Dual-mode microwave cavity for fast identification of liquids in bottles

Summary form only given, as follows. An open metal cavity loaded with a ceramic dielectric resonator and a lumped inductor - capacitor structure allows for simultaneous excitation of a dielectric resonator mode at 2 GHz and a lumped element mode at 100 MHz. Both modes exhibit strongly overlapping evanescent fields above the aperture outside the cavity, which can be used for dielectric and conductivity measurements on liquids stored in non-metallic bottles. This method enables liquid category identification within one second.