Patent ID: 8866523
Filing Date: 2014-10-21
Classification: H03L

Abstract:
1. An apparatus for signal edge alignment, comprising: a signal source that generates a first square wave signal and a second square wave signal; a phase delay circuit that receives the first square wave signal and the second square wave signal, and generates a delayed version of the first square wave signal and a delayed version of the second square wave signal according to a phase tuning signal; a data circuit, that generates a third square wave signal according to the delayed version of the second square wave signal; and a phase calibration circuit that receives the third square wave signal and the first square wave signal, and generates at the least one phase tuning signal to the phase delay circuit for tuning a phase difference between the delayed version of the first square wave signal and the delayed version of the second square wave signal, such that a signal edge of the third square wave signal aligns with a signal edge of the first square wave signal; wherein, the first square wave signal, the second square wave signal and the third square wave signal have a same frequency, and wherein the data circuit generates digital signals of a plurality of bits, and the third square wave signal is one of the digital signals, such that a radio-frequency digital-to-analog converter (RFDAC) receives the digital signals and the delayed version of the first square wave signal to generate an RF signal.