No abstract

A compact folded-patch UHF RFID tag antenna (30 mm × 30 mm × 3 mm or 0.0912λ × 0.0912λ × 0.009λ) is proposed for metallic surface applications. Two large C-shaped slots, which can be easily tuned by adjusting their lengths, are incorporated into the folded-patch for providing tuning mechanisms that can be employed in the production line for tuning the tag resonant frequency on the fly. The slots are tactfully embedded into the patch structure so that they occupy no footprint. The slots are large enough so that their lengths can be easily adjusted by employing a penknife and some copper tapes. This provides an impromptu tuning mechanism so that the tag resonant frequency can be easily corrected in the production line. With reference to the effective isotropic radiated power of 4 W, the proposed tag antenna can be read from 10 m on metal. The read range is found to be able to go beyond 5.5 m when the tag is placed on a dielectric with permittivity ranging from 1 to 12.

No abstract

In this paper, an innovative type of smart antenna based on genetic algorithm (GA) has been developed and tested. The new GA embedded solution simplifies the control of smart antenna system with increment of the accuracy of beam coverage and decrement of beam availability in compare with the conventional switch beam smart antenna. Scanning antenna of the system determined the location of mobile users through its band passed radio frequency power detector circuitry. GA then operates to optimize and steer the coverage beams to cater for dynamic users' distribution with minimum power usage. The experiment with GA embedded control system smart antenna shows good result in beam formation and steering to handle mobile users.