Michler, FabianFabianMichlerNeugebauer, MarcelMarcelNeugebauerScheiner, BenedictBenedictScheinerWeigel, RobertRobertWeigelLurz, FabianFabianLurz2022-04-212022-04-212022-01IEEE Topical Conference on Wireless Sensors and Sensor Networks (WiSNeT 2022)http://hdl.handle.net/11420/12342A common technique to control the transmit frequency of modern radar systems are phase-locked loops (PLLs). This paper presents an alternative PLL-free design, where a microcontroller (MCU) is used in a digital control loop to stabilize the output frequency of a voltage-controlled oscillator (VCO). Using a commercial 24 GHz integrated radar transceiver and the MCU, a discrete proportional (P) control algorithm tunes the VCO in real time without requiring a hardware PLL. In continuous-wave (CW) mode, a measurement precision of 7.6 μm is achieved. In a pulsed dual-tone operation mode, the unambiguous range is extended to 1.4 m by still achieving an accuracy of 25 mm.endistance measurementDoppler radarfrequency controlfrequency-locked loopConference Paper10.1109/WiSNet53095.2022.9721354Other