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:
Apr. 10, 2012
Filed:
Jan. 30, 2008
Suguru Fujita, Tokyo, JP;
Lei Huang, Singapore, SG;
Ping Luo, Singapore, SG;
Panasonic Corporation, Osaka, JP;
Abstract
Provided is a modulation device which generates a phase modulation signal and an amplitude modulation signal and can correct an I/Q orthogonal shift and reduce degradation of the ON/OFF ratio. In the device, a phase shifter () controls voltage applied to a capacitor in accordance with a control signal outputted from a phase control unit () and adjusts the capacitance so as to shift the phase of a carrier generated by an oscillator (). The phase control unit () estimates a phase shift of a phase shifter () in accordance with an output RF signal (S) by using the phase shift estimation method. Furthermore, the phase control unit () performs tuning of the phase shifter () according to the estimated value of the phase shift of the phase shifter () so that a phase difference between carries of an I signal (S) and a Q signal (S) is 90 degrees.