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. 25, 2014
Filed:
Dec. 09, 2012
Phuong Thu-minh Huynh, Fairfax, VA (US);
Phuong Thu-Minh Huynh, Fairfax, VA (US);
Other;
Abstract
A calibration technique to compensate for the quadrature phase error between the in-phase and quadrature sampling clocks controlling the quadrature bandpass sampling delta-sigma analog-to-digital demodulator (QBS-ADD) is provided. A low-frequency test tone is injected in the feedback path, up-converted to the radio frequency (RF) frequency, and added to the input of the QBS-ADD. The test tone is demodulated by the QBS-ADD into an in-phase signal and a quadrature signal. The in-phase and quadrature signals are converted into the frequency domain by the discrete Fourier transform. The quadrature phase error is quantified based on the complex Fourier complex coefficients; and the phase difference between the in-phase and quadrature sampling clocks is corrected.