Layout-Based Tuning Solution for Reconfigurable SIW Resonant Sensors

Accelerated increase in the number of resonant sensors that must operate at close frequencies and in volume-constrained spaces makes decoding useful sensing information particularly difficult due to interference between their response signals. To address this concern, the paper presents a novel, flexible solution for modifying the operating frequency of substrate-integrated waveguide (SIW) resonant sensors. This feature allows fast and cost-effective frequency tuning of the SIW resonant sensors, in order to reduce the interferences. Also, the rejection circuits used in some filter models can benefit from this feature, if their response has to fit different radio standards. A test circuit with three layout tuning elements (LaTEs) was used to test the novel electronic tuning solution. The circuit was fabricated as double-sided printed circuit board. The structure allowed 940 MHz frequency deviation, covered in eight discrete steps. The frequency deviation can be either increased or reduced by choosing different distances from the LaTE group and the shortcircuit termination of the resonant SIW circuit.