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:
Dec. 24, 2002
Filed:
Dec. 18, 2001
A. Clifford Barker, Tulsa, OK (US);
Other;
Abstract
A high-resolution apparatus and method provide direct digital measurement of electrical properties such as resistance, capacitance or inductance. An excitation signal derived from a high-frequency source is applied to a network containing an unknown device to produce a network output signal with an amplitude that corresponds to the electrical property to be measured. Amplitude variations in the network output signal are converted to corresponding phase variations in a third signal by adding the network output signal to a reference signal that is phase shifted by 90-degrees with respect to the excitation. The third signal is then applied to a phaselocked loop that employs the above-mentioned high-frequency source in combination with a pulse delete circuit to produce an output that multiplies phase information contained in the third signal by orders of magnitude. Conventional methods can then be used to measure the resulting greatly magnified phase changes corresponding to minute changes in the electrical properties of the device under test.