A Harmonic Automotive Radar for Bicycle Detection with RFID Tags at 79/158 GHz

We present a harmonic radar system based on an RFID tag to improve traffic safety for outside vehicles like pedal cyclists. The tag consists of a high gain amplifier chain focused on low power consumption and a frequency doubler. This allows for detection up to a distance of 80 m, with the received signal being close to clutter-free. The transceiver chip with its receive channel at the harmonic frequency is also presented. It expands a conventional radar system at the fundamental frequency. In conjunction with a two-channel backend, the two receivers at different frequencies can be measured simultaneously. Thereby the harmonic receive channel can be directly compared with its fundamental equivalent.