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Hier finden Sie wissenschaftliche Publikationen aus den FraunhoferInstituten. A SiGe fractionalN frequency synthesizer for mmwave wideband FMCW radar transceivers
 IEEE transactions on microwave theory and techniques 64 (2016), No.3, pp.847858 ISSN: 00189480 

 English 
 Journal Article 
 Fraunhofer FHR () 
Abstract
A millimeterwave (mmwave) frequency synthesizer is presented focusing on an ultrahighspeed fractionalN frequency divider and a highly linear phasefrequency detector (PFD). All circuits are integrated into a highfrequency SiGe bipolar technology. The programmable frequency divider can be operated at input frequencies between dc and 57 GHz for division factors in the entire integer range from 12 to 259. The PFD is optimized for fractionalN synthesis, which requires an extremely linear characteristic due to the modulation of its input frequency. The frequency divider and the PFD are used together with an 80GHz wideband voltagecontrolled oscillator (VCO) and transceiver for a high precision mmwave frequencymodulated continuouswave (FMCW) radar sensor. As shown by the experimental results the realized circuits stabilize the mmwave VCO with an extremely low phase noise below 97 dBc/Hz at 10kHz offset around its center frequency of 80 GHz and can generate a highly linear frequency ramp with a bandwidth of 24 GHz. Furthermore, the accuracy of the synthesizer is demonstrated by FMCW radar distance measurements inside a waveguide and in free space. Inside the waveguide a standard deviation of the phase of the target below 0.0018 degrees (which corresponds to 9.4 nm) was measured.