Chipless substrate integrated waveguide tag for millimeter wave identification

Millimeter wave identification (MMID) enables new improvement, such as the high number of different codes that can be `written´ on a tag, location sensing through narrow-beam antennas etc. In this paper novel compact chipless MMID tag is presented. The tag consists of a slot etched on the top of circular Substrate Integrated Waveguide (SIW) cavity. Reader concept based on frequency domain measurement using VNA and phase discrimination is proposed. Single cavities with different resonant frequency are tested showing high sensitivity, the measured resonant frequencies present a shift less than 2% compared to the designed ones. A tag based on multiple cavities is also tested. The design developed in this paper at Ka-band, brings enhancement in term of miniaturization, configurability and fabrication cost.