IC Design Education Center

We demonstrate how to improve the turn-off speed of Ag-based volatile atomic switches with an Al2O3 electrolyte by understanding the origin of filament instability. Under the current sweep mode, our findings reveal that the formation of Ag–Te bonding due to the insertion of a GeSbTe layer (Ag/GeSbTe/Al2O3-based device) prevents the formation of a thick and stable Ag filament. As a result, the end of the filament appears to have the size of a single Ag atom, when analyzed based on the quantum conductance model. Thus, the instability of the Ag filament is maximized because of the large surface energy of the small filament. Furthermore, the low thermal conductivity of GeSbTe maximizes the internal thermal energy and accelerates the spontaneous dissolution of the unstable Ag filament. Based on these observations, the GeSbTe layer was introduced into the Ag/HfO2-based volatile atomic switch to quantify its effects on the turn-off speed. Our results show that the turn-off speed can be increased by more than a hundredfold by controlling both the amount of metal ions in the electrolyte and the internal thermal energy.

This paper presents a low-power coherent receiver for UWB pulsed radar for motion detection. Due to accuracy of the radar motion detection, coherent detection scheme is adopted in the receiver. To relax the stringent requirement of timing synchronization, sliding correlation detection is proposed. The clocking step which determines detection resolution is determined by 2 ns which is half of a pulse width or equivalent to 30 cm. Receiver is designed in 0.13-mum CMOS process from 1.5 V supply. The pulse center frequency is 4 GHz. The receiver includes a high voltage gain LNA, a analog correlator, a sampling comparator and a flip flop. The whole receiver excluding an LNA consumes 0.9 mA of DC current and 10 pJ/pulse at the pulse rate of 16 MHz. The active size is 600 times 380 mum <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> .

To achieve information superiority in the theater of operations, establishing a robust communication infrastructure is unquestionably required. Although many studies related to tactical network architectures and requirements have been conducted, detailed technical approaches remain open research areas. In particular, routing and mobility management to ensure a robust communications infrastructure in a tactical network have not been studied extensively. In this paper, the architecture of IPv6-based tactical network is designed based on commercial technologies, which can be developed at a low cost and in short time. Major movement patterns of network nodes and networks in the tactical network are also taken into account. Based on the proposed architecture and movement patterns, a method of routing and mobility management is proposed. In addition, a tactical network testbed is simply established by implementing the proposed methods, and the functions of the routing and mobility management are also verified to work well in the testbed.

Ultra wideband (UWB) systems promise a revolution in radio technology with the ability to support data rates 1Gb/s. Transceivers exemplifying two different system approaches, namely, multi-band OFDM and pulse-based schemes, continue to make significant strides in performance compared to prior years. In addition to high data-rate applications, these systems can provide highly efficient communications in terms of data-rate per unit power. The UWB approach is thus suited for wireless sensors, where the data rate is relatively modest, but battery lifetime is of critical importance. Another emerging application for UWB systems is in the area of vehicular radar. Transceivers and synthesizers for the above applications are discussed in this session.