Resources Contact Us Home
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
Film deposition method and film deposition apparatus
Cenotaph facility and method including auctioning of items associated with honoree
Natural product energy drink and method of use thereof
Electronic apparatus
Steerable endoscope and improved method of insertion
Functionalizing a sensing ribbon on a whispering gallery mode microresonator using light force to fabricate a whispering gallery mode sensor
Image processing apparatus, image processing method, and program and storage medium therefor
  Randomly Featured Patents
Dispensing device for flawing substances having a pressure controlled pump arrangement
Compositions inducing cleavage of RNA motifs
Canister lid
Thin-film magnetic head and method of manufacturing same
Electronic apparatus having polycrystalline semiconductor thin film structure
User control of task priority
Ink ejector nozzle chamber with fluid deflection
Composition for oral administration of peptides
Bicycle brake shoe with heat dissipating means
Compact modular wireless telephone