Transponders

The necessity to control all the activities within the marine environment is nowadays vital for most official authorities. Besides protecting the ecosystem and providing safety and surveillance along the transportation corridors, illegal immigration and sustainable economic activities are also issues to cover. Since early nineties, a lot of efforts have been devoted to develop monitoring systems based on transponders (VMS or AIS). Such systems use active on-board devices to track ship positions via satellite communications. Despite of their great performance, the experience has shown, however, that this approach does not have the required independency and other alternatives are necessary. Among them, the one gathering more benefits is the integration of remote sensing, specially Synthetic Aperture Radar (SAR), with operational transponders. Certainly, this solution provides redundancy, 7/24 and all-weather monitoring capability, independently from the targets to track.

In this article we discuss the realization of antenna gate structures for inductively coupled passive HF RFID systems. Antenna gates are currently used in several applications, from industrial tracking to access control: in these structures the identification process is realized with the use of more antennas disposed in a configuration that makes them similar to doors. Nowadays these structures can reach a maximum width of 1.50-1.60 meters due to the limitations deriving from the CEPT ERC Recommendation 70-03 annex 9 on electromagnetic emissions from electronic devices. Next to this, limitations also derive from the decrease of the electromagnetic field with the distance and from physical constrains due to the fact that the field strength is proportional to the dimensions of the antennas. The purpose of this article is to describe a possible optimum configuration of antennas allowing the detection of tags across a 2 meters wide gate reducing as much as possible its dimensions.

This paper gives an overview of Software Defined Optical Networks (SDON's) and how they can be implemented. It traces the evolution of Optical networks upto GMPLS and traces the idea of SDN and builds upto OpenFlow. The paper explores the need for SDON's and explains what a SDON solution could look like, including the hardware. It also seeks to explain how OpenFlow could be used as a part of this solution to overcome the limitations of GMPLS.

... RF-enabled smart cards are durable and reliable. RF-enabled smart cards and sealed RF readers prevent damage when identity creden-tials and readers are exposed to dirt, water, cold, and other harsh environmental conditions. -Security. ... [1] Parul Oswal, Michelle Foong ...

This work focuses on presenting a new efficiency Acoustic Frequency IDentification system in the hope of improving underwater monitoring. Earth is a water planet as ocean's covers about two-thirds of the earth surface. Such extension remains unexploited to satisfy humans' needs. Recently, attempts grow toward invigorating monitoring aqueous environments such as oceans, rivers, lakes, ponds and reservoirs. In this paper we propose wireless identification system for underwater applications. As a versatile system we can use it in different underwater domain. We may list: The marine domain (discovery and monitoring of pollution, underwater animals), and the public one (intelligent monitoring of pool). Current studies show that there are many techniques of underwater wireless indentification, but still with a lot of short-comings due to environmental constraints. The concept of underwater AFID draws its legitimacy from RFID by realizing reversal engineering.

This paper presents design, fabrication, and implementation of a novel electromechanical energy scavenging and wireless interrogation scheme using low frequency components of musical vibrations to overcome challenges associated with previously reported passive transponders such as: short transmission range, misalignment sensitivity, and complicated receiver circuitry. The transponder has two phases of operation: 1) mechanical vibration phase, in which an acoustic receiver (a piezoelectric cantilever) converts the sound vibration into electrical power and charges a capacitor; and 2) electrical radiation phase, in which the stored charge is dumped into an LC tank, forcing it to oscillate at its natural resonance frequency and emitting the energy to an outside receiver. In a pressure sensing configuration, the distance between a planar coil and a ferrite core is modulated by the pressure, thus changing the inductance and in turn inducing a change in the frequency of the emitted signal. A prototype transponder was built and tested using a PZT cantilever with a mechanical resonant frequency of 435 Hz encapsulated in a glass capsule (length=40 mm, diameter=8 mm) along with a rectifier circuitry and a storage capacitor. The inductive pressure sensor located outside the capsule had a sensitivity of 2.5k Hz/kPa. We were able to easily pick up the transmitted RF pulses at distances of up to 7 cm without the tight requirement on alignment between the receiver and the transponder coils.

... troller and systems where the transponder is “chipless.” Das and Harrop [1] argue that the largest market in RFID lies with chip-less RFID as opposed to any type of chipped RFID because the cost of chipless tags is generally much lower than that of other tag types due to the ...

ABSTRACT Planning and routing in future elastic optical networks will depend on the underlying technology and more specifically on whether standard grid or flex-grid technology will be used. In particular, for dynamic flex-grid networks, resource allocation and routing concern both path establishment and allocation of specific spectrum, which in turn relates to the modulation format of the transmitted signals. Moreover, if variable bandwidth transponders are utilized simultaneous optimization of allocated spectrum and transponder reach should be performed. In this context, all the above should be integrated in both planning and operation phases of an elastic flex-grid optical network. This paper elaborates on a methodology for integrating design constraints into the planning and operation of elastic optical networks and investigates the benefits of flex-grid technology with variable bandwidth OFDM transponders regarding both the blocking performance and spectral efficiency when compared to their standard-grid counterparts.

The paper exemplifies the development of a surface acoustic wave (SAW) temperature measurement system, showing the advantages of wireless data transmission and passive sensor operation. It includes results of research on lithium niobate, langasite and gallium-orthophosphate, three piezoelectrica used as substrate crystals for the SAW devices. Critical parameters, limits and prospects of the materials as well as technological issues concerning the metallization and the lifetime of reflective SAW delay lines are discussed. The packaging and assembly of high temperature (HT) stable transponders is explained. A slot antenna, a patch antenna and a dipole antenna, thus providing maximum flexibility for the sensor geometry, are investigated. A phase matching algorithm, enhancing the measurement resolution by two orders of magnitude compared to a conventional peak detection algorithm, is described. A fully integrated SAW temperature sensor system is presented, basing on a frequency modulate...

... RF-enabled smart cards are durable and reliable. RF-enabled smart cards and sealed RF readers prevent damage when identity creden-tials and readers are exposed to dirt, water, cold, and other harsh environmental conditions. -Security. ... [1] Parul Oswal, Michelle Foong ...

A transponder for UHF RFID with sensor interface for external capacitive sensors is described. The sensor interface consists of a capacitive voltage divider and a 10 bit successive approximation analog to digital converter. The power consumption is about 30 muWDC and the transponder is wirelessly powered with RF waves from the reader device. Wireless measurement of capacitance is demonstrated at a distance of 30 cm with 0.5 W erp transmission power. Low operation distance is mostly due to low efficiency of the rectifying Schottky-diodes in the particular BiCMOS process.