Fast power transistors require a tight control of their switching trajectory to exploit them at full speed, without degrading reliability and delivered electromagnetic emission figures of merit. By using active gate drivers in place of conventional ones, the switching trajectory can be shaped to reduce current and voltage overshoots, as well as the amplitude of oscillations. However, the tuning of such drivers is still an open issue. This paper investigates the damping of oscillations by means of active gate drivers, and proposes a method to tune them a-priori. The target switching waveforms are evaluated by means of non-linear damping elements in simulation, easing the tuning procedure. The proposed method was assessed on a digital active gate driver, providing the initial set-point for the adaptive controller. The convergence time measured experimentally was found to be as low as$\mathrm {50~ \mu \text {s} }$for the overall load current range, whilst not affecting the conversion efficiency of the dc-dc converter exploited as test case.

Communication systems based on in-pipe acoustic propagation have great potential to cover areas in which traditional infrastructure is unavailable. Characterization of the channel plays an important role in the design of any communication system. However, in case of spatially large channels, this aspect needs further investigations. In the present work, a method for the characterization of an acoustic channel is presented. This is based on the measurement of the complex transfer functions relating voltages and pressures at the channel ports. Such a technique was validated on a 75 m long segment of a urban water distribution pipeline. The measurements assessed the frequency selectivity of the acoustic channel and the wave propagation speed. From experimental results, the response of the acoustic channel had an overall low-pass behavior, but it showed several deep notches at low frequency.