A transmitter includes a processing circuit to generate I level data and Q level data that, when respectively converted to I baseband input and Q baseband input, cause a carrier signal modulated by the I baseband input and the Q baseband input to have a desired edge shape in the time domain. The edge shape includes a low portion, a high portion, and an edge portion between the low portion and the high portion. The edge portion has a desired edge time compatible with the frequency of the carrier signal. The transmitter further includes a digital-to-analog converter (DAC) to convert the I level data to the I baseband input and the Q level data to the Q baseband input, and an in-phase and quadrature (I/Q) modulator to perform I/Q modulation of the carrier signal according to the I baseband input and the Q baseband input.