Abstract. A novel microstrip antenna which is dedicated to

Abstract. The idea of multiband development board designed to support and advance the technique of battery-less autonomous semi-passive RFID transponders is presented in the paper. The extra function of harvesting energy from the electromagnetic field of different radio communications systems, the ultra efficient power conditioner and the energy storage block are applied in the proposed construction. The facility of utilizing gathered energy is provided to support designers in developing applications of automatic object identification. Since the evaluation board is to work without a galvanic cell, the particular emphasis is put on the mechanisms that improve energy efficient operation of the whole electronic circuit. The construction principles and operation modes (charging, cold start, sleep with charging, sleep, measurement and cut-off) of the storage unit are described in depth in the paper. The preproduction batch of the demonstrators has been manufactured on automated assembly line at ELMAK Ltd. Company, according to the elaborated model. It confirms that the author's demonstrator of the battery-less autonomous semi-passive transponder can be reproduced on an industrial scale. On the basis of the preproduction series, the performance parameters of the final product have been estimated. The presented study should significantly contribute to the RFID technique therefore the authors set up the evaluation process of marketing research and product commercialization. fication of moving objects, e.g. in the public transport (AVI -automatic vehicle identification) [7]. So it can be concluded that the observed applicable potential of the RFID technology justifies the need to develop new designs of electronic transponders. New more sophisticated solutions of electronic tags will be a factor of innovative progress in the discussed scope of use. Transponder in RFID systemIn terms of hardware (Fig. 1), an RFID system consists of a read/write device (RWD), which includes a transmitter (TX) and a receiver (RX), its antenna and at least one electronic transponder that is intended for marking an object. Communication in this system (read/write data) is provided with one (single system) or with multiple transponders simultaneously (anti-collision system). The marked objects during the identification process may be placed in fixed points (static system) or may dynamically change their location (dynamic system). The interrogation zone (IZ) is the main parameter of the RFID system, because it determines the efficiency of a given automated process [5]. The size of the IZ strongly depends on the above mentioned arrangements of RWD and transponders.According to the main classification of the RFID systems it is possible to distinguish applications operating in the inductive or radiative coupling regime. In the first group, the carrier frequency f 0 is between 100 kHz and 135 kHz (typically 125 kHz) for the LF band or 13.56 MHz of the HF band whereas in the

The interrogation zone IZ is the most important parameter when RFID systems are considered. Its predictability is determined by the construction and parameters of antenna built in a read/write device. The IZ should be of sufficient size and appropriate to requirements established for an application of object automated identification. The method of shaping an antenna radiation pattern provides effective yet unconventional opportunities in this area. The idea and practical solution of the phased antenna array dedicated to UHF read/write devices are presented in the paper. On the basis of tests carried out, the authors pointed out the possibility of using developed devices for the synthesis of a determined IZ in anti-collision RFID system.

An attempt to increase the geometric size of the interrogation zone in UHF RFID systems with a phased array antenna is presented in this paper. The interrogation zone should be as large as possible. However, energy can be transferred to transponders only to a limited distance. The greatest flexibility in developing RFID applications and shaping the interrogation zone can be achieved using a phased array antenna. The perceived issues have been effectively dealt with and the solution has been proposed on the basis of an elaborated model. Conducted studies have been used to develop a software tool in the Mathcad environment. The research results are analyzed in detail for different system configurations and can be implemented in practical projects to be developed in cooperation with the industry.

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