Up-converter and up-conversion method

The invention provides an up-converter and an up-conversion method. The up-converter comprises a double-path digital-to-analog converter for converting an input baseband signal into two paths of orthogonal mid-frequency and low-frequency signals and outputting the two paths of orthogonal mid-frequency and low-frequency signals, and an analog orthogonal modulator for receiving the two paths of orthogonal mid-frequency and low-frequency signals, modulating the two paths of orthogonal mid-frequency and low-frequency signals into mid-frequency signals by using a local oscillation signal of a first oscillator in the up-converter and outputting the mid-frequency signals. According to the up-converter and the up-conversion method, the volume of the up-converter, the circuit complexity and the implementation cost are reduced; and furthermore, the analog orthogonal modulator replaces a frequency mixer and is used for processing the signals, so that spurious signals are reduced, and the signals are relatively clean.