Exploring the use of active microwave resonators for stored-product insect detection

Abstract

New sensors are presented which have as their central component an active microwave resonator. The active microwave resonators are planar and contain an active component which compensates for energy loss in the resonator. The result is a very narrow transmission or output spectrum which responds to changes in the immediate proximity of the sensor. This sensor is applied to stored-product insect detection. The ability of the sensor to detect insects both outside and inside individual grain kernels is demonstrated. The sensor is also able to detect insects in small samples of grain, which means it could potentially be used to monitor grain bins for infestations. A technique is proposed which analyses the signal from the sensor to provide an indication of insect presence, and the technique is used to characterize the detection efficiency of the sensor for internal Sitophilus oryzae in wheat kernels at different developmental stages.