US 9,813,086 B2
RF transmitter, integrated circuit device, wireless communication unit and method therefor
Chao Lu, Fremont, CA (US); Hua Wang, San Francisco, CA (US); Paul Cheng Po Liang, Hsinchu County (TW); and Sang Won Son, Palo Alto, CA (US)
Assigned to MediaTek Singapore Pte. Ltd, Solaris (SG)
Filed by MediaTek Singapore Pte. Ltd., Singapore (SG)
Filed on Aug. 22, 2013, as Appl. No. 13/972,924.
Claims priority of provisional application 61/740,584, filed on Dec. 21, 2012.
Prior Publication US 2014/0177755 A1, Jun. 26, 2014
Int. Cl. H04B 1/04 (2006.01); H03F 1/02 (2006.01); H03F 1/32 (2006.01); H03F 3/195 (2006.01); H03F 3/21 (2006.01); H03F 3/24 (2006.01)
CPC H04B 1/0475 (2013.01) [H03F 1/025 (2013.01); H03F 1/0294 (2013.01); H03F 1/3241 (2013.01); H03F 3/195 (2013.01); H03F 3/211 (2013.01); H03F 3/24 (2013.01); H04B 1/0483 (2013.01); H03F 2200/336 (2013.01); H03F 2200/537 (2013.01); H03F 2200/541 (2013.01); H04B 2001/0408 (2013.01); H04B 2001/0425 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A radio frequency, RF, transmitter comprising:
a digital power amplifier comprising a plurality of power amplifier cells;
at least one digital signal processing module operably coupled to the digital power amplifier and comprising at least one digital pre-distortion component arranged to apply at least one digital pre-distortion codeword to the plurality of power amplifier cells,
wherein the at least one digital pre-distortion codeword is applied to at least a first one of the plurality of power amplifier cells and the at least one digital pre-distortion codeword is applied to at least a second one of the plurality of power amplifier cells via at least one digital filter and a phase offset component arranged to introduce a phase offset into a signal path to the at least second one of the plurality of power amplifier cells, wherein the phase offset is representative of a sampling frequency, fs, of at least one digital pre-distortion codeword sequence, x(n) and is configured to attenuate multiples of the sampling frequency, fs; and
a combiner arranged to combine outputs of the plurality of power amplifier cells thereby generating an analogue RF signal for transmission over an RF interface based at least partly on the digitally filtered at least one digital pre-distortion codeword.