Substrate integrated waveguide-based self-triplexing antenna-sensor

Abstract

In this paper, a Substrate Integrated Waveguide (SIW) based self-triplexing antenna-sensor is introduced. The proposed structure can act as a sensor for concurrent detection of three chemical materials. Further, it can be used as a self-triplexing antenna for simultaneous operation at three different frequencies. To that end, initially, a half mode circular SIW cavity is designed. Then, it is divided into three parts. In each part, the position of maximum electric field is determined and subsequently, three holes are located in the positions for material insertion. Finally, considering the vacuum as the inserted material for each hole, each cavity is adjusted to operate at its operation frequency (4.8, 5.8, and 6.6 GHz). Altering the permittivity of the objects inserted in the holes, the resonant frequencies are changed and consequently the type of material is determined. The simulated and measured results validated the performance of proposed antenna-sensor as well. In all the frequency bands, the reflection coefficients as well as mutual coupling among ports are below −20 dB. It should also be expressed that such an SIW structure with the capability of sensing and propagation is provided for the first time.