الفهرس 
Low Power Wireless Network OverviewOnly 14 pages are availabe for public view
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Abstract
This thesis is an attempt to design a low power RF transceiver in the 902-928MHz Industrial/Scientific/Medical (ISM) band, starting from high level application needs down to network layer considerations and ending up with the physical layer prerequisites to achieve such demands for upper layers. The main motive behind this work is minimizing power consumption to tens of micro watts instead of tens of milli-watts, enabling a wireless node to work independent of conventional power sources(batteries) and rely on energy harvesting techniques thus removing the periodic maintenance (e.g. battery replacement) in Wireless Sensor Networks (WSN).
The ability to comply with traditional wireless communication standard`s (e.g. Blue-tooth, WiFi) specifications is difficult under ultra-low power budget, that’s why new tailored standards emerged for these considerations (e.g. IEEE 802.15.4). Some of these networks operate at custom proprietary standard specification and networking protocols. In addition, achieving this power budget on the physical layer requires not only block level optimization, but rather a complete architecture make over; for example replacing the Phase locked loop (PLL) with digitally calibrated oscillators to meet the required frequency accuracy for transmission thus skipping the use of power hungry LC oscillators and frequency dividers. To maintain frequency stability without the use of PLLs, a new method for accurate frequency calibration is implemented here using a digital calibration algorithm combined with digital to analog converter (DAC) to control the ring oscillator (RO) frequency prior transmission.
The work presented here is a joint project with Texas A&M University which made it possible to fabricate the transceiver on 180nm IBM technology, manufacture a testing board and perform full characterization in their labs. We succeeded in achieving transmission energy figure of 0.2nJ/bit @ -15dBm output power and a data rate of 3Mbps. This also gave a deeper insight on the practical issues faced in such designs providing opportunities for further investigation and future improvements.