Organic electronics create new opportunities of inexpensive RFID tag production techniques such as printing processes, which are only possible with soluble materials like polymers. Concepts for the production of fast integrated circuits based on p-type organic transistors have been demonstrated [1] using soluble polymers for active layer and insulating layer. A number of organic RFIDrelated building blocks and components have recently been published [2,[4][5][6][7]. This paper presents a passive organic transponder that uses a base-carrier frequency of 13.56MHz, designed for item-level tagging. The transponder prototype carries no ID and is mainly designed as a feasibility study. In the near future, data storage and implementation of a communication protocol will be pursued. Due to low charge carrier mobilities of µ≈0.02cm 2 /Vs the internal clock signal of the polymer-based transponder cannot be generated from the carrier signal as is done in many silicon-based RFID applications. The developed organic devices are air stable, even without encapsulation and all measurements were taken under ambient conditions. The manufacturing process of the transponder prototype is completely compatible with a printing process for mass production. The minimum structure size for printing is 20µm. Regarding the prototype transponder, all electrodes are patterned with a lithography mask using standard photolithography. The minimum structure size using this process is 5µm. The substrate for all devices is a flexible polyester film. Up to six different layers for Source/Drain-electrodes, polymer semiconductor for transistors, insulator for transistors, semiconductor for diodes, insulator for capacitors and gate-electrodes are applied. The field effect transistors (FET) are based on a top gate concept with source and drain consisting of a 40nm gold layer. The semiconducting layer of approximately 50nm thickness is applied by a spincoating process using a p-type soluble polymer poly 3-hexylthiophene (P3HT). A 300nm thick soluble organic copolymer blend is spincoated on as insulating layer [1]. Rectifier diodes are developed based on soluble poly 3-alcylthiophene (P3AT) as p-type semiconductor whereas anode and cathode are realized as metal contacts [2]. The capacitors are made with a proprietary blend of soluble insulating polymer between two metal electrodes. [1]. Copper was chosen in order to get high quality loop antennas that were structured by common etching techniques. Figure 15.1.1 shows the system overview of the reader that drives an organic transponder at a certain distance d. On the reader side a serial resonance circuit of reader loop antenna and a tuning capacitor is supplied by a signal generator that produces a 13.56MHz sine voltage with amplitude U g,p . The reader antenna has five turns of 10cm diameter and is matched to a 50Ω impedance.The transponder loop antenna in conjunction with the input capacitance of the organic rectifier represent a parallel resonance circuit that is tuned to the carrier frequency of 13.56MHz...

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