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:
Oct. 28, 2008
Filed:
Jan. 20, 2006
Taizo Yamawaki, Tokyo, JP;
Yoshiaki Harasawa, Maebashi, JP;
Taizo Yamawaki, Tokyo, JP;
Yoshiaki Harasawa, Maebashi, JP;
Renesas Technology Corp., Tokyo, JP;
Abstract
With a dual mode transmitter capable of handling two modulation methods for nonconstant amplitude modulation and constant amplitude modulation, respectively, speed-up of transition between modes is implemented. In a mode handling the constant amplitude modulation, first capacitors included in a low-pass filter constituting an AM loop, and a second capacitor included in an integrator are kept recharged from a first constant-voltage power supply and a second constant-voltage power supply by use of a first switch and a second switch, respectively. By doing so, a value of voltage to be recharged at the time of a mode changeover is decreased, and further, a first variable-gain amplifier starts control of a gain while avoiding a region where the output voltage of the first variable-gain amplifier has slow response against an input voltage.