Ultra-low power radio transceiver for wireless sensor networks

摘要: The objective of this thesis is to present the design and implementation ultra-low power radio transceivers at microwave frequencies, which are applicable wireless sensor network (WSN) and, in particular, requirement Speckled Computing Consortium (or SpeckNet). This was achieved through quasi-MMIC prototypes monolithic integrated circuit (MMIC) with dc consumption less than 1mW communication ranges operating least one metre. A made up widely distributed autonomous devices incorporating sensors cooperatively monitor physical environments. There different kinds applications perform a wide range activities. Among these, certain set require that nodes collect information about environment. Each node operates autonomously without central control. However, there many challenges associated nodes. These must consume extremely low communicate their neighbours bit-rates order hundreds kilobits per second potentially need operate high volumetric densities. Since constraint most challenging requirement, transceiver prolong limited battery capacity node. also be compact, 5×5 mm2, achieve target size for over metre allow between deployed nodes. Different topologies discussed choose architecture specifications required project. conventional heterodyne homodyne unsuitable methods due hungry circuits complexity. super-regenerative method because it has drawback inherent frequency instability its characteristics strongly depend on performance oscillator. Instead, more efficient modulation demodulation such as on-off keying (OOK) presented. Furthermore, considerations shown can used relatively large output voltages small input powers using an OOK system. important does not use additional increase gain or sensitivity consequently achieves lower This details both commercial in-house device technology while retaining adequate RF performance. It building blocks including amplifiers, oscillators, switches detectors. integration presented compact minimize described. To requirements receiver, detector voltage receiver measured have 1mVp-p -60dBm 1 consuming much 420μW. The first prototype combines all GaAs MMIC process pseudomorphic electron mobility transistor (PHEMT). successfully centre 10GHz antenna shows -10.4dBm transmitter, total 840μW. Based prototype, 24GHz band designed further improve reduce advanced 50nm gate-length metamorphic (MHEMT) technology.