Dual UHF RFID band miniaturized multipurpose planar antenna for compact wireless systems

Abstract

In this paper, we will discuss the design and development of a miniaturized dual UHF band antenna, resonating on the RFID bands. The antenna resonates on 433MHz and on the European RFID band (865MHz–868MHz). This antenna design is an updated version of the miniaturized 433MHz antenna model [1], with an improved performance and dual band characteristic. This type of planar antenna can be used in different type of small compact wireless systems, such as small RFID reader units, wireless sensor network nodes, and different indoor/outdoor wireless devices. The biggest challenge in designing such an antenna was the size of the antenna, for which different miniaturization techniques [2] have been used. Miniaturization techniques like shorting the radiating part of the antenna with the ground plane, similar to PIFA (Planar Inverted F Antenna) [3], and using closely coupled parallel meander line approach greatly helped in reducing the size of the antenna. The design and structure of the planar [4] antenna makes it very stable and less vulnerable to the external environmental factors, like different type of hand and walls effects. The reduced size of the antenna, with an ability to resonate on multiple most commonly used frequencies with a good gain and omni-directional radiation pattern makes it a good competitor for replacing the old antenna model with the new multipurpose small, low cost antenna model.