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A preliminary proof-of-concept of an innovative system combining the technologies of Radio over Fiber (RoF) and Time Modulated Array (TMA) Antennas is proposed. Through a theoretical and experimental analysis, the straightforward realization of steerable antenna arrays for capillary indoor wireless signal distribution is demonstrated.

This paper gives an overview on the development of microwave phototransistors within SiGe Bipolar and BiCMOS technologies. The physics and design of SiGe/Si Heterojunction Bipolar Phototransistors (HPT) are covered. A comprehensive analysis of the photodetection mechanisms and its localization into the structure is provided. After a description of the scaling rules, applications are presented in the field of Microwave-Photonics for short range and low-cost applications. Perspectives are then highlighted that includes the frequency increase, the enlargement of functionality and even on-chip optical links.

Commercial couplers designed for 1550nm are conveniently adopted for realizing efficient Radio-over-Fiber links operating at 850nm on the standard G.652 single mode fiber. In particular, exploiting the mode filtering properties observed in these couplers when excited at 850nm, a multi-wavelength system over the standard G.652 fiber is obtained, opening the possibility to easily integrate in currently developed infrastructures such low cost systems operating in the first optical window.

This paper describes a method to achieve superdirectivity in dipole array by employing only two elements, a driven element and a shorted parasitic element. To maximize the directivity, initially the array is assumed to be fully driven and the required current excitation coefficients are calculated. Then the parasitic elements are added such that the parasitic array achieves almost the same directivity as the fully driven array when optimal loads (inductive, capacitive, short) are connected to the parasitic element. It is observed that a shorted parasitic element placed very near to the driven element could enhance the directivity to a high value. The directivity can be further enhanced by placing the elements on a trapezoidal shaped substrate. A two element parasitic dipole antenna array with a directivity of 9.17 dBi is presented.

Tagging power cords is not only useful for tracking insulated or hidden electrical cables. Implementing sensory functionalities to the UHF RFID tag in addition to its unique ID is of great interest in the wireless sensing of house electrical appliance activities. Tags dedicated to electrical cables for read distances of 10–12 feet are commercially available (Sentry cable RFID Tag, Vizinex company). The core of the tag is a fiber-reinforced composite material and the mounting uses zip ties or metal banding which makes these tags bulky. Therefore, this type of tags can only be fixed on cables once the electrical installation is complete.

The purpose of this paper is to clarify the principles, advantages and disadvantages of commercial RFID modules combining a loop and a RFID IC for the excitation of dipole-like antennas. Using a circuit modeling of the tag topology, the influence of the main parameters (dipole radiation resistance and Q factor, module position along the dipole, mutual coupling between the loop module and the dipole) are stressed. A special attention is brought to the determination of the optimal coupling for a given dipole.

Different approaches based on various wireless technologies have been proposed so far for indoor localization. Radio frequency Identification (RFID) indoor localization seems to be a promising way of research. The identification capability of this technology combined to localization methods improves the results obtained by other wireless technologies such as Wifi, GPS, Zigbee. This paper details some localization techniques used for RFID Tags localization in Indoor environment. In particular, Fingerprinting methods are compared to Distance estimation methods. We will show through several simulation experiments, using NS2 and Matlab software, that fingerprinting techniques outperform Distance estimation techniques for localization and tracking tasks.

A 60 GHz differentially-fed four-port printed antenna (DFFPPA) is proposed in the context of a high data rate transmitter. The transmitter architecture is based on the Impulse Radio Multi-band On Off Keying (IR-MBOOK). The transmitter contains two differential power amplifiers (DPA) whose outputs are directly connected to the DFFPPA which is excited by two differential feeds through two slots. The first slot is excited by the differential outputs of the first DPA, which covers bands 1 and 2 from 57.05 to 60.27GHz. The differential outputs of the second DPA, which covers bands 3 and 4 from 60.3 to 63.7 GHz, excite the printed antenna through the second slot. Simulated results gains around 7.1 dBi are obtained for each differential output. The transmitter architecture promises high data rate and low power consumption in a compact surface.

International audience; Green's functions for semi-infinite media are derived and used to calculate the reflected electromagnetic fields by plane composite dielectric surfaces. The method is not demanding in terms of computer resources and calculation time; it is thus applied to exterior building facades in urban environments. The method takes into account the architectural details which are usually neglected in ray-tracing algorithms.

A microstrip antenna fed by a conductor-backed coplanar waveguide is demonstrated. The addition of a back-side metallic ground plane involves a possible leakage of the CPW mode into Parallel Plate Modes (PPMs) or the excitation of these PPMs by the back-radiation of the coupling slot. A theoretical model, based on the solution of coupled integral equations, is validated by experimental results. It is shown that the power leakage can be avoided by a proper choice of the substrate characteristics.

Coplanar wave (CPW)-fed slot antennas printed on multilayer dielectric substrates are numerically analyzed using a full-wave integral equation technique and the method of moments. The Green's function is derived with an iterative formulation. Results obtained with a simplified and a rigorous model of the feeding CPW lines are compared. The mutual coupling between the slot antennas in an array environment is calculated for a three-layer high-low-high permittivity combination. The theoretical results are verified with measurements.