Ivan K. Meshkov

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.

The radio-photon method of forming directional radio emission in a wide frequency band

The task of the antenna array radiation pattern optical control for ultra-wideband radio emission is considered in the paper. A fiber-optic phasing scheme is proposed, which is part of a complex fiber-optic device. The control device layout and the radio-photon segment layout photos are presented. An analytical model of the optical phasing process is developed that provides the frequency bands number calculation. The number of bands, on which a wide frequency range should be divided, depends on the permissible level of the array radiation pattern distortion. The results of experimental approbation of the radio lobe phasing control in the frequency band of 200 MHz, divided into 3 subbands of 70 MHz, are presented.

Constructive functional principles and control objectives executed with the device for optical signal splitting and chirping

This paper describes functional principles of a device for optical signal splitting and chirping. The offered device is to fulfill functions of such optical signal distortions compensation within FOCL RoF as linear attenuation (LA) and chromatic dispersion (CD); and it should also split optical signals for its feeding to radio emitting components, compounding aerial array (AA), and control radio emitting antenna lobe. In the meantime the device for optical signal splitting and chirping can inject losses into transferred signal, though they should be within tolerant values for conventional FOCL components.

Optical signal splitting and chirping device modeling

This article examines the devices for optical signal splitting and chirping device modeling. Models with splitting and switching functions are taken into consideration. The described device for optical signal splitting and chirping represents interferential splitter with profiled mixer which provides allocation of correspondent spectral component from ultra wide band frequency diapason, and signal phase shift for aerial array (AA) directive diagram control. This paper proposes modeling for two types of devices for optical signal splitting and chirping: the interference-type optical signal splitting and chirping device and the long-distance-type optical signal splitting and chirping device.

Optical device models for RoF systems

This paper studies engineering design and modeling of an optical device intended for Radio-over-Fiber (RoF) antenna array radio emitting management. Design and assembled models of the device are based on either profiled multiple-wave interferometer or long-haul ring topology FOCL. To construct the interferential type OSCD (optical signal splitting and chirping device) models optical ceramic glass mixer processed with the ITHP (intense twist under high pressure) method was used. Loss and transmission coefficients with account of splitting for all the prototype units were measured — on frame-controller equipment and on RoF segment test bench equipment. Satisfactory measurement results obtained allow to make conclusion on OSCD models applicability for RoF test segments. The designed models and test bench pictures are also illustrated in this article.

Interference fiber optic device for RoF antenna radiators control

Calculation of profiled optical element is described in the paper. This element is a part of fiber optic device intended to be used in Radio-over-Fiber systems. Calculation is based on Manakov equation system for forward and backward inter-group interference rays. Numerical integration of second order wave equation is used only for 50 microns element length. For 200 microns element length this calculation is diverged. 3D profile for element refractive index is obtained from calculations.