The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 06, 1989
Filed:
Dec. 29, 1987
Applicant:
Inventors:
Assignees:
Communications Research Laboratory, Tokyo, JP;
Ministry of Posts and Telecommunications, Tokyo, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01Q / ;
U.S. Cl.
CPC ...
343719 ; 343841 ; 324323 ; 324344 ;
Abstract
An antenna element such as a monopole, dipole or loop antenna is located in the earth or on the floor of the sea so as to receive pre-earthquake electromagnetic waves generated prior to the occurrence of an earthquake. Unwanted noise waves propagating in the air such as man-made noise are effectively eliminated by a reflector laid on the surface of the earth or by the sea water and only the required pre-earthquake waves are detected by the antenna element, whereby earthquakes can be predicted reliably.