The switching loss of the secondary side rectifiers in LLC resonant converters can have a noticeable impact on overall efficiency complete power supply and constrain upper limit optimum frequencies converter. Two are main contributions to rectifiers: one hand, reverse recovery (Qrr), most noticeably while operating above series frequency; other output capacitance (Coss) hysteresis loss, not pre...

The parasitic effects in stranded, twisted, and Litz wire windings operating at high frequencies are studied. The skin and proximity effects tha t cause the winding parasitic resistance of an inductor t o increase with the operating frequency are considered. An expression for the ac resistance as a function of the operating frequency is given. The measured and calculated values of the inductor ...

Electroceuticals are medical devices that employ electric signals to alter the activity of specific nerve fibers to achieve therapeutic effects. The rapid growth of RF microelectronics has resulted in the development of very small, portable, and inexpensive shortwave and microwave radio frequency (RF) amplifiers, raising the possibility of utilizing these new RF technologies to develop non-cont...

We report the temperature-dependent mechanical properties of nanofabricated silicon resonators operating in the megahertz range. Reduction of temperature leads to an increase of the resonant frequencies of up to 6.5%. Quality factors as high as 1000 and 2500 are observed at room temperature in metallized and nonmetallized devices, respectively. Although device metallization increases the overal...

Dual-hequency patch antennas may provide an alternative to large-bandwidth planar antennas, in applications in which large bandwidth is really needed for operating at two separate transmitreceive bands. When the two operating frequencies are far apart, a dual-frequency patch structure can be conceived to avoid the use of separate antennas. In this paper, a critical overview of possible solution...

Tanzania telecommunication sector has witnessed fast growth in the number of mobile telephone users now served by seven cellular operators. Until February 2012, there were about 26 million mobile phone subscribers served by more than 4,000 base stations spread all over the country. Despite the many advantages brought by these systems, there is increased public concern over possible adverse heal...

Abstract Information technology demands high-speed optoelectronic devices, but going beyond the one terahertz (THz) barrier is challenging due to difficulties associated with generating, detecting, and processing high-frequency signals. Here, we show that femtosecond-laser-driven phonons can be utilized coherently manipulate excitonic properties of semiconductors at THz frequencies. The precise...

1 Motivation Wireless networks share the same unlicensed parts of the radio spectrum with devices of various types. For examples, cordless phones, wireless sensor networks, Bluetooth and microwave ovens can all access frequencies around 2.4 GHz. As a result, wireless networks operating near these devices are very likely to encounter interference from them. Since most of these devices do not kno...