Circuits and methods are provided for use in an RF transmitter to complement the digital generation of a non-constant envelope modulation signals therein. The method includes: obtaining multiple Transport Blocks from a base station within one Transmission Time Interval ; selecting a TB compliant with a condition of transmitting a Buffer Status Report among the multiple TBs; and bearing a BSR of a Logical Channel Group and a Control Element sub-header of the BSR onto the selected TB and sending the TB to the base station. In accordance with a difference between the counted value latched to the reference channel and the counted value latched to the target channel, a time difference is calculated. The fuel atomizer defines a spill-return bore and a swirl chamber.