An engineering model for high-speed switching in GeSbTe phase-change memory

Ge2Sb2Te5 is the most successful phase-change alloy in non-volatile memory using the amorphous-crystal phase transition. In deriving further high performance in switching, especially SET speed (from amorphous to crystal transition) should still be modified. In this work, It was examined an ideal Ge2Sb2Te5 alloy based on the Kolobov model using ab-initio molecular dynamics simulations. As a result, it was cleared that a uniaxial exchange between vacancies and Ge atoms is the crucial role in realizing high-speed switching and a large contrast in the resonance bonding state in the alloy. The vacancy engineering enables the alloy switching speed extremely faster.

Four-way electronic switch for tracking balloon borne transmitter using sequential lobe switching

The tracking of meteorological balloons using dipole matrix array antenna by sequential lobe switching with the help of a motor driven mechanical UHF phasing switch had been in operational use in our national upper air network from last 25 years. A solid state four-way electronic switch at 400 MHz using high conductance-high speed switching diodes has been designed to replace the aged motor driven mechanical phasing switch. Microstripline technique has been used in designing UHF switch to achieve proper impedance, matching, routing and addition of UHF signals received from the four antenna bays. For sequential switching of antenna array and synchronisation of data reception and display system the intelligence is generated by a compact logic in-built in the phasing switch. Unlike, mechanical switch, the present system has no switching noise and has low insertion loss (2 dB), thus improving the data acquisition capability of ground reception system. The design of switch is modular, light weight and highly rugged to suit all types of environmental conditions.

An RF Approach to Modelling Gallium Nitride Power Devices Using Parasitic Extraction

This paper begins with a comprehensive review into the existing GaN device models. Secondly, it identifies the need for a more accurate GaN switching model. A simple practical process based on radio frequency techniques using Vector Network Analyser is introduced in this paper as an original contribution. It was applied to extract the impedances of the GaN device to develop an efficient behavioural model. The switching behaviour of the model was validated using both simulation and real time double pulse test experiments at 500 V, 15 A conditions. The proposed model is much easier for power designers to handle, without the need for knowledge about the physics or geometry of the device. The proposed model for Transphorm GaN HEMT was found to be 95.2% more accurate when compared to the existing LT-Spice manufacturer model. This work additionally highlights the need to adopt established RF techniques into power electronics to reduce the learning curve while dealing with these novel high-speed switching devices.