ULTRA-LINEAR FEEDFORWARD
AMPLIFIER WITH ADAPTIVE CONTROL
AND METHOD FOR ADAPTIVE CONTROL
 Inventor: Kiomars Anvari, Walnut Creek, Calif.
 Assignee: Aval Communications, Inc., Walnut Creek, Calif.
 Appl. No.: 422,596
 Filed: Apr. 14, 1995
Related U.S. Application Data
 Continuation-in-part of Ser. No. 282,132, Jul. 28, 1994, Pat. No. 5,485,120.
 Int. CI.6 H03F 1/26
 U.S. CI 330/149; 330/151
 Field of Search 330/52, 149, 151
 References Cited
U.S. PATENT DOCUMENTS 3,922,617 11/1975 Denniston et al 330/149
inn ilium in urn Iiiii urn inn mil urn urn urn nun m urn mi
[ii] Patent Number: 5,594,385  Date of Patent: Jan. 14, 1997
4,412,185 10/1983 Gerard 330/149
5,119,040 6/1992 Long et al 330/151 X
5,386,198 1/1995 Ripstrand et al 330/52
Primary Examiner—Steven Mottola
Attorney, Agent, or Firm—Townsend and Townsend and
An adaptive control system and method is provided in a feed-forward linear amplifier, and in particular a multichannel linear amplifier, wherein analyzed distortion or error detection of nonlinear distortion components of the output signal of a main amplifier element is used to correct distortion in amplification of an information signal. Analysis of the distortion is based on a sweep of the entire operating frequency band from which the distortion components are extracted. I.F. sampling (sub-harmonic sampling) may be used in analog-to-digital conversion of an I.F. signal to detect the distortion within a pass-band.