Abstract: A direct-conversion transmitter including an oscillator, a frequency divider, a transmitter, and a filter is provided. The oscillator generates an oscillating signal with an original frequency. The frequency divider performs frequency dividing on the oscillating signal, so as to generate a carrier signal. The transmitter receives the carrier signal from the frequency divider and generates an output signal based on the carrier signal and a data signal. The filter is coupled between the frequency divider and the transmitter. The filter filters out an interference signal fed-back from the transmitter to the oscillator, wherein the interference signal may cause the oscillating signal to float.

Abstract: An edge alignment apparatus includes: a signal source, for generating a first and a second square wave signals; a phase delay circuit, for receiving the first and the second square wave signals to generate a delayed first and a delayed second square wave signals; a data circuit, for generating a third square wave signal according to the delayed second square wave signal; and a phase calibrating circuit, for receiving the third square wave signal and the delayed first squared wave signal to generate at least one phase tuning signal to the phase delay circuit for tuning a phase difference between the delayed first and the delayed second square wave signals, such that a signal edge of the third square wave signal aligns with that of the first square wave signal. The first, second and third square wave signals have a same frequency.