High Resolution Radars

A radar system is capable of determining the distance, the direction and the velocity of a target by transmitting an EM wave and measuring the echoed signal. Radars are employed in many fields. Typical applications include: air/marine traffic surveillance, military applications like air/ground/sea target location or missile defence/guidance, and driver assistance and pre-collision safety systems for the automotive market.
 
The determination of both the distance and the velocity of the target requires that some modulation is applied to the transmitted EM wave. Often a linear frequency modulation of the carrier is employed, which allows to assess the distance and the velocity of the target by means of a simple system architecture. Such a radar is called Frequency-Modulated Continuous-Wave (FMCW) radar. The transmitter irradiates a sinusoidal wave whose frequency is continuosly changed following a ramp. The trasmitted signal is also used to demodulate the echo backscattered by the target, such that the downconverted signal will have an intermediate frequency that depends on the time of flight of the EM wave, i.e. on the instantaneous position of the target. Both the distance and the velocity of the target can be recovered, with a resolution that increases as both the carrier frequency and the modulation bandwidth are increased.
 
Integrated circuits for high resolution radar applications are traditionally implemented with compound semiconductor technologies. Our research aims at pure CMOS implementations compliant with the requirements of high resolution FMCW radars.