A High Resolution SF-LFM Radar System based on USRP X310

In this paper, we investigate a step-frequency linear-frequency-modulation (SF-LFM) radar for high resolution ranging and imaging based on USRP X310 equipped with UBX-160 daughter-boards. A wideband LFM baseband signal is adopted in this platform because of its high quality of amplitude and frequency characteristics while can be easily generated by digital techniques and match filter processing is used while it's insensitive to doppler shift of echo data. The transmitting signal is divided into two channels through power divider, one channel is transferred to transmitting horn antenna through amplifier, and the other is transferred directly to the receiver. The receiving signal at each step frequency band is deconvoluted by using inverse filter technique while the receiving signal of second channel is regarded as reference signal. A reflection spectrum reconstruction method is proposed to synthesize wideband response signal and a one-dimensional distance image can be obtained. With the movement of Tx/Rx, a B-scan radar profile can be obtained and 2-dimensional image can be obtained.