Majlesi Journal of Telecommunication Devices: 21 (1)

Open Access Article

1 - A structure to reduce voltage in microparticles separation by using dielectrophoresis mechanism

This paper presents a new structure in order to reduce voltage in dielectrophoresis (DEP). DEP is one of the most popular techniques to separate microparticles which needs an electric field in microfluidic devices. In this design we bend the microchannel (L-shaped) to r More

This paper presents a new structure in order to reduce voltage in dielectrophoresis (DEP). DEP is one of the most popular techniques to separate microparticles which needs an electric field in microfluidic devices. In this design we bend the microchannel (L-shaped) to reduce applying voltage. Also we change the outlet channel size which effectively reduces voltage. In the old design, we needed 2.5 V to separate 3.5 um and 4 um in diameter particles. In the new design, we keep constant all the effective parameters and bend the middle of the measuring microchannel and change the outlet microchannel size from 40 um to 50 um. We need 1.45 V to separate microparticles in the new conditions. Manuscript profile

Open Access Article

2 - Two efficient approaches for improving field emission properties of ZnO NRs
Marziyeh Advand Bahram Azizollah Ganji Mohammad Reza Kolahdouz

The structure of pure and Al doped ZnO (AZO) nanorods (NRs) has been studied. A post annealing procedure in oxygen ambience at 400ﹾC were used in order to improve crystallinity of both group of samples. The XRD patterns illustrate that the Al doped ZnO NRs were successf More

The structure of pure and Al doped ZnO (AZO) nanorods (NRs) has been studied. A post annealing procedure in oxygen ambience at 400ﹾC were used in order to improve crystallinity of both group of samples. The XRD patterns illustrate that the Al doped ZnO NRs were successfully synthesized using our method. Then, the field emission properties of the as grown NRs before and after annealing process were evaluated by our home-made setup. Experimental results show that Al density in ZnO NRs directly affects FE properties of these samples. The oxygen post annealing process leads to a significant improvement in the field emission performances of pristine and doped ZnO NRs including considerably lower turn on voltage, and higher emission current. Manuscript profile

Open Access Article

3 - Li-Fi Technology; the Communications of Future

In this paper, we discussed about the history of Li-Fi technology and expressed about elements of Li-Fi technology briefly. In addition of above that will be discussed capabilities and objections of Li-Fi technology. At the end of this paper we will predict of Li-Fi tec More

In this paper, we discussed about the history of Li-Fi technology and expressed about elements of Li-Fi technology briefly. In addition of above that will be discussed capabilities and objections of Li-Fi technology. At the end of this paper we will predict of Li-Fi technology future and communications future then will be compared the Li-Fi technology with Wi-Fi technology also will be compared the types of Li-Fi lamps. Manuscript profile

Open Access Article

4 - Selecting the best wavelet packet pier inspired by biological methods
Alireza Rezaee

In this project, a new method for selecting the best wavelet packet pier is presented. The method of complex organisms from simple gradual chromosomes early to more complex organisms have been inspired by the current. In this algorithm, first, the best pier to the lowes More

In this project, a new method for selecting the best wavelet packet pier is presented. The method of complex organisms from simple gradual chromosomes early to more complex organisms have been inspired by the current. In this algorithm, first, the best pier to the lowest level of analysis based on the shannon entropy measure using Genetic Algorithm (GA) is selected, then the pier to create optimal early population to a higher level is used and the work until the last level of analysis is repeated. The results show that this way, with a gradual increase during chromosomes best wavelet packet pier with higher convergence rate, higher accuracy and less computation than previous methods is selected. In addition, previous methods based on GA, the best possible level of analysis did not exist, but this method, access is provided. Manuscript profile

Open Access Article

5 - A New Proposal for PCRR- Based Optical Channel Drop Filter
Zohreh Rashki Seyyed Javad SeyyedMahdavi Chabok

Ring resonators are useful elements especially in channel drop filters. A novel configuration of photonic crystal ring resonators(PCRRs) based on optical channel drop filters (CDFs) with triangular lattice is proposed. The rods of this structure is silicon with the ref More

Ring resonators are useful elements especially in channel drop filters. A novel configuration of photonic crystal ring resonators(PCRRs) based on optical channel drop filters (CDFs) with triangular lattice is proposed. The rods of this structure is silicon with the refractive index nsi=3.46 and the surrounding environment is air with the refractive index of nair=1. The widest photonic band gap obtains for the filling ratio of r/a = 0.2. The normalized transmission spectra of CDF are observed using Two- Dimensional-finite difference time domain (2D-FDTD) method. The photonic band gap (PBG) is calculated by plane wave expansion (PWE) method. The simulation shows, 100% dropping efficiency and suitable quality factor at 1534.5nm wavelength achieved for this filter. Also in this paper, we investigate parameters which have an effect on resonant wavelength and transmission spectra in this CDF, such as refractive index of inner rods and the refractive index of whole rods of the structure. The area of the proposed structure is about 10.32μm × 10.32μm which is suitable for photonic integrated circuits and optical communication network applications. Manuscript profile

Open Access Article

6 - Reduction of Computational Complexity in Adaptive Estimation of Multi-path Non-stationary Channels

The operation of a wireless system depends on obtaining an accurate estimation of the channel. Moreover, the cyclical changes of the system resulting from a nonsyncronousness of the receiver and transmitter carrier frequencies can affect the operation of the estimator t More

The operation of a wireless system depends on obtaining an accurate estimation of the channel. Moreover, the cyclical changes of the system resulting from a nonsyncronousness of the receiver and transmitter carrier frequencies can affect the operation of the estimator that is used to estimate channel parameters. The adaptive filters techniques are suitable for detecting this carrier frequency offset and channel changes in mobile communication receivers. Studies of the operation of adaptive filter algorithms to estimate the ability of non-stationary channel algorithms have always been a lively research area. This study uses QAM in analyzing MIMO-OFDM system operation to show that system operation has improved. A review of the results from simulations reveals that this procedure has significantly reduced computational complexity while having maintained system operation using low-pass filtering in time domain to reduce the effects of inter-symbol interference and noise in each cycle. Simulated results show that this is a very useful method to use in next generation wireless and modern cellphone (4G) systems. Manuscript profile

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