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:
Sep. 03, 1996
Filed:
Sep. 29, 1995
Shinichi Ohmagari, Tokyo, JP;
Osamu Yamamoto, Tokyo, JP;
NEC Corporation, , JP;
Abstract
It is an object of the present invention to provide a transmitter which is inexpensive and small in size and is reduced in power dissipation and besides wherein the output power of a power amplifier can be varied to an arbitrary value. A phase modulator, a variable attenuator, a high power amplifier, a directional coupler, a detector, an error amplifier, a switch and an analog multiplier form an envelope feedback loop. The envelope feedback loop controls an envelope of a modulated wave detected by the detector so that a base band signal and the envelope of the modulated wave may coincide with each other. The circuits mentioned above, a smoothing circuit, another error amplifier, another switch and an adder form an operation point feedback loop. The operation point feedback loop smoothes an error of an output envelope detection signal of the detector and controls so that the smoothed error may be in the minimum.