A compact UWB-RFID sensor tag with reconfigurable band-notch deployment

In UWB-RFID sensor system, the interference from other wireless protocol with the frequency overlapped each other is becoming a main issue to determine the accuracy of sensitivity in terms of a specific identification. One solution to tackle the problem is to etch a U-slot on antenna facet that can render a tag with band-notch in a specific frequency, and the band-notch can be further reconfigured by adding a PIN diode on the U-slot set by a DC bias. However, when increasing the compactness of the tag further while decreasing the EM interference brought by the added circuitry of DC bias as much as possible, a revised solution is proposed in this paper. The U-slot is placed on the grounding plane, not on the antenna facet anymore. Simulation has verified that the revised solution can be able to form the same band-notch in a given frequency band segment, and the circuitry routine used for delivering DC bias could be naturally constructed by the networking serially formed by the proposed micro-strip feed line, the substrate, the via hole, the PIN diode and the grounding plane.