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:
Oct. 26, 1993
Filed:
Apr. 16, 1991
Thomas Roche, Spotslyvania, VA (US);
Design Tech International, Inc., Springfield, VA (US);
Abstract
A transmitter has a transmitting antenna which may be formed as a loop etched onto a printed circuit board. The transmitting system includes an oscillator which generates a signal at a fundamental frequency to be transmitted and which is fed to a radiating loop or transmitting antenna. Located inside of this loop, and which may also be etched onto the printed circuit board, is an inner passive loop which is in series with a capacitor or which is connected to the outer loop by the capacitor. The size of the capacitor and the printed inner loop operate to remove harmonics of the fundamental frequency generated by the oscillator. In this way, the present invention operates to transmit a signal at a fundamental frequency which is at a high power level while lowering the power of signals unintentionally transmitted at harmonics of this fundamental frequency by utilizing a circuit which is simple, inexpensive and compact.