Portable 9.4/18.8 GHz harmonic radar system using pulse Pseudorandom code principle

We propose a 9.4/18.8 GHz portable harmonic radar for bee searching to investigate colony collapse disorder of bees in the world. This harmonic radar uses Pseudorandom (PRN) code principle to achieve high sensitivity. An analog real time processing circuit for portable application is proposed. This high sensitivity radar can detect the -106 dBm signal, which is 13 dB below the -93 dBm noise level. The field test has been performed to verify the function, and the transponder can be found in the grass within the 1-m distance.