in one embodiment , a power amplification system of a radio - frequency transmitter includes a digital signal source that provides a digital input signal to an interleaved - bit - stream generator , which outputs a digital switching signal to a switching power amplifier . the interleaved - bit - stream generator has an eight - path interleaving architecture that helps reduce the effective clock - rate requirements of the interleaved - bit - stream generator . the interleaved - bit - stream generator includes an array of fractional - delay filters for receiving the digital input signal and outputting eight fractionally delayed digital output signals to a bit - stream generation array adapted to output eight corresponding bit streams to a serializer block that interleaves and combines the eight bit - streams into the digital switching signal . the relative phases of the interleaved signals may be adjusted to achieve certain desired effects .