Planar Inverted Antenna With Embedded Patch Excitor for On-Metal Tag Design

For the first time, a non-resonating patch is embedded inside a planar inverted antenna structure for the design of a low-profile metal-mountable tag antenna. The tag has a compact and low profile with a footprint of 40 mm
$\times40$
mm
$\times3.3$
mm. Efficient coupling between the excitation patch and the radiating patch, which are separated by a narrow and long slotline can improve the radiation efficiency. The slotline can provide sufficient shunt capacitance so that the antenna reactance can match with the chip reactance. The antenna and chip impedances are in conjugate match for the proposed tag, maximum power transfer between the chip and the antenna is possible for a better radiation performance. Being tested with 3.28 W effective isotopically radiated power (EIRP), the proposed tag can attain a good read range of ~ 16 m. The tag antenna’s resonant frequency is very stable, and it is not significantly impacted by the metallic backing object underneath.