Increased sensivity of tracking of portable devices based on biological organisms

In this study a miniaturized asymmetric planar antenna array was built and analyzed. In order to reduce the coupling between the elements and to improve the impedance matching of the array two techniques were employed: slightly shifted one of the elements and use a ferrite based transformer. In the design, the miniaturization is achieved by placing the elements of the arrangement closed to each other (≪lambda/2). The concept is based on the ability of some insects, which have very small physical dimensions compared to the wavelength of the communication signal, to detect other insects of the same species. This is the case of the fly Ormia ochracea that has high ability to control the phase difference of the received signals. For practical applications, a prototype of a planar Bow-tie antenna was built on Rogers TMM6 substrate to operate around 300 MHz. The measures show reflection coefficient below -10 dB and coupling coefficients around -20 dB, within the desired range. It was carried out using the vector network analyzer (R&S ZVB20).