Negative impedance converter

About: Negative impedance converter is a research topic. Over the lifetime, 5801 publications have been published within this topic receiving 87636 citations.

A zero voltage switching forward converter topology

Abstract: A zero voltage switching forward converter topology is presented in this paper. The topology employs an auxiliary circuit. Only a few small rating components and devices are added. The merits of the proposed topology include: lossless switching independent of the input and load conditions, simple control and power circuitry, and ability to operate in either voltage or current mode control. A steady state analysis is presented and the design procedure is illustrated. A 100 W 300 kHz prototype zero voltage switching forward converter is built which shows an efficiency improvement of approximately 5% as compared to a conventional hard switching forward converter.

Sudden Change of Electrical Characteristics at Lasing Threshold of a Semiconductor Laser

Abstract: Accurate forward electrical characteristics of multiquantum-well (MQW) lasers have been measured using ac admittance measurements together with dc I-V plot. The synchronous step offsets of apparent conductance, apparent capacitance, junction voltage, series resistance, and ideality factor at the onset of lasing were observed for the first time. With this effect, the lasing threshold can be deduced immediately by the LCR Meter. It is also found that the junction voltage jumps abruptly to a saturated value at the onset of lasing, and the starting and end points of jumping exactly correspond to the maximum of the second derivative of lasing power with respect to current and the kink point of the first derivative, respectively. All of the phenomena may help to verify and improve existing semiconductor laser models. In addition, negative capacitance effect in LDs was observed

Modeling and design considerations for negative capacitance field-effect transistors

Abstract: Stabilization of ferroelectric negative capacitance (NC) in a transistor gate stack is a promising pathway towards future low power electronics. However, most modeling efforts of such NCFETs are based on single-domain Landau theory, which is an oversimplification that leads to incorrect predictions and device design. By extending the Landau model to describe more than one domain, it is shown how an internal metal electrode inherently destabilizes NC. Consequently, NCFETs have to be designed without internal metal electrode to function. Furthermore, the use of single-domain Landau theory to model NCFETs with HfO 2 based ferroelectrics is critically discussed.

Capacitive coupling based transient negative bit-line voltage (Tran-NBL) scheme for improving write-ability of SRAM design in nanometer technologies

Abstract: Increasing process variation can significantly degrade the write-ability of an SRAM. In this paper, we propose negative bit- line voltage technique to improve cell write-ability without using any on-chip or off-chip negative voltage source. Capacitive coupling is used to generate a transient negative voltage at the low bit-line during write operation. Simulations in 45 nm PD/SOI technology show a 103times reduction in the write-failure probability with the proposed technique.