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
Sulfonated amorphous carbon, process for producing the same and use thereof
Erasing a non-volatile memory (NVM) system having error correction code (ECC)
Systems and methods for printing images outside a normal color gamut in image forming devices
Wideband antenna
Fabrication of high gradient insulators by stack compression
High brightness laser diode module
Multifunction switch for vehicle having lighting module
  Randomly Featured Patents
Thin film gas sensor
Device using a detection circuit to determine whether an output current thereof is source-induced or load-induced, and method therefor
Human chorionic gonadotropin superagonists
Lighting fixture arm
Use of handwritten notations from photographs
Shoe sole
Compostable thermoplastic products
Hanging waste basket
Image processing system for compressing image data including binary image data and continuous tone image data by a sub-band transform method with a high-compression rate
Wireless steering column switch levers