Guzel I. Abdrakhmanova

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.

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.

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.

UWB RoF bench experimental testing with radio link based on phased antenna array

The paper describes the results of experimental investigation of the bench, which represents UWB RoF communication system. This bench performs the first prototype of such system and allows it to study from different sides and on different scales. The whole scheme of the bench as well as the detailed description of its elements and characteristics are presented, also the specific issues regarding the connection of the elements are observed. The specific feature of this scheme is application of the phased antenna array as the radiating element of the radio part, which revealed the uncommon questions of matching RoF signal, being transformed from optical into radio domain. The experiment methods are explained in detail. The obtained results are presented and thoroughly analyzed, which revealed that the bench characteristics satisfy the thresholds, set before. Also the experiments on data transmission proved the possibility of successful high-speed data transmission in IR-UWB frequency range on the basis of Radio-over-Fiber technology.

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.