Design of a Wideband E-Band Radar Frontend for a Novel Incoherent Self-Mixing Radar Principle

A novel self-mixing radar method is verified in E-band (60 to 90 GHz) employing a 15.2 GHz wideband frequency modulated continuous wave (FMCW) chirp on a transmitter (Tx) and receiver (Rx) frontend. The radar principle is able to determine distance information between multiple targets while being independent of the distance to the targets. This is achieved utilizing multiple reflections of an FMCW signal with a delay in time and down converting those to an intermediate frequency (IF) signal, using a special self-mixing mixer. Tx and Rx do not rely on time and frequency coherency and therefore do not need to have a physical connection. A multi-chip demonstrator frontend assembly with substrate integrated waveguide (SIW) H-plane horn antennas is designed to prove the radar concept by measurement. To the best of the authors’ knowledge, the self-mixing radar principle is novel.