Compact Low-Cost Fmcw Harmonic Radar For Short Range Insect Tracking

We present two frequency modulated continuous wave (FMCW) harmonic radar prototypes for application in insect tracking. They respectively operate in the maritime radar allocations of the S-band and X-band. Short-range operation ensures that the modules are compact enough to be used as portable instruments or even mounted onto an unmanned aerial vehicle (UAV). Given the output power of 3W and 10W respectively, the S-band prototype provides up to 40m of range while the X-band version has a maximum range of 15m. Both systems have a range resolution of approximately 1m and can run off general purpose batteries. Our investigations support an observation that harmonic tags exhibit highly non-linear behaviour at low incident power levels. As a result, harmonic radar systems become increasingly less efficient in terms of the maximum detection range relative to the transmit power at higher frequencies.