Design of high speed 2-stage OTA for high capacitive load of 120pF and 2.96V

High speed operational transconductance amplifier (OTA) is used to drive high capacitive loads to reduce the charging time while providing adequate gain and stability. A 2-stage amplifier is proposed to provide high slew rate and sufficient gain and stability. 45nm process technology is used to compare performance with differential and telescopic amplifier designs. Resistive feedback and noise-gain compensation techniques are used to drive 120pF load and provide 2.96V at output for a high slew rate of 2.2V/µs.

Garnering sympathy: moral appeals and land bargaining under autocracy

Local governments in autocracies typically undercompensate residents for their land and take it through eminent domain, while residents lack effective formal channels for bargaining with them. I find that some residents nonetheless can defend against such predation through extralegal land bargaining. By sending resistance signals to challenge the legitimacy of local governments, publicize their grievances, and garner public sympathy, such residents embarrass governments, make it likely higher-level governments will punish local governments, and spur concessions. Such signals, however, are often costly or unavailable, so only resistant entrepreneurs can send them. I illustrate the argument by treating ‘nail-house resistance’ in China as a resistance signal: by refusing to vacate their houses, engaging in violence or self-burning, or turning to the media, some residents stop land takings or gain compensation. The findings enrich our understanding of the political and moral economy of land bargaining and institutional change in a transitional autocracy.

A 28GHz Power Amplifier with Analog Predistortion Linearizer in 65nm CMOS

This paper proposes that a radio frequency power amplifier is suitable for a 5G millimeter wave. It adopts a three-stage single-ended structure at 28GHz. An analog predistortion linearization method is used to improve the linearity of the power amplifier (PA). As a result, there is a significant improvement in power-added efficiency (PAE) and linearity is achieved. The Ka-band PA is implemented in TSMC 65nm CMOS process. At 1.2V supply voltage, the PA proposed in this paper achieves a saturated output power of 15.9dBm and a PAE of 16%. After linearization, the output power at the 1dB compression point is increased by 2dBm, with efficient gain compensation performance.

Adaptive Pitch Controller of a Large-Scale Wind Turbine Using Multi-Objective Optimization

This paper deals with the control problems of a wind turbine working in its nominal zone. In this region, the wind turbine speed is controlled by means of the pitch angle, which keeps the nominal power constant against wind fluctuations. The non-uniform profile of the wind causes tower displacements that must be reduced to improve the wind turbine lifetime. In this work, an adaptive control structure operating on the pitch angle variable is proposed for a nonlinear model of a wind turbine provided by FAST software. The proposed control structure is composed of a gain scheduling proportional–integral (PI) controller, an adaptive feedforward compensation for the wind speed, and an adaptive gain compensation for the tower damping. The tuning of the controller parameters is formulated as a Pareto optimization problem that minimizes the tower fore-aft displacements and the deviation of the generator speed using multi-objective genetic algorithms. Three multi-criteria decision making (MCDM) methods are compared, and a satisfactory solution is selected. The optimal solutions for power generation and for tower fore-aft displacement reduction are also obtained. The performance of these three proposed solutions is evaluated for a set of wind pattern conditions and compared with that achieved by a classical baseline PI controller.