US4931798A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electromagnetic anechoic chamber with an inner electromagnetic wave reflection surface and an electromagnetic wave absorption small ball disposed in the chamber
Assignee: Tokin Corp
•
Filing: 1988-06-02
•
Granted: 1990-06-05
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Expires: 2008-06-02
Abstract
Abstract For effectively suppressing echo of an electromagnetic wave emitted from an electromagnetic device (24) disposed in a closed space (13) which is defined by a shielding wall (10), an electromagnetic anechoic chamber comprises an absorption member (28) disposed in the space. The wall has an inner surface which reflects the electromagnetic wave into the space as a reflected wave. The reflected wave is directed to a particular position in the space. The absorption member is located at the particular position. Preferably, the inner space is formed along a substantially ellipsoidal shape having a first and a second focus point (14, 16). The electromagnetic device and the absorption member are locsated at the first and the second focus points, respectively.
Inventors
- 👤 Masanori Kogo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 00:04
CPC Classifications
G; G01; G01R; G01R29/00; G01R29/08; G01R29/10; G01R29/105; G01R1/00; G01R1/02; G01R1/18
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
135 words
An electromagnetic anechoic chamber for providing a closed space for containing an electromagnetic device emitting an electromagnetic wave therein, an echo of the electromagnetic device being suppressed within said closed space, said electromagnetic anechoic chamber comprising: an electromagnetically shielding wall having an inner surface of a substantially ellipsoidal shape with a first and a second focus point, said inner surface defining said closed space and reflecting said electromagnetic wave into said closed space as a reflected wave; electromagnetic absorption means located at said first focus point for absorbing said reflected wave to thereby remove the reflected wave from said closed space; and receiving means located between said first and said second focus points for receiving said electromagnetic wave, said second focus point being determined as a specific point at which said electromagnetic device is located.
Claim 2
Dependent Claim
135 words
An electromagnetic anechoic chamber for providing a closed space for containing an electromagnetic device emitting an electromagnetic wave therein, an echo of the electromagnetic device being suppressed within said closed space, said electromagnetic anechoic chamber comprising: an electromagnetically shielding wall having an inner surface of a substantially ellipsoidal shape with a first and a second focus point, said inner surface defining said closed space and reflecting said electromagnetic wave into said closed space as a reflected wave; electromagnetic absorption means located at said first focus point for absorbing said reflected wave to thereby remove the reflected wave from said closed space; and receiving means located between said first and said second focus points for receiving said electromagnetic wave, said second focus point being determined as a specific point at which said electromagnetic device is located.
Claim 3
Dependent Claim
31 words
An electromagnetic anechoic chamber as claimed in claim 1, wherein said shielding wall comprises a plurality of plates which are connected to one another to generally form said substantially ellipsoidal shape.
Claim 4
Dependent Claim
28 words
An electromagnetic anechoic chamber as claimed in claim 1, wherein said absorption means comprises a base member of urethane foam and carbon black impregnated in said base member.
Claim 5
Dependent Claim
24 words
An electromagnetic anechoic chamber as claimed in claim 3, wherein said absorption means further comprises an additional member mechanically coupled to said base member.
Claim 6
Dependent Claim
16 words
An electromagnetic anechoic chamber as claimed in claim 4, wherein said additional member is of ferrite.
Claim 7
Dependent Claim
17 words
An electromagnetic anechoic chamber as claimed in claim 3, wherein said base member has a spherical surface.
Claim 8
Dependent Claim
25 words
An electromagnetic anechoic chamber as claimed in claim 6, wherein said base member is generally spherical and has a plurality of radially outwardly projecting portions.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-06-04 | 1993-12-04 | 1994-06-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-06-04 | 1997-12-04 | 1998-06-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-06-04 | 2001-12-04 | 2002-06-05 | $7700.00 | Window Closed / Lapsed |