Irina L. Vinogradova

IR-UWB radio-over-fiber system components development

The paper describes the application of IR-UWB technology for organizing the radio part of Radio-over-Fiber system. Four physical layer components are proposed and designed in the paper: three microstrip filters and UWB antenna. Firstly the effective SCRF mask was calculated to ensure electromagnetic compatibility with existing radio services. Then this mask was considered as a cost function for filters design. The simulation was made with Agilent Genesys™ and CST Microwave Studio. All the devices have shown good performance and could be implemented on one circuit board for reducing losses.

UWB-RoF optical signal relevant to state committee on radio frequency spectral mask and its chirping task

The article covers issues on optical pulses modeling for UWB-RoF transmission system and State Committee on Radio Frequency (SCRF) spectral mask. It is assumed that the whole range is covered only by a modulator (information source). The problem concerns pulse transmission received over a fiber optic line of 100 km in length. It was found that the output optical signal obtains significant chirping, which has a negative impact on the Radio-over-Fiber (RoF) transmission system. In this paper, it is proposed to select the optical pulses at a predetermined optical line, or use a chirped small amplitude Gaussian pulse on the input. This can significantly increase, more than twofold, the length of the optical line.

Experimental study of wireless part of laboratory bench, implementing IR-UWB radio-over-fiber system

Wireless part of the laboratory bench, implementing IR-UWB Radio-over-Fiber system, is described in the paper. Experimental prototype of fractal antenna radiating system (FARS) is considered, various transmission modes of the laboratory bench, which allow to investigate technical specifications, are described. Research results are presented and analyzed.

Experimental demonstration of high-speed data transmission based on Gaussian pulses for IR-UWB radio-over-fiber systems

Experimental bench, which provides high-speed data transmission for IR-UWB Radio-over-Fiber systems on the basis of Gaussian pulses, is presented in the paper. Experiment setup and results are described and discussed.

The fiber optic device for signal positive chirping by interferential method with tuning of chirp size

The device for positive chirping of a signal in a fiber optical line is offered. The device is based on two Fabry–Perot resonator with additional fiber optical cannels. If to execute the amalgamator from an erbium doped material, the device will supply amplification of a target signal, which is important for distribution access systems (for example, Radio-over- Fiber systems (RoF)). The device provides selectivity for spectral components of entrance radiation, that allows to operate of chirp. Built-in the converter of length provides in additional fiber optical cannels tuning the chirp under the given size.

Simulation of the coherent MDM transmission using principal modes of the optical fiber as signal carriers

In this paper we demonstrate computer simulation results obtained for the coherent mode division multiplexed (MDM) 5x5 QPSK transmission using principal modes (PMs) of the stepped-index few-mode fiber (FMF) as a basis of independent signal carriers. The output signal recovering and the fiber propagation matrix determination are considered to be carried out in optical domain by means of reconfigurable multibranch diffractive optical elements (DOEs). Both the cases of Gaussian and Nyquist raised-cosine pulse shaping are considered for optical signal modulation. The simulation results show, that the transmission in the basis of PMs in strong coupling regime allows the reliability of the coherent MDM system to be fundamentally improved. As a result, utilization of the optical signal processing for MDM transmission could minimize substantially the DSP circuit complexity required for the real-time recovering of the transmitted signal.

The approach to a segment construction for all networks with a switching mode, independent of the protocol

The approach to creation of the device ensuring function of switching, independent of the protocol, is considered. The device is of interest with construction completely of optical networks. The task of a presence of an interference picture in the complex profile resonator of a Fabry-Perot type is decided. The decision is carried out by numerical integration of the wave equation of the second order, and also developed simplified methods. The simplification allows to integrate the equation of the first order. The result for resonators of length up to 200 microns is received.

Fiber optic communication line segment containing amplifier EDFA

Present article is devoted to study of a connection opportunity of erbium-doped fiber (amplifier EDFA), to the fiber-optic communication line (FOCL) by means of a unique fiber. As a result of it powerful pump radiation and information radiation are transferred in common on singlemode fiber. Such way of connection EDFA to FOCL is of interest at operation of a transfer line on explosive objects and etc., where entering electrical and electronic components into the certain zone is not supposed. The numerical ratings of nonlinear effects influence on an information signal are carried out for a case: an information at DWDM-signal in a range 1530 ... 1560 nm, pump on a wavelength 980 nm. As a making fiber was considered standard single mode fiber with a step structure of a refraction parameter change such as SF. Among nonlinear effects the following are considered: nonlinear attenuation and refraction, modulation instability, compelled_scatterion on acoustic waves and parametrical processes. Is shown, that the basic limiting factor on a pump is the self-focusing capacity, limiting at the end length of a supplying fiber in limits up to two kilometers. On such length the influence of nonlinear effects appears insignificant, that does not worsen appreciable quality of transfer.

Fiber optic to radio-photonic equipment constructive principle for pipeline multiple defect monitor

This paper describes objectives on inner pipeline fault detection device modeling designated to monitor pipeline in real time. Due to high demands to high-speed and miniature measurements of such devices it is suggested to use implementations on the basis of fiber optic and radio-photonic mode of operation. A functional equipment design containing fiber optic generation and complex optic impulses transformation transmitted into radio trunk circuits are developed. Physical implementation of the suggested model is estimated as well as an analytical model for propagation of pilot signal on the basis of the Maxwell system of equations for partially conductive and simultaneously scattering medium.

All-optical interface objectives for heterogeneous segments and suggested synchronization circuit

This article is dedicated to interface devices for all-optical synchronization of optical backbone and subscriber line network segments. It is obvious that this type of devices must be all-optical. Due to the importance of phaselock loop (PLL) circuits essential for each telecommunication device an all-optical circuit has been suggested which fundamental principle of operability is in phase cross-modulation effect between tuned and strobe optical signals. Physical parameters of the circuit and time of PLL execution have been calculated. It is shown that this response time is suitable for highspeed devices.