A UHF-band RFID system handling many RF tags has some advantages over a bar code system such as simultaneous multi-reading and long read range. Especially, it has been strongly desired by the logistics and the retail industries for efficiency of operation. Recently, user-friendly RFID systems are being studied. We focused on a gate system using RFID technologies. If the tag moving direction can be recognized at the RFID gate system, it will be very useful for the efficiency of inventory management and the checking of pilferage or shoplifting. In this paper, new methods of tag moving direction detection using the difference of passing time of two antennas without expensive external sensors is proposed and evaluated. Two methods are proposed for the specific procedure. The first one is to detect the time when the received power goes over the preset threshold. The second one is to estimate the aimed time using the maximum likelihood approach. Some experimental results of these methods are also shown and their feasibility is proved.
In the design of concentration and distribution stages of analog video signal systems, the use of broadband analog switches helps to reduce the number of expensive bandwidth-reduction CODECs. However, these switches must satisfy severe crosstalk attenuation requirements. To suppress the crosstalk, switch components and packaging must be chosen carefully and switch configurations and their implementation must also be considered. Moreover, the conventional design for one-to-one crosstalk cannot be applied to adistribution service for video signals, and a more detailed design that considers crosstalk phase conditions is required. However, no method of allocating the crosstalk attenuation objective to each component in the switch has yet been established for connecting one inlet to multiple outlets .This paper presents a model for crosstalk addition based on the generation mechanism of crosstalk and proposes the concept of equivalent power sum multiplicity. Using this model and concept, a method is proposed of allocating a crosstalk attenuation objective to each cornponent of the switch in order to satisfy the overall quality.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.