DOUBLE FREQUENCY CONVERSION MODULATION SYSTEM AND FREQUENCY CONVERSION METHOD

摘要

A double frequency conversion modulation system and frequency conversion method in the technical field of wireless communications. The system includes: a double-port digital-to-analogue converter, a double-port fixed low pass filter, a fixed local oscillator quadrature frequency converter, a first fixed low pass filter, a variable local oscillator frequency converter and a second fixed low pass filter connected successively. The present invention takes advantage of direct frequency conversion, so that there is no need to design a simulated band pass filter with high frequency, which can support a much wider modulated frequency band while effectively meeting orthogonality, greatly lowering the requirements on the device and circuit design.