- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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A MEMS BPSK to ASK converter
摘要： Purpose – The purpose of this paper is to investigate the feasibility of using micro electromechanical systems (MEMS) to convert a binary phase shift keying (BPSK) signal to a simpler amplitude shift keying (ASK) scheme. Design/methodology/approach – The prototype is designed within the SOIMUMPs? fabrication process constraints. The fabrication constraints imposed geometric limitations on what could be tested. These constraints were used to build a mathematical model, which in turn was used to optimize the response using MATLAB?. The optimized design was tested using ?nite element analysis with CoventorWare?, and ?nally lab tests on the fabricated device were performed to con?rm theoretical predictions. Findings – Theoretical predictions compared well with lab measurements on a prototype device measuring 2.9 mm2. The prototype was tested with a carrier frequency of 174 kHz at a BPSK data rate of 3 kHz and carrier amplitude of 6 V. With these parameters, ASK modulation indices of 0.96 and 0.94 were measured at the two output sensors. Originality/value – This study provides a MEMS solution for BPSK to ASK conversion. The study also identi?es what limits betterment of the modulation index and data rate. Such a device has potential application in wireless sensor network (WSN) nodes that have energy harvesters and sensors that are also built in MEMS. Being a MEMS device, it can facilitate integration in such WSN nodes and, hence, potentially reduce size and costs.
关键词： Modulation index,Mixer,ASK detector,Micro electro mechanical systems (MEMS),BPSK converter
更新于2025-11-14 17:28:48
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Pivotal techniques evaluation in QEPAS system for engineering applications
摘要： Efforts were made in this study to evaluate a series of pivotal techniques in standard quartz tuning fork (QTF) based quartz enhanced photoacoustic spectroscopy (QEPAS) systems for engineering applications. In current QEPAS systems, a scanning ramp combined with high frequency sinusoidal signal is used to drive the light source for photoacoustic excitation, the scanning cycle was optimized for the first time in experiments guaranteeing that photoacoustic energy accumulation finished to achieve the largest photoacoustic signal, and the optimum modulation index was verified by experiments to be ~5 instead of the simulated result 2.2. As an important step for engineering applications, a long-term (~8 months) experiment was also carried out to evaluate the stability of QTF’s property. In addition, several photoacoustic spectrophone configurations were compared in the optimum geometry parameters, dual-tubes on beam was verified in experiments to be the most efficient one compared with half on-beam and off-beam structures in standard QTF based systems, which is consist with the summary of published papers.
关键词： Modulation index,Scanning cycle,Long-term stability,Quartz enhanced photoacoustic spectroscopy,Photoacoustic spectrophone
更新于2025-09-09 09:28:46