Resources Contact Us Home
Browse by: INVENTOR PATENT HOLDER PATENT NUMBER DATE
 
 
Method and apparatus for amplifying a signal










Image Number 11 for United States Patent #5673001.

A unique method and apparatus modifies the load impedance at the output of a power amplifier by varying a voltage variable capacitor (VVC) (310) to maximize the efficiency of the power amplifier (304). A comparator (509) generates amplifier control signal (211) based upon a detected power output signal (216) and a reference signal. In addition to providing power control, the control signal is also coupled to a VVC circuit (506) to control the output impedance of the power amplifier. In an alternate embodiment, a separate VVC control signal (527) based upon a comparison of the power control signal and the battery voltage is coupled to a VVC. In another alternate embodiment, a second VVC can be coupled in parallel to the first VVC. The second VVC is preferably controlled by a signal (805) based upon the current in the power amplifier. Finally, an alternate embodiment incorporates a VVC circuit (506) at the input of the power amplifier to compensate for variations in input impedance to improve other power amplifier parameters such as IM, gain, output power and noise level.








 
 
  Recently Added Patents
Pyrazole kinase modulators and methods of use
Methods and apparatus to determine impressions using distributed demographic information
Switching module and switching synchronization system
Crystalline form of zofenopril calcium
Generating a funding and investment strategy associated with an underfunded pension plan
Circuit for compressing data and a processor employing same
Pose-variant face recognition using multiscale local descriptors
  Randomly Featured Patents
Cantilever for atomic force microscope and method of manufacturing the cantilever
Plants and seeds of hybrid corn variety CH417193
Process and composition for color stabilized distillate fuel oils
Closed-loop mosquito insecticide delivery system and method
Condenser shroud cover for DC cooler
Method and apparatus for reducing electromagnetic radiation emission
Electronically commutated two-axis gyro control system
Bias configuration for a magnetomechanical EAS marker
Electrophotographic lithographic printing plate precursor
Instant yogurt preparation