The multi-channel signal processing device includes a multi-channel continuous waveform (CW) phase shifter module configured to generate phase control and filter interference therein for multiple local oscillator (LO) signals at a same frequency, a multi-channel up-converter module configured to up-convert the multiple LO signals to a desired frequency and filter respective image signals therein, and a multi-channel wideband mixer module configured to receive and mix the up-converted LO signals at the desired frequency from the multi-channel up-converter module with radio frequency (RF) signals.