Modern numerical methods for field calculations are having problems dealing with singularities correctly. This paper provides two alternative methods that are able to handle electric fields including singularities in tip-like configurations. These configurations occur in atomic force microscopes. Another focus will be the suitability of coupling the presented methods with usual numerical methods. [ABSTRACT FROM AUTHOR]
Class-D amplifiers are suiteble for amplification of audio signals. One argument is their high efficiency of 90% and more. Today most of the audio signals are stored or transmitted in digital form. A digitally controlled Class- D amplifier can be directly driven with coded (modulated) data. No separate D/A conversion is needed. Classical modulation schemes like Pulse-Width-Modulation (PWM) cause aliasing. So a very high switching rate is required to minimize the aliasing component within the signal band. This paper shows a first implementation of the new SB-ZePoC modulation scheme (Zero Position Coding with Separated Baseband), which allows the generation of a binary signal with separated baseband. Therefore Class-D amplifiers using SB-ZePoC can be run with very low switching rates. Some benefits and problems in the design process because of low switching rates will be discussed. Measurements of a real-time implementation will be presented. [ABSTRACT FROM AUTHOR]
This paper presents a novel realization concept for Clock-and-Data-Recovery circuits. Our Design uses a nonlinear phase detector architecture, which is based on the Alexander phase detection method. In order to ensure circuit functionality in the RF region, we use very fast switching HLO-Flip-Flops (high-speed latching operation flip-flop) in our design. The primal goal in our design was the minimization of self induced jitter of the phase detector. The accuracy of our circuit design and the functionality in the GHz regime is confirmed by various circuit simulations executed with the SPECTRE Simulator. [ABSTRACT FROM AUTHOR]