US 11,949,769 B2
Accurate sign change for radio frequency transmitters
Voravit Vorapipat, Santa Clara, CA (US); Morteza Nick, San Francisco, CA (US); Krishna Chaitanya Reddy Gangavaram, San Jose, CA (US); and Antonio Passamani, Munich (DE)
Assigned to Apple Inc., Cupertino, CA (US)
Filed by Apple Inc., Cupertino, CA (US)
Filed on May 2, 2022, as Appl. No. 17/734,801.
Application 17/734,801 is a continuation of application No. 17/236,522, filed on Apr. 21, 2021, granted, now 11,368,277.
Prior Publication US 2022/0345288 A1, Oct. 27, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. H04L 7/00 (2006.01); H04L 27/04 (2006.01); H04L 27/36 (2006.01)
CPC H04L 7/0091 (2013.01) [H04L 27/04 (2013.01); H04L 27/365 (2013.01); H03F 2200/336 (2013.01)] 20 Claims
OG exemplary drawing
 
1. Transmitter circuitry, comprising:
a digital front end configured to generate a positive data signal, a negative data signal, and a sign selection signal based on an input signal;
sign selection circuitry configured to adjust a polarity of the sign selection signal by generating a first adjusted sign selection signal based on a transition of the positive data signal; and
a digital-to-analog converter configured to generate a transmission signal based on the first adjusted sign selection signal.