Patent Number: 6,801,082

Title: Power amplifier circuit and method using bandlimited signal component estimates

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.

Inventors: Midya; Pallab (Palatine, IL), Grosspietsch; John (Libertyville, IL), Washington; Michael (Stone Mountain, GA)

Assignee: Motorola, Inc.

International Classification: H03G 3/00 (20060101); H03F 3/20 (20060101); H03F 1/02 (20060101); H03F 3/21 (20060101); H03F 003/38 ()

Expiration Date: 10/05/2021