Ling-Feng Mao

Research on application of nonlinear system in communication jamming

In this paper, the application of chaos in communication jamming is investigated. We first develop a nonlinear system which acts as a guide unit of jamming and the system is in a state of chaos. Then the jamming signal is set to be the output of the chaotic nonlinear system. Jamming effects and jamming levels of the system driven by different enemy communication signals are thus studied and compared with the effects and levels of white noise blanketing jamming. Simulation results show that the jamming signal can cover corresponding enemy communication signal in frequency domain and get fine jamming effects. Finally, we conclude that the jamming effects of the system mentioned above are obviously better than the effects of white noise blanketing jamming. Furthermore, if the frequency points of enemy communication signal are in the pass band of the nonlinear system frequency spectrum, the communication jamming system achieves an optimal effect of jamming.

STT MTJ data-aware write boost design in 28nm process

With the development of IOT (Internet Of Things) and portable intelligent product markets, power consumption becomes the top priority of IC design in which memory devices always consume considerable power. Spin-torque-transfer (STT) switching magnetic tunnel junction (MTJ) shows great advantage in zero retention power, non-volatile, fast read/write speed, which can be a good candidate for embedded memory of these application. In this paper, we proposed a new kind of write assist circuit for STT MTJ memory. It can lift the writability with low voltage power source, and with Data aware design of writing 0 and 1, it can further reduce the dynamic power.

Time domain characteristics for sub-wavelength defect in one-dimensional structure

The characteristics for sub-wavelength defect have been theoretically investigated through time domain simulation. The calculation is based on a one-dimensional structure which contains copper and water. The reflected ultrasonic signal for different frequencies is obtained. The normalized mean steady-state pressure is oscillating periodically when the ratio of defect size and wavelength changes from 0.0025 to 1. These results can be used to determine the sub-wavelength defect characteristics such as material and size from the wave magnitude and oscillating periods in ultrasonic testing.

Nature of the interstitials in titanium dioxide and their impact on transmission coefficient: ab initio calculations

The ab initio calculations about the properties of the interstitials doping in the rutile TiO2 and their impact on the transport coefficients are reported. As the doping of the Zr or Ti interstitials in the TiO2, the lattice Ti4+ ions acquire the excess electrons so reduced to the Ti3+ or Ti2+ ions. However, the Cu interstitials could not lose enough electrons to reduce the lattice Ti4+ ions. Furthermore, the Ti or Cu interstitials in the ZrO2 also are unable to promote the lattice Zr4+ ions to form the lattice Zr3+ or Zr2+ ions. The high transport coefficients are observed in the defected TiO2 with the Ti or Zr interstitials as the high concentration of the Ti3+ or Ti2+ ions. So, the Zr interstitials are the favorable choice for the extra-doping to improve the transport properties in the TiO2-based resistive random access memory.