SAW based Delay Locked Loop concept for VCO linearization in FMCW Radar sensors

A novel linearization approach for VCOs in FMCW radar sensors is proposed. The principle relies on a SAW delay line that is applied to generate a reference beat signal. With the proposed concept it is possible to realize a Delay Locked Loop that generates a pre-distorted VCO tuning voltage. The system can be realized in CMOS technology. For the verification of the concept a test system was set up where the logic is implemented in a FPGA. In this paper the linearization principle and the test results of the demonstrator are presented.