Abstract: For generating wideband radar linear frequency modulation (LFM) signal, the FPGA circuit and wideband DAC circuit are used to generate 50 MHz ~550 MHz LFM IF signal. The IF signal is up-converted to 2 GHz~2.5 GHz RF bands, and then after double octave obtains 4 GHz ~5 GHz wideband LFM signal. To further improve the RF output signal amplitude/phase characteristics, the amplitude/phase pre-distortion calibration methods are used, the IF and RF circuits are carefully designed, experiments and analysis are carried out. According to the measurement results, the spurious signal involved in the system output is lower than -55 dB, the ripple in the band is below ±2 dB. This system is quite stable and its performance meets the requirement of actual application.