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:
Feb. 19, 2013
Filed:
Jun. 17, 2010
Douglas L. Lewis, Sykesville, MD (US);
Andrew E. Feldman, Columbia, MD (US);
Christopher L. Eddins, Jessup, MD (US);
Douglas L. Lewis, Sykesville, MD (US);
Andrew E. Feldman, Columbia, MD (US);
Christopher L. Eddins, Jessup, MD (US);
The Johns Hopkins University, Baltimore, MD (US);
Abstract
An apparatus for sensing motion having a transmitter for transmitting a carrier signal; a frequency control connected to the transmitter for controlling the frequency of the carrier signal; a first receiver for receiving the reflected transmitted carrier signal; a second receiver for receiving the reflected transmitted carrier signal, the second receiver being placed out of phase by less than a wavelength of the carrier signal from the first receiver; means for subtracting the carrier signal received by the second receiver from the carrier signal received by the first receiver to produce an error signal; wherein when motion is sensed by the apparatus, the error signal moves from zero thereby causing a corrective signal to be generated and sent to the frequency control, the frequency control forcing the error signal to zero.