We utilize cross-phase modulation to observe all-optical switching in microring resonators fabricated with hydrogenated amorphous silicon (a-Si:H). Using 2.7-ps pulses from a mode-locked fiber laser in the telecom C-band, we observe optical switching of a cw telecom-band probe with full-width at half-maximum switching times of 14.8 ps, using approximately 720 fJ of energy deposited in the micro...

Graduate School of Frontier Sciences, The University of Tokyo Kashiwanoha 5–1–5, Kashiwa-shi, Chiba, 277–8561 JAPAN Graduate School of Science and Engineering, Chuo University Kasuga 1–13–27, Bunkyo-ku, Tokyo, 112–8551, JAPAN School of Engineering, The University of Tokyo Hongo 7–3–1, Bunkyo-ku, Tokyo, 113–8656, JAPAN Research Center for Advanced Science and Technology, The University of Tokyo ...

This paper presents a novel RF MEMS (Micro Electromechanical System) fixed-fixed switch for very fast switching. Using the obtained equations, the switching time depends on the stiffness and effective mass of the switch beam so that the switching time will be decreased by higher stiffness (spring constant) and lower effective mass. In new design, the suspension bridge is a three-layer beam so t...

in this paper, a dc-dc resonant converter with high voltage gain and small size is studied. to reduce the size and weight of this converter, the operating frequency should be as high as possible. in this research, the frequency changes from 120 to 200 khz. due to the high operating frequency, it is necessary to reduce the switching losses using soft switching methods. resonant converters are su...

This paper presents the design of dual band frequency reconfigurable fork shape planar dipole in the Industrial, Scientific and Medical (ISM) band (2.4GHz and 5.2 GHz). The proposed antenna can be used for WLAN applications. Antenna operates in dual as well as single band mode depending on switching combination. The proposed antenna gives bandwidth of 12.5% and 6.7% for 2.4 GHz and 5.2 GHz resp...

Using the PWM control for switching power supplies the peaks EMI noise appear at the switching frequency and its harmonics. Using randomize or chaotic PWM control techniques in these systems the power spectrum is spread out in all frequencies band spectral emissions, but with a bigger ripple in the output voltage. The proposed nonlinear feedback control method, which induces chaos, is based by ...

A reconfigurable microstrip patch antenna with RF pin diode switches is implemented for dual band of 2.4 GHz and 5.6 GHz WLAN Software Defined Radio (SDR) applications. For the dual band SDR system, the use of a single antenna with a wide bandwidth to cover both of the bands can be limiting for low power level signal applications due to wideband noise as well as changing radiation pattern at di...

this paper presents a novel control method to improve the efficiency of low-voltage dc-dc converters at light loads. pulse width modulation (pwm) converters have poor efficiencies at light loads, while pulse frequency modulation (pfm) control is more efficient for the same cases. switching losses constitute a major portion of the total power loss at light loads. to decrease the switching losses...

In this paper, an adaptive hysteresis band current controller is proposed for active power filter to eliminate harmonics and to compensate the reactive power of three-phase rectifier. The adaptive hysteresis band current controller, proposed by Bose [An adaptive hysteresis band current control technique of a voltage feed PWM inverter for machine drive system, IEEE Trans. Ind. Electron. 37 (5) (...

0142-0615/$ see front matter 2012 Elsevier Ltd. A http://dx.doi.org/10.1016/j.ijepes.2012.08.024 ⇑ Corresponding author. Tel./fax: +90 312 212 13 3 E-mail address: [email protected] (I. Colak). In this study, an enhanced SPWM modulation scheme is developed in order to minimize total harmonic ratio (THD) by eliminating the side band harmonics that are not paid attention in regular modulation sc...