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. 30, 1992
Filed:
Oct. 18, 1990
George T Harvey, Princeton, NJ (US);
Michael S Heutmaker, Trenton, NJ (US);
AT&T Bell Laboratories, Murray Hill, NJ (US);
Abstract
An integrated circuit (11) is tested at a high microwave frequency through the use of a laser beam (19) having a repetition rate much lower than the test frequency. Electric fields of the test signal extend into an electro-optic material (12) that modulates part of the laser beam. Another part of the laser beam is converted to an electrical pulsed signal that is applied to a microwave mixer (33) along with part of the test frequency signal. A harmonic of the pulsed signal mixes with the test frequency to yield a difference frequency that can be used as a phase reference for analyzing the phase of the test signal. The component pulses (30) of the laser beam have a pulse width which is much shorter than the separation of the pulses, which make it inherently rich in higher harmonics of the fundamental pulse repetition rate.