摘要：In this study we present the design and realization of a tunable dual band wireless power transfer(TDB-WPT)coupled resonator *** frequency response of the tunable band can be controlled using a surface-mounted *** transmitter(Tx)and the receiver(Rx)circuits are *** top layer contains a feed line with an impedance of 50Ω.Two identical half rings defected ground structures(HR-DGSs)are loaded on the bottom using a varactor *** propose a solution for restricted WPT systems working at a single band application according to the operating *** effects of geometry,orientation,relative distance,and misalignments on the coupling coefficients were *** validate the simulation results,the proposed TDB-WPT system was fabricated and *** system occupied a space of 40 mm×40 *** can deliver power to the receiver with an average coupling efficiency of 98%at the tuned band from 817 to 1018 MHz and an efficiency of 95%at a fixed band of 1.6 GHz at a significant transmission distance of 22 *** results of the measurements accorded well with those of an equivalent model and the simulation.

摘要：A new space-time block codes based on quasi-orthogonal designs are put forward. First the channel model is formulated. Then the connection between orthogonal /quasi-orthogonal designs and space-time block codes is explored. Finally we make simulations for the transmission of 4 bits/s/Hz and 6 bits/s/Hz using eight transmit antennas using the rate 3/4 quasi-orthogonal space-time block code and the rate 1/2 full-diversity orthogonal space-time block code. Simulation results show that full transmission rate is more important for very low signal noise ratio (SNR) and high bit error probability (BEP), while full diversity is more important for very high SNR and low BEP.

摘要：The DC-DC converters are widely used in photovoltaic generating systems as an interface between PV module and the load. These converters must be chosen to be able to match the maximum power point (MPP) of PV module when climatic conditions change with different resistive load values. So DC-DC converters must be used with MPPT controller in order to reduce losses in the global PV system. This article focuses on the effect of climatic conditions on design of two components (inductance, capacitance) for three topologies of DC-DC converters commonly used in PV systems. When climatic conditions change, the boundary of inductance and capacitance parameters of DC-DC converter will change. These two parameters must be properly sized to achieve optimal efficiency for each converter. The design optimization is based on two principles: 1) for a steady-state operation in a continuous conduction mode, the inductance value for all choppers must be greater than the maximum value of boundary inductance, and 2) in order to limit the output voltage ripple of DC-DC converter below a desired value, the filter capacitance must be larger than the maximum value of boundary capacitance.

摘要：Recently, nuclear material monitoring becomes very important especially in the emerging nuclear regions. In this paper, the Universal Mobile Telecommunication System (UMTS) network is proposed to handle the communication between local Dose Rate Measuring units and Central Monitoring unit. To achieve this purpose, a scheme is proposed to compute dose rate and transfer its values in conjunction with time stamp and location to the Central Monitoring unit of the Network using Wide Band Code Division Multiple Accessing (WCDMA) system. Specification and Language (SDL) language is used to design, implement and simulate the proposed scheme. Simulation results show the functionality of this scheme.