No abstract

The modeling language VerilogAMS supports a new double precision datatype (wreal) that enables analog accuracy in the digital simulation domain. It is therefore possible to seperate high frequency signal paths, like those in RF frontends, from the rest of the chip, which comes in very handy for fast verification purposes. After an introduction to analog and digital modeling, a strategy to model the RF and LO signal flow path for a bluetooth transceiver system is presented. Especially the nonuniform oversampling, which is introduced through wreal to electrical and vice versa conversion, is analyzed and compared to traditional uniform sampling ratios. The proposed approach is demonstrated for an industrial available RF frontend, including biasing and analog to digital conversion. Simulation comparisons for different complexities of the frontend and different modeling approaches like passband, baseband and transistorlevel conclude the paper. General TermsModeling, VerilogAMS, wreal, nonuniform sampling

Abstract. Our approach of a closed-loop combustion control is built on an intensively evaluated robust cylinder pressure sensor with integrated smart electronics and an openly programmed engine control unit. The presented pressure sensor consists of a steel membrane and a highly strain-sensitive thin film with laser-welded electrical contacts. All components are optimized for reliable operation at high temperatures. The sensor setup safely converts the in-cylinder pressure of a combustion engine at temperatures of up to 200 ∘C into the desired electrical values. Furthermore, the embedded smart electronics provides a fast analogue to digital conversion and subsequently computes significant combustion parameters in real time, based on implemented thermodynamic equations, namely the 50 % mass fraction burned, the indicated mean effective pressure, the maximum pressure and a digital value, which represents the intensity of knocking. Only these aggregated parameters – not the running pressure values – are sent to the engine control unit. The data communication between the smart sensor and the engine control unit is based on the controller area network bus system, which is widely spread in the automotive industry and allows a robust data transfer minimizing electrical interferences. The established closed-loop combustion control is able to control the ignition angle in accordance with the 50 % mass fraction burned at a certain crankshaft angle. With this loop, the combustion engine is controlled and run efficiently even if the ignition angle is intentionally incorrectly adjusted. The controlled and automatic correction of simulated ageing effects is demonstrated as well as the self-adjustment of an efficient operation when different fuels are used. In addition, our approach saves the computing capacity of the engine control unit by outsourcing the data processing to the sensor system.