments for transmitting energy conveyed in the form of a guided surface-waveguide mode along the surface of a terrestrial medium by exciting a polyphase waveguide probe.

First claim

Therefore, the following is claimed:

1. An apparatus, comprising:
a polyphase waveguide probe configured to create a plurality of resultant fields that are substantially mode-matched to a Zenneck surface wave mode on a surface of a terrestrial medium, wherein a radial surface current density of the Zenneck surface wave mode is substantially expressed by

J
ρ

⁡

(

ρ
,
ϕ
,
0

)

=

I
o

⁢
γ

4

⁢

H
1

(
2
)

⁡

(

-
jγρ

)

,

where γ is a surface wave radial propagation constant given by γ=j√{square root over (k o 2 +u 2 2 )} and u 2 is a vertical propagation constant given by

u
2

=

-
j

⁢

⁢

k
o

1
+

(

ɛ
r

-

j
⁢

⁢
x

)

,

⁢
where

x
=

σ

ωɛ
o

,

σ is a conductivity of the terrestrial medium, ω is equal to 2πf, where f is a frequency of excitation of the polyphase waveguide probe, ∈ o is a permittivity of free space, ∈ r is a relative permittivity of the terrestrial medium, and a free-space wave number k o is equal to

2
⁢
π

λ
o

,

where λ o is a free-space wavelength of the polyphase waveguide probe, j is equal to √{square root over (−1)}, ρ is a radial coordinate, z is a vertical coordinate normal to the terrestrial medium, φ is an azimuthal coordinate, I o is a net polyphase probe current, and H 1 (2) (−jγρ) is a Hankel function of a second kind and first order with complex argument −jγρ, for an e +jωt time variation, where t is time.

2. The apparatus of claim 1 , wherein a radiation resistance of the polyphase waveguide probe is substantially zero.

3. The apparatus of claim 1 , wherein a height of the polyphase waveguide probe is less than λ/2π at an operating frequency of the polyphase waveguide probe, where λ is a wavelength at the operating frequency.

4. The apparatus of claim 1 , wherein the resultant fields substantially synthesize a wave front incident at a complex Brewster angle of the terrestrial medium, resulting in substantially zero reflection.

5. The apparatus of claim 1 , wherein an excitation source is electrically coupled to the polyphase waveguide probe.

6. An apparatus, comprising:
a polyphase waveguide probe configured to create a plurality of resultant fields that are substantially mode-matched to a Zenneck surface wave mode on a surface of a terrestrial medium, wherein the Zenneck surface wave mode is substantially expressed as

H
ϕ

=

-
γ

⁢

⁢

I
o

4

⁢

ⅇ

-

u
2

⁢
z

⁢

H
1

(
2
)

⁡

(

-
jγρ

)

,

⁢

E
ρ

=

-
γ

⁢

⁢

I
o

4

⁢

Assignees

• Cpg Technologies Llc

Inventors

• Corum James F
• Corum Kenneth L

Classifications

• H01Q1/00

  Details of, or arrangements associated with, antennas (arrangements for varying orientation of directional pattern H01Q3/00) · CPC title

• H01P5/00 Primary

  Coupling devices of the waveguide type · CPC title

• H01P3/00

  Waveguides; Transmission lines of the waveguide type · CPC title

• G01S13/0218

  Very long range radars, e.g. surface wave radar, over-the-horizon or ionospheric propagation systems (for meteorological use G01S13/95) · CPC title

• G01S13/88

  Radar or analogous systems specially adapted for specific applications (electromagnetic prospecting or detecting of objects, e.g. near-field detection, G01V3/00) · CPC title