United States Patent  [li] Patent Number: 5,251,330
Chiba et al.  Date of Patent: Oct. 5,1993
 References Cited
U.S. PATENT DOCUMENTS
4,053,854 10/1977 Havens 455/91
4,565,980 1/1986 Ashida 455/110
4,805,028 2/1989 Nishioka et al 358/225
FOREIGN PATENT DOCUMENTS
61- 163730 7/1986 Japan .
62- 274906 11/1987 Japan .
63-67925 3/1988 Japan .
0222524 10/1991 Japan 455/127
M. J. Koch, et al., "A High Efficiency 835 MHz Linear Power Amplifier for Digital Cellular Telephony", IEEE 1989, pp. 17-18.
H. L. Krauss, et al., "CW, FM, and AM Transmitters", Single-Sideband Transmitters; Solid State Radio Engineering, pp. 477-522.
Primary Examiner—Reinhard J. Eisenzopf
Assistant Examiner—Christine K. Belzer
Attorney, Agent, or Firm—Cushman, Darby & Cushman
This invention relates to a linear transmitter which controls the bias voltage of either the drain electrode or collector electrode of an amplifier for radio frequency based on the envelope of the modulated signal, and is characterized in that it controls the bias voltage of the radio frequency amplifier in digital arithmetic processing by generating the envelope using in-phase envelope component and quadrature envelope component obtained from the base band signals.
12 Claims, 32 Drawing Sheets