<p>Variable gain commutating amplifier apparatus and methods for use in a polar modulator are described. The apparatus may include two or more commutating amplifier stages configured to be switched to an output load based on a desired amplitude and/or transmit power level. The amplifier stages may include cross-coupled differential pairs to cancel RF carrier feedthrough. An additional R-2R ladder circuit may be provided to further extend the dynamic range by reducing the output power at the lowest output stages.</p>
申请公布号
WO2009089478(A1)
申请公布日期
2009.07.16
申请号
WO2009US30638
申请日期
2009.01.09
申请人
SEQUOIA COMMUNICATIONS;GROE, JOHN;FARIAS, MICHAEL;SHAPIRO, ERIC