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:
Jan. 05, 1988
Filed:
Oct. 23, 1986
Allen P Edwards, Palo Alto, CA (US);
David R Gildea, Menlo Park, CA (US);
Chung Y Lau, Foster City, CA (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
Calibration of a vector modulator is done using a scalar detector to measure the amplitude of the RF output signal, phase shifters to adjust the relative phases of the I and Q components of the RF carrier, and variable attenuators in the I and Q modulation signal input lines to adjust the relative amplitude of the modulation signals. DC signal sources provide reference signals for the I and Q modulation inputs, carrier leak compensation signals, and calibration signals for balancing the amplitude of the I and Q modulation signals. An iterative four step calibration process is followed until no change in the results is observed. The quadrature phase error is minimized by adjusting the phase shifters. The carrier leakage is minimized by adjusting the carrier leak compensation sources to minimize RF output with the modulation inputs grounded. The amplitudes of the I and Q modulation signals are balanced by adjusting the attenuators until the output amplitudes are equal. Finally, the quadrature calibration signal sources are adjusted until the output amplitudes they produce are balanced.