Laboratory Scale Fabrication Techniques for Passive UHF RFID Tags Tamer Elsherbeni 1 , Khaled ElMahgoub 1 *, Lauri Sydänheimo 2 , Leena Ukkonen 2 , Atef Elsherbeni 1 and Fan Yang 1 . 1 Center of Applied Electromagnetic System Research (CAESR), Department of Electrical Engineering, University of Mississippi, USA. 2 Rauma Research Unit, Institute of Electronics, Tampere University of Technology, Finland taelshe konen ri@olemiss.edu, kelmahgo@olemiss.edu, lauri.sydanheimo@tut.fi, leena.uk @tut.fi, atef@olemiss.edu, fyang@olemiss.edu. Abstract This paper presents an overview of various radio frequency identification (RFID) tag fabrication methods and briefly describes the advantages and disadvantages of each method. The purpose of this paper is to provide readers with the RFID fabrication techniques that can be applied in laboratory scale experiments. The performance results of laboratory made RFID tags based on two fabrication methods (etching and screen printing) and different substrates (paper, thin transparent film, polyethylene terephthalate (PET), and fabrics) are provided. These results prove the effectiveness of the presented laboratory scale fabrication methods for RFID tags. Introduction In today’s world the role of RFID has increased considerably. RFID is a technology which uses RF signals for automatic identification of objects. RFID tags are used for many applications in various areas such as electronic toll collection, asset identification and many others applications. A RFID system consists of two basic components, a reader (interrogator) and a tag (transponder). RFID tag can either be active, operated by a battery, or passive. A passive tag consists of an antenna and an application specific integrated circuit (ASIC) known as a chip. Passive ultra high frequency (UHF) RFID systems which achieve read ranges longer than 1 meter are defined as long range systems. These systems operate at the UHF center frequencies of 866MHz (Europe), 915MHz (America), and 950MHz (Asia and Australia) [1]. In this paper two different fabrication techniques for RFID tags (screen printing and etching) are discussed. The advantages and disadvantages of each method are provided. Experimental data of prototype RFID tags fabricated from these two methods is provided. Fabrication Techniques Etching The etching processes can be classified into two categories: wet and dry etching. The process of wet etching uses liquid chemicals or etchants to remove metallic substrates. A photoresist mask is used to protect the desired pattern on the substrate when the etchant is applied. “The wet etching process can be presented in three steps: 1) application of the etchant to the substrate; 2) reaction between the etchant and the material being removed;