| Harmonic radar techniques are used for entomology applications, where the milligram mass radio transceiver can be carried by insects without impeding their movement, unlike heavy battery powered radio collars. Conventional radar is not useful as the ground-based insects are not visible in all the clutter from their surroundings. The focus of this work is to design and test a diplexer that would replace the two antennas of the harmonic radar system with a single antenna. This design comprises a quarter wavelength transformer (X-Band to K-Band), a coaxial to WR-42 waveguide transition, and a diplexer section. An alternate diplexer, embedded with choked flanges to face EMI challenges was also designed and fabricated. The design is shown to function although at reduced range compared to the two antenna system. Measurements reveal that the system is not interference limited, but limited by losses in the diplexer. |
