Miniaturized patch antenna for RFID tags on metallic surfaces

The majority of commercial ultra high frequency radio frequency identification tags are based on the dipole antenna, whose performance degrades significantly when the tag is placed near a conducting surface. In this article, we present a radio frequency identification patch tag to operate on conducting surfaces. The antenna provides good bandwidth and return loss level at 915 MHz. It has a very small size on low dielectric material, without the need for shorting pins or walls, which significantly lowers the fabrication cost in mass production using monolithic microwave integrated circuits.