Majlesi Journal of Telecommunication Devices: 19 (3)

Open Access Article

1 - Tunable Wideband Absorber with Ferrite Metamaterial
Mostafa Maleki Mohammad Sadegh Abrishamian

We proposed a new absorber based on Crescent Split Ring Resonators (CSRRs) that shows wideband absorption. This absorber is made of biased ferrite slab by embedding CSRRs. Simulation and analysis is carried out by FDTD method. The results show that the corresponding hig More

We proposed a new absorber based on Crescent Split Ring Resonators (CSRRs) that shows wideband absorption. This absorber is made of biased ferrite slab by embedding CSRRs. Simulation and analysis is carried out by FDTD method. The results show that the corresponding high absorption mainly originates from the CSRR’s geometry. This structure can be tuned by external magnetic field. Manuscript profile

Open Access Article

2 - A New Model of Pull-in Voltage for MEMS Variable Capacitive with Fully-clamped Diaphragm
Bahram Azizollah Ganji Sara Gholinezhad Shafagh

In this paper a new model of Pull-in Voltage for MEMS capacitor with fully clamped diaphragm is presented. This model not only makes it possible to calculate the exact value of pull-in voltage in a capacitor but also provides the ability to detect the accurate deflectio More

In this paper a new model of Pull-in Voltage for MEMS capacitor with fully clamped diaphragm is presented. This model not only makes it possible to calculate the exact value of pull-in voltage in a capacitor but also provides the ability to detect the accurate deflection of a fully clamped diaphragm. By introducing this model, the precise value of pull-in voltage at the border, between stable and un-stable state, can be calculated. As an advantage of this new achievement, it is exhibited that the all theoretical equations are fully compatible with simulation results using finite element analysis (FEA). Manuscript profile

Open Access Article

3 - A new structure for microchip capillary electrophoresis with high velocity and resolution and efficiency
Seyyedeh Sepideh Taheri Otaghsara Bahram Azizollah Ganji Morteza Fathipur

Separation of charged particles is a major problem in biological and chemical researches. There are several techniques for separate charged particles, one of them is electrophoresis. electrophoresis separates electrically charged particles by applying external uniform e More

Separation of charged particles is a major problem in biological and chemical researches. There are several techniques for separate charged particles, one of them is electrophoresis. electrophoresis separates electrically charged particles by applying external uniform electric field. In recent years,conventionalcross-form of geometry has been used for microchip electrophoresis. this paper represents new cross-form geometry of microchip capillary electrophoresis with low separation time and high resolution and efficiency and are respectively equal to 100s,3.1,1166.5 while these values for conventional geometries are respectively equal to 120s,2.85,1004.8. these geometries are simulated by comsol. Manuscript profile

Open Access Article

4 - Substrate Temperature Effect on Photovoltaic Performance of Lead Sulfide (PbS) Nanostructures Deposited by Chemical Vapor Deposition (CVD) Method
Mohsen Cheraghizade Ramin Yousefi Farid Jamali-Sheini

PbS nanostructures for solar cell application, deposited in different substrate temperatures by CVD method. FESEM images show nanostructures with rod and spherical volumes and porous surface for samples. XRD analysis verified formation of cubic crystalline nanostructure More

PbS nanostructures for solar cell application, deposited in different substrate temperatures by CVD method. FESEM images show nanostructures with rod and spherical volumes and porous surface for samples. XRD analysis verified formation of cubic crystalline nanostructures. Photovoltaic measurements also shown that with increasing in substrate temperature, efficiency conversion of cells was increased. Manuscript profile

Open Access Article

5 - A New Double-Bridge RF MEMS Switch with Low Actuation Voltage and High Isolation
Somayye Molaei Bahram Azizollah Ganji

This paper presents a new dual beam RF MEMS capacitive shunt switch with low voltage, low loss and high isolation for K-band applications. In this design, we have proposed the step structure to reduce the air gap between the bridge and the signal line, thus the actuatio More

This paper presents a new dual beam RF MEMS capacitive shunt switch with low voltage, low loss and high isolation for K-band applications. In this design, we have proposed the step structure to reduce the air gap between the bridge and the signal line, thus the actuation voltage is reduced to 2.9V. Furthermore, to reach more isolation, we used Aluminum Nitride (AlN) as a dielectric layer instead of conventional dielectric materials such as and which has more led to increase the down-state capacitance and increase the isolation of switch. The results show that the switch in up position involve less than -10 dB from 1 to 40 GHZ and more than -0.72 dB from 1 to 22 GHZ. In down state, switch has an excellent isolation at the frequency range of K-band. The maximum isolation of -58 dB is obtained at resonance frequency of 27 GHZ. Furthermore, we used the -match circuit to improve the reflection and isolation of switch. In this case, the double-bridge switch has the return loss of around -12 dB at the range of 1-31 GHZ. The insertion loss of switch is less than -0.8 dB at the range of 1-27 GHZ. The isolation around -40 dB is obtained at the range of 15-40 GHZ. The proposed dual beam switch is the wideband and low-loss switch that appropriate for applications of K-band frequencies. Manuscript profile

Open Access Article

6 - Point Target Localization and Imaging with Plane Wave using SAR
Hajar Abedi Bijan Zakeri

In this work a plane wave is used to localize a point target and in addition to speeding up the imaging scenario rather than moving the antenna to synthesize the long aperture as done in conventional SAR instead of moving the antenna to synthetize the long aperture a si More

In this work a plane wave is used to localize a point target and in addition to speeding up the imaging scenario rather than moving the antenna to synthesize the long aperture as done in conventional SAR instead of moving the antenna to synthetize the long aperture a single plane wave transmitter and a linear passive antenna array for the receiver are used. Single plane wave transmitter in far field is considered as an abundance of narrow beam width along a line parallel to the target. Transmitter antenna illuminates the target in all positions directions that the radar used to move in SAR technique. The Linear array is put in a closer distance to the target and collects the back scattered field coherently in a several positions. This collection will be considered as a strip map SAR mode. The proposed technique is implicitly the same as SAR technique. The SAR standard imaging image processing, back projection algorithm is used to construct the image. Since the proposed technique transmits a plane wave for a single time and the linear array collects data in all positions simultaneously, the speed of this technique is considerably more than the conventional SAR Manuscript profile

XML

List of Articles