Michael T Washington

US Patent:

6838931, Jan 4, 2005

Filed:

May 12, 2004

Appl. No.:

10/844123

Inventors:

Pallab Midya - Palatine IL, US
John Grosspietsch - Libertyville IL, US
Michael Washington - Stone Mountain GA, US

Assignee:

Motorola, Inc. - Schaumburg IL

International Classification:

H03F 338

US Classification:

330 10, 330129

Abstract:

A power amplifier circuit for receiving a variable envelope input signal and for producing an amplified output signal is provided. The power amplifier circuit includes an envelope approximation circuit, an envelope amplifier circuit, a phasor approximation circuit, a quadrature modulation circuit, and a power amplifier. The envelope approximation circuit receives the variable envelope input signal and produces a bandlimited estimated envelope signal, corresponding to the amplitude of the variable envelope input signal. The bandlimited estimated envelope signal is then amplified by an envelope amplifier circuit. The amplified envelope signal is then coupled to the supply input of the power amplifier. The phasor approximation circuit receives the variable envelope input signal and produces a bandlimited estimated phasor signal. The quadrature modulation circuit receives the estimated phase signal and produces a modulated phase signal.

US Patent:

20040124913, Jul 1, 2004

Filed:

Dec 31, 2002

Appl. No.:

10/334843

Inventors:

Pallab Midya - Palatine IL, US
John Grosspietsch - Libertyville IL, US
Michael Washington - Stone Mountain GA, US

International Classification:

H03F003/38
H03G003/20

US Classification:

330/010000, 330/136000

Abstract:

A power amplifier circuit for receiving a variable envelope input signal and for producing an amplified output signal is provided. The power amplifier circuit includes an envelope approximation circuit, an envelope amplifier circuit, a phasor approximation circuit, a quadrature modulation circuit, and a power amplifier. The envelope approximation circuit receives the variable envelope input signal and produces a bandlimited estimated envelope signal, corresponding to the amplitude of the variable envelope input signal. The bandlimited estimated envelope signal is then amplified by an envelope amplifier circuit. The amplified envelope signal is then coupled to the supply input of the power amplifer. The phasor approximation circuit receives the variable envelope input signal and produces a bandlimited estimated phasor signal. The quadrature modulation circuit receives the estimated phase signal and produces a modulated phase signal. The modulated phase signal is then coupled to the signal input of the power amplifier. The power amplifier then produces an amplified output signal.