Stealth antenna having electromagnetic wave absorber with sandwich structure

Patent metadata

Field	Value
Publication number	US-12424763-B2
Application number	US-202217931966-A
Country	US
Kind code	B2
Filing date	Sep 14, 2022
Priority date	Sep 14, 2021
Publication date	Sep 23, 2025
Grant date	Sep 23, 2025

Abstract

A stealth antenna includes an electromagnetic wave absorbing structure and an antenna patch embedded in the electromagnetic wave absorbing structure. The electromagnetic wave absorbing structure includes an upper dielectric layer, a lower dielectric layer and a spacer disposed between the upper dielectric layer and the lower dielectric layer. The upper dielectric layer includes a dielectric fabric and a conductive coating layer combined with at least a portion of the dielectric fabric. The lower dielectric layer includes a dielectric fabric and has a dielectric constant lower than that of the upper dielectric layer. The antenna patch is disposed between the spacer and the lower dielectric layer.

First claim

What is claimed is:

1. A stealth antenna comprising:
an electromagnetic wave absorbing structure having a sandwich structure including an upper dielectric layer, a spacer and a lower dielectric layer so that the electromagnetic wave absorbing structure has an absorbing band determined by a dielectric constant and a thickness thereof, the absorbing band being a frequency range of electromagnetic waves that the electromagnetic wave absorbing structure is able to absorb; and
an antenna patch embedded in the electromagnetic wave absorbing structure and disposed between the spacer and the lower dielectric layer,
wherein
the upper dielectric layer includes a dielectric fabric and a conductive coating layer coated on a portion of the dielectric fabric so that the upper dielectric layer has a first area where the conductive coating layer is disposed, and a second area where the conductive coating layer is not disposed, the second area overlapping the antenna patch in a plan view such that the conductive coating layer is absent from an area above the antenna patch, the dielectric fabric including first fibers arranged along a first direction and second fibers arranged along a second direction perpendicular to the first direction,
wherein the lower dielectric layer includes a dielectric fabric impregnated with a resin and having a dielectric constant lower than that of the upper dielectric layer,
wherein the spacer is disposed and entirely continuous between the upper dielectric layer and the lower dielectric layer, the spacer including a porous foam formed of a resin,
wherein an operating frequency of the stealth antenna overlaps the absorbing band of the electromagnetic wave absorbing structure,
wherein a sheet resistance of the upper dielectric layer is 350 ohm/sq to 400 ohm/sq.

2. The stealth antenna according to claim 1 , wherein the conductive coating layer includes at least one of nickel, cobalt, and iron.

3. The stealth antenna according to claim 1 , wherein the dielectric fabric of the upper dielectric layer or the dielectric fabric of the lower dielectric layer includes a glass fiber or an aramid fiber.

4. The stealth antenna according to claim 1 , wherein the spacer includes a plurality of partition walls extending in a vertical direction.

5. The stealth antenna according to claim 4 , wherein the antenna patch is embedded in the lower dielectric layer so that an upper surface of the antenna patch and an upper surface of the lower dielectric layer are coplanar.

6. The stealth antenna according to claim 1 , wherein the absorbing band of the electromagnetic wave absorbing structure includes at least one of C-band, X-band and Ku-band.

Assignees

• Korea Advanced Inst Sci & Tech

Inventors

• Kim Chun-Gon
• Jang Woo-Hyeok
• Jang Min-Su
• Jin Do-Hyeon

Classifications

• H01Q1/40

  Radiating elements coated with or embedded in protective material · CPC title

• H01Q1/38

  formed by a conductive layer on an insulating support {(patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface  H01Q15/142)} · CPC title

• H01Q17/005

  using woven or wound filaments; impregnated nets or clothes · CPC title

• H01Q1/286

  substantially flush mounted with the skin of the craft · CPC title

• H01Q9/0407

  Substantially flat resonant element parallel to ground plane, e.g. patch antenna (dipole H01Q9/285; monopole H01Q9/40) · CPC title